GroupDIY

Project Specific Discussions => Preamplifiers => Topic started by: Hairball Audio on July 21, 2014, 04:57:47 PM

Title: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 21, 2014, 04:57:47 PM
(http://www.hairballaudio.com/elements/wp-content/uploads/2014/07/lineup.jpg)

Elements is built on the classic single op amp, transformer coupled microphone preamplifier circuit found in many classic console designs.   A discrete op-amp in the standard 2520 provides variable gain, while the input and output transformers perform a wide range functions including circuit isolation, impedance matching, additional step up gain, and in some cases much of the tonal color.

This is a tried and true design that forms a simple but classic base for the Elements concept.  Sonically, the possibilities are endless.  The type of transformers, op amp, and capacitor selections have a drastic effect on the final sound. In addition to providing a base template for you to design your own mic pre, we’ve designed three unique mic pres that all have their own distinctive signature.

Offered in 500 series format, these pres will work in any standard 500 series rack and are a great first build for recordists familiar with basic soldering technique.

Features

Metalwork made in the USA:
A different color anodized aluminum faceplate according to which element kit you select.  Clam shell side panel enclosure made from two pieces of 20 gauge steel, zinc electroplated, and coated in trivalent chromate, for maximum noise rejection at low and high frequencies.

Elements PCB:
The Elements PCB has been custom designed by Eisen Audio (Brooklyn, NYC) and draws from their popular DIY500 products (now discontinued), which were the first do-it-yourself kits in 500 series format.

Each kit includes:
Gold contact pushbutton switches and a gold plated DI jack that won’t tarnish over time.  Standard potentiometers for gain and output from BI Tech’s P260 series.  We auditioned several conductive plastic potentiometers, and found that these perform exceptionally well in terms of construction longevity and end-of-track noise.  If you prefer stepped controls, we’ve worked with Eisen Audio and DIYRecordingEquipment.com to offer a simple and easy to install Grayhill switch and circuit that can be used in the gain and/or output position.

Transformers:
Our Gold, Copper, and Bronze Elements kits utilize high quality input and output transformers from Jensen, Cinemag, and Ed Anderson.

Op Amps:
We’ve commissioned two custom-designed discrete op amps in 2520 format: BA512 and Raindog, in addition to our Hairball JE-990 op amp.

DI:
The IC buffered DI is activated by relay when a instrument cable is inserted into the gold plated DI jack.  The on-board DI buffer is prior to the input transformer, meaning the DI utilizes the entire mic pre signal chain.  It’s a built-in complete DI box circuit.

Passives:
Elements complete kits feature only the best board-level passive components.  Hairball Audio worked with Jens Jungkurth of Eisen Audio, leaning on his years of rebuild and design work, to select parts for dependability and performance.  Jens’ years of working on classic recording boxes and consoles were invaluable for the capacitor selection and resistor trimming.

Welcome to the Elements series of Mic Pres!


--------

Schematic:
http://www.hairballaudio.com/elements/schematic.pdf (http://www.hairballaudio.com/elements/schematic.pdf)

Build Guide:
http://www.hairballaudio.com/blog/d_assembly/elements-mic-pre-series/ (http://www.hairballaudio.com/blog/d_assembly/elements-mic-pre-series/)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mikefatom on July 21, 2014, 08:45:16 PM
Cool beans Mike!

Congrats on the new pres.  They look great.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: EmRR on July 29, 2014, 12:53:19 AM
How are the output controls implemented?  Sounds like they are not the typical 600 ohm T's.   
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 29, 2014, 01:00:12 AM
How are the output controls implemented?  Sounds like they are not the typical 600 ohm T's.

Correct.  There is an class A/B output fader that uses a 10K lin pot (or optional Grayhill).

I'll post the schematic in the first post now.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: EmRR on July 29, 2014, 09:44:20 AM
Very interesting touches all over that drawing!  Thanks.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 29, 2014, 09:46:57 AM
Very interesting touches all over that drawing!  Thanks.

Designed by Jens from Eisen Audio, for lots of flexibility.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on August 04, 2014, 02:19:43 PM
Any update on the build guide for the Silver?

I think I have parts for at least a couple of pres!  8)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 04, 2014, 02:22:32 PM
Any update on the build guide for the Silver?

I think I have parts for at least a couple of pres!  8)

It'll be posted by the end of this week.

We'll have the schematic and recommended values for the other parts.

Thanks!

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 14, 2014, 11:09:51 PM
Here is are the guides and help files.

http://www.hairballaudio.com/blog/d_assembly/elements-mic-pre-series/ (http://www.hairballaudio.com/blog/d_assembly/elements-mic-pre-series/)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Unit7 on August 17, 2014, 04:08:29 PM
Hi Mike!
I ordered the Gold Element a while ago. As I could eventually go for 10+ of these I'm considering testing different capacitors to see how they'd affect the sound. Would you discourage this, or could you give some directions on which caps that would have the most impact?
Thanks!
Paul
Title: Re: [BUILD] Hairball Audio - Elements
Post by: LeeYoo on August 17, 2014, 05:38:58 PM
Nice design.
Bit confused..
Why did you drop the DI's input impedance from the standard 1meg to 200k (R301).
Would't that kill the "tone" of a guitar.
Leo..
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 18, 2014, 06:57:16 PM
Nice design.
Bit confused..
Why did you drop the DI's input impedance from the standard 1meg to 200k (R301).
Would't that kill the "tone" of a guitar.
Leo..

Typical DI input Z can range from 100K-several Meg.  The Jensen DI product is 100K IIRC.  We actually found this impedance to work best across a wide variety instruments.  Basically, we thought is sounded best there.

YMMV and of course and you can always put what sounds best for your ears and instrument.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 18, 2014, 07:08:11 PM
Hi Mike!
I ordered the Gold Element a while ago. As I could eventually go for 10+ of these I'm considering testing different capacitors to see how they'd affect the sound. Would you discourage this, or could you give some directions on which caps that would have the most impact?
Thanks!
Paul

The gold actually has the least capacitors.  Many of the caps are omitted or shorted for the sake of keeping it as uncolored as possible. The caps that we needed we selected to be as transparent as possible.

Where there are multi-layer capacitors, they can be switched for polystyrene film or something like that but they add a ton of color.  I would leave the MLCC alone.

You could look at trying different caps for: C505/C601

They would have the most effect.  If you don't see any significant DC voltage at these caps, you could try a polarized cap like a United Chemi-con KZH series cap which may open it up a little.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Greenote on August 20, 2014, 06:47:40 PM
 Just got my copper kit and put it together last eve.

The output is very low unless the gain knob is pinned. Is the 20K rev. log the best choice pot here?
I haven't had much time to test yet perhaps I'll look at the solder joints on both pots.

Pretty smooth assembly thanks to an excellent build guide.  Kit was missing 2 transformer screws and a 20K resistor, but I had spares.

Note: C501 10uF/25V Kemet Tantalum is polarized. Hairball indicated + side is closest to edge connector.

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 20, 2014, 07:42:36 PM
Just got my copper kit and put it together last eve.

The output is very low unless the gain knob is pinned. Is the 20K rev. log the best choice pot here?
I haven't had much time to test yet perhaps I'll look at the solder joints on both pots.

Pretty smooth assembly thanks to an excellent build guide.  Kit was missing 2 transformer screws and a 20K resistor, but I had spares.

Note: C501 10uF/25V Kemet Tantalum is polarized. Hairball indicated + side is closest to edge connector.

Hi,

Most likely it's working correctly.  Especially if you're using a dynamic and quiet source.  It's not the pot value (which needs to be that high), it's really the the limitations of a pot and single op-amp pre.  The gain math is very sensitive at max gain so you see a lot of change at the end of the pot.  It's one of the advantages to using the Grayhill option for the gain knob.  It is more classically stepped like a Lola. (4dBish per step).

Sorry about the transformer screws.   We messed that up.  We're sending those out tomorrow!

Thanks,

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Greenote on August 20, 2014, 10:50:33 PM
Okay, good to know, Might have to order the stepped jobs.
No worries on the screws, although you can pack em with the Bronze.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on August 21, 2014, 12:07:13 PM
Mike, do you know if the CM-2511 and EA11148 need a zobel network? I checked the data sheets and didn't see any mention of them. EDIT: looking again, I think it's RLoad:150k for the CM-2511?

Also, what is the recommended part for U300?

Thanks!!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on August 22, 2014, 05:30:18 PM
Hi guys...

Just finished my first of two Golds.

After a first power-on, I believe I have a problem:
I am too getting extremely weak signal out of a SM58 with both pots cranked up... And the DI signal is so weak, I am barely getting a signal from my bass with passive pickups. With both pots cranked up I can get a "decent" level, but it is highly distorted and thin.

I am also measuring a slight DC offset.

Where should I start looking?

Thanks!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 24, 2014, 11:00:11 PM
Hi guys...

Just finished my first of two Golds.

After a first power-on, I believe I have a problem:
I am too getting extremely weak signal out of a SM58 with both pots cranked up... And the DI signal is so weak, I am barely getting a signal from my bass with passive pickups. With both pots cranked up I can get a "decent" level, but it is highly distorted and thin.

I am also measuring a slight DC offset.

Where should I start looking?

Thanks!

If you have two, I'd start by switching out the op-amp to confirm that is working correct.  Most likely that is fine.

After that, I'd look for bi-polar caps inserted incorrectly then resistor values.  It you can get at them, check your supply rails and make sure one of them isn't tripping a fuse.

You could build the second and see if you have the same issue.

Report back when you go over the build,  we'll get it sorted.  Posting a PCB image here may help.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 24, 2014, 11:02:19 PM
Mike, do you know if the CM-2511 and EA11148 need a zobel network? I checked the data sheets and didn't see any mention of them. EDIT: looking again, I think it's RLoad:150k for the CM-2511?

Also, what is the recommended part for U300?

Thanks!!

If you're building your a Bronze, it's in the BOM you can see by downloading the build guide.

If you're building a silver and not using a Raindog op-amp, then you can use those as a starting point and dial it in from there.  That is covered in the Silver guide.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 24, 2014, 11:04:14 PM
Hi guys...

Just finished my first of two Golds.

After a first power-on, I believe I have a problem:
I am too getting extremely weak signal out of a SM58 with both pots cranked up... And the DI signal is so weak, I am barely getting a signal from my bass with passive pickups. With both pots cranked up I can get a "decent" level, but it is highly distorted and thin.

I am also measuring a slight DC offset.

Where should I start looking?

Thanks!

You used the build guide correct?

Building the second could rule out any component issues, though that would be rare.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on August 25, 2014, 01:42:06 PM
You used the build guide correct?

Building the second could rule out any component issues, though that would be rare.

To the T...

Will update you on the second build!

Thanks!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on August 27, 2014, 01:36:16 PM
May I suggest that this image from your build guide is wrong?

(http://www.hairballaudio.com/blog/wp-content/uploads/2014/08/elements46.jpg)

According to Jensen's website (http://www.jensen-transformers.com/datashts/11dmcf.pdf), primary should be BROWN-RED and secondary should be ORANGE-YELLOW...
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 27, 2014, 02:03:09 PM
Yikes.  May appear so.  I'll be back at the shop in an hour and post back.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 27, 2014, 03:12:28 PM
You are correct.  Red and Orange need to be swapped.

However this actually has little effect on the audio other then some super HF rolloff.  Basically it's like having an inductor on the output rather than a transformer.  Does not change the gain or distortion.

The Mic Pre itself has slightly more 63dB of gain which is normal. (60-65dB).  However, if you have the variable input, most of this gain is near the end of the pot and it's very sensitive.  That is why we have the Grayhill upgrade do get a better sweep.  The variable is meant to be a budget option.

That said it should sound great.  It's hard to know if your having an issue or just not excited about the variable pot performance.

Did you build the second one yet?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 27, 2014, 05:11:07 PM
Build guide updated and everyone has been notified.

Thanks for the catch!

Looking back at your symptoms, it definitely seems like something is not right at all.  If you like post some pictures.  Worst case you can send it in and we'll look at it.

Keep me posted, we'll get you up and running!

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on August 27, 2014, 06:32:21 PM
Good! Thanks for your quick replies.

Upon swapping wires, gain was somewhat better on a SM-58, but most importantly DC offset disappeared from the output.

Still no joy on the DI input with my bass though. The relay seems to work, as the XLR input is effectively muted when a jack is inserted on the front panel. But I can barely get any signal and when I do, it's still thin and distorted.

I also discovered I had confused C104 and C105 for C303 and C601 so I swapped these but it didn't fix my DI problem.

Waiting for missing parts in order to build Gold #2.

Cheers!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 27, 2014, 06:38:52 PM
Good! Thanks for your quick replies.

Upon swapping wires, gain was somewhat better on a SM-58, but most importantly DC offset disappeared from the output.

Still no joy on the DI input with my bass though. The relay seems to work, as the XLR input is effectively muted when a jack is inserted on the front panel. But I can barely get any signal and when I do, it's still thin and distorted.

I also discovered I had confused C104 and C105 for C303 and C601 so I swapped these but it didn't fix my DI problem.

Waiting for missing parts in order to build Gold #2.

Cheers!

Cool.  Keep me posted.  Build up number two and see what happens.

If you like post some images.  Sometime I can spot things but this build is mostly straight forward.  Gold has lots of components that are shorted/jumpered make sure you have all those.

It should not sound thin.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 27, 2014, 06:41:47 PM
Good! Thanks for your quick replies.

Upon swapping wires, gain was somewhat better on a SM-58, but most importantly DC offset disappeared from the output.

Still no joy on the DI input with my bass though. The relay seems to work, as the XLR input is effectively muted when a jack is inserted on the front panel. But I can barely get any signal and when I do, it's still thin and distorted.

I also discovered I had confused C104 and C105 for C303 and C601 so I swapped these but it didn't fix my DI problem.

Waiting for missing parts in order to build Gold #2.

Cheers!
Also have a good look at the R Values in the DI section.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on August 28, 2014, 03:32:10 PM
Here are two pictures I just took...

Full: http://i.imgur.com/i88NC2E.jpg
DI section: http://i.imgur.com/I1Fc351.jpg

Thanks for your time!
P
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 28, 2014, 05:59:54 PM
Looks like a good clean build!

Maybe a defective part.

Have you double checked all our cabling/patchbay to make sure something isn't out of polarity or unbalanced?

You could always send it in if you like, we're happy to look over weird acting builds.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Greenote on August 28, 2014, 07:00:28 PM
My first build was a copper. It sounds good, I just finished the stepped pot board, but haven't put it in yet.

Second build is a Bronze. I used the stepped pot on this one. I got no sound and realized I'd forgot the shorting resistor in R606. It's now working (sorta) however it' very distorted at most gain stages and cuts in and out. I've looked over my traces and parts placements.

I'm suspecting something amiss in the Input stage or the Opamp. I have several types of 2520 DOAs. Can I pop in a J99 from my Lola or the working DOA from the Copper?

Any other ideas.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 28, 2014, 07:04:57 PM
My first build was a copper. It sounds good, I just finished the stepped pot board, but haven't put it in yet.

Second build is a Bronze. I used the stepped pot on this one. I got no sound and realized I'd forgot the shorting resistor in R606. It's now working (sorta) however it' very distorted at most gain stages and cuts in and out. I've looked over my traces and parts placements.

I'm suspecting something amiss in the Input stage or the Opamp. I have several types of 2520 DOAs. Can I pop in a J99 from my Lola or the working DOA from the Copper?

Any other ideas.

You could try another DOA but we do test them before we ship.

Make sure the two silver can-type (TO39) output transistors on the op amp are not touching.  You can use your fingers and pry them apart a little.

Trying another opamp would help to figure out if it's the op-amp or main PCB.

Report back!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on August 28, 2014, 07:37:13 PM
Looks like a good clean build!

Maybe a defective part.

Have you double checked all our cabling/patchbay to make sure something isn't out of polarity or unbalanced?

You could always send it in if you like, we're happy to look over weird acting builds.

Mike

Thanks Mike... gain issues with the mic input have been sorted out as far as I'm concerned... I'm just not used to cranking volume controls so much. I might look into upgrading the pots to Grayhills, eventually.

The DI situation however, isn't solved. Tried different instruments and cables without success. Although "some" signal passes through, it is still highly distorted. It's even more obvious with a signal from a higher-gain source such as music playing back from my iPhone. Just nasty distorted.

I'll hold on to shipping it back until I get the other one finished and tested... plus, I really enjoy troubleshooting stuff ;)

We'll move on from there.
P
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 28, 2014, 07:48:54 PM
Looks like a good clean build!

Maybe a defective part.

Have you double checked all our cabling/patchbay to make sure something isn't out of polarity or unbalanced?

You could always send it in if you like, we're happy to look over weird acting builds.

Mike

Thanks Mike... gain issues with the mic input have been sorted out as far as I'm concerned... I'm just not used to cranking volume controls so much. I might look into upgrading the pots to Grayhills, eventually.

The DI situation however, isn't solved. Tried different instruments and cables without success. Although "some" signal passes through, it is still highly distorted. It's even more obvious with a signal from a higher-gain source such as music playing back from my iPhone. Just nasty distorted.

I'll hold on to shipping it back until I get the other one finished and tested... plus, I really enjoy troubleshooting stuff ;)

We'll move on from there.
P

Ya we actually made the Grayhill the default gain option this morning.

Sounds like a funky part.  We'll gladly look at it for you.

Keep me posted!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Greenote on August 29, 2014, 04:11:20 PM
Bronze: I used the DOA from the copper in my Bronze build. It's way less distorted, but the sound is cutting in an out.

I was looking at Fern's Jensen OTP issue, so I thought I'd double check the EA wiring an see if a similar mistake was made.

The schem appears on your site. http://www.hairballaudio.com/docs/B11148/b11148.pdf
This is for the B frame package I assume but the wiring should be the same.

This doesn't seem to match up to the picture in the build guide for the Bronze Tranformer.

I won't assume the Rain Dog is bad until I sort out the OTP wiring.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 29, 2014, 04:32:57 PM
The wiring looks right (on my phone now). Both windings in parallel.  I'll double check when I get back to my computer but it appears right.

Should not be cutting out at all.  Something is up.  Post a picture?  Send it in for a check if you like.

Keep me posted!

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 29, 2014, 04:36:04 PM
If it's cutting out you may want to try re flowing any suspect solder joints on the main PCB.  Cold joint could cause that.  Make sure the output transistors in the output stage are not swapped or backwards.  The Q600 and 601.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 29, 2014, 08:20:48 PM
That wiring is definitely right.

With distortion and cutting out I would suspect:

1:  Op-amp output transistors (silver cans) are touching.  Though we confirm they are not when they ship.  Make sure they didn't get pushed back together in shipping on installation.

2. Output transistors Q600/601 are reversed or installed backwards.

3. Cold solder joint.

4. Damaged semi conductor.

Mike

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Greenote on August 29, 2014, 11:56:05 PM
Thanks!

1. No-touchey Confirmed. used 512 DOA, distortion gone
2. I have these correct.
3. I've re-hit most the joints.
4. Hmm.

I'll re-heat remaining pads. then likely post a pic if I'm still having issues.  I have a few different ic's, just hoping not to have to undo a chip as I don't have desoldering gun.

BTW, This kit was missing 200k resistors (had 100ks) Also the ceramic 100pf paired with R503 was the wrong value. I had these in my cache.

Stepped Gain is the way to go!
Cheers

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 12:02:51 AM
Thanks!

1. No-touchey Confirmed. used 512 DOA, distortion gone
2. I have these correct.
3. I've re-hit most the joints.
4. Hmm.

I'll re-heat remaining pads. then likely post a pic if I'm still having issues.  I have a few different ic's, just hoping not to have to undo a chip as I don't have desoldering gun.

BTW, This kit was missing 200k resistors (had 100ks) Also the ceramic 100pf paired with R503 was the wrong value. I had these in my cache.

Stepped Gain is the way to go!
Cheers

Which was the wrong value, the cap?  Those definitely should have been correct.  It's the only ceramic disc cap we have.

Sorry about the 200K issue we knew about that one, thought we caught all of them.

So it works fine with the BA512?  Or are there still issues?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 01:41:59 AM
Just finish building my copper preamp but i am not getting any sound. Both pots are cranked but still no sound. Any ideas?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 01:48:00 AM
That could be many things.

-missing a link/short
-backwards polar cap is tripping the fuses on the PCB.
-missing component.
-BA512 not seated right.
-transformer not wired correctly.

Post a couple pics of the PCB?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 02:11:22 AM
Pic1
Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 02:11:58 AM
Pic2
Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 02:12:46 AM
Pic3
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 02:20:04 AM
There is no opamp.  Did you get a BA512 opamp in your kit?

Like:

http://www.hairballaudio.com/shop/product_info.php?cPath=37&products_id=140
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 02:21:14 AM
C503 should not be shorted.  Cut that short.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 02:25:18 AM
Yes, i do have the op amp. I took it off so i can get a better picture of the components.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 02:28:14 AM
You have shorts where you should have omits.

Read the build guide about shorts and omits:
http://www.hairballaudio.com/blog/d_assembly/elements-mic-pre-series/elements-populating-the-pcb/

Near the start.  Omit means leave it empty.  You need to cut out those shorts on C502, C503, C504.  I think that's it.  Look for other omits in the BOM.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 02:29:35 AM
R500 is the only position you short in the copper I believe.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 02:30:59 AM
Basically you're shorting your signal to ground (killing it) before it even hits the op-amp.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 02:39:35 AM
What a rookie mistake. Thanks so much for your help!!!!!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 03:10:19 AM
I am still not getting any sound. I removed the shorts fromc502-c504.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 03:26:31 AM
No signal leads me to believe the fuses are getting tripped by something.  Things that could trip the fuses:

- C104/105 are reversed in polarity (these seem right)
- Q600/601 are in backwards or are swapped.  Looking at your photo, they are in the right direction but make sure you have the PNP in the PNP spot and the NPN in the NPN spot.
- resistor shorts

No tripping issues causing no signal would be:
- transformers wired wrong.
- maybe an issue with the DI switching (does the DI pass signal?)

I need to sleep.  Go through it carefully and I'll check this thread in the morning.  Try the DI see if the relay circuit is weird.

R504 is 20KΩ?

Good luck!

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on August 30, 2014, 11:12:25 AM

2. Output transistors Q600/601 are reversed or installed backwards.


That will cause the fuses to trip.. Found that out the hard way when I took out the fuse to troubleshoot!  :P
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 01:34:42 PM

2. Output transistors Q600/601 are reversed or installed backwards.


That will cause the fuses to trip.. Found that out the hard way when I took out the fuse to troubleshoot!  :P

Ya, you're reverse biasing the transistors which will pull a ton of current.  More than the 100mA fuse limit and they will trip.  They are reset when you power cycle your rack.

One thing you can do to check is get your DMM then find a GND point on the PCB you can clip to.  One of the sides of R303 or R301 for example.   To determine which side is grounded, look for the side that has continuity to the GND pin.  Then clip you back lead to that and clip your other lead to the leg of a fuse that is furthest from the edge card. 

Now carefully slide it into the rack (you'll need an empty space to two to the right to let the DMM leads come out) and power your rack.  Test each leg furthest from the edgecard.  You should see a 16VDC, -16VDC, and 48VDC at the legs.  If one or more is 0VDC that fuse is tripping.

Mike

Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 02:07:16 PM
No signal leads me to believe the fuses are getting tripped by something.  Things that could trip the fuses:

- C104/105 are reversed in polarity (these seem right)
- Q600/601 are in backwards or are swapped.  Looking at your photo, they are in the right direction but make sure you have the PNP in the PNP spot and the NPN in the NPN spot.
- resistor shorts

No tripping issues causing no signal would be:
- transformers wired wrong.
- maybe an issue with the DI switching (does the DI pass signal?)

I need to sleep.  Go through it carefully and I'll check this thread in the morning.  Try the DI see if the relay circuit is weird.

R504 is 20KΩ?

Good luck!

Mike

Everything seems to be right and no, i am not getting any sound when using the DI
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 02:13:51 PM
No signal leads me to believe the fuses are getting tripped by something.  Things that could trip the fuses:

- C104/105 are reversed in polarity (these seem right)
- Q600/601 are in backwards or are swapped.  Looking at your photo, they are in the right direction but make sure you have the PNP in the PNP spot and the NPN in the NPN spot.
- resistor shorts

No tripping issues causing no signal would be:
- transformers wired wrong.
- maybe an issue with the DI switching (does the DI pass signal?)

I need to sleep.  Go through it carefully and I'll check this thread in the morning.  Try the DI see if the relay circuit is weird.

R504 is 20KΩ?

Good luck!

Mike

Everything seems to be right and no, i am not getting any sound when using the DI

See if you can check your V rails at the fuses as described in the last post.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 02:25:13 PM
See if you can determine if you're rails are ok.   That's the next thing we need to know.  That's  definitely help track down the issue.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: midnitestudios on August 30, 2014, 02:29:17 PM
I have sound! Apparently I forgot to solder two joints from the relay. I got sound from a Condenser mic and from Dynamic mic. I will test out the DI later on today. Thanks again Mike for all your help!!!!   8)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 30, 2014, 02:31:49 PM
I have sound! Apparently I forgot to solder two joints from the relay. I got sound from a Condenser mic and from Dynamic mic. I will test out the DI later on today. Thanks again Mike for all your help!!!!   8)

Killer man.  Glad you found it.

 8)

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Greenote on September 01, 2014, 11:51:39 AM
Bronze update. Re-did all my solder joint. I decided to check my patching and my lunch boxes. I do have an issue with some cabling, but the bronze is still cutting out . I'll check the op-amp again.
Might send it to you for a look.
Lola's and Copper sounding great though!

T
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on September 01, 2014, 12:40:20 PM
Bronze update. Re-did all my solder joint. I decided to check my patching and my lunch boxes. I do have an issue with some cabling, but the bronze is still cutting out . I'll check the op-amp again.
Might send it to you for a look.
Lola's and Copper sounding great though!

T
Looking at the pic, Q600 looks like might be in backwards. Check the PCB overview here: http://www.hairballaudio.com/blog/wp-content/uploads/2014/07/Elements_PCB.jpg
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 02, 2014, 01:28:05 AM
Bronze update. Re-did all my solder joint. I decided to check my patching and my lunch boxes. I do have an issue with some cabling, but the bronze is still cutting out . I'll check the op-amp again.
Might send it to you for a look.
Lola's and Copper sounding great though!

T
Looking at the pic, Q600 looks like might be in backwards. Check the PCB overview here: http://www.hairballaudio.com/blog/wp-content/uploads/2014/07/Elements_PCB.jpg

Ya Q600 looks backwards (might just be the angle).

If it's not, send me an email (info at hairballaudio dot com) and I'll give you the address to ship it in.  We'll fix it up!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Greenote on September 02, 2014, 10:16:57 AM
Thanks Mike~ that was the ticket. Not sure how I got that wrong.
It sounds great. Seems to have more gain than the Copper.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 02, 2014, 10:37:19 AM
Indecline with the eagle eye!

Ya it has 3dBu more gain.  It also has a lot more "fixed" gain from the input TX so at any point in the gain stage it's  a lot hotter than Gold or Copper.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on September 05, 2014, 03:21:13 PM
Looks like a good clean build!

Maybe a defective part.

Have you double checked all our cabling/patchbay to make sure something isn't out of polarity or unbalanced?

You could always send it in if you like, we're happy to look over weird acting builds.

Mike

Thanks Mike... gain issues with the mic input have been sorted out as far as I'm concerned... I'm just not used to cranking volume controls so much. I might look into upgrading the pots to Grayhills, eventually.

The DI situation however, isn't solved. Tried different instruments and cables without success. Although "some" signal passes through, it is still highly distorted. It's even more obvious with a signal from a higher-gain source such as music playing back from my iPhone. Just nasty distorted.

I'll hold on to shipping it back until I get the other one finished and tested... plus, I really enjoy troubleshooting stuff ;)

We'll move on from there.
P

Ya we actually made the Grayhill the default gain option this morning.

Sounds like a funky part.  We'll gladly look at it for you.

Keep me posted!

The mystery thickens...

Just finished the second unit and it does the exact same thing on the DI input. ???
... tried on different sources, guitars, basses, synths, ipod.

Here's how it sounds (this is also very weak, I gave it 36 dB of gain in Pro Tools): http://www5.zippyshare.com/v/4870545/file.html

Any idea on what might be wrong?

Thanks
Phil
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 05, 2014, 05:52:19 PM
Do you want to send one in?  I may need to just test it.

DI is definitely ok on our Gold here.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on September 05, 2014, 07:07:31 PM
Do you want to send one in?  I may need to just test it.

DI is definitely ok on our Gold here.

I fear I might have to... I'll send you an email.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on September 06, 2014, 04:09:14 PM
Any chance I can order the Grayhill gain rotary add on by itself? I got my Silver working this morning, it's basically a Bronze with an SL Red Dot. Sounds great!!

Can't wait to experiment with future Silver builds  ;)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 08, 2014, 12:05:00 AM
Any chance I can order the Grayhill gain rotary add on by itself? I got my Silver working this morning, it's basically a Bronze with an SL Red Dot. Sounds great!!

Can't wait to experiment with future Silver builds  ;)

Ya I'll get that up this week.  Shoot me an email if you want to buy one in the mean time.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on September 11, 2014, 11:20:02 AM
Any chance I can order the Grayhill gain rotary add on by itself? I got my Silver working this morning, it's basically a Bronze with an SL Red Dot. Sounds great!!

Can't wait to experiment with future Silver builds  ;)

Ya I'll get that up this week.  Shoot me an email if you want to buy one in the mean time.

Mailed! Thanks!!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 11, 2014, 06:14:17 PM
Do you want to send one in?  I may need to just test it.

DI is definitely ok on our Gold here.

I fear I might have to... I'll send you an email.

Update for those following along.  We messed up on the Golds and sent the wrong IC.  We sent the dual instead of the single version which has the wrong pinout.  If you ordered a gold, you'll be getting an email w/ a new IC coming your way soon.

Thanks,

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrbobbailey on September 13, 2014, 03:24:52 PM
Mike,

Have there been any new discoveries on this.  I've verified all of your suggestions above except for testing the V rails.  The fuses are are soldered such that I'm going to have a hard time clipping to a bare lead.  Before I go in and de-solder these, is there anything else that was missed?

B
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 13, 2014, 03:38:36 PM
Mike,

Have there been any new discoveries on this.  I've verified all of your suggestions above except for testing the V rails.  The fuses are are soldered such that I'm going to have a hard time clipping to a bare lead.  Before I go in and de-solder these, is there anything else that was missed?

B

I think I have all the issues in this thread sorted.  One of the copper builders sent a unit into me and it was an error with resistor values. 

What are your symptoms?

Do you have an image of the stuffed PCB?

You could clip to the ground and +V on the opamp sockets, and the ground  and -V to test the rails there.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on September 13, 2014, 05:08:54 PM
I've been looking at the metal L-brackets and have been thinking.. Hmmm, could a Carnhill be mounted here?  ;D

It would require some cutting of the PCB to make room. Not sure if there are traces under there as mine is assembled and in the lunchbox. Maybe I'll pop it out today and look  ;)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrbobbailey on September 14, 2014, 04:28:02 PM
Mike,

Have there been any new discoveries on this.  I've verified all of your suggestions above except for testing the V rails.  The fuses are are soldered such that I'm going to have a hard time clipping to a bare lead.  Before I go in and de-solder these, is there anything else that was missed?

B

I think I have all the issues in this thread sorted.  One of the copper builders sent a unit into me and it was an error with resistor values. 

What are your symptoms?

Do you have an image of the stuffed PCB?

You could clip to the ground and +V on the opamp sockets, and the ground  and -V to test the rails there.

Mike

Much like Indecline, no sound or DI signal.  My lunchbox and signal path are fine; tested with a Lola.  I'll send along a couple of photos.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrbobbailey on September 14, 2014, 04:30:14 PM
Imgage 2
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrbobbailey on September 14, 2014, 04:31:02 PM
image 3
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 14, 2014, 05:17:29 PM
I don't see anything obvious. 

If you can get DMM leads into your module do this with or without the op-amp in place.

1.  With your DMM set to DC V clip your common DMM lead to the GND socket and the test lead to the +16V.  Power on and confirm you have roughly  +16V DC.
2.  With your DMM set to DC V clip your common DMM lead to the GND socket and the test lead to the -16V.  Power on and confirm you have roughly  -16V DC.
3.  With your DMM set to AC V clip your common DMM lead to the GND socket and the test lead to the output and INSER THE OP-AMP.  Power on and set the output and gain to max.  What is your AC reading?  Should be several volts.

#3 will test if the signal is dying before or after the op-amp.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on September 14, 2014, 05:51:31 PM
Do you hear the relay when a 1/4" is inserted to the DI?

On mine, I had swapped the output transistors (600 & 601) that caused both +-15v rails to trip the fuses.  No sound, no DI and no relay click when the DI was activated. 

I triple checked those transistors too  :-X
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on September 20, 2014, 07:03:02 PM
So, after getting the switched gain, my build still isn't acting right.

It was very distorted and clipping my convertor inputs on almost all gain settings. At full gain and open on the fader, I get nothing but loud white noise. I've gone over components and solder joints and touched up everything that looked fishy. Nothing changed until I looked at the schematic. It seems the schematic shows Q600 - 2690AYS and Q 601 -1220AYS. In the pictures on the build page it's opposite of this, with the 1220AYS as Q600  :o

So I swapped them and I think I fried the transistors.. again. Can someone confirm which transistors are suppose to be in Q600 and Q601?





Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 20, 2014, 07:34:41 PM
So, after getting the switched gain, my build still isn't acting right.

It was very distorted and clipping my convertor inputs on almost all gain settings. At full gain and open on the fader, I get nothing but loud white noise. I've gone over components and solder joints and touched up everything that looked fishy. Nothing changed until I looked at the schematic. It seems the schematic shows Q600 - 2690AYS and Q 601 -1220AYS. In the pictures on the build page it's opposite of this, with the 1220AYS as Q600  :o

So I swapped them and I think I fried the transistors.. again. Can someone confirm which transistors are suppose to be in Q600 and Q601?

Looks like the schematic is wrong.

600 is 1220 and 601 is 2690.  Just confirmed on our working pres.

If you need new ones, shoot me an email, we'll get them out.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on September 20, 2014, 08:13:40 PM
So, after getting the switched gain, my build still isn't acting right.

It was very distorted and clipping my convertor inputs on almost all gain settings. At full gain and open on the fader, I get nothing but loud white noise. I've gone over components and solder joints and touched up everything that looked fishy. Nothing changed until I looked at the schematic. It seems the schematic shows Q600 - 2690AYS and Q 601 -1220AYS. In the pictures on the build page it's opposite of this, with the 1220AYS as Q600  :o

So I swapped them and I think I fried the transistors.. again. Can someone confirm which transistors are suppose to be in Q600 and Q601?

Looks like the schematic is wrong.

600 is 1220 and 601 is 2690.  Just confirmed on our working pres.

If you need new ones, shoot me an email, we'll get them out.

Mike

Thanks Mike, I have a couple spares at home I can swap them with. It still leaves me with the clipping distortion and the noise burst at max gain, fader up.

One strange thing about the noise, it shows on my Lola meters and LAZ525 with full gain. Any idea on that? I have a feeling it's my "smoking gun" clue to get the Silver working right.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: EmRR on September 23, 2014, 02:35:18 PM
Theoretical musing.  The Gold. 

When driving long lines, is the output driver equivalent/stronger/weaker than a 990 by itself?  How does this compare to a Hardy M-1 type implantation with no output control?  How does transient response compare between the two methods when hung on 500 feet of star-quad snake?

I wonder since I'd be inclined to lose the output control section entirely if building one of those.   
Don't worry too much about this question Mike, it's a bit off topic for most people! 
Title: Re: [BUILD] Hairball Audio - Elements
Post by: furn1979 on September 23, 2014, 05:06:33 PM
Do you want to send one in?  I may need to just test it.

DI is definitely ok on our Gold here.

I fear I might have to... I'll send you an email.

Got the pre and parts back today and everything works and sounds ROCK SOLID!

BTW, the greyhill option is definitely worth the extra bucks.

Thanks Mike!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: FattyMA4 on October 03, 2014, 04:18:33 AM
I have to troubleshoot my BRONZE module.

How does one do that, outside of the Lunchbox?

And, what am I looking for?

I have the LED glowing, when the Phantom is engaged.

Otherwise, I have nothing.

I'd like to get clips, or some sort of attachment to extend from the lunchbox power supply, so I can read voltages.

Can I test Continuity?

ALSO, can the Output XFormer DOUBLE Pri-Hi/Pri Lo/Sec/Hi/Sec Lo, be solder bridged together, since they're heading the same place?

Thats the one thing that I see or trace back, that looks out of the ordinary.



ANNNNND, the 0.1u Caps, say 100n. Am I crazy, or is this maybe the wrong caps? Ughh.....

I'm obviously a newbie.

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1960_zps5cb9fbc3.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1960_zps5cb9fbc3.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1959_zpsff41f1f4.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1959_zpsff41f1f4.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1961_zpsdc828b71.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1961_zpsdc828b71.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1957_zps28bae897.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1957_zps28bae897.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1956_zpsc60903dd.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1956_zpsc60903dd.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1958_zpsac42c80b.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1958_zpsac42c80b.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1955_zps088b3f4b.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1955_zps088b3f4b.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1953_zps03aa4d21.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1953_zps03aa4d21.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1954_zps8c132aab.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1954_zps8c132aab.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1951_zpsa9be9c08.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1951_zpsa9be9c08.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1950_zpsfa78e4fe.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1950_zpsfa78e4fe.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1947_zpsd54e3170.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1947_zpsd54e3170.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1952_zps5bd9a17b.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1952_zps5bd9a17b.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1948_zps13079e64.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1948_zps13079e64.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1949_zpsc2da62ff.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1949_zpsc2da62ff.jpg.html)

(http://i221.photobucket.com/albums/dd227/fattyma4/IMG_1967_zps12b46290.jpg) (http://s221.photobucket.com/user/fattyma4/media/IMG_1967_zps12b46290.jpg.html)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 03, 2014, 02:01:31 PM
On a airplane right now so can't see much until I get back tomorrow.  100nF = 0.1uF.

Make sure your output transistors are not switched.  More help when I get back tomorrow.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: FattyMA4 on October 06, 2014, 04:15:17 PM
Exchanged the Output Transistors, and am passing signal. BUT, I made a messsssss out of my board. Whoa, baby.... Real bad.

Is there anything that would possibly be hindering some low end, in a Bronze?
Or, is it just a module without much low end?

Yes, I know vacation is still upon us. I shall be patient.
At least Im passing signal!!

Thanks, Mike!

Or, anyone else, with any input....
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 06, 2014, 04:17:09 PM
Exchanged the Output Transistors, and am passing signal. BUT, I made a messsssss out of my board. Whoa, baby.... Real bad.

Is there anything that would possibly be hindering some low end, in a Bronze?
Or, is it just a module without much low end?

Yes, I know vacation is still upon us. I shall be patient.
At least Im passing signal!!

Thanks, Mike!

Or, anyone else, with any input....

Bronze should have TONS of low/low-mid.  That's it's "thing".   Are you in the USA?  Maybe just send it in here?

Or I can post some tips tomorrow as I get caught up here (I'm back).

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: FattyMA4 on October 06, 2014, 04:58:28 PM
I'm going to bring it to "my guy" tomorrow.  See if he can help.
Then, yes, I'm in the USA. I will gladly pay for you to check out my disaster..... Haha!

I'll get back atcha after tomorrow's testings.

Thank you, Mike, for being the BEST customer service EVER, in the history of DIY Builds!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: FattyMA4 on October 08, 2014, 04:30:52 AM
Hey Mike,

Turns out, those Transistors were backwards, OF COURSE. However, my buddy was able to jump them to the next proper point.

Just a question, now.

When I try to saturate the heck out of it, it REALLY is displeasing to the ear. Like clipping, instead of a sweet OverDrive-ish.....

Did I do something else wrong now?

I might just send it to you.

Do you have any other suggestions, firstly?

Title: Re: [BUILD] Hairball Audio - Elements
Post by: FattyMA4 on October 08, 2014, 04:32:14 AM
Oops....

You're not back, for another day or two.

I can be patient.

Take your time, bud.

Thank you very much, Mike.


-Matt
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 08, 2014, 08:01:06 PM
Hey Mike,

Turns out, those Transistors were backwards, OF COURSE. However, my buddy was able to jump them to the next proper point.

Just a question, now.

When I try to saturate the heck out of it, it REALLY is displeasing to the ear. Like clipping, instead of a sweet OverDrive-ish.....

Did I do something else wrong now?

I might just send it to you.

Do you have any other suggestions, firstly?

We're back.

Hard to say.  Sure you're not pushing your converters?  Maybe you're hitting it too hard?  Might be something damaged or still a transistor issue.  Hard to say with out seeing/hearing.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: FattyMA4 on October 08, 2014, 08:10:34 PM
Yay! Welcome back.

I'll get you pics and samples, right away.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: FattyMA4 on October 09, 2014, 03:26:57 AM
I think I might be good....
I maybe had wilder expectations.
I've A/B'ed wjth every other Pre that I have, and it's not as crazy as some, but definitely better than others.

At least it's passing signal, there's lower end back again, and the OD sound usable.
I think i feel alright about it.

I've truly only done Bass DI A/B'ing, so far. But, ill drive some 4038, or some TLM 103 or 414 on some drum room sound, and see what transpires.....

Again, Mike, thank you very much, for looking out for me. I appreciate it, much.....

I can't wait to not be so afraid of a Rev A 1176 build.... You have no idea!

Talk soon.

Thanks, man!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Houstnwehavuhoh on October 13, 2014, 08:31:33 PM
Hey there,
Recently did a copper pre without any issues so it seemed; tested it today and wasn't getting any sound out of it until it was cracked and it was just distortion at that point. I did order the variable pots and Im aware most of the gain is at the end of the turn, but Im not actually passing a signal from the mic, just getting distortion and thats when its turned all the way up. Doesn't appear I have any of the polarized components backwards, and I haven't shorted anything extra (just R500). I haven't check my lunchbox yet, as I was in a hurry, but I haven't had any issues with it thus far (still worth checking). Was wondering what I should check or if pictures would help?

Thanks
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 13, 2014, 08:42:59 PM
Hey there,
Recently did a copper pre without any issues so it seemed; tested it today and wasn't getting any sound out of it until it was cracked and it was just distortion at that point. I did order the variable pots and Im aware most of the gain is at the end of the turn, but Im not actually passing a signal from the mic, just getting distortion and thats when its turned all the way up. Doesn't appear I have any of the polarized components backwards, and I haven't shorted anything extra (just R500). I haven't check my lunchbox yet, as I was in a hurry, but I haven't had any issues with it thus far (still worth checking). Was wondering what I should check or if pictures would help?

Thanks

I'd have to see images.  Make sure the output transistors are right.
Does the Di work?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Houstnwehavuhoh on October 13, 2014, 09:49:46 PM
Unfortunately I did not try the DI, will have to do tmw

Phantom power LED lit up however, if that helps at all.

There are more pictures if you click this one. Sorry for the insane zoom

(http://imagizer.imageshack.us/v2/xq90/540/aTCASc.jpg) (https://imageshack.com/i/f0aTCAScj)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 13, 2014, 10:21:11 PM
Does the DI work?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Houstnwehavuhoh on October 14, 2014, 12:10:35 AM
Yes the DI works
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 14, 2014, 12:13:59 AM
Yes the DI works

Sounds like maybe your DI isn't switching.  By default it's in DI mode.  Are all 8 relay leads soldered?  Do through the Relay sec ion and check the soldering, make sure you didn't miss a lead.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: FattyMA4 on October 14, 2014, 12:46:13 AM
Hey Mike,

I just plugged my Coles 4038 in, and did some A/B'ing, and there is DEFINITELY not the low end in my Bronze, like there should be.

Could there be low end from the DI, but not from the Mic Input?
Is that a possibility? At all?
I think it runs through the same thing, once you get to that certain point....

I'm think I'm just gonna send it out to ya.

How does one go about doing such a thing?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Houstnwehavuhoh on October 14, 2014, 11:04:11 AM
Wow I'm really sorry, I definitely didn't solder one of the leads on the relay  :o my mistake, should've looked more carefully. Thank you for helping me troubleshoot and for the quick reply! Will solder it up after work and give her a go.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 14, 2014, 12:18:29 PM
Hey Mike,

I just plugged my Coles 4038 in, and did some A/B'ing, and there is DEFINITELY not the low end in my Bronze, like there should be.

Could there be low end from the DI, but not from the Mic Input?
Is that a possibility? At all?
I think it runs through the same thing, once you get to that certain point....

I'm think I'm just gonna send it out to ya.

How does one go about doing such a thing?

Hard to say what's going on.

Send us an email to "[email protected]".

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darnell on December 04, 2014, 11:52:28 PM
Hey all.

I bought 4 Silver kits hoping I could build a specific Eisen API I bought on this forum when i first started recording.  It's really simple, and I've always prefered the pre to other APIs (512 and VP26/25).  So I finally got my Cinemag 75101APC inputs in yesterday.  Heated up the iron, made a coffee, and opened the transformer box and my got out my 99% finished Silver kit. Went to put the Cinemag on the PCB where the canister type tranny goes...........

And it doesn't fit....................

I guess the pin spacing on the Cinemag is a little smaller than whatever Hairball is sending with the Bronze, ect.  So it's not possible to just bend the pins out from the canister. I believe it's the same pin spacing as the EA2622 as well.  So if you grabbed the Silver kit trying to use canister type input trannies from Cinemag or EA, it looks like they are not drop in. 

After some creative mounting (double sided tape and flying leads) i got it wired up and working.  Haven't compared to my original Eisen yet, but it's passing signal and everything seems to be working.  I'll report back with some observations once i get the Silver and Eisen in the same room.

Any ideas on mounting the next Silvers input tranny?  I did double sided tape on this one and flipped the Input canister so the pins face up.  The tape adds about a .08 inch. And now those upward facing pins are a little too close to mount the other metal cover. 

Lemme know if you have ideas.

D.






Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 05, 2014, 05:33:24 PM
Hey all.

I bought 4 Silver kits hoping I could build a specific Eisen API I bought on this forum when i first started recording.  It's really simple, and I've always prefered the pre to other APIs (512 and VP26/25).  So I finally got my Cinemag 75101APC inputs in yesterday.  Heated up the iron, made a coffee, and opened the transformer box and my got out my 99% finished Silver kit. Went to put the Cinemag on the PCB where the canister type tranny goes...........

And it doesn't fit....................

I guess the pin spacing on the Cinemag is a little smaller than whatever Hairball is sending with the Bronze, ect.  So it's not possible to just bend the pins out from the canister. I believe it's the same pin spacing as the EA2622 as well.  So if you grabbed the Silver kit trying to use canister type input trannies from Cinemag or EA, it looks like they are not drop in. 

After some creative mounting (double sided tape and flying leads) i got it wired up and working.  Haven't compared to my original Eisen yet, but it's passing signal and everything seems to be working.  I'll report back with some observations once i get the Silver and Eisen in the same room.

Any ideas on mounting the next Silvers input tranny?  I did double sided tape on this one and flipped the Input canister so the pins face up.  The tape adds about a .08 inch. And now those upward facing pins are a little too close to mount the other metal cover. 

Lemme know if you have ideas.

D.

Hi,

We were trying to keep the transformer footprints pretty limited for ease of use since 99% of builder buy the standard bronze, gold, and copper kits. 

What we did for some smaller footprint transformer designs here was buy a piece of perforated PCB board like this:
http://www.robotroom.com/Circuit-Board-Tips/Single-Sided-Single-Hole-Perf-Board.jpg

We cut it to a side slightly larger than the transformer and mounted it to the main PCB using 1/4" standoffs and the 10428 mounting holes.  Then we added flying leads down to the 10468 pads.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darnell on December 06, 2014, 12:31:52 PM
Hey Mike. Thanks for replying. Love the Silver kit so far. Really clean layout and great labeling.

Ill prob try the board mounting idea you suggested. I bought 2 inputs from Cinemag, so i can try it with the second one.

I still have 2 more Silver kits that i need to get transformers for, so i may inquire about a custom can for the last 2. What pin spacing are you using your complete kit transformers? If its not crazy expensive, i will prob just suck it up and get exact fit transformers from cinemag.

Thanks.
D.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 06, 2014, 12:39:52 PM
Hey Mike. Thanks for replying. Love the Silver kit so far. Really clean layout and great labeling.

Ill prob try the board mounting idea you suggested. I bought 2 inputs from Cinemag, so i can try it with the second one.

I still have 2 more Silver kits that i need to get transformers for, so i may inquire about a custom can for the last 2. What pin spacing are you using your complete kit transformers? If its not crazy expensive, i will prob just suck it up and get exact fit transformers from cinemag.

Thanks.
D.

We use the CM-2511 in the bronze and the spacing and winding info can be found here:
http://cinemag.biz/mic_input/PDF/CM-2511.pdf

Dave can probably pop the 75101A into that can/pinout.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darnell on December 10, 2014, 01:45:50 PM
So, no dice on the can swap from cinemag.

Dave said this....

Hi Daryl;
The pin spacing for the CM-75101APC is different than for the CM-2511PC.  (Note that "PC" needs to show on the part number so that we know which version you want, versus lead wires.)  The reason for this is that the lamination stack for the CM-2511PC ( $55.46) is bigger.   The pins are staked into the bobbin, so we cannot change them around for different spacing.  How about attaching wires to the CM-75101APC pins and mounting it to the chassis with, for example, a capacitor clamp?  You can run the wires over to the printed circuit card.
All the best,
David


So my next option will be either use the 75101apc with zip ties holding it on, or order the regular 75101 with flying leads. 

I guess my question is, can i drill a mounting hole in the center of the PCB pin pads to allow for the tranny to be mount correctly onto the board and just fly the leads underside over to the row on the left?  Or will that compromise the grounding/layout on one or both sides of the PCB.  Seem to me as long as i isolate the tranny so it won't short any of the pads/pcb layout that goes to that left hand row, I should be ok, and the tranny will fit correctly and function just like the upsidedown 75101apc i have in there now with the double sided tape.

Just to put my mind at ease.... Mike, do you sell just the boards if i end up screwing this one up?  ;)

If it looks like a go, i can order up a couple 75101 with flying leads and start drilling.

d.

 
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 10, 2014, 01:55:06 PM
We did this in an early proto.  I think we drilled out the pads a little so the tie down wires would fit.

This is the Jensen JT16.  This ended up being a little thicker than a stand module.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: JustDavid on January 07, 2015, 02:00:13 PM
I built a copper and bronze pre-amp, both builds went smoothly, the bronze is great but I've got an issue with the copper. The copper unit is passing signal, both on DI and Mic input, but the stepped gain isn't affecting the input gain level. In other words, regardless if the step of the gain stage, the preamp output level is set only by the output pot. I checked back to make sure all solder points were solid and that I didn't miss any. All resistor values look right. Anything else that may be causing this other than the greyhill assembly?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 07, 2015, 02:08:34 PM
I built a copper and bronze pre-amp, both builds went smoothly, the bronze is great but I've got an issue with the copper. The copper unit is passing signal, both on DI and Mic input, but the stepped gain isn't affecting the input gain level. In other words, regardless if the step of the gain stage, the preamp output level is set only by the output pot. I checked back to make sure all solder points were solid and that I didn't miss any. All resistor values look right. Anything else that may be causing this other than the greyhill assembly?

I would reflow all of the solder joints (Grayhill and Resistor) and make sure none of them are touching.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: JustDavid on January 07, 2015, 02:58:05 PM
I built a copper and bronze pre-amp, both builds went smoothly, the bronze is great but I've got an issue with the copper. The copper unit is passing signal, both on DI and Mic input, but the stepped gain isn't affecting the input gain level. In other words, regardless if the step of the gain stage, the preamp output level is set only by the output pot. I checked back to make sure all solder points were solid and that I didn't miss any. All resistor values look right. Anything else that may be causing this other than the greyhill assembly?

I would reflow all of the solder joints (Grayhill and Resistor) and make sure none of them are touching.

I just popped it apart and reflowed , nothing appears to be touching. still no change.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 07, 2015, 06:32:17 PM
I built a copper and bronze pre-amp, both builds went smoothly, the bronze is great but I've got an issue with the copper. The copper unit is passing signal, both on DI and Mic input, but the stepped gain isn't affecting the input gain level. In other words, regardless if the step of the gain stage, the preamp output level is set only by the output pot. I checked back to make sure all solder points were solid and that I didn't miss any. All resistor values look right. Anything else that may be causing this other than the greyhill assembly?

I would reflow all of the solder joints (Grayhill and Resistor) and make sure none of them are touching.

I just popped it apart and reflowed , nothing appears to be touching. still no change.

Can you take a picture of it?  Email [email protected]  if you like.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: JustDavid on January 18, 2015, 10:24:56 PM
So now that my Copper is up and running, flawlessly might I add, I found some issues with my Bronze pre. Although at first it seemed to be fine I noticed some small issues.

1) When the DI is engaged, there is a high pitch ringing noise, and an intermittent chirp/squeal, almost like RF interference or something. It is apparent at all gain stages and output volumes (at various amplitudes). At first I thought it was noisy electronics in the instruments, but the issue is not happening in my copper. Engaging the pad helps the matter slightly but doesn't really resolve the issue.

2) when in DI and Mic mode, With the Grayhill fully clockwise, and the pad engaged, the last 1/8th turn "clicks" and then it makes a equaling noise. But this only happens with the grayhill fully counter clockwise…not that I would ever probably need to max this thing out like that, it would seem to be an indication of something not being quite right.

3) With a mic connected, the final position of the Grayhill decreases gain, with slight distortion. normal?

 The bronze seems to have more "noise" than the copper, perhaps this is normal.
 Most these observations where made without a mic/guitar/etc being plugged in, just the sound of the module itself. My primary issue is with the DI ringing/squeal. I plan on reflowing some of the gray hill points to see if that fixes the final stepped gain issue. Any thoughts would be appreciated. I would rather try to trouble shoot this thing so I can learn something in the process.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 19, 2015, 01:57:16 PM
So now that my Copper is up and running, flawlessly might I add, I found some issues with my Bronze pre. Although at first it seemed to be fine I noticed some small issues.

1) When the DI is engaged, there is a high pitch ringing noise, and an intermittent chirp/squeal, almost like RF interference or something. It is apparent at all gain stages and output volumes (at various amplitudes). At first I thought it was noisy electronics in the instruments, but the issue is not happening in my copper. Engaging the pad helps the matter slightly but doesn't really resolve the issue.

2) when in DI and Mic mode, With the Grayhill fully clockwise, and the pad engaged, the last 1/8th turn "clicks" and then it makes a equaling noise. But this only happens with the grayhill fully counter clockwise…not that I would ever probably need to max this thing out like that, it would seem to be an indication of something not being quite right.

3) With a mic connected, the final position of the Grayhill decreases gain, with slight distortion. normal?

 The bronze seems to have more "noise" than the copper, perhaps this is normal.
 Most these observations where made without a mic/guitar/etc being plugged in, just the sound of the module itself. My primary issue is with the DI ringing/squeal. I plan on reflowing some of the gray hill points to see if that fixes the final stepped gain issue. Any thoughts would be appreciated. I would rather try to trouble shoot this thing so I can learn something in the process.

Something is wrong.  You'll have to go through the whole build again.

Bronze is nosier, but only interns of measurement, should be nothing you anecdotally hear.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: martinswain on February 21, 2015, 01:27:31 PM
Hi Mike,

I'm having issues with my builds as well. Apologies if this has been posted multiple times, but I'm having some strange things happening with my Bronze and Copper modules. I'll start with the Bronze because it's minor in comparison to the Copper.

Like the user who posted above, the Grayhill switch doesn't increase gain until I switch it to the last notch position, where there's a massive increase in gain. In other words, none of the other gain positions do anything to increase or decrease gain. Any ideas what this could be?

As for my Copper module, I'm getting some weird distortion. At first I thought it might've been the output transistors being overheated and creating a short, as I foolishly put them in the wrong way (the right slots, just facing the opposite direction to what they should've been). I bought some new transistors and soldered them in, but to no avail. This led me to think that it might've been a coupling capacitor (again I felt that I'd overheated it). I've replaced this capacitor and still no change to the signal. **note that although the coupling capacitor I've replaced is physically smaller and radial rather than axial, it is still the same value and brand as the one in the bill of materials.

I can't see any obvious signs of solder bridges

I've attached pictures of my Copper module. Any help you (or any other user that's had these issues) can give would be appreciated. Thanks!

(http://i237.photobucket.com/albums/ff69/martinswain/IMG_0160_zps4t7mhxtr.jpg)

(http://i237.photobucket.com/albums/ff69/martinswain/IMG_0161_zpsltawjnq5.jpg)

(http://i237.photobucket.com/albums/ff69/martinswain/IMG_0162_zpshevi9dcb.jpg)

(http://i237.photobucket.com/albums/ff69/martinswain/IMG_0166_zpsj8xw6te2.jpg)

(http://i237.photobucket.com/albums/ff69/martinswain/IMG_0159_zpszq7yrt7k.jpg)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on February 23, 2015, 01:38:05 PM
Hi Mike,

I'm having issues with my builds as well. Apologies if this has been posted multiple times, but I'm having some strange things happening with my Bronze and Copper modules. I'll start with the Bronze because it's minor in comparison to the Copper.

Like the user who posted above, the Grayhill switch doesn't increase gain until I switch it to the last notch position, where there's a massive increase in gain. In other words, none of the other gain positions do anything to increase or decrease gain. Any ideas what this could be?

That is a short or cold joint on the Grayhill PCB most likely.  The soldering on that board looks pretty bad.  You need to reflow and get rid of all that extra solder.

As for my Copper module, I'm getting some weird distortion. At first I thought it might've been the output transistors being overheated and creating a short, as I foolishly put them in the wrong way (the right slots, just facing the opposite direction to what they should've been). I bought some new transistors and soldered them in, but to no avail. This led me to think that it might've been a coupling capacitor (again I felt that I'd overheated it). I've replaced this capacitor and still no change to the signal. **note that although the coupling capacitor I've replaced is physically smaller and radial rather than axial, it is still the same value and brand as the one in the bill of materials.

I'd look for cold joints.  The soldering looks really off.

We offer a repair service online if that interests you.  I just had one with the same issues you have in for repair and it was just a bunch of bad soldering.  I reflowed the joints and it worked.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: martinswain on February 24, 2015, 04:38:19 AM
Thanks for your honest reply, Mike. I'll definitely check through and have a look. Some of the resistors don't look very neat on the Grayhill switch, so I'll reflow them and make them better. I'll also check the other solder joints.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: brandonsullivan on March 01, 2015, 11:58:05 PM
I accidentally inverted the polarity of one of the 470uF capacitors on the Copper build and ended up having to cut one of the leads to remove it from the PCB. Can I solder capacitor leads together like you can with resistors in order for it to reach the pad on the PCB?

Thanks for any help.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: josephdhemphill on April 18, 2015, 08:16:01 PM
Just finished the Copper build and am running into and issue.

ISSUE: Preamp passes audio for about 30 seconds (via DI and MIC) before it slowly fades out. Audio will not come back unless I power cycle my lunchbox which tells me I am tripping one of those sexy little fuses! I messed something up...haha

From reading through this thread I found that these are common reasons for tripping the fuses:
- C104/105 are reversed in polarity (220/25v Vishays)
***Mine are in correct polarity

- Q600 = PNP = 1220AYS Ridge facing back of card
-Q601 = NPN = 2690AYS Ridge facing back of card
***Mine are correctly placed and in correct polarity

- Resistor Shorts
***R500 is the only shorted Resistor

-Transistor Wiring
PRI-HI = Brown
PRI-LOW = Red
SEC-HI = Green
SEC-LO = Grey
Blue/Purple = Soldered and taped together

I have tried to go through and check all polarity on all caps and they look to be in the correct placement. Transistors look correct as well.

Any tips would be much appreciated! Thanks guys!

Note: Picture was taken without op amp installed so you could see better. I have a few other photos that are closer as well.

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 20, 2015, 01:36:51 PM
Ya that sounds like you're pulling too much current.  Really the only power hogs would be: BA512, DI IC, DI circuit, output transistors.

The DI IC is in right?
DO you have all the relay leads soldered?  There are 8.

I'd also reflow and odd looking joints.

Try powering it on w/o BA512 and listen to hear if the DI relay switch off after 30 sec like before. 

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: josephdhemphill on April 20, 2015, 10:05:07 PM
Ya that sounds like you're pulling too much current.  Really the only power hogs would be: BA512, DI IC, DI circuit, output transistors.

The DI IC is in right?
DO you have all the relay leads soldered?  There are 8.

I'd also reflow and odd looking joints.

Try powering it on w/o BA512 and listen to hear if the DI relay switch off after 30 sec like before. 

Mike

Thanks so much for the reply Mike! I really appreciate your help!

I took a peek inside when I got home today...

The IC (U300) is facing the correct direction. The tab is on the same side as the dot.
On the relay, All 8 leads are soldered.
I didn't feel as though I had any odd looking joints, but I went a head and reflowed almost all of them just to be safe...they look solid to me.

I tried to power it up without the Op Amp in like you suggested...I didn't get any sound. I re-installed the op amp and I had the same issue. Worked for about 30 seconds then slowly faded out while slowly distorting on the way out...

Crazy!

Any other ideas Mike...
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 20, 2015, 10:18:39 PM
Ya that sounds like you're pulling too much current.  Really the only power hogs would be: BA512, DI IC, DI circuit, output transistors.

The DI IC is in right?
DO you have all the relay leads soldered?  There are 8.

I'd also reflow and odd looking joints.

Try powering it on w/o BA512 and listen to hear if the DI relay switch off after 30 sec like before. 

Mike

Thanks so much for the reply Mike! I really appreciate your help!

I took a peek inside when I got home today...

The IC (U300) is facing the correct direction. The tab is on the same side as the dot.
On the relay, All 8 leads are soldered.
I didn't feel as though I had any odd looking joints, but I went a head and reflowed almost all of them just to be safe...they look solid to me.

I tried to power it up without the Op Amp in like you suggested...I didn't get any sound. I re-installed the op amp and I had the same issue. Worked for about 30 seconds then slowly faded out while slowly distorting on the way out...

Crazy!

Any other ideas Mike...

Right, you wouldn't get audio with no op-amp, I was just curious if the unit was still powering down without the op-amp...you'd have to listen for the relay flipping off.

After it powers down (most likely because the onboard fuses are tripping), pull out the unit and touch the Q600/601cases with your finger.  Are they really hot?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: josephdhemphill on April 21, 2015, 08:25:40 AM
Hey Mike, I tried what you suggested.

Powered the unit...let it trip...then powered down the Lunchbox. Q600/Q601 did not seem hot to the touch...

As far as  listening to the relay...sorry I misunderstood you on that test. I didn't notice it flip, but I will try again when I get home to make sure.

Again, thanks for the help...I have taken a handful of photos if you need to see any specific areas!

Thanks Mike!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: josephdhemphill on April 23, 2015, 10:18:51 PM
Hey Mike...

Sorry I was a day or two before I was able to test. When the unit is powered on I can here the relay flip when I insert a 1/4" cable. I can here it flip with or without the op amp in.

Q600/Q601 do not seem to get hot to the touch either.

Any other ideas why the signal fades and distorts out?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 23, 2015, 10:30:11 PM
Hey Mike...

Sorry I was a day or two before I was able to test. When the unit is powered on I can here the relay flip when I insert a 1/4" cable. I can here it flip with or without the op amp in.

Q600/Q601 do not seem to get hot to the touch either.

Any other ideas why the signal fades and distorts out?

I'm pretty stumped.  Maybe a bad op-amp, but unlikely.

Are you in the USA?  Might be easier to send in for repair. 

Feel free to continue to ask Q's here though.  Check your cap polarities.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: josephdhemphill on April 24, 2015, 06:26:35 AM
It's crazy man! I think this is what I will do. I have a gold build on deck. I am going to do that one and be beyond careful. If that one turns out great with no issues I will probably need to just send you the copper because I am stumped as well! Maybe as I build the copper I will realize a mistake from the bronze...or maybe it's a weird op amp thing. Who knows. I will keep you posted.  I hope to get in to the gold this weekend! Seriously Mike, I appreciate your help brother. Not just with me but with everyone else too. Major props to you and Hairball for being killer!

Standby...I'll keep y'all posted!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: josephdhemphill on May 16, 2015, 02:25:41 PM
Hey Mike,

I have been MIA for a bit but I finally got around to building the GOLD kit. Haven't finished it, but as I was building the GOLD I remembered you saying that it could be a bad op amp, but it was unlikely. So I was thinking...well I have the GOLD op amp right here...maybe I will give that a test...It WORKED! I was so pumped!

In my deductive reasoning it seems as if the COPPER op amp may be faulty...am I correct in assuming that or could we still be looking at a different issue possibly?

If it is merely a bad op amp, do you think you guys could send me another?

Thanks again for all your help man!

Joe
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on May 17, 2015, 08:19:45 PM
Hey Mike,

I have been MIA for a bit but I finally got around to building the GOLD kit. Haven't finished it, but as I was building the GOLD I remembered you saying that it could be a bad op amp, but it was unlikely. So I was thinking...well I have the GOLD op amp right here...maybe I will give that a test...It WORKED! I was so pumped!

In my deductive reasoning it seems as if the COPPER op amp may be faulty...am I correct in assuming that or could we still be looking at a different issue possibly?

If it is merely a bad op amp, do you think you guys could send me another?

Thanks again for all your help man!

Joe

If the op-amp is bad, we'd probably want to repair.

Send me an e-mail to the info at hairballaudio dot com address and we'll get you sorted.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: area8 on July 01, 2015, 03:41:35 PM
Just finished a Silver build, using a JLM14 input transformer (and 47K load resistor to get about 2900 input Z, no Zobel) and std EA output. I've only tried 2520 type opamps, so far, and a hybrid to start with, and each combo has same results:  no audio, and nothing appearing on output (as monitored through my ISA One with meter and headphone amp) UNTIL the gain pot gets all the way up, then the meter pegs. So, I'm guessing oscillation at full gain. I'm also guessing that maybe I've used a wrong value resistor or cap or something, maybe in the gain/feedback section.  I've triple-checked that the transistors are right. Oh, I tried to follow the Copper parts list as much as possible (with the input transformer exception), and plan to experiment with various 2520 and 990 type opamps (I particular favor 990s, and love my two Lolas with them, but have a bunch of API type preamps, too).

I could take pics later, but wanted to run this by you guys and see if anyone has seen this behavior before.  BTW, does anyone have a list of what would be "normal" voltages at various points that might help troubleshoot, sort of like the old Sams books?

Thanks to all of you for this thread (especially Mike, of course) - it really helps to read through all the previous problems and their resolutions.

Cheers,
Frank at Area8
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 01, 2015, 05:22:32 PM
Just finished a Silver build, using a JLM14 input transformer (and 47K load resistor to get about 2900 input Z, no Zobel) and std EA output. I've only tried 2520 type opamps, so far, and a hybrid to start with, and each combo has same results:  no audio, and nothing appearing on output (as monitored through my ISA One with meter and headphone amp) UNTIL the gain pot gets all the way up, then the meter pegs. So, I'm guessing oscillation at full gain. I'm also guessing that maybe I've used a wrong value resistor or cap or something, maybe in the gain/feedback section.  I've triple-checked that the transistors are right. Oh, I tried to follow the Copper parts list as much as possible (with the input transformer exception), and plan to experiment with various 2520 and 990 type opamps (I particular favor 990s, and love my two Lolas with them, but have a bunch of API type preamps, too).

I could take pics later, but wanted to run this by you guys and see if anyone has seen this behavior before.  BTW, does anyone have a list of what would be "normal" voltages at various points that might help troubleshoot, sort of like the old Sams books?

Thanks to all of you for this thread (especially Mike, of course) - it really helps to read through all the previous problems and their resolutions.

Cheers,
Frank at Area8

Have you referenced the schematic?

http://www.hairballaudio.com/blog/wp-content/uploads/2015/06/hba-elements-pcb-v1-3_schematic-production.pdf

Also this page:
http://www.hairballaudio.com/blog/d_assembly/elements-mic-pre-series/elements-silver-component-guide/

No output is weird.  Make sure your not missing something like R606 or R302 or C303 and a few others that are in series with the signal.  If you leave these components out they need to be replaced with a short or the signal will die there.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: area8 on July 01, 2015, 05:40:09 PM
Thanks for the quick reply, Mike -
Yes, I've used the schematic and the other docs you provided.  (I didn't fall for the swapped transistors there, btw.)

Actually, I have a couple of ideas to try.
I'll put this on an extender, and get the scope out (when I can - friends coming in from Edmonton today for a few days).

Gracias,
Frank
Area8
Upstate
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 06, 2015, 04:56:16 PM
Thanks for the quick reply, Mike -
Yes, I've used the schematic and the other docs you provided.  (I didn't fall for the swapped transistors there, btw.)

Actually, I have a couple of ideas to try.
I'll put this on an extender, and get the scope out (when I can - friends coming in from Edmonton today for a few days).

Gracias,
Frank
Area8
Upstate

Cool.  I uploaded a new version last week that should have those transistors fixed now.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: area8 on July 14, 2015, 05:03:23 PM
This is a first for me, even after some 45 years in audio electronics - I seem to have a bad input transformer (a JLM14). 

If I inject a signal past it at C501 (which is a jumper in my case), the amp works fine (with a gar2520) all the way through to the output load.  I haven't yet de-soldered the transformer to see what is going on with it.

Fortunately, I have other input transformers to try out (including the EA 10468), and I'm sure I'll get it going - just as soon as I get back from a summer vacation. 

I'm happy to say that, ignoring the 3rd party transformer for whatever reason, the build on the Elements Silver preamp seems to have worked exactly as it should, first time.

Cheers,
Frank
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 15, 2015, 11:35:22 PM
This is a first for me, even after some 45 years in audio electronics - I seem to have a bad input transformer (a JLM14). 

If I inject a signal past it at C501 (which is a jumper in my case), the amp works fine (with a gar2520) all the way through to the output load.  I haven't yet de-soldered the transformer to see what is going on with it.

Fortunately, I have other input transformers to try out (including the EA 10468), and I'm sure I'll get it going - just as soon as I get back from a summer vacation. 

I'm happy to say that, ignoring the 3rd party transformer for whatever reason, the build on the Elements Silver preamp seems to have worked exactly as it should, first time.

Cheers,
Frank

Funny enough we just had a repair come in with a bad input transformer and is was a PITA to find it as the source.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: area8 on July 16, 2015, 06:00:31 PM
Secondary reads > 2M resistance. That's different.
Frank
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 16, 2015, 06:08:33 PM
Secondary reads > 2M resistance. That's different.
Frank

That ain't right.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Indecline on August 02, 2015, 02:02:14 PM
Two quick things..

Does anyone have the Mouser part # or the brand for the push button switches?  I butchered my kit ones while desoldering them from my old board.

And... I was wondering if any of you guys had interesting ideas for xfr/opamp combos for the next build?  ;)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 03, 2015, 12:54:44 PM
Two quick things..

Does anyone have the Mouser part # or the brand for the push button switches?  I butchered my kit ones while desoldering them from my old board.

And... I was wondering if any of you guys had interesting ideas for xfr/opamp combos for the next build?  ;)

Those are CIT switches, mouser doesn't stock them (I don't think). We can send you a replacement if you like. Email us.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Siegfried Meier on August 03, 2015, 09:33:33 PM
Hey guys,

I'm also trying an EA2622 on input of a silver kit.  I wired it with longer leads since the spacing is too tight, and I placed it so the dot lines up with the dot on the board, but I get no signal...I hear a rushing/hiss sound which I believe is from the BA512 opamp, but I get no signal...

Does the EA2622 work with this board?  Do I have it the wrong way around?

Thanks!
Sig
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 03, 2015, 09:37:45 PM
Hey guys,

I'm also trying an EA2622 on input of a silver kit.  I wired it with longer leads since the spacing is too tight, and I placed it so the dot lines up with the dot on the board, but I get no signal...I hear a rushing/hiss sound which I believe is from the BA512 opamp, but I get no signal...

Does the EA2622 work with this board?  Do I have it the wrong way around?

Thanks!
Sig

Do you have a datasheet for the 2622?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Siegfried Meier on August 03, 2015, 10:08:46 PM
I just attempted swapping the trafo around, still no signal at all...

http://www.classicapi.com/catalog/images/gallery/2622/2622-specs.pdf
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 03, 2015, 10:18:18 PM
I just attempted swapping the trafo around, still no signal at all...

http://www.classicapi.com/catalog/images/gallery/2622/2622-specs.pdf

You need to line-up the dots.

Check the schematic.
http://library.hairballaudio.com/images/2015/06/hba-elements-pcb-v1-3_schematic-production.pdf

You most likely have a component error.  Like if R503, C501, R506...were empty there would be no signal.  However, if R501 was shorted you'd have no signal.  The Silver is a bit more of an advanced build, you have to be comfortable reading a schematic and determining compensation networks.  Trace the signal and see where it dies. Is it before the op-amp, after the op-amp? Before the output fader, after the fader?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Siegfried Meier on August 03, 2015, 10:42:47 PM
Ya, I've built a few of these in the same manner, but this is the first with an EA2622 and the BA512...

Maybe it's just too late, but I can't see any components I might have messed up...the input transformer or the opamp could be faulty.

(http://www.siegfriedmeier.com/electronics/Hairball%20Silver%20Not%20Working.jpg)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 03, 2015, 10:51:59 PM
I don't have time to look over this right now, but you have a cap in C500 but nothing in R500. You need to gave a R or short in 500 to complete that zobel.  Probably not your problem though.  You need to trace the signal, that is the easiest basic thing to figure out where the issue is.  You can stare at the PCB for hours, or take 5 minutes with a DMM and short out where the signal dies.

Bad op-amp> try another one from one of your other kits.  The transformer pinout is fine. Think it's damaged? Tracing the signal will tell you that.

Good luck!

Thanks,

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: jtn191 on August 19, 2015, 09:57:00 PM
Hi
I'm getting a faint hum with no increase in volume when gain or output are increased.  48V light works...durring the build, I did have a LOT of difficulty getting the pad for C505 to solder...I very well may have charred that cap. You can see it's darkened in the picture. I'll go over my build a few more times. Thanks!

http://i.imgur.com/UbbKwE5.jpg

*edit I put a jumper in for R606 and now I'm getting a constant "crickets at night" sound that gets louder as I turn the output up. Still no signal...something tells me it's that crispy cap
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 21, 2015, 12:01:37 AM
Hi
I'm getting a faint hum with no increase in volume when gain or output are increased.  48V light works...durring the build, I did have a LOT of difficulty getting the pad for C505 to solder...I very well may have charred that cap. You can see it's darkened in the picture. I'll go over my build a few more times. Thanks!

http://i.imgur.com/UbbKwE5.jpg

*edit I put a jumper in for R606 and now I'm getting a constant "crickets at night" sound that gets louder as I turn the output up. Still no signal...something tells me it's that crispy cap

Hard to say.  Do through all the components carefully and make sure you shorts and omits are correct.  Look for cold joints or missed joints.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: jtn191 on August 26, 2015, 01:50:47 PM
I was all ready to buy a replacement cap...but hadn't plugged in a mic yet. My sm57 works fine! I guess it's just a DI issue
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 26, 2015, 01:52:18 PM
I was all ready to buy a replacement cap...but hadn't plugged in a mic yet. My sm57 works fine! I guess it's just a DI issue

Phantom mic ok?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: jtn191 on August 27, 2015, 08:42:46 PM

Phantom mic ok?

yeah phantom works...just put the whole thing through it's paces. Strangely enough, the only problems are the DI doesn't work and the gain switch doesn't seem to be doing anything. As I go through the whole range, the gain stays uniform. Looking at the schem, a faulty C505 may be the culprit to the gain switch.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 31, 2015, 12:38:00 PM

Phantom mic ok?

yeah phantom works...just put the whole thing through it's paces. Strangely enough, the only problems are the DI doesn't work and the gain switch doesn't seem to be doing anything. As I go through the whole range, the gain stays uniform. Looking at the schem, a faulty C505 may be the culprit to the gain switch.

Or a short (or missed solder) on the gain switch itself. 
Title: Back plane input died
Post by: Sparqee on September 16, 2015, 08:20:49 PM
One of my two bronz's has suddenly stopped passing audio from the back plane.  That is to say; if I use the front panel DI input it works fine but audio routed in from my rack does not pass.  I double checked my rack slot with a different 500 unit and the rack is fine.

Any suggestions on where to start trouble shooting my Bronz?

Thanks,

Title: Re: Back plane input died
Post by: Hairball Audio on September 16, 2015, 08:27:09 PM
One of my two bronz's has suddenly stopped passing audio from the back plane.  That is to say; if I use the front panel DI input it works fine but audio routed in from my rack does not pass.  I double checked my rack slot with a different 500 unit and the rack is fine.

Any suggestions on where to start trouble shooting my Bronz?

Thanks,

If you're DI works fine, but the rear XLR does not, it's certainly a relay flipping issue.

The relay is set to DI in it's "normal" mode. Meaning with no power it's just stuck in DI mode. Make sure all 8 pins on the DI are soldered, including the 2 that are separated from the other 6. Those are the power supply pins.  If that's fine I would suspect the transistor maybe failed.

Send us an email and we can ship you some parts.

Mike
Title: Re: Back plane input died
Post by: Sparqee on September 17, 2015, 01:57:36 PM
One of my two bronz's has suddenly stopped passing audio from the back plane.  That is to say; if I use the front panel DI input it works fine but audio routed in from my rack does not pass.  I double checked my rack slot with a different 500 unit and the rack is fine.

Any suggestions on where to start trouble shooting my Bronz?

Thanks,

If you're DI works fine, but the rear XLR does not, it's certainly a relay flipping issue.

The relay is set to DI in it's "normal" mode. Meaning with no power it's just stuck in DI mode. Make sure all 8 pins on the DI are soldered, including the 2 that are separated from the other 6. Those are the power supply pins.  If that's fine I would suspect the transistor maybe failed.

Send us an email and we can ship you some parts.

Mike
Email sent. Thanks.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Johnnigrah on September 21, 2015, 11:41:34 PM
Hey guys!
My entire build works great, except for the +48V button and the LED.
The signal comes through fine with a dynamic mic, but with a condenser there is no signal, regardless of if the phantom power button is pressed or not.
I've already tried the different cables/different mics deal, so it has to be something with the electronics.

Thanks!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 21, 2015, 11:46:51 PM
Hey guys!
My entire build works great, except for the +48V button and the LED.
The signal comes through fine with a dynamic mic, but with a condenser there is no signal, regardless of if the phantom power button is pressed or not.
I've already tried the different cables/different mics deal, so it has to be something with the electronics.

Thanks!

What unit do you have? Copper, Bronze, or Gold?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Johnnigrah on September 22, 2015, 12:32:28 AM
Oops my bad for not specifying. I have the copper kit

Hey guys!
My entire build works great, except for the +48V button and the LED.
The signal comes through fine with a dynamic mic, but with a condenser there is no signal, regardless of if the phantom power button is pressed or not.
I've already tried the different cables/different mics deal, so it has to be something with the electronics.

Thanks!

What unit do you have? Copper, Bronze, or Gold?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 22, 2015, 12:40:03 AM
Oops my bad for not specifying. I have the copper kit

Hey guys!
My entire build works great, except for the +48V button and the LED.
The signal comes through fine with a dynamic mic, but with a condenser there is no signal, regardless of if the phantom power button is pressed or not.
I've already tried the different cables/different mics deal, so it has to be something with the electronics.

Thanks!

What unit do you have? Copper, Bronze, or Gold?

Mike

We had two bad input transformers that displayed a similar behavior. Not saying that's the issue, but let's run a test.

Try this, you can remove the module from the rack, no need to power it.  Grab you DMM and set it to measure Ω/resistance. Place one probe on either green (wire) pad.  Now test that against each of the other pads. Which pads have less than 1Ω of resistance to the green? 

Thanks,

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Johnnigrah on September 22, 2015, 01:03:08 AM
I found that the orange one (and of course green measured against green) is < 1ohm. What does this mean?

Oops my bad for not specifying. I have the copper kit

Hey guys!
My entire build works great, except for the +48V button and the LED.
The signal comes through fine with a dynamic mic, but with a condenser there is no signal, regardless of if the phantom power button is pressed or not.
I've already tried the different cables/different mics deal, so it has to be something with the electronics.

Thanks!

What unit do you have? Copper, Bronze, or Gold?

Mike

We had two bad input transformers that displayed a similar behavior. Not saying that's the issue, but let's run a test.

Try this, you can remove the module from the rack, no need to power it.  Grab you DMM and set it to measure Ω/resistance. Place one probe on either green (wire) pad.  Now test that against each of the other pads. Which pads have less than 1Ω of resistance to the green? 

Thanks,

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 22, 2015, 01:11:35 AM
I found that the orange one (and of course green measured against green) is < 1ohm. What does this mean?

Oops my bad for not specifying. I have the copper kit

Hey guys!
My entire build works great, except for the +48V button and the LED.
The signal comes through fine with a dynamic mic, but with a condenser there is no signal, regardless of if the phantom power button is pressed or not.
I've already tried the different cables/different mics deal, so it has to be something with the electronics.

Thanks!

What unit do you have? Copper, Bronze, or Gold?

Mike

We had two bad input transformers that displayed a similar behavior. Not saying that's the issue, but let's run a test.

Try this, you can remove the module from the rack, no need to power it.  Grab you DMM and set it to measure Ω/resistance. Place one probe on either green (wire) pad.  Now test that against each of the other pads. Which pads have less than 1Ω of resistance to the green? 

Thanks,

Mike

It means your input transformer is probably not the problem, that is normal.

Obviously you've checked the components in the +48 box on the PCB? Values are correct? Re-flowed solder?

If you can attach a clip lead to a ground point and the other to the circuit side of the +48 fuse and plug the unit in. Enable phantom and measure the DC, see if you get +48(ish) after the fuse.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Johnnigrah on September 22, 2015, 02:07:17 AM
Just now tried both of those things and still no luck unfortunately

I found that the orange one (and of course green measured against green) is < 1ohm. What does this mean?

Oops my bad for not specifying. I have the copper kit

Hey guys!
My entire build works great, except for the +48V button and the LED.
The signal comes through fine with a dynamic mic, but with a condenser there is no signal, regardless of if the phantom power button is pressed or not.
I've already tried the different cables/different mics deal, so it has to be something with the electronics.

Thanks!

What unit do you have? Copper, Bronze, or Gold?

Mike

We had two bad input transformers that displayed a similar behavior. Not saying that's the issue, but let's run a test.

Try this, you can remove the module from the rack, no need to power it.  Grab you DMM and set it to measure Ω/resistance. Place one probe on either green (wire) pad.  Now test that against each of the other pads. Which pads have less than 1Ω of resistance to the green? 

Thanks,

Mike

It means your input transformer is probably not the problem, that is normal.

Obviously you've checked the components in the +48 box on the PCB? Values are correct? Re-flowed solder?

If you can attach a clip lead to a ground point and the other to the circuit side of the +48 fuse and plug the unit in. Enable phantom and measure the DC, see if you get +48(ish) after the fuse.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Johnnigrah on September 22, 2015, 06:25:53 PM
Update: tried resoldering the fuse and 48V section again, and even tried the unit in different spaces in my lunchbox.
Upon checking with DMM I still do not have the 48V signal for some reason

Just now tried both of those things and still no luck unfortunately

I found that the orange one (and of course green measured against green) is < 1ohm. What does this mean?

Oops my bad for not specifying. I have the copper kit

Hey guys!
My entire build works great, except for the +48V button and the LED.
The signal comes through fine with a dynamic mic, but with a condenser there is no signal, regardless of if the phantom power button is pressed or not.
I've already tried the different cables/different mics deal, so it has to be something with the electronics.

Thanks!

What unit do you have? Copper, Bronze, or Gold?

Mike

We had two bad input transformers that displayed a similar behavior. Not saying that's the issue, but let's run a test.

Try this, you can remove the module from the rack, no need to power it.  Grab you DMM and set it to measure Ω/resistance. Place one probe on either green (wire) pad.  Now test that against each of the other pads. Which pads have less than 1Ω of resistance to the green? 

Thanks,

Mike

It means your input transformer is probably not the problem, that is normal.

Obviously you've checked the components in the +48 box on the PCB? Values are correct? Re-flowed solder?

If you can attach a clip lead to a ground point and the other to the circuit side of the +48 fuse and plug the unit in. Enable phantom and measure the DC, see if you get +48(ish) after the fuse.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 23, 2015, 12:29:00 PM
You have no 48V on the front panel side of the fuse? What about the edge card side?

What are you using for your ground reference lead?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Johnnigrah on September 23, 2015, 07:05:54 PM
On both sides of the fuse I'm getting <1V for some reason...

I referenced both with grounded metal and a negative battery terminal. The other fuses are getting ~15V but nothing on this specific fuse.

You have no 48V on the front panel side of the fuse? What about the edge card side?

What are you using for your ground reference lead?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 23, 2015, 07:32:08 PM
On both sides of the fuse I'm getting <1V for some reason...

I referenced both with grounded metal and a negative battery terminal. The other fuses are getting ~15V but nothing on this specific fuse.

You have no 48V on the front panel side of the fuse? What about the edge card side?

What are you using for your ground reference lead?

Mike

If you're not getting anything on the edge card side something is either:

1) wrong with your rack +48 supply
2) you measurement method
3) or the +48 edge card finger, or slot has gunk on it so they are no making contact.

Nothing other than the gold finger and the card connector sit between that fuse leg and your rack +48 supply.

Did you try another module in that spot. Does the +48 work?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Johnnigrah on September 23, 2015, 08:14:03 PM
You are the MAN, Mike.

I took everything out of my rack unit and noticed some bad connections in the unit itself. I resoldered them and viola!

Perfection.

Thanks so much for bearing with me and my funny little problem haha.

Cheers!
Title: Silver Element - Quad 8/Pacifica-ish unit
Post by: finbase on September 26, 2015, 11:18:39 AM
Hi folks!

I'm just about pulling the trigger and trying out my wings with the silver platform...

My ultimate goal is to create somewhat Quad 8/Pacifica-ish sounding unit, and according to the folklore found in the internet the best transformer options "tonewise" would be Cinemag's CMOQ-2S output and CM75101 input transformers.
The DOA would be Seventh circle's SC10. I've not done any real calculations yet, but I just thought that these three would be the main "tonefactors".

Nevertheless, you are suggesting using CM2511 as the input transformer. Since there's no datasheet available on the CM75101 (at least I didn't find one), I thought posting here... (I also contacted Cinemag, but haven't got any reply yet.)

So my question is are CM75101 and CM2511 interchangeable? Is there any significant or notable differences between the two, as far as the electric operating or the sound is concerned?

Thank you!
Finbase
Title: Re: Silver Element - Quad 8/Pacifica-ish unit
Post by: finbase on September 27, 2015, 02:37:11 AM
Hi folks!

I'm just about pulling the trigger and trying out my wings with the silver platform...

My ultimate goal is to create somewhat Quad 8/Pacifica-ish sounding unit, and according to the folklore found in the internet the best transformer options "tonewise" would be Cinemag's CMOQ-2S output and CM75101 input transformers.
The DOA would be Seventh circle's SC10. I've not done any real calculations yet, but I just thought that these three would be the main "tonefactors".

Nevertheless, you are suggesting using CM2511 as the input transformer. Since there's no datasheet available on the CM75101 (at least I didn't find one), I thought posting here... (I also contacted Cinemag, but haven't got any reply yet.)

So my question is are CM75101 and CM2511 interchangeable? Is there any significant or notable differences between the two, as far as the electric operating or the sound is concerned?

Thank you!
Finbase

Hello again!

Okey, here's some info from Cinemag, if anyone else is interested in making the Quad8-stylish pre:

QuadEight and the Pacifica used the CM-75101A...   ...The CMOQ-2S is a very good choice.   If you want less of the vintage steel sound, the CMOQ-2L (50% high-nickel + 50%    steel) is.  (They may have used a 49% nickel alloy for the Pacifica, but that is only what I have heard and not been able to document.)...

...The CM-2511... was never used by QuadEight.  It has a taller lamination stack and the inductance of the primary is a little higher.  It will handle a little more signal level.  CM-75101A and CM-2511 are interchangeable...


OK, I'll guess it's my time to start gathering the more detailed specs. The building instructions on Hairball Audio's website are very coherent!

BTW, hats off for the Cinemag! They're customer service has been always very friendly and fast. Throughout all my DIY projects this far they've been extremely polite even towards a guy like me, who is a complete novice as far as electronics are concerned. They seem to take all their customer seriously. Rare kind of geneorisity!

Best,
finbase
Title: Re: [BUILD] Hairball Audio - Elements
Post by: collinTHEbrewer on October 22, 2015, 09:55:48 AM
Hey guys. I just completed my second copper build. For those who haven't pulled the trigger on one of the elements preamps, I highly recommend it. It's very easy, clearly instructed, and cheap!

I had one issue that I resolved, but I wanted to share it with you all.

Upon completing the build, I popped the unit into my rack and hooked up a dynamic mic. No output. The 48V light would come on, so I knew something was working. I saw an earlier recommendation that no sound may mean some of the 3 fuses were blowing due to a current surge. I double checked all my resistor values and cap values. Finally I realized I had swapped the PNP and NPN transistors like a dummy...  :o

I swapped them to the correct positions and boom! It worked like a champ! Smooth analog goodness for the rest of my days.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mattvon on October 30, 2015, 09:46:55 PM
Hi all, I'm undertaking a Gold build and have really enjoyed it so far.  I've built a number of other projects (including a Rev D and a PM1K racking job)...great kit and very well documented.

I've come up against a bit of a challenge with figuring out which of the three multilayer ceramic caps are which.  The Gold build calls for a 33pF in C302, a 680pF in C500 and a 10pF in C504.  None of the caps have codes on them (or, if they do, are so small I can't see them even with my magnifying glass)...

My DMM has the ability to test capacitors, but I'm getting very odd readings.  I've got one which tests a 1.15nF (1150pF), one which tests at .19nF (190pF) and one which tests at .24nF (240pF).

I'd guess that my DMM isn't able to accurately gauge the values of these caps because they're so small, but I'm thinking that I'm probably okay assuming that the "1150pF" cap is actually the 680pF, the "240pF" cap is actually the 33pF, and the "190pF" cap is the 10pF.   This appears to be possibly correct, as the "240pF" cap has a smaller leg spacing, matching the holes for C302.

I've included a picture of each cap and the reading from my DMM...any help would be greatly appreciated!

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 30, 2015, 10:01:33 PM
Hi all, I'm undertaking a Gold build and have really enjoyed it so far.  I've built a number of other projects (including a Rev D and a PM1K racking job)...great kit and very well documented.

I've come up against a bit of a challenge with figuring out which of the three multilayer ceramic caps are which.  The Gold build calls for a 33pF in C302, a 680pF in C500 and a 10pF in C504.  None of the caps have codes on them (or, if they do, are so small I can't see them even with my magnifying glass)...

My DMM has the ability to test capacitors, but I'm getting very odd readings.  I've got one which tests a 1.15nF (1150pF), one which tests at .19nF (190pF) and one which tests at .24nF (240pF).

I'd guess that my DMM isn't able to accurately gauge the values of these caps because they're so small, but I'm thinking that I'm probably okay assuming that the "1150pF" cap is actually the 680pF, the "240pF" cap is actually the 33pF, and the "190pF" cap is the 10pF.   This appears to be possibly correct, as the "240pF" cap has a smaller leg spacing, matching the holes for C302.

I've included a picture of each cap and the reading from my DMM...any help would be greatly appreciated!

The codes are on there. You just need to get in good light and look very close. There are three digits, last one is the number of zeros. So 680 will be "681".

But ya reading small black numbers on darker blue can be tricky, proper light is the key.

The issue is that your DMM leads have capacitance, which makes reading lower values very hard.  If all else fails, try them as you've noted.

http://www.eevblog.com/forum/testgear/measure-pf-with-fluke87v/

Thanks,

Mike

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mattvon on October 31, 2015, 12:18:31 PM
Hi Mike, thanks very much for your reply.  I was able to see that there are markings on the caps, but was barely able to see them at all, even under bright light.  I am pretty sure I have them in the right positions--it followed the erroneous readings of my DMM, so I'm thinking they're right, but...

I finished up the build and got the unit in my rack.  The good news--I have DI and it sounds great!  The bad news--I don't have any signal when running a mic into the unit (and the DI unplugged)...not sure if this might be related to my ceramic cap issue or some other part of the build.  I tested another 500-series preamp in the same slot, so my mic->cable->patchbay->500-series rack input is known good.

Thoughts?  I'm hoping it's a bonehead simple issue...I can provide pics if it would be helpful.  Thanks in advance!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 31, 2015, 12:28:00 PM
Hi Mike, thanks very much for your reply.  I was able to see that there are markings on the caps, but was barely able to see them at all, even under bright light.  I am pretty sure I have them in the right positions--it followed the erroneous readings of my DMM, so I'm thinking they're right, but...

I finished up the build and got the unit in my rack.  The good news--I have DI and it sounds great!  The bad news--I don't have any signal when running a mic into the unit (and the DI unplugged)...not sure if this might be related to my ceramic cap issue or some other part of the build.  I tested another 500-series preamp in the same slot, so my mic->cable->patchbay->500-series rack input is known good.

Thoughts?  I'm hoping it's a bonehead simple issue...I can provide pics if it would be helpful.  Thanks in advance!

There is a very common issue that causes that.

The DI Relay has 8 pins and 6 of those pins are close together and the other 2 (power pins) are on the other end of the relay. If you miss soldering those 2 pins, which happens a lot, only your DI will work.

If it's not that there is most likely another issue causing your relay not to get power. Without power, the relay "normal mode" is set to DI input.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mattvon on October 31, 2015, 12:34:27 PM
Yup, that was it!  Thanks so much for your quick reply...
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on December 03, 2015, 02:06:32 AM
Hi all.

Just assembled two Copper kits. I did have one extra 100K resistor in both of the kits. Resistor R502 is installed and i couldnt find any use to the extra 100K´s.  I didnt see another 100K in the BOM either.

Safe to plug in or do i have a fried unit? In other words, should there be another 100k somewhere else than R502?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 03, 2015, 02:30:38 AM
Hi all.

Just assembled two Copper kits. I did have one extra 100K resistor in both of the kits. Resistor R502 is installed and i couldnt find any use to the extra 100K´s.  I didnt see another 100K in the BOM either.

Safe to plug in or do i have a fried unit? In other words, should there be another 100k somewhere else than R502?

I don't have access to the BOMs right now. It's likely we simply tossed an extra 100k in all those kits.

The units are fused, you can't really hurt them. Give them a try!

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on December 18, 2015, 03:10:47 AM
Yah ok, so i did just that. Im having slight issues here, if anyone knows whats going on please, help  :o

I dont know how much gain i should have comparing to a pre like Lola, but both seem kinda quiet and they distort fast! Its almost like i cannot get any peaks to hit 0 in my daw, peaks stop around -8 and then the wave just starts clipping.

The other of the two is even more quiet. Ive tried to switch opamps, no luck there. I have grainhill mods in both of them (in and out)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 18, 2015, 12:29:07 PM
Yah ok, so i did just that. Im having slight issues here, if anyone knows whats going on please, help  :o

I dont know how much gain i should have comparing to a pre like Lola, but both seem kinda quiet and they distort fast! Its almost like i cannot get any peaks to hit 0 in my daw, peaks stop around -8 and then the wave just starts clipping.

The other of the two is even more quiet. Ive tried to switch opamps, no luck there. I have grainhill mods in both of them (in and out)

Doesn't sound right.  All of our pre's have between 63-65 dB of gain so you should have plenty.  Do you have the output pot fully CW?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on December 19, 2015, 03:58:04 AM
Yah ok, so i did just that. Im having slight issues here, if anyone knows whats going on please, help  :o

I dont know how much gain i should have comparing to a pre like Lola, but both seem kinda quiet and they distort fast! Its almost like i cannot get any peaks to hit 0 in my daw, peaks stop around -8 and then the wave just starts clipping.

The other of the two is even more quiet. Ive tried to switch opamps, no luck there. I have grainhill mods in both of them (in and out)

Doesn't sound right.  All of our pre's have between 63-65 dB of gain so you should have plenty.  Do you have the output pot fully CW?

Mike

Yes output pots fully clockwise.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: yourdudeness on December 20, 2015, 04:09:58 PM
Hi everyone,

After some troubleshooting, I could make my silver work. As part of the troubleshooting I shorted C505. Now it is passing signal, sounding beautiful with a ribbon mic, but I cannot pump the input above about half because it starts distorting a lot and then at about "7" I get no signal at all. Could this have to do with C505? Also, would it be ok to use a polarized electrolityc? According to the 990 datasheet it´s okay, but just wanted to make sure. Thanks.

edit: Tried a polarized cap for c505. Works better but when I crank the input up to eleven, I get a low frequency hum. DI distorts like crazy, (although sounds kinda neat on guitar), but it´s almost a fuzz distortion, and a low level. THe buffer IC heats up a lot. Is ti normal for it to heat up so much? Any pointers as to what could be wrong? A bad OpAmp?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 21, 2015, 02:10:22 PM
Hi everyone,

After some troubleshooting, I could make my silver work. As part of the troubleshooting I shorted C505. Now it is passing signal, sounding beautiful with a ribbon mic, but I cannot pump the input above about half because it starts distorting a lot and then at about "7" I get no signal at all. Could this have to do with C505? Also, would it be ok to use a polarized electrolityc? According to the 990 datasheet it´s okay, but just wanted to make sure. Thanks.

edit: Tried a polarized cap for c505. Works better but when I crank the input up to eleven, I get a low frequency hum. DI distorts like crazy, (although sounds kinda neat on guitar), but it´s almost a fuzz distortion, and a low level. THe buffer IC heats up a lot. Is ti normal for it to heat up so much? Any pointers as to what could be wrong? A bad OpAmp?

You need C505, it blocks DC from the pot. You want something pretty hi value and polarized.  470-1000uF.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: cmac on January 17, 2016, 02:22:14 PM
I have an issue with my Copper Pre build.  Thanks in advance for any thoughts and or help.  The most frustrating thing is I built the first one of two copper preamps I ordered and it worked the first time I plugged it in.  Sounds awesome too.  But I goofed on my second build and accidentally soldered the smaller Blue capacitors in the pads for the bigger Blue Capacitors. I accidentally placed the smaller blue caps, which are the 220uf/25v caps,  in C505 C506 which are supposed to be the 470uf/16v caps. I realized this immediately after I soldered both of them in place.  I had to get them out of these pads and possibly fried them? As far as I can tell, noting this is the first DIY set of builds I have done, there is no reason why the bigger 470uf caps would not have taken to these pads after I finally was removed the smaller capacitors. The bigger concern to me is If overheated the smaller 220uf/25v caps trying to get them out of the wrong pads? I know they were hot because it burned my fingers a few times gripping them while trying to heat the solder, to pull them out of the incorrect pad. I resoldered the 220uf/25v caps in their proper place, C104 and C105 and continued the build without incident. 

I have sifted through this thread and have checked everything I can think of on this bad pre.  All of the polarized caps I have checked. Verified all of the solder joints.  Checked the Garyhill Input PCB for proper resistor placement.  Swapped the Op-Amp from this non working pre and put it into my Copper Pre that was working.  And the preamp still worked, thus verifying a good Op-Amp on my bad pre.  I will attach pics of the build.  Seems everything is in order unless I simply fried the small blue caps. 

On startup of this bad pre, it sounds like the beginning of the pink floyd song wish you were here.  That weird high pitched noise.  It lasts for 15 seconds or something like this and then the signal will pulse on and off in two bursts, like click click, showing up in my DAW.  I can even control the loudness of these clicks with the output trim pot.   Hope this all makes sense and appreciate any suggestions. 

Title: Re: [BUILD] Hairball Audio - Elements
Post by: cmac on January 17, 2016, 02:33:56 PM
This is a better quality picture for zooming in.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 18, 2016, 11:34:26 PM
It's hard to fry caps (at least in my experience), I think the pads would fry and fall off first. 

Look for any cold joints.  Looks like the gain/output switch resistor soldering could be cleaned up.

If all else fails send it on it.

http://www.hairballaudio.com/build-support-services

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: okdaniel on January 20, 2016, 01:47:35 AM
Hey hey hey. I ordered a silver that I just received. 

I was going to throw an LL1538XL input xfrmr that I had stashed away in there because I spotted holes for one on the image on the Hairball site for the silver.

I notice that these holes are now gone for this PCB revision. I assume it was removed because nobody cared to use them.

If that's true, is it just a matter of adapting it in there size wise, or were there issues with this model and the base silver design? Seems like I can just drop in there with the same orientation as the earlier PCB shown on the Hairball site. Am I wrong here?

Anyone else used an LL1538 with these? Anybody try a zobel with it at all, or no zobel as recommended by
Lundahl?

My first idea is Lundahl + SGA-SOA-2 for the DOA followed by the EA mini 1166. Thanks to anyone with any insight here.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 20, 2016, 02:50:03 PM
Hey hey hey. I ordered a silver that I just received. 

I was going to throw an LL1538XL input xfrmr that I had stashed away in there because I spotted holes for one on the image on the Hairball site for the silver.

I notice that these holes are now gone for this PCB revision. I assume it was removed because nobody cared to use them.

If that's true, is it just a matter of adapting it in there size wise, or were there issues with this model and the base silver design? Seems like I can just drop in there with the same orientation as the earlier PCB shown on the Hairball site. Am I wrong here?

Anyone else used an LL1538 with these? Anybody try a zobel with it at all, or no zobel as recommended by
Lundahl?

My first idea is Lundahl + SGA-SOA-2 for the DOA followed by the EA mini 1166. Thanks to anyone with any insight here.

We removed them to keep the build super simple.  You can definitely rig it on there and it'll work. The datasheet should have a suggested zobel.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: okdaniel on January 20, 2016, 10:17:58 PM
Thanks! I'll rig it up.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: cmac on January 25, 2016, 10:55:33 PM
It's hard to fry caps (at least in my experience), I think the pads would fry and fall off first. 

Look for any cold joints.  Looks like the gain/output switch resistor soldering could be cleaned up.

If all else fails send it on it.

http://www.hairballaudio.com/build-support-services

Mike

Alright,  so I eventually figured out I soldered Q600 and Q601 backwards. Which mike clearly states in the directions to pay attention to these two transistors, though they look exactly alike they're not! Ultimate dumb @$$ epiphany for me. I  built the first Pre no problem and was moving along too quickly on my second build. Lesson learned, take your time! Swapped those two transistors and now have a pair of great Copper Preamps.  Drum overhead mics sound great smashed through these.  And thanks to Mike for always offering help, I know it is appreciated!


Title: Re: [BUILD] Hairball Audio - Elements
Post by: Ataraxia on January 30, 2016, 06:22:20 AM
Hi,

Is it possible to plug a line level signal straight into the XLR mic input on the rear of the rack  or should I pad the signal first?

Thank you,
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on February 01, 2016, 03:14:56 PM
Hi,

Is it possible to plug a line level signal straight into the XLR mic input on the rear of the rack  or should I pad the signal first?

Thank you,

You can use the front panel pad. The only issue is that the mic input impedance is not optimal for a line level source impedance. You *might* get some roll off. Give it a try.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Ataraxia on February 04, 2016, 09:48:28 AM
Ok, thank you for the Quick reply,

cheers
Title: Re: [BUILD] Hairball Audio - Elements
Post by: pethell on March 10, 2016, 08:27:41 PM
hi
i have build two fully working  lola's (very nice sounding) but i am having trouble getting the copper working :-(
it passes audio, (condenser 48v and dynamic) but the stepped gain knob doesn’t work.
i have build two units and they have the same problem… where to start ?

all the best
                              peter
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 10, 2016, 08:34:05 PM
hi
i have build two fully working  lola's (very nice sounding) but i am having trouble getting the copper working :-(
it passes audio, (condenser 48v and dynamic) but the stepped gain knob doesn’t work.
i have build two units and they have the same problem… where to start ?

all the best
                              peter

right angle connector fully soldered? All the grayhill pins including center pin soldered?

post a few images if you like.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 19, 2016, 07:24:24 AM
Hey Mike !

I just have ordered 1 element copper and 1 fet/500 rev A. Can't wait to receive those (over france) !

I just have one question for you !

Is there any chance to find the schematic of the copper? I would really love take an eye on it !!!

Thanks in advance for your answer !

Best
Adrien
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 19, 2016, 12:48:55 PM
Hey Mike !

I just have ordered 1 element copper and 1 fet/500 rev A. Can't wait to receive those (over france) !

I just have one question for you !

Is there any chance to find the schematic of the copper? I would really love take an eye on it !!!

Thanks in advance for your answer !

Best
Adrien

Hi,

Here is the elements schematic:
http://library.hairballaudio.com/images/2015/06/hba-elements-pcb-v1-3_schematic-production.pdf

you can use the elements master BOM to see the copper values.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 19, 2016, 05:47:21 PM
Wao thank you!
I'll come backline to post here d'urine my build! I Know the package os on Paris, should have it by the beginning of the week!

Adrien
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 24, 2016, 07:34:09 PM
Hi there!

Khadr almost done building the copper!

Il guess I have an issue with r608.
On the BOM, it should be 1k, and the last resistor I have is a 100k.

Should I go buy a 1k resistor ta my local store or the 100k fit on here?

Thanks in advanced for your answer!
Adrien
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 24, 2016, 10:18:17 PM
Hi there!

Khadr almost done building the copper!

Il guess I have an issue with r608.
On the BOM, it should be 1k, and the last resistor I have is a 100k.

Should I go buy a 1k resistor ta my local store or the 100k fit on here?

Thanks in advanced for your answer!
Adrien

No don't use the 100K. We can send you one but if you are in EU it might be quicker locally.

Let me know.

Thanks,

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 25, 2016, 08:45:30 AM
It wat I thought too !

No problem, we gonna go to our local supplier!
So it's a 1k, what is the voltage? .25V

Thanks in advance !
Adrien
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 25, 2016, 10:19:21 AM
It wat I thought too !

No problem, we gonna go to our local supplier!
So it's a 1k, what is the voltage? .25V

Thanks in advance !
Adrien

.25W or bigger.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Lachlan C. on March 29, 2016, 05:55:10 AM
Hi HB!

I have a Elements Coper that was built from a kit in for repair that is functioning ok but has a bit of self noise at higher gains (no input with the gain and output trim pegged its around -45). I have another full functioning unit here that is dead silent with the controls full up.

Voltages look ok and I have reflowed multiple joints. I was wondering if you had any advice as to where to go looking?

Many thanks,

Lach
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Lachlan C. on March 31, 2016, 03:21:39 AM
Ok, so I still having haven't found the cause of the noise. ..

1)I've swapped opamps (with known working one) and noise is still present on higher gain settings.

2)When I pull the opamp noise goes (makes sense).

3) Double checked gain resistors on input attenuator PCB.

4) Switching pad or phase switches produces large spike is output - DC leaking somewhere?

5) I tested 470uF Radial and 10uf Coupling Tants (and tried replacing) - noise is still present.

Not sure where else to look. 

Also do you have a link to a schematic - the one of the first page is not working.

Many thanks!

Lach
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 31, 2016, 09:05:12 AM
Hey Mike !

We have finish to build the element copper..

Guess what.. Not working !
I suppose we have made some mistake at some point, but here is the result after the first plug :

No MIC IPUT SIGNAL
DI signal : we have input and output,  but there (a lot of) distortion.

I figured out that my friend has burn the C505-470uF/16v (the plastic around the capacitor is burn at the top end of it..)

We have double checked all the component, everything seems to be in good order..


Do you have any idea where it can come from?  :-[

Thanks in advance

Adrien
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 31, 2016, 12:34:35 PM
Ok so after I have double checked everything here is what I have find…

There is some drop off on some resistors :

R301 (200k) - 126K
R304 (240R) - 9,2R
R404 (620 R) - 10R
R405 (620R) - 10R
R606 (43R)  - 2R
R607 (1K) - 200R

I'll post some pictures of my build.. If there is anything that jump off the pictures !

Thanks in advance !
Adrien
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 31, 2016, 12:35:09 PM
Pic 1
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 31, 2016, 12:36:44 PM
Pic 2
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on March 31, 2016, 12:38:03 PM
Piuc 3 (Burned Condo)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 01, 2016, 02:09:45 PM
Ok, so I still having haven't found the cause of the noise. ..

1)I've swapped opamps (with known working one) and noise is still present on higher gain settings.

2)When I pull the opamp noise goes (makes sense).

3) Double checked gain resistors on input attenuator PCB.

4) Switching pad or phase switches produces large spike is output - DC leaking somewhere?

5) I tested 470uF Radial and 10uf Coupling Tants (and tried replacing) - noise is still present.

Not sure where else to look. 

Also do you have a link to a schematic - the one of the first page is not working.

Many thanks!

Lach

Not too sure without working on it.

Schematic:
http://library.hairballaudio.com/images/2015/06/hba-elements-pcb-v1-3_schematic-production.pdf

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 01, 2016, 02:11:18 PM
Ok so after I have double checked everything here is what I have find…

There is some drop off on some resistors :

R301 (200k) - 126K
R304 (240R) - 9,2R
R404 (620 R) - 10R
R405 (620R) - 10R
R606 (43R)  - 2R
R607 (1K) - 200R

I'll post some pictures of my build.. If there is anything that jump off the pictures !

Thanks in advance !
Adrien

You can't really measure resistors on the PCB without considering how they interact with other components in parallel. To them you'd have to lift one leg off the PCB.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 01, 2016, 02:12:30 PM
Pic 2
Q600 and 601 are in backwards it appears.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 01, 2016, 02:15:12 PM
Hey Mike !

We have finish to build the element copper..

Guess what.. Not working !
I suppose we have made some mistake at some point, but here is the result after the first plug :

No MIC IPUT SIGNAL
DI signal : we have input and output,  but there (a lot of) distortion.

I figured out that my friend has burn the C505-470uF/16v (the plastic around the capacitor is burn at the top end of it..)

We have double checked all the component, everything seems to be in good order..


Do you have any idea where it can come from?  :-[

Thanks in advance

Adrien

The relay is set to DI by default. If the DI is working and the mic input is not, there is an issue with your DI flipping section.  The distortion is caused by the Q600/601 transistors being in backwards.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 01, 2016, 02:56:52 PM
Ok, so I still having haven't found the cause of the noise. ..

1)I've swapped opamps (with known working one) and noise is still present on higher gain settings.

2)When I pull the opamp noise goes (makes sense).

3) Double checked gain resistors on input attenuator PCB.

4) Switching pad or phase switches produces large spike is output - DC leaking somewhere?

5) I tested 470uF Radial and 10uf Coupling Tants (and tried replacing) - noise is still present.

Not sure where else to look. 

Also do you have a link to a schematic - the one of the first page is not working.

Many thanks!

Lach

I'd be suspicious of the output section. Check your Q600/601 placement, orientation and the components around it as well as the load components.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on April 02, 2016, 08:32:58 AM
thanks Mike I'll check that ! :)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 03, 2016, 02:00:49 AM
I also got one extra 100k resistor and a 1k resistor missing.
Unfortunately they did not have any at my local store is it possible to get the missing 1k resistor shipped to me?

thanks

Thomas
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 04, 2016, 03:11:12 AM
the first of my two copper elements is done...this thing sounds amazing. I did a side by side with my Neve 1073 and it sounds just like it. Very happy
once I get the missing 1k resistor I can build the second one (Please Mike, send this to me)

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 04, 2016, 01:39:51 PM
I also got one extra 100k resistor and a 1k resistor missing.
Unfortunately they did not have any at my local store is it possible to get the missing 1k resistor shipped to me?

thanks

Thomas

Definitely.  Send us an email from the site.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 04, 2016, 02:27:24 PM
thanks, will do

Your site seems to be down, getting error: "Cannot connect to database"
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 04, 2016, 02:30:42 PM
thanks, will do

Your site seems to be down, getting error: "Cannot connect to database"

Ya it's down for a few minutes.  You can email "info (at) hairballaudio (dot) com" with your address and part missing.

Thanks,

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 04, 2016, 02:40:03 PM
site is back up

I sent the message

thanks

Thomas
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on April 07, 2016, 04:53:33 PM
Hey Mike !

I have double check all the soldering point and have turn Q600 & Q601 in the right side, everything appears to be in good order ! I'll have a session on tomorrow where I'll have a chance to test it… hope everything will be fine !

Thanks for your help !

Best
Adrien
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 07, 2016, 11:29:10 PM
missing resistor arrived.

Thank you!!!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Sinkia on April 08, 2016, 01:42:39 PM
Have done my first session today with the element copper.. the sound of this unit is AWESOME !

female singer -> telefunken ak-47 -> element copper = tons of love !

Thank you so much for developing some great stuff like it !

Next stop is gonna be a lola I guess.. just for different flavor !

Cheers !
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 08, 2016, 06:13:08 PM
Hi Mike,

I am in the process of stuffing my second Element Copper and on R604 and R605 it states to use 3R5 resistors however my kit came with two 4R5 Resistors instead.

Is that safe/ok or do I need to get the 3R5 ?

thanks

Thomas
Title: Re: [BUILD] Hairball Audio - Elements
Post by: CiaoPatsy on April 09, 2016, 07:22:19 PM
Been having a strange issue with my Copper.

Works fine and sounds great until the output randomly goes down by around half. Audio isn't distorted when it does this, it just gets way quieter and I have to jack up the gain to get it to a nominal level.

It will work perfectly for hours and then do this seemingly at random, or other times it may be turned on and right away be like this.

I've reflowed all solder points multiple times with no luck....any other ideas?

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 11, 2016, 12:22:21 PM
Have done my first session today with the element copper.. the sound of this unit is AWESOME !

female singer -> telefunken ak-47 -> element copper = tons of love !

Thank you so much for developing some great stuff like it !

Next stop is gonna be a lola I guess.. just for different flavor !

Cheers !

Awesome!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 11, 2016, 12:24:31 PM
Been having a strange issue with my Copper.

Works fine and sounds great until the output randomly goes down by around half. Audio isn't distorted when it does this, it just gets way quieter and I have to jack up the gain to get it to a nominal level.

It will work perfectly for hours and then do this seemingly at random, or other times it may be turned on and right away be like this.

I've reflowed all solder points multiple times with no luck....any other ideas?

That does sound like a loose or cold joint. Something making intermittent connection.  I would check everything including the output stage.  If you have any Grayhill boards reflow all of that those connections including to the main PCB.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 16, 2016, 12:06:37 AM
I just finished my second Elements Copper Pre Amp...(my 5th Hairball build all together )
I ran into a problem with this one.
After I was done there was no sound at all, so I started checking and the capacitor in C401 was dead. So I ordered a new one from Mouser.
It came today and I replaced it. Now I am getting sound but not even close to the volume of the first copper.
I have to up input and output by 3 steps each more than on the first copper.

Is there anything you can think of to check. This is where my electronics knowledge ends...

Could it be the capacitor in C401?  I thought I had the exact one of the kit but the one that came with the kit shows .1 uf and 63v and one that came from mouser says .1 uf 100 volt (mouser part 594-2222-370-22104)
since the BOM didn't specify the voltage I did not pay attention to this...I probably should have.

Could that be the reason or is there anything else you can think off

The unit works and it's not the end of the world but I would really like to get them both as close as possible.

thanks

Thomas
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 18, 2016, 10:39:22 AM
I just finished my second Elements Copper Pre Amp...(my 5th Hairball build all together )
I ran into a problem with this one.
After I was done there was no sound at all, so I started checking and the capacitor in C401 was dead. So I ordered a new one from Mouser.
It came today and I replaced it. Now I am getting sound but not even close to the volume of the first copper.
I have to up input and output by 3 steps each more than on the first copper.

Is there anything you can think of to check. This is where my electronics knowledge ends...

Could it be the capacitor in C401?  I thought I had the exact one of the kit but the one that came with the kit shows .1 uf and 63v and one that came from mouser says .1 uf 100 volt (mouser part 594-2222-370-22104)
since the BOM didn't specify the voltage I did not pay attention to this...I probably should have.

Could that be the reason or is there anything else you can think off

The unit works and it's not the end of the world but I would really like to get them both as close as possible.

thanks

Thomas

The cap voltage would not cause that.

Low volume could be a lot of things:
-Gain resistor swapped values
-Any improper resistor value or cap value
-Improper transformer wiring
-missing a link
-bad op-amp (switch the op-amp with your other build...does the low gain follow the op-amp?)

We also have a $50 flat rate repair on those.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 19, 2016, 02:43:39 AM
I just finished my second Elements Copper Pre Amp...(my 5th Hairball build all together )
I ran into a problem with this one.
After I was done there was no sound at all, so I started checking and the capacitor in C401 was dead. So I ordered a new one from Mouser.
It came today and I replaced it. Now I am getting sound but not even close to the volume of the first copper.
I have to up input and output by 3 steps each more than on the first copper.

Is there anything you can think of to check. This is where my electronics knowledge ends...

Could it be the capacitor in C401?  I thought I had the exact one of the kit but the one that came with the kit shows .1 uf and 63v and one that came from mouser says .1 uf 100 volt (mouser part 594-2222-370-22104)
since the BOM didn't specify the voltage I did not pay attention to this...I probably should have.

Could that be the reason or is there anything else you can think off

The unit works and it's not the end of the world but I would really like to get them both as close as possible.

thanks

Thomas

The cap voltage would not cause that.

Low volume could be a lot of things:
-Gain resistor swapped values
-Any improper resistor value or cap value
-Improper transformer wiring
-missing a link
-bad op-amp (switch the op-amp with your other build...does the low gain follow the op-amp?)

We also have a $50 flat rate repair on those.

Mike

I exchanged the op amps, same result. I compared the values visually and with a Meter between the two units and only R501 was different in readings (visually the same). The Resistor on the second copper read 0.22 (20k setting) and the first one 0.33... they are both supposed to be 4.7k as you know. But I know once in the PCB readings can be off. So I took the one from the second copper out and it does read 4.7k, so I put it back in.

Both seem to be otherwise identical.  All the Caps return a similar value...again, I know on the PCB it's tough to get correct readings and visually everything looks the same.
transformers are wired correctly as well.
The other strange thing is that the second copper sounds completely different, much brighter than the first...both sound fantastic but not alike.
So I am not sure what to do... I wanted a somewhat matched pair.

Since part of this whole thing is to learn I am a bit hesitant to ship it in... but might end up doing so.

Any further ideas?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 20, 2016, 03:58:47 PM
I just finished my second Elements Copper Pre Amp...(my 5th Hairball build all together )
I ran into a problem with this one.
After I was done there was no sound at all, so I started checking and the capacitor in C401 was dead. So I ordered a new one from Mouser.
It came today and I replaced it. Now I am getting sound but not even close to the volume of the first copper.
I have to up input and output by 3 steps each more than on the first copper.

Is there anything you can think of to check. This is where my electronics knowledge ends...

Could it be the capacitor in C401?  I thought I had the exact one of the kit but the one that came with the kit shows .1 uf and 63v and one that came from mouser says .1 uf 100 volt (mouser part 594-2222-370-22104)
since the BOM didn't specify the voltage I did not pay attention to this...I probably should have.

Could that be the reason or is there anything else you can think off

The unit works and it's not the end of the world but I would really like to get them both as close as possible.

thanks

Thomas

The cap voltage would not cause that.

Low volume could be a lot of things:
-Gain resistor swapped values
-Any improper resistor value or cap value
-Improper transformer wiring
-missing a link
-bad op-amp (switch the op-amp with your other build...does the low gain follow the op-amp?)

We also have a $50 flat rate repair on those.

Mike

I exchanged the op amps, same result. I compared the values visually and with a Meter between the two units and only R501 was different in readings (visually the same). The Resistor on the second copper read 0.22 (20k setting) and the first one 0.33... they are both supposed to be 4.7k as you know. But I know once in the PCB readings can be off. So I took the one from the second copper out and it does read 4.7k, so I put it back in.

Both seem to be otherwise identical.  All the Caps return a similar value...again, I know on the PCB it's tough to get correct readings and visually everything looks the same.
transformers are wired correctly as well.
The other strange thing is that the second copper sounds completely different, much brighter than the first...both sound fantastic but not alike.
So I am not sure what to do... I wanted a somewhat matched pair.

So the issues didn't follow the op-amps?

Does the one still have low gain?

Mike

Since part of this whole thing is to learn I am a bit hesitant to ship it in... but might end up doing so.

Any further ideas?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 20, 2016, 05:16:57 PM
Yep the second unit still has the lower volume
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 20, 2016, 05:22:31 PM
Yep the second unit still has the lower volume

That's probably also why it sounds so weird. 

Set your DMM to read resistance (Ω) and put one lead on a green lead of the input transformer. Now test the Ω between the green and each of the other leads and not the Ω reading for each color to green.  Test the other unit and see if you see anything different.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 20, 2016, 05:39:41 PM
Yep the second unit still has the lower volume

That's probably also why it sounds so weird. 

Set your DMM to read resistance (Ω) and put one lead on a green lead of the input transformer. Now test the Ω between the green and each of the other leads and not the Ω reading for each color to green.  Test the other unit and see if you see anything different.

Mike

thanks, will do
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 20, 2016, 11:32:33 PM
Yellow, Grey and Violet show different readings on the units.

Bad Copper:                                      Good Copper
at 2k                                                       at 2k
Orange: .002                                     Orange: .003   
Yellow:   .002                                     Yellow:   .174
Grey:       .002                                     Grey:       .172
Violet:    .002                                      Violet:    .333


at 20k                                                     at 20k
Black:      .24                                        Black:      .24
White:     .24                                       White:     .25
Red:          .25                                        Red:          .25
Brown:    .26                                        Brown:    .26

Faulty Input transformer?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 20, 2016, 11:43:05 PM
Yellow, Grey and Violet show different readings on the units.

Bad Copper:                                      Good Copper
at 2k                                                       at 2k
Orange: .002                                     Orange: .003   
Yellow:   .002                                     Yellow:   .174
Grey:       .002                                     Grey:       .172
Violet:    .002                                      Violet:    .333


at 20k                                                     at 20k
Black:      .24                                        Black:      .24
White:     .24                                       White:     .25
Red:          .25                                        Red:          .25
Brown:    .26                                        Brown:    .26

Faulty Input transformer?

Looks that way.  Send me an email. Info at hairballaudio dot com

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 26, 2016, 03:32:44 AM
new Input Transformer arrived today and yes, that was it... all great now.
This baby sounds fantastic!!!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 28, 2016, 07:02:38 PM
now that my bad copper is a great copper :) the other copper has a bit of humming I noticed

It's not too bad, I can lower the input and up the output to compensate but since my other copper is absolutely noiseless I would like to try to get this one there as well.

I checked the slot and cabling and they are fine so it's definitely the copper itself.
The wires on the transformers are as short as it can be and the soldering is clean.
Other than that are there any usual suspects I can check on?

thanks
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 28, 2016, 07:05:20 PM
now that my bad copper is a great copper :) the other copper has a bit of humming I noticed

It's not too bad, I can lower the input and up the output to compensate but since my other copper is absolutely noiseless I would like to try to get this one there as well.

I checked the slot and cabling and they are fine so it's definitely the copper itself.
The wires on the transformers are as short as it can be and the soldering is clean.
Other than that are there any usual suspects I can check on?

thanks

Is it closer to the power supply? Does the hum follow the unit? Try putting it in the slot furthest from the supply.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: mrtomcat on April 28, 2016, 08:32:41 PM
I moved it to the middle slot and the hum was the same the other slots are full
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on May 02, 2016, 02:04:41 PM
I moved it to the middle slot and the hum was the same the other slots are full

You could send it in, but I would suspect something localized to your set up.

Are the green wires on the input tx soldered well? Do you have the full enclosure on?

Mike
Title: GOLD - Persistent buzz
Post by: tctonn on May 27, 2016, 05:56:06 PM
Hi Mike,

I finished the build on my Gold unit and it seems to be working well. It has decent level with both the DI and main inputs and all controls are working smoothly. But it has a persistent low level buzz that goes up and down with the gain. It's quiet but it is there consistently. The noise becomes especially pronounced with the last step of the gain knob.

The self noise on the Gold is very low other wise and none of my other units in the rack are having any issues.

Any ideas where I should start poking?

Thanks!

Travis
Title: Re: GOLD - Persistent buzz
Post by: Hairball Audio on May 31, 2016, 11:47:23 AM
Hi Mike,

I finished the build on my Gold unit and it seems to be working well. It has decent level with both the DI and main inputs and all controls are working smoothly. But it has a persistent low level buzz that goes up and down with the gain. It's quiet but it is there consistently. The noise becomes especially pronounced with the last step of the gain knob.

The self noise on the Gold is very low other wise and none of my other units in the rack are having any issues.

Any ideas where I should start poking?

Thanks!

Travis

I would suspect something external to start. What is your rack brand? Where is the power supply in relation to the rack space your pre is in?  Does moving it to a space further from the supply help?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: radtunez on June 13, 2016, 08:21:55 PM
Hey Mike,

Finished up my build on my Copper, and alas, no signal :( The only indication that *something* may be working is that the LED light comes up on my 48V. Otherwise, nothing. I checked all of my joints, and they look pretty good to me. I attached a photo. I also cross referenced my component placement with other successful copper build photos, and it looks like I got that all right. And I checked all resistors were working before I put em in. Here are a couple of points in my build I was wondering if you think may be the culprit, otherwise I'd love some advice on where to troubleshoot:

- I accidentally soldered the fuses on below the indent in the lead - would the resulting elongated lead cause issues there?
- I had poor flow on my blue gain capacitors and spent a while (a lot of heat) rectifying those joints, but I read in another post that it'd be pretty hard to fry them, yeah?

Thanks,

Ryan

http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8378_zps3myyl3yd.jpg (http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8378_zps3myyl3yd.jpg)
http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8376_zpsc17smkzf.jpg (http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8376_zpsc17smkzf.jpg)
http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8375_zps5nezgj4w.jpg (http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8375_zps5nezgj4w.jpg)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Lachlan C. on June 16, 2016, 12:39:08 AM
Ok, so I still having haven't found the cause of the noise. ..

1)I've swapped opamps (with known working one) and noise is still present on higher gain settings.

2)When I pull the opamp noise goes (makes sense).

3) Double checked gain resistors on input attenuator PCB.

4) Switching pad or phase switches produces large spike is output - DC leaking somewhere?

5) I tested 470uF Radial and 10uf Coupling Tants (and tried replacing) - noise is still present.

Not sure where else to look. 

Also do you have a link to a schematic - the one of the first page is not working.

Many thanks!

Lach

I'd be suspicious of the output section. Check your Q600/601 placement, orientation and the components around it as well as the load components.

Hi Mike, put it on the back burner but am still having noise issues. Here is my findings ....

Swapped input transformer - no change, noise still present

Replaced output BJTs - no change, noise still present

Installed 68pf cap into C502 space - this reduced noise but did not eliminate it.

Any thoughts?

Just to be clear, I have tried the other noise free unit in the same lunchbox slot and it worked perfectly.

Thanks for your help, I appreciate it!

Lach

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on June 20, 2016, 01:06:50 PM
Ok, so I still having haven't found the cause of the noise. ..

1)I've swapped opamps (with known working one) and noise is still present on higher gain settings.

2)When I pull the opamp noise goes (makes sense).

3) Double checked gain resistors on input attenuator PCB.

4) Switching pad or phase switches produces large spike is output - DC leaking somewhere?

5) I tested 470uF Radial and 10uf Coupling Tants (and tried replacing) - noise is still present.

Not sure where else to look. 

Also do you have a link to a schematic - the one of the first page is not working.

Many thanks!

Lach

I'd be suspicious of the output section. Check your Q600/601 placement, orientation and the components around it as well as the load components.

Hi Mike, put it on the back burner but am still having noise issues. Here is my findings ....

Swapped input transformer - no change, noise still present

Replaced output BJTs - no change, noise still present

Installed 68pf cap into C502 space - this reduced noise but did not eliminate it.

Any thoughts?

Just to be clear, I have tried the other noise free unit in the same lunchbox slot and it worked perfectly.

Thanks for your help, I appreciate it!

Lach

If you can, try swapping op-amps with your friend. See if the noise follows the op-amps.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on June 20, 2016, 01:11:32 PM
Hey Mike,

Finished up my build on my Copper, and alas, no signal :( The only indication that *something* may be working is that the LED light comes up on my 48V. Otherwise, nothing. I checked all of my joints, and they look pretty good to me. I attached a photo. I also cross referenced my component placement with other successful copper build photos, and it looks like I got that all right. And I checked all resistors were working before I put em in. Here are a couple of points in my build I was wondering if you think may be the culprit, otherwise I'd love some advice on where to troubleshoot:

- I accidentally soldered the fuses on below the indent in the lead - would the resulting elongated lead cause issues there?
- I had poor flow on my blue gain capacitors and spent a while (a lot of heat) rectifying those joints, but I read in another post that it'd be pretty hard to fry them, yeah?

Thanks,

Ryan

http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8378_zps3myyl3yd.jpg (http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8378_zps3myyl3yd.jpg)
http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8376_zpsc17smkzf.jpg (http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8376_zpsc17smkzf.jpg)
http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8375_zps5nezgj4w.jpg (http://i1167.photobucket.com/albums/q622/twicetheking/IMG_8375_zps5nezgj4w.jpg)

Hard to say.

The soldering is the first thing the pops out to me. It's no bad, but not great either.  Reflow and weird joints and trim your leads. Does the DI work?

Repair info if that interests you:
http://www.hairballaudio.com/build-support-services

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Lachlan C. on June 20, 2016, 05:28:59 PM

[/quote]

If you can, try swapping op-amps with your friend. See if the noise follows the op-amps.

Mike
[/quote]

Thanks for replying, Mike. I did try swapping opamps between units and the noise does not follow to other unit, I.e. opamp is not causing issues. It's a strange fault!

Lach
Title: Re: [BUILD] Hairball Audio - Elements
Post by: analogexplosions on June 24, 2016, 08:06:16 PM
I'm having the strangest issue with a Copper right now.  This will be the second of these I've built, first one worked perfect the first time.

This one, not so much.  I get signal through the DI, and with a dynamic/Non-48v mic and everything works as expected.  When 48v is engaged, the LED lights, but no sound comes through the mic.  The strangest part is that the Copper itself becomes microphonic and if i tap anywhere on it, I get signal of my tapping.  ( like, I can audibly hear my tapping on the pre coming through the speakers)

What idiotic thing could I have overlooked?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: ln76d on June 28, 2016, 05:46:59 PM
Somwhere you lose ground connection
Title: DI works fine, but no mic sound?
Post by: achase4u on July 01, 2016, 10:37:53 AM
Ruh Roh!  Where should I look here?  There is a relay to switch between the mic and DI automatically, correct?  Perhaps somehow it is stuck in DI mode?  Thoughts on where to check?

On the plus side.  The DI sound uhhhhhhhhhmazing!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: achase4u on July 01, 2016, 10:53:48 AM
Ok - so I noticed the issue.  At R200, I actually have nothing installed, and I have a left over 100k resistor.  It has the same color code as the 100k resistor at r502 BIAS.  Since there is only one 100k resistor needed in this build, it seems I got two 100ks instead of one 100k and another 1k?

I measured every resistor before I installed it.  So this leads me to believe the reason I didn't install anything at R200 is because I didn't have one, and I have this left over 100k.  The only scenario I can imagine where I used the 1k somewhere I shouldnt, would be at R502 bias, because that would have left over the 100k resistor.

I realize how silly it is to load up a build before all components are placed and you've got an extra left over - but it just totally slipped my mind I guess.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on August 17, 2016, 12:44:20 AM
Im having similar issue. DI and dynamic works, but no phantom.

Ive had an extra 100k in all of my 4 copper kits btw.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: blackartmixing on August 25, 2016, 10:56:51 AM
Hi have built two Copper pres and i have the same problem with both.  I get DI but no mic input.  i know that has been mentioned in the thread so far but i've checked and both have the relay soldered in correctly.  i've tried to add more solder to the joints and all solder points appear to be good but still i'm not getting any switching. 

Can anyone advise how i can troubleshoot this further please??
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 25, 2016, 11:02:46 AM
Hi have built two Copper pres and i have the same problem with both.  I get DI but no mic input.  i know that has been mentioned in the thread so far but i've checked and both have the relay soldered in correctly.  i've tried to add more solder to the joints and all solder points appear to be good but still i'm not getting any switching. 

Can anyone advise how i can troubleshoot this further please??

Possibly another bad component in the relay circuit.  When you power the unit on, with nothing in the DI jack, you should hear a small click in the relay switching it to mic. 
Title: Re: [BUILD] Hairball Audio - Elements
Post by: blackartmixing on August 25, 2016, 11:45:23 AM
Hi have built two Copper pres and i have the same problem with both.  I get DI but no mic input.  i know that has been mentioned in the thread so far but i've checked and both have the relay soldered in correctly.  i've tried to add more solder to the joints and all solder points appear to be good but still i'm not getting any switching. 

Can anyone advise how i can troubleshoot this further please??

Possibly another bad component in the relay circuit.  When you power the unit on, with nothing in the DI jack, you should hear a small click in the relay switching it to mic.

Actually the mic input works when i reset the power to the chassis then i plug in a DI and that works but when i remove the DI it doesn't switch back to the mic input  >:(
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 25, 2016, 11:49:56 AM
Hi have built two Copper pres and i have the same problem with both.  I get DI but no mic input.  i know that has been mentioned in the thread so far but i've checked and both have the relay soldered in correctly.  i've tried to add more solder to the joints and all solder points appear to be good but still i'm not getting any switching. 

Can anyone advise how i can troubleshoot this further please??

Possibly another bad component in the relay circuit.  When you power the unit on, with nothing in the DI jack, you should hear a small click in the relay switching it to mic.

Actually the mic input works when i reset the power to the chassis then i plug in a DI and that works but when i remove the DI it doesn't switch back to the mic input  >:(

That's weird. Make sure the edge card gold contacts are super clean.   Check all the components and values in the relay circuit.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: blackartmixing on August 26, 2016, 04:56:59 AM
Hi have built two Copper pres and i have the same problem with both.  I get DI but no mic input.  i know that has been mentioned in the thread so far but i've checked and both have the relay soldered in correctly.  i've tried to add more solder to the joints and all solder points appear to be good but still i'm not getting any switching. 

Can anyone advise how i can troubleshoot this further please??

Possibly another bad component in the relay circuit.  When you power the unit on, with nothing in the DI jack, you should hear a small click in the relay switching it to mic.

Actually the mic input works when i reset the power to the chassis then i plug in a DI and that works but when i remove the DI it doesn't switch back to the mic input  >:(

That's weird. Make sure the edge card gold contacts are super clean.   Check all the components and values in the relay circuit.

Did a bit more reflow work and all looks to be good now.  thanks for you time
Title: Re: [BUILD] Hairball Audio - Elements
Post by: 3dB on September 23, 2016, 11:21:50 PM
Mike,

I've built a Copper, Bronze and Lola over the past couple of weeks - all nice amps! I'd like to use INPUT#2 on my Purple Audio Sweet Ten for these modules. Any reason why I couldn't just jumper over from pins 8 & 10 to pins 7 & 9 on the edge connector?

Thanks,

Rob
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 23, 2016, 11:29:13 PM
Mike,

I've built a Copper, Bronze and Lola over the past couple of weeks - all nice amps! I'd like to use INPUT#2 on my Purple Audio Sweet Ten for these modules. Any reason why I couldn't just jumper over from pins 8 & 10 to pins 7 & 9 on the edge connector?

Thanks,

Rob

Should work.  Jumper 7 w/ 8 and jumper 9 w/10.

Mike
Title: BUILD Hairball Audio Elements
Post by: Laurapax on November 07, 2016, 02:03:12 PM
I had meant to add that Im using Steves Guide to Photoshop Elements & Premiere Elements 7 and that I referred to the section on "Adjusting Audio Levels on the Timeline."

___
NEW XRumer + SocPlugin: revolutional method in SEO and SMM
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Diamondj421 on November 10, 2016, 06:19:20 AM
Guess who's back! I think I jinxed myself, bragging about the ease of which I completed my first build, a Lola. I got a Bronze pre today and just finished it. Plugged it in and all seemed well until I turned the gain and output knobs up half way while using the DI. The signal got very distorted. It appears to be working ok when using the mic input but it's hard to tell since I can't turn it up too much (Neighbors aren't fans of loud noises at 6am. Weird, I know). While trying to run the green wire through the PCB a second time after it came out, I may have fried the pad but it's still good if connected to the cable next to it, no? Could that be the cause? Thanks in advance!

Jeff
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on November 10, 2016, 10:42:51 AM
Guess who's back! I think I jinxed myself, bragging about the ease of which I completed my first build, a Lola. I got a Bronze pre today and just finished it. Plugged it in and all seemed well until I turned the gain and output knobs up half way while using the DI. The signal got very distorted. It appears to be working ok when using the mic input but it's hard to tell since I can't turn it up too much (Neighbors aren't fans of loud noises at 6am. Weird, I know). While trying to run the green wire through the PCB a second time after it came out, I may have fried the pad but it's still good if connected to the cable next to it, no? Could that be the cause? Thanks in advance!

Jeff

The DI will be distorted unless the output is full CW. You want the output maxed for the cleanest signal.  Try that.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Diamondj421 on November 10, 2016, 03:17:09 PM
Gain at 12 o'clock and output all the way up, it still sounds muffled and distorted. I know this is a more colorful pre than my Lola, just didn't know if it's supposed to be this extreme. Haha. Here are some samples.  Please pardon the cheesy-ness.

https://drive.google.com/open?id=0B5xJ9UrTIGjtdnlXcUNCWnRNekU (https://drive.google.com/open?id=0B5xJ9UrTIGjtdnlXcUNCWnRNekU)

https://drive.google.com/open?id=0B5xJ9UrTIGjta2FXak5JS0FzSWc (https://drive.google.com/open?id=0B5xJ9UrTIGjta2FXak5JS0FzSWc)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Diamondj421 on November 11, 2016, 04:31:33 AM
With enough time, I will prevail! Turns out that one of the TO-220s was mounted backwards. Tricky little SOBs! Thanks anyway! Like everything else, it sounds phenomenal!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Chrome Heart on December 12, 2016, 05:17:45 PM
I finished the Elements Gold kit a few days ago. Very nice preamp.  It was an easy and well documented build, and only took an afternoon to complete. Well done, Mike. I'll need to get a couple more.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Geekmusic on December 21, 2016, 06:33:27 PM
Hi Mike,
I just finished the build of a Gold preamp. The instrunctions were great, but i still managed to mess something up. DI and Mic Input seem to work, 48v seems to work,  pad works, Outputcontroll works, but...
The Input control (grayhill switch) doesn't do anything. No matter which position the switch is in i get the same (rather weak) level of amplification.  Could you give me a hint where i should start my search?

Thanks,
Philip
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 21, 2016, 08:01:47 PM
Hi Mike,
I just finished the build of a Gold preamp. The instrunctions were great, but i still managed to mess something up. DI and Mic Input seem to work, 48v seems to work,  pad works, Outputcontroll works, but...
The Input control (grayhill switch) doesn't do anything. No matter which position the switch is in i get the same (rather weak) level of amplification.  Could you give me a hint where i should start my search?

Thanks,
Philip

I would check all the solder joints on that mini PCB.  Look for shorts.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Geekmusic on December 22, 2016, 07:38:37 AM
Hi Mike,
I just desoldered the mini pcb to check (see attached images). Althoug its not the cleanest job i've ever done the joints look ok. The weird thing is, that i just measured the resisance between the outer legs that connect the mini pcb to the main pcb. I always get 20kOhms no matter what the switch position is. Center leg to outer leg reads no connection.
Could i have a broken switch?

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Geekmusic on December 22, 2016, 05:48:11 PM
Hi Mike,
I just measured connections to understand how the switch pcb works (sorry, im an electronics noob). Looking at the pcb from the top and measuring resistance between the left leg (that connects to the main pcb) and the resistors, resistance just adds up from r1 to r10. I get the same measurements starting from the right pin going through resistors in the oposite direction. So far i can confirm that currently all components starting from the left leg ->r1->...->r10-> right leg are connected in serial. Turning the switch does not change the measurements.
The middle leg (connection to the main pcb) is not connected to any of the resistors. The only connection i get from that pin is to the center pin of the rotary switch. This does not change regardless of switch position. Am i wrong in assuming that the three legs that connect to the main pcb should basically work like a pot? So if i measure the resistance between left and middle leg with the switch in position 6 i should get the resistance of r1+r2+...+r6?

To me it looks like a broken switch... could i be right?

Thanks,
Philip
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 27, 2016, 05:15:39 PM
Hi Mike,
I just desoldered the mini pcb to check (see attached images). Althoug its not the cleanest job i've ever done the joints look ok. The weird thing is, that i just measured the resisance between the outer legs that connect the mini pcb to the main pcb. I always get 20kOhms no matter what the switch position is. Center leg to outer leg reads no connection.
Could i have a broken switch?

No the outer legs always show total resistance of the chain.  What you want to do is measure between the middle leg and on of the outer legs.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 27, 2016, 05:18:46 PM
Hi Mike,
I just measured connections to understand how the switch pcb works (sorry, im an electronics noob). Looking at the pcb from the top and measuring resistance between the left leg (that connects to the main pcb) and the resistors, resistance just adds up from r1 to r10. I get the same measurements starting from the right pin going through resistors in the oposite direction. So far i can confirm that currently all components starting from the left leg ->r1->...->r10-> right leg are connected in serial. Turning the switch does not change the measurements.
The middle leg (connection to the main pcb) is not connected to any of the resistors. The only connection i get from that pin is to the center pin of the rotary switch. This does not change regardless of switch position. Am i wrong in assuming that the three legs that connect to the main pcb should basically work like a pot? So if i measure the resistance between left and middle leg with the switch in position 6 i should get the resistance of r1+r2+...+r6?

To me it looks like a broken switch... could i be right?

Thanks,
Philip

You want to measure between the middle and one closest to the daughter board edge.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Geekmusic on December 27, 2016, 05:48:15 PM
If I measure between the middle leg and any of the outer legs there is no connection.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dobrobson on December 29, 2016, 12:58:53 PM
Hey Mike!

I've been working on my first preamp build, an Elements Copper, and have hit a snag. It's passing signal, both mic and DI, but both are real dirty sounding and low volume. I've double checked all of my connections and that everything is in the right place, but I can't get to the bottom of it. Any thoughts?

Thanks!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 29, 2016, 02:44:50 PM
Hey Mike!

I've been working on my first preamp build, an Elements Copper, and have hit a snag. It's passing signal, both mic and DI, but both are real dirty sounding and low volume. I've double checked all of my connections and that everything is in the right place, but I can't get to the bottom of it. Any thoughts?

Thanks!

Both are acting the exact same?

Make sure if there are a pads that should be shorted...they are shorted.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dobrobson on December 29, 2016, 03:22:59 PM
Both are acting the exact same?

Make sure if there are a pads that should be shorted...they are shorted.

Yes - with both knobs cranked, I get similar levels and distortion from the DI and mic input (same effect on condensers and dynamics).

Also, much less importantly but still frustrating - one of the two knobs won't tighten fully and comes loose after one turn. Pot stem looks normal, maybe I just need to replace the cap screws?  I can upload pictures tonight if that helps.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 29, 2016, 03:26:32 PM
Yes - with both knobs cranked, I get similar levels and distortion from the DI and mic input (same effect on condensers and dynamics).

Also, much less importantly but still frustrating - one of the two knobs won't tighten fully and comes loose after one turn. Pot stem looks normal, maybe I just need to replace the cap screws?  I can upload pictures tonight if that helps.

And you have the output full CW? Maxed out is the output default position (cleanest gain) with proper gain setting.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dobrobson on December 29, 2016, 06:32:28 PM
And you have the output full CW? Maxed out is the output default position (cleanest gain) with proper gain setting.

I do! I'll take some pictures of the board and post here tonight. Thanks for your help!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dobrobson on December 30, 2016, 12:33:29 AM
Here are a few photos...

(https://lh3.googleusercontent.com/MPdhGF-UKIzP5tgWGRs4XR-L3FjVjdAm_oGbjrw02UtFP2Ob5CmiBNoXw64O6sZnXt6qFjRYRMezRAJFscWN3_-WhdBy7HjymU4x30rq0Nc3wz13EbC1oQ4oJ0_ESaFVfD5rN-lji-8V_FNoyTeQqCYOOuuEYpObetOBqXYewYU3F4ZE7dMQXTq4-oDxQHk8Q_4GmHAg3pNeZ-gkmmIUZxECgoxBC-oYU6g--alQrf-HKZL_6XtlLI_DMsJkwnyPgExDKXbhCHIN-kEGqEXq9Uyx5tvxW4h3F9Aqnk0U-qoaGoim1i8xtVq0zAHlZi5tywgMA0XOmFhKHObImBIcCgvlvnu11vFv_UC1cHa1Ck8Ru6K2WOyI0pAw2RF97X58vWzIFr8kMfa_3gqUacdCVnI7uN01crtj7N0-O9MmGnla4KplH-QSO9mEcoRFIv6X3AOvjRwRsI1OEHF5pxj4BA4qkYr7cr5OBxMkry7CKZMlzOz4ABRcpoEh6aptVWlk8EPvtdSvEsMw5lgNEob2pOq0gd-O-Za7aqGW-7PbO4FEdeV8S5RktC4yzTwng5lFmuDZmk7f=w1920-h925)

(https://lh3.googleusercontent.com/LfXMiBeOG_3O0xnErVCk4T-N657ZWe6LpGJYlF3LIe2tfMqFFtrP-tTyEUkF9afbhrBVj3IUb7IgrgEPs1g1b0nvalqP2Gvrq-kAVORgp_MC1BJX9BQxTdUwdp2fiyUjniyjbkg_iD6W6bhz_us7IUmXN5yR-D4z_nV0dOuUNTHdt18rUmm209DBJoSxvGeqYxh_HQgei5XyminQQk9e7iTBs6WNPH0ygfinCqwnwkAxdqE_tiGgwoo9QbYqavh4hg5369vKj-Ms7r259EPRrQTsrf5eqBpEdAifDZT8ctFrTkD6BLuaevgpmfROdZZMYbCSO7_52LS5IrFYw1MTc5asOBl1O0ZjoW8g3ssSW5GdB_vykWzNFYaGTou8H8hUmZ4Pfcg86iaZEOjPeA_V7qhX9XbVree17duoid6rxXEWmGIri1WSnt67UmZaflwu1x3nDpLmBvUOI8Y38eHDmKgSp4PwLKSrl9ICEXhSdv__yrCIJBWnhkeiX9m74Qxez1nNzSIdcNJ3HukMCtMiQ890o9UZ5GkLMgI3xPreNChr6gX-l-qwVI9WmY1fTSJMhSI7UWvp=w1050-h632)

(https://lh3.googleusercontent.com/Wp25N-9oZavpZGu7JdIoJ__R1uqgS9O07MVHhy9aCLtGyF8KhxCDp4CvdAnP-uIWpambM3CZho2ksc_bVEGhHb2CLnaJdTL_ZPLjTAv3HgyDkalAz1OUahzKOcLSg24J8CAUnh-yHr958bcsP2pq1bnCCwI5GP8BGIIblu9sf_sHPE4FFcpittoi4QWqk8Lh1-N04bqHLBYc8SKsg16s22jUsNMVGWNhsa9TnpFaUAV47U4LuuR5OJ1xzbxBeMqfnxtXevjVJ-DJ6BVlYCyQ5lXIk0_I0Ve5_x4PMTm1MgxmzLUGPx43mLV6GK66EVW8V2hVZz2HG6hPD0q0eode9kQFPI4BZ3843QK6yQhxOanQtR6yMfrLv9XiyDfRwE4azRsUtEbFyqZ4VUhlaBnUvTbNPTZRwNvfxraJ2jvoUBxEOCgwo8v3pX2_8scS0gZ0OlE8GICwtzbQkpnzSSHBJXGaDKqSWuWxzH65Yytef_T-jxWfDT8My423gBYhjuZQJmEjKScJ47FG_EFepsoKQukAdzJnHrP-LsF6tBfPTQ4Bj2t3Ha6ILkKpS6zngLNyJ-1qZsz9=w1050-h632)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 04, 2017, 11:43:38 PM
You sure the blue and purple on the output transformer are properly connected?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dobrobson on January 06, 2017, 01:28:39 PM
Double checked and they are. Not sure what happened but now I can't get the thing to pass any signal at all... may need to send these up your way to see if you guys can salvage them for me!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 06, 2017, 01:35:06 PM
Double checked and they are. Not sure what happened but now I can't get the thing to pass any signal at all... may need to send these up your way to see if you guys can salvage them for me!

Weird.  They are always salvageable and our repair rate for those is super low.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dobrobson on January 06, 2017, 02:20:49 PM
No worries, I'm sure I just goofed something up. Still really enjoyed the build experience!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 06, 2017, 02:29:45 PM
No worries, I'm sure I just goofed something up. Still really enjoyed the build experience!

If you want send it on in. We'll get it working for $50.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: hillamps on January 10, 2017, 05:54:54 PM
Just finished up my first Silver Pre this weekend. I love the open design on these that let you configure things on your own. I set it up to similar to a basic 2520  and loaded in a discrete opamp I had. Sound was excellant. I installed a dip socket  under the opamp pins so I could test it with an IC op amp. All I had was a Radio Shack 741 generic op amp but I decided to give it a test. This pre sounds pretty damn good with a cheap opamp in it! I have some "audio" grade IC opamps on order from Mouser and now I can swap them in and out to see how they sound.  I love this open design and the chance to experiment. I can still install a discrete opamp over  the dip socket so I will also test out some discretes. I will be ordering more of these kits real soon. Great product for a technician/musician like me!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 10, 2017, 06:07:48 PM
Just finished up my first Silver Pre this weekend. I love the open design on these that let you configure things on your own. I set it up to similar to a basic 2520  and loaded in a discrete opamp I had. Sound was excellant. I installed a dip socket  under the opamp pins so I could test it with an IC op amp. All I had was a Radio Shack 741 generic op amp but I decided to give it a test. This pre sounds pretty damn good with a cheap opamp in it! I have some "audio" grade IC opamps on order from Mouser and now I can swap them in and out to see how they sound.  I love this open design and the chance to experiment. I can still install a discrete opamp over  the dip socket so I will also test out some discretes. I will be ordering more of these kits real soon. Great product for a technician/musician like me!

Very cool!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: martinswain on February 15, 2017, 01:03:06 PM
Hi Mike,

It's me again, the guy who posted issues with the Copper module all the way back on page 6 of this thread! Well, my Bronze module works, and I've used it on multiple sessions and love how it sounds, but still can't seem to get my Copper module to work.

I'm at a loss. I have reflowed solder connections on the input and output sections, reflowed solder on the Grayhill switch, checked diodes to see if they were broken, replaced capacitors and re-inserted the op-amp sockets. The issue I'm having is that the signal is really distorted, and will kinda cut out if 'too much' signal passes through on the higher gain settings. The Grayhill switch increases gain no problem, and the output pot turns signal up and down no problem.

Could it possibly be a damaged op-amp? I was thinking about plugging in the op-amp from my Bronze module into the Copper to see if I could rule this out, but didn't want to do so in case I damaged anything. Can I swap the op-amp over to check?

I'm an absolute noob at electronics, as you can probably tell, but I want to persevere and get better so I don't have to bug people all the time. Any help you could give (again) would be a huge benefit.

Thanks.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on February 15, 2017, 01:07:46 PM
Hi Mike,

It's me again, the guy who posted issues with the Copper module all the way back on page 6 of this thread! Well, my Bronze module works, and I've used it on multiple sessions and love how it sounds, but still can't seem to get my Copper module to work.

I'm at a loss. I have reflowed solder connections on the input and output sections, reflowed solder on the Grayhill switch, checked diodes to see if they were broken, replaced capacitors and re-inserted the op-amp sockets. The issue I'm having is that the signal is really distorted, and will kinda cut out if 'too much' signal passes through on the higher gain settings. The Grayhill switch increases gain no problem, and the output pot turns signal up and down no problem.

Could it possibly be a damaged op-amp? I was thinking about plugging in the op-amp from my Bronze module into the Copper to see if I could rule this out, but didn't want to do so in case I damaged anything. Can I swap the op-amp over to check?

I'm an absolute noob at electronics, as you can probably tell, but I want to persevere and get better so I don't have to bug people all the time. Any help you could give (again) would be a huge benefit.

Thanks.

You should be able to swap the op-amp.  See if it's an op-amp issue.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: amcmaken on March 06, 2017, 12:22:02 PM
I built a Bronze pre-amp and it's not passing signal from the mic input. I can confirm it sends phantom power. I've tried the pre with both dynamic and condenser mics to no avail. When I turn up the Grayhill (input) I can hear the gain increase, but no signal from the mic is getting through or being amplified. I texted the DI and it works and sounds great! The Grayhill controls that just fine. There is clearly some sort of disconnect between the input and Grayhill, but I've been over the BOM and Build Guide several times and can't find where I'm missing anything. Any suggestions?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 06, 2017, 07:31:01 PM
I built a Bronze pre-amp and it's not passing signal from the mic input. I can confirm it sends phantom power. I've tried the pre with both dynamic and condenser mics to no avail. When I turn up the Grayhill (input) I can hear the gain increase, but no signal from the mic is getting through or being amplified. I texted the DI and it works and sounds great! The Grayhill controls that just fine. There is clearly some sort of disconnect between the input and Grayhill, but I've been over the BOM and Build Guide several times and can't find where I'm missing anything. Any suggestions?

The relay, by default, is set to DI.  If your mic input is not working but your DI is, it's because your relay is not flipping on.  The relay has 8 leads, 2 of them are separated from the other 6.  Make sure all 8 leads are soldered.

Also, check your resistors in the relay section and the diode orientation.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: amcmaken on March 08, 2017, 10:35:29 AM
The relay, by default, is set to DI.  If your mic input is not working but your DI is, it's because your relay is not flipping on.  The relay has 8 leads, 2 of them are separated from the other 6.  Make sure all 8 leads are soldered.

Also, check your resistors in the relay section and the diode orientation.

Mike

Mike,

Thank you so much! I did manage to miss soldering two of the relay leads. My Bronze is working like a charm now!

Sometimes you're staring right at the problem, but just need to know where to look.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 08, 2017, 10:40:02 AM
Mike,

Thank you so much! I did manage to miss soldering two of the relay leads. My Bronze is working like a charm now!

Sometimes you're staring right at the problem, but just need to know where to look.

Awesome!
Title: Re: GOLD - Persistent buzz
Post by: tctonn on March 11, 2017, 05:21:05 PM
I would suspect something external to start. What is your rack brand? Where is the power supply in relation to the rack space your pre is in?  Does moving it to a space further from the supply help?

Mike

Hey Mike,

I finally had a chance to trouble shoot this and by checking all the components and reflowing a few joints. It looks like the noise was likely environmental.  However...

The output signal is really, really low. It sounds good and if I boost it in my DAW the S/N ratio seems good. But the level seems to be 15-20db below what I get out of any of my other gear.

 I've done a very thorough check against your build guides and a few pics of successful builds on here.  Any ideas where I should start hunting?
Title: Re: GOLD - Persistent buzz
Post by: Hairball Audio on March 13, 2017, 01:25:48 PM
Hey Mike,

I finally had a chance to trouble shoot this and by checking all the components and reflowing a few joints. It looks like the noise was likely environmental.  However...

The output signal is really, really low. It sounds good and if I boost it in my DAW the S/N ratio seems good. But the level seems to be 15-20db below what I get out of any of my other gear.

 I've done a very thorough check against your build guides and a few pics of successful builds on here.  Any ideas where I should start hunting?

Do you have the output pot fully clockwise? That is the default position. 

What is your signal source? A mic?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dobrobson on March 29, 2017, 04:50:11 PM
Got my two Copper repairs a few weeks back and happy to report that they are AMAZING. I'll be using my Pre73 as a doorstop from now on... thanks, Mike!!!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 29, 2017, 05:11:30 PM
Got my two Copper repairs a few weeks back and happy to report that they are AMAZING. I'll be using my Pre73 as a doorstop from now on... thanks, Mike!!!

Nice!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Siegfried Meier on May 19, 2017, 06:18:53 PM
Hey guys!

Still struggling with a silver I started a long, long time ago...things got busy.  I've built 4 of these in pretty much the exact same way and they're working flawlessly after several years of use.

However, this one...not so much.  I've replaced quite a number of components and still not happy.  I'm getting hot transistors, but the BA512 opamp doesn't get warm at all - odd, since it has a massive heatsink on there.  My guess is that there's no power getting to the opamp, hence no mic pre output level at all.   Transistors are definitely not backwards, I've checked that a million times to make sure...

Any help much appreciated...I've scoped and checked this thing over many, many times now...

I do hear the relay click when it turns on, and I'm using the EA-10468 input and EA-11148-500 Output transformers.

I'm seeing -15v at the opamp, but no +15...what exactly drives the positive voltage at the opamp?
 
Thanks,
Sig

EDIT - Ahhhhh a solder bridge at C100!  I looked a hundred times before I even checked with the meter and found it.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Siegfried Meier on May 20, 2017, 12:21:42 PM
She works beautifully, DI and all.  The only issue I'm having is the 11th and final gain position tends to drop the signal significantly.  What would have caused that? 
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on May 20, 2017, 12:29:40 PM
She works beautifully, DI and all.  The only issue I'm having is the 11th and final gain position tends to drop the signal significantly.  What would have caused that?

The gain switch is a resistor ladder. In the 1st position (lowest gain) all of the resistors in the ladder are activated. In the 11th position (highest gain) none of the resistors are activated. It's a dead short. You have an issue at the 11th node of the switch.

I would check the solder joint on the 11th node of the grayhill. To be sure, you could reflow all of those joints.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Jussi De Nys on May 25, 2017, 06:45:04 PM
Hi! I'm finally building my lola's (2). First one is almost done!
I got to the first testing stage and there's no smoke ( hallelujah! ). The phantom button makes a click when pushed and lights up to a nice blue. The same goes for the Line engage button. The phase invert button does not make a clicking sound/feeling and only lights up when being pushed in , it stops being blue when it loses my touch. It seems to me that this button might be broken or something, it doesn't click like the other two. I can only hope that ( since there's no smoke and everything lights up) this might be a simple mistake, I saddly don't have the "know how". It's my first build, maybe I should have started with a simpler one :-) Hope you can help me out! thanks in advance!
Greetings from Belgium,
Jussi.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on June 04, 2017, 12:10:31 AM
Hey guys,

Im having an issue with my 2 coppers, Im not getting any phantom. Dynamic mics and DI works like should, and the 48v led lits up. I have tried different 500-slots. Any ideas?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on June 08, 2017, 05:28:25 PM
Hey guys,

Im having an issue with my 2 coppers, Im not getting any phantom. Dynamic mics and DI works like should, and the 48v led lits up. I have tried different 500-slots. Any ideas?

Really could only be a bad solder joint or misplaced component on something in the +48 box of the PCB or on the switch itself. Try reflowing that stuff.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: EastLeedsWest on June 26, 2017, 11:44:21 AM
Hey All, I built a copper about a year ago and it came out like a dream. It had been doing daily work until last week. Out of nowhere it stopped working. I unscrewed it from my chassis and before I pulled it out the +48v light came on and it went back to normal. Screwed it back in, light went out. This process will repeat consistently among multiple chassis and I'm completely stumped as to what could be causing it. Has anyone else experienced this? Any ideas on where to start looking for the problem?

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on June 26, 2017, 02:42:28 PM
Hey All, I built a copper about a year ago and it came out like a dream. It had been doing daily work until last week. Out of nowhere it stopped working. I unscrewed it from my chassis and before I pulled it out the +48v light came on and it went back to normal. Screwed it back in, light went out. This process will repeat consistently among multiple chassis and I'm completely stumped as to what could be causing it. Has anyone else experienced this? Any ideas on where to start looking for the problem?

I would start with scrubbing the edge connector with isopropyl alcohol. Get it good an clean.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: ssttoo on July 05, 2017, 01:38:04 AM
Just built the second Copper. The first  one works fine, the second is very very quiet. You only hear some faint signal when both gain and output are max'd. Same behavior in DI, same with condenser mic and phantom power (I tried sm57 first). Any pointers where to start looking, anything specific to low volume symptom? I swapped the opamps between the two units, same result: first unit works, second too quiet.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 05, 2017, 11:32:39 AM
Just built the second Copper. The first  one works fine, the second is very very quiet. You only hear some faint signal when both gain and output are max'd. Same behavior in DI, same with condenser mic and phantom power (I tried sm57 first). Any pointers where to start looking, anything specific to low volume symptom? I swapped the opamps between the two units, same result: first unit works, second too quiet.

Usually a bad joint somewhere in the signal chain. Start by making sure all of the components are correct, then reflow joints looking closely at that larger caps with long leads.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: tonesontail on July 05, 2017, 03:39:00 PM
Howdy, and thanks for any help provided. I smart searched the forum, and did not find anything on this issue, so...

I am helping a colleague trouble shoot a pair of Gold Elements pres, and they are both exhibiting the same phenomenon.  As the Output pot (VR600) is rotated CCW, the distortion specs go way up and there is an audible hum. I measured over 50% THD+N with a 1khz and .775v on my AP ATS-1 with the pot turned fully CCW. THD+N is less than 1% with the VR600 fully CW. I have checked all of the parts in the 600 section of the build and they are all correct. The NFB components are also correct, and R506 and C506 are Shorts as per the BOM.

Looking at the http://library.hairballaudio.com/images/2015/06/hba-elements-pcb-v1-3_schematic-production.pdf schematic, with the Shorts in place, the 990's Output and NFB loop are DC coupled to ground through VR600 and R600(100R). Could this be generating a massive load on the 990, and causing the distortion? The 990's were provided pre-built.

I know that the Jensen paper shows that the output can be DC coupled directly to the OP TX, but ordinarily has L3/R15 to suppress oscillation, but this has been omitted from this design. I see that C601 blocks DC from reaching the A/B output buffer, so I do not see that section as being the problem.

Could both pre-built opamps be out of spec or bad? Would you suggest putting in a say a 470uf NP cap in at C600 to see if the noise goes away? Is this a know issue?

Thanks

ToT
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 06, 2017, 12:37:22 PM
Howdy, and thanks for any help provided. I smart searched the forum, and did not find anything on this issue, so...

I am helping a colleague trouble shoot a pair of Gold Elements pres, and they are both exhibiting the same phenomenon.  As the Output pot (VR600) is rotated CCW, the distortion specs go way up and there is an audible hum. I measured over 50% THD+N with a 1khz and .775v on my AP ATS-1 with the pot turned fully CCW. THD+N is less than 1% with the VR600 fully CW. I have checked all of the parts in the 600 section of the build and they are all correct. The NFB components are also correct, and R506 and C506 are Shorts as per the BOM.

Looking at the http://library.hairballaudio.com/images/2015/06/hba-elements-pcb-v1-3_schematic-production.pdf schematic, with the Shorts in place, the 990's Output and NFB loop are DC coupled to ground through VR600 and R600(100R). Could this be generating a massive load on the 990, and causing the distortion? The 990's were provided pre-built.

I know that the Jensen paper shows that the output can be DC coupled directly to the OP TX, but ordinarily has L3/R15 to suppress oscillation, but this has been omitted from this design. I see that C601 blocks DC from reaching the A/B output buffer, so I do not see that section as being the problem.

Could both pre-built opamps be out of spec or bad? Would you suggest putting in a say a 470uf NP cap in at C600 to see if the noise goes away? Is this a know issue?

Thanks

ToT

You're measuring with a 0dBu input? That is VERY high for mic pre. Use something -20 dBu to -40dBu. I deal the generator output impedance would be 150Ω. Also, with the output fully CCW your signal may have deteriorated enough to be unusable,  there is not really a realistic recording situation to have the output all the way down. It should be wide open (full CW), then pulled back to add add distortion or "push" the gain structure. Below 12 o'cklock, with the gain up its a fuzz box on purpose.

Op-amps are all tested before ship. Design has been used for 10+ years by both us and Eisen Audio. There is something else going on. Don't over think it. You have your generator set up incorrectly, or something it is misplaced in the build.

Mike.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: BrettAudio on August 07, 2017, 10:39:24 AM
Hello,

I'm just starting my copper build and I've gone through and checked all of my resister values.  After matching everything up I have one oddity: for what should be resister 502 should be a 100K and what I have left is a 82K that is a close but seems a little low.  Thoughts on if that will make a large difference?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 07, 2017, 01:16:29 PM
Hello,

I'm just starting my copper build and I've gone through and checked all of my resister values.  After matching everything up I have one oddity: for what should be resister 502 should be a 100K and what I have left is a 82K that is a close but seems a little low.  Thoughts on if that will make a large difference?

If the color codes read 100K you're fine.  DMM's have a hard time reading high values because their resistance is in parallel with the resistor you are testing.  If the DMM has a resistance of 1M and the resistor is 100K, you'll see a lower reading.

Mike
Title: Copper C301 and C302
Post by: BrettAudio on August 08, 2017, 09:48:14 PM
Hello.

I'm working on the two caps C301 and C302.  It is not clear to me what one is what.  It looks like the smaller package (wider pin/hole spacing) fits the holes for the 100pF cap C301 space and the larger package seems to better fit the C302 space.

My instincts say the larger package would be the 100pF cap and that I would adjust the legs to fit in the holes.

If someone has a good clarification for me on what one is what, I greatly appreciate the help.

Thanks,
Brett
Title: Re: Copper C301 and C302
Post by: Hairball Audio on August 10, 2017, 11:53:32 AM
Hello.

I'm working on the two caps C301 and C302.  It is not clear to me what one is what.  It looks like the smaller package (wider pin/hole spacing) fits the holes for the 100pF cap C301 space and the larger package seems to better fit the C302 space.

My instincts say the larger package would be the 100pF cap and that I would adjust the legs to fit in the holes.

If someone has a good clarification for me on what one is what, I greatly appreciate the help.

Thanks,
Brett

The blue caps have values on them. They are just super small and you need to get in the right light.  100pf should have 101 then a letter stamped on it.

Mike
Title: Re: Copper C301 and C302
Post by: BrettAudio on August 10, 2017, 02:44:44 PM
The blue caps have values on them. They are just super small and you need to get in the right light.  100pf should have 101 then a letter stamped on it.

Mike

Hello,

Thank you for the information.
I'll take a closer look.

Thanks again,
Brett
Title: Re: Copper build complete and working!
Post by: BrettAudio on August 10, 2017, 05:11:31 PM
 :D

Hello.

I wanted to report that I completed my first build on my first ever 500 piece of gear.

I fired it up, then I recalled I still need to solder the pins for the in/out gain stage.  Did that, slid it back into the API lunchbox and awesomeness!!!

Mike,
Thank you to you and your team for making great parts.  I'm super stoked to start recording with the copper.

Up next, a Lola mix pre!!!

Thanks,
Brett

(http://)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on August 11, 2017, 04:11:44 AM
Really could only be a bad solder joint or misplaced component on something in the +48 box of the PCB or on the switch itself. Try reflowing that stuff.

Mike

Hi! I did reflow the switch and +48 box. No luck there. Ive looked the board for hours and compared it to a fully working preamp and I cant find anything wrong. My solder joints are solid. Dynamic mics work, DI works, +48 led lights up but no phantom.

I noticed that when I have the +48v switch in down position, the other switches (phase and pad) make a really loud popping noise when pushed down. Like, breaking speakers loud. Is this normal?

Pics of my build
https://www.dropbox.com/s/30ooc2omqac67ju/IMG_20170811_105855.jpg?dl=0
https://www.dropbox.com/s/u5evb3m95y6kuuw/IMG_20170811_110223.jpg?dl=0
Title: Re: Copper build complete and working!
Post by: Hairball Audio on August 16, 2017, 06:45:14 PM
:D

Hello.

I wanted to report that I completed my first build on my first ever 500 piece of gear.

I fired it up, then I recalled I still need to solder the pins for the in/out gain stage.  Did that, slid it back into the API lunchbox and awesomeness!!!

Mike,
Thank you to you and your team for making great parts.  I'm super stoked to start recording with the copper.

Up next, a Lola mix pre!!!

Thanks,
Brett

(http://)

Nice!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 16, 2017, 07:01:52 PM
Hi! I did reflow the switch and +48 box. No luck there. Ive looked the board for hours and compared it to a fully working preamp and I cant find anything wrong. My solder joints are solid. Dynamic mics work, DI works, +48 led lights up but no phantom.

I noticed that when I have the +48v switch in down position, the other switches (phase and pad) make a really loud popping noise when pushed down. Like, breaking speakers loud. Is this normal?

Pics of my build
https://www.dropbox.com/s/30ooc2omqac67ju/IMG_20170811_105855.jpg?dl=0
https://www.dropbox.com/s/u5evb3m95y6kuuw/IMG_20170811_110223.jpg?dl=0

Hmmmmm maybe a bad switch?  Do you know how to test a DPDT switch like that?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on August 18, 2017, 09:29:33 AM
Hmmmmm maybe a bad switch?  Do you know how to test a DPDT switch like that?

Mike

Ummmm maybe. Ill desolder it and test the continuity with a dmm after that?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 18, 2017, 12:20:34 PM
Ummmm maybe. Ill desolder it and test the continuity with a dmm after that?

You could remove and test the phantom cap with your DMM.  If that's fine, check to see if any of you transformer wires other than GRY are shorted to ground. Yellow/Orange/Violet should have low Ω but more than like 2Ω.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: hiegdk on August 27, 2017, 07:11:23 PM
Just finished my 4th Lola and having an issue with the Line button not lighting up when pressed. Anything obvious I should check (other than the solder points of the switch)?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on August 28, 2017, 11:34:50 AM
Just finished my 4th Lola and having an issue with the Line button not lighting up when pressed. Anything obvious I should check (other than the solder points of the switch)?

Is the line engaging? Just the light is not working?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: gvalles on September 05, 2017, 04:38:04 PM
Hi! I just finished building my first Hairball Element Series, a Copper. I'm getting no sound out of it (tested with dynamic mic) and the when phantom power is switched on it actually measures 103v in the XLR input of my lunchbox.

I won't have time to open the unit at least until next week but I figured that this phantom power symptom could be enough of a clue of what I did wrong to someone who knows electronics and this circuit.

Thanks!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 07, 2017, 12:38:46 PM
Hi! I just finished building my first Hairball Element Series, a Copper. I'm getting no sound out of it (tested with dynamic mic) and the when phantom power is switched on it actually measures 103v in the XLR input of my lunchbox.

I won't have time to open the unit at least until next week but I figured that this phantom power symptom could be enough of a clue of what I did wrong to someone who knows electronics and this circuit.

Thanks!

AC or DC? Measured where? Referencing what?

Power is supplied by the lunchbox. My guess is a measuring error.

Make sure your edge card is clean and you have all the shorts in...check solder connections around the big caps that attach to a ground pad.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: gvalles on September 11, 2017, 12:32:50 PM
Thank you Mike.
Your guess was absolutely right. I measured phantom power with my multimeter set do AC volts on that day. Pretty dumb. So Phantom measures correctly actually, at 47.9V from pin 1 to pins 2 and 3 and 2 and 3 measure 0v.

The sound issue persists. All I get is static. The static does increase with raising both the input and the output trims, if that's any clue.


I'll check the shorts (Copper only has one I believe) and the solder joints on the big caps on Wednesday.




AC or DC? Measured where? Referencing what?

Power is supplied by the lunchbox. My guess is a measuring error.

Make sure your edge card is clean and you have all the shorts in...check solder connections around the big caps that attach to a ground pad.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: gvalles on September 11, 2017, 01:03:51 PM
Forget everything I wrote so far... I decided to open it up very quickly to see if there was any obvious mistake and... voilà, one component wasn't soldered on both sides... works like a charm now!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on September 26, 2017, 05:38:48 AM
You could remove and test the phantom cap with your DMM.  If that's fine, check to see if any of you transformer wires other than GRY are shorted to ground. Yellow/Orange/Violet should have low Ω but more than like 2Ω.

Mike

Hi Mike!

I tested the 48v switch, its good. I also changed the phantom cap, still no phantom power!!  :-\

I measured the mini 1166 output transformer wires against pad 5 GND at the 500 connector:

Brown: 34.1 ohms
Red: 0.3 ohms
Green: no reading, no beep when tested continuity
Grey: no reading, no beep when tested continuity

I got the same readings from other working pre.

Whats next? I currently have 5 working coppers and this one that doesnt want to co-operate.   ???
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 26, 2017, 11:32:59 AM
Hi Mike!

I tested the 48v switch, its good. I also changed the phantom cap, still no phantom power!!  :-\

I measured the mini 1166 output transformer wires against pad 5 GND at the 500 connector:

Brown: 34.1 ohms
Red: 0.3 ohms
Green: no reading, no beep when tested continuity
Grey: no reading, no beep when tested continuity

I got the same readings from other working pre.

Whats next? I currently have 5 working coppers and this one that doesnt want to co-operate.   ???

Oh I mean check the input transformer (10468) for readings to ground (green wires).

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on September 27, 2017, 03:32:30 AM
Oh I mean check the input transformer (10468) for readings to ground (green wires).

Mike

Hi, readings are:

BRN 9.5
RED 1.8
WHT 9.5
BLK 1.8
VIO no reading, no continuity
GRY 165.7
YEL 166.2
ORG 0.0
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 27, 2017, 02:09:26 PM
Hi, readings are:

BRN 9.5
RED 1.8
WHT 9.5
BLK 1.8
VIO no reading, no continuity
GRY 165.7
YEL 166.2
ORG 0.0

Your primary values are way off.  Is it possible to remove BRN, RED, WHT, BLK from the PCB and remeasure against green(s)? You can keep greens in the PCB.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on September 28, 2017, 02:19:45 AM
Your primary values are way off.  Is it possible to remove BRN, RED, WHT, BLK from the PCB and remeasure against green(s)? You can keep greens in the PCB.

Mike

Hi, here are the measurements with brn red wht and blk removed from pcb:

BRN no measurement, no continuity
RED 18.3
WHT no measurement, no continuity
BLK no measurement, no continuity

I kept green wires in the pcb.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 28, 2017, 01:34:00 PM
Hi, here are the measurements with brn red wht and blk removed from pcb:

BRN no measurement, no continuity
RED 18.3
WHT no measurement, no continuity
BLK no measurement, no continuity

I kept green wires in the pcb.

What is the Ω between BRN and RED?  If you have a reading between BRN and RED (you should), check between BRN and green again, you should have something there.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: darkus on September 28, 2017, 01:59:48 PM
What is the Ω between BRN and RED?  If you have a reading between BRN and RED (you should), check between BRN and green again, you should have something there.

Mike

Hi,

This is getting really strange.

Brn-red 16.8
Brn-grn 30.8

I swear god I didnt get continuity between brn-grn this morning when I posted the results above, and I tried several times. I checked a 1k resistor with my DMM and I have confirmed that its not broken.

I could try to swap the transformer from a working copper, if you do think the optrafo is the reason why Im not getting 48v. I have measured the rack slot and I know its giving me 48v like it should
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 28, 2017, 02:09:29 PM
Hi,

This is getting really strange.

Brn-red 16.8
Brn-grn 110

I swear god I didnt get continuity between brn-grn this morning when I posted the results above, and I tried several times. I checked a 1k resistor with my DMM and I have confirmed that its not broken.

I could try to swap the transformer from a working copper, if you do think the optrafo is the reason why Im not getting 48v. I have measured the rack slot and I know its giving me 48v like it should

It happens, some times you don't get continuity because wires are hanging around and pads are weird.

What you're getting makes sense for a bad input tx.

Shoot us an email, we'll send you a new one.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Kevinkiley on October 02, 2017, 01:33:50 AM
Hello!
First time building a mic pre. I’ve built some guitar pedals and a microphone before so I’m not a complete novice.
I just finished the copper and I’m getting externally low output from the mic pre with a 57 plugged in. The DI works/sounds great but with the gain all the way up the pre barely registers in protools

Here’s a pic
https://imgur.com/gallery/6nLqY
I can upload more if needed

Thanks!
Kevin
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 02, 2017, 12:34:06 PM
Hello!
First time building a mic pre. I’ve built some guitar pedals and a microphone before so I’m not a complete novice.
I just finished the copper and I’m getting externally low output from the mic pre with a 57 plugged in. The DI works/sounds great but with the gain all the way up the pre barely registers in protools

Here’s a pic
https://imgur.com/gallery/6nLqY
I can upload more if needed

Thanks!
Kevin

Does the DI sound too low as well?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Kevinkiley on October 02, 2017, 12:42:09 PM
Does the DI sound too low as well?

No the DI is perfect!

Thanks
Kevin
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 02, 2017, 12:47:48 PM
No the DI is perfect!

Thanks
Kevin

That's super weird.

I wonder if your relay is not flipping over to the mic input.  If the relay isn't being powered correctly it just sits in its default mode which is DI mode.

Check all those DI part values and soldering.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Kevinkiley on October 02, 2017, 01:45:44 PM
That's super weird.

I wonder if your relay is not flipping over to the mic input.  If the relay isn't being powered correctly it just sits in its default mode which is DI mode.

Check all those DI part values and soldering.

Mike

Got it. Resoldered all the points in the DI section and it working great!

Thanks for the help mike! looking forward to building some more Hairball stuff!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 02, 2017, 01:51:54 PM
Got it. Resoldered all the points in the DI section and it working great!

Thanks for the help mike! looking forward to building some more Hairball stuff!

Nice!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: rwrwrw on November 13, 2017, 03:33:23 PM
Hi,

I recently built a Gold preamp and the DI seems to not be working properly. It sounds quiet and super distorted. I've tried it with the gain all the way down & the output up, the pad in, different instruments and cables (I checked all these too and they are working fine) but no luck. XLR In and out work great. I resoldered some parts but that did not help. I've attached a photo and can include more if needed. Any help is greatly appreciated!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on November 15, 2017, 02:08:51 AM
It would have to be something in the DI Buffer box on the PCB.  Check all solder joints and values.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: rwrwrw on November 18, 2017, 02:52:11 PM
I checked all the parts and everything seems to be in the right place as far as I can tell. I re-soldered all the parts in the DI buffer box  but I'm still having the same issue. Seems like the DI output is even lower in volume and crispier sounding. XLR I/O still works fine. Maybe theres something wrong with the LME49720?

Any points I should test?

I attached a new photo.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on November 27, 2017, 11:53:10 AM
I checked all the parts and everything seems to be in the right place as far as I can tell. I re-soldered all the parts in the DI buffer box  but I'm still having the same issue. Seems like the DI output is even lower in volume and crispier sounding. XLR I/O still works fine. Maybe theres something wrong with the LME49720?

Any points I should test?

I attached a new photo.

Could be.  They are sensitive to heat.  You could check the AC signal at the input pin VS the output pin (see datasheet). They should be the same(ish).

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: rwrwrw on December 03, 2017, 02:15:08 PM
Which pins do you mean? On one of the transformers? Also I could not find what data sheet you are referring to... thanks again for your patience haha
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 04, 2017, 01:09:45 PM
Which pins do you mean? On one of the transformers? Also I could not find what data sheet you are referring to... thanks again for your patience haha

On the DI Op-amp.  Google "LME49720 Datasheet".

Mike

Title: Re: [BUILD] Hairball Audio - Elements
Post by: ssttoo on December 24, 2017, 01:14:01 AM
One of my Coppers stopped working today. I had with an AKG C1000 as a room mic, it was a little quiet so  turned up the gain and the output and recorded again, only this time the track was silent. I tried moving to different slots in the 500 chassis. My other Copper still works fine so I do the exact same thing with the two of them and the 1st one doesn't seem to do anything. Neither the DI, nor the mic input seem to work.

The phantom power is the only thing that works fine - it lights up the AKG414

Any pointers to start debugging are welcome!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 26, 2017, 01:35:31 PM
One of my Coppers stopped working today. I had with an AKG C1000 as a room mic, it was a little quiet so  turned up the gain and the output and recorded again, only this time the track was silent. I tried moving to different slots in the 500 chassis. My other Copper still works fine so I do the exact same thing with the two of them and the 1st one doesn't seem to do anything. Neither the DI, nor the mic input seem to work.

The phantom power is the only thing that works fine - it lights up the AKG414

Any pointers to start debugging are welcome!

Swap the op-amps.  Maybe a bad op-amp?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: ssttoo on December 26, 2017, 03:27:31 PM
> Swap the op-amps.  Maybe a bad op-amp?

Ha, why didn't I think of that! Thanks Mike! Unfortunately that didn't fix it :( I swapped the op-amps and the unit that works still works, and the one that doesn't still doesn't.

Two other things I noticed about the non-working unit:
1) turning up the gain increases the noise a little
2) plugging into the DI and touching the cable has an ever-so-slight buzz
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 28, 2017, 01:16:27 PM
> Swap the op-amps.  Maybe a bad op-amp?

Ha, why didn't I think of that! Thanks Mike! Unfortunately that didn't fix it :( I swapped the op-amps and the unit that works still works, and the one that doesn't still doesn't.

Two other things I noticed about the non-working unit:
1) turning up the gain increases the noise a little
2) plugging into the DI and touching the cable has an ever-so-slight buzz

Check all of your component placement.
Solder Joints.

We also have a killer repair deal on those:
http://www.hairballaudio.com/build-support-services

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: ssttoo on December 28, 2017, 02:50:48 PM
Thanks, I'll try reflowing all joints. Though it was working while testing, just failed on the first real-life usage. Do you have any pointers as to identifying faulty components?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on December 28, 2017, 03:03:28 PM
Thanks, I'll try reflowing all joints. Though it was working while testing, just failed on the first real-life usage. Do you have any pointers as to identifying faulty components?

It's difficult to test a 500 series unit without an extender jig. If you can, insert it without op-amp and test the DC V between the op-amp pins:

0V/GND and +16
0V/GND and - 16

See if you're even getting DC V to the op-amp pins.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Bendo on January 03, 2018, 08:38:30 AM
Hi all.

My kit arrived with only one component missing. Since I live pretty far away, (Southern most tip of africa) and don't necessarily want to wait for a single replacement cap to be sent, I'd like to know if I can substitute the part locally without compromising the preamp.

The missing component is C500 which has a value of 680pf and is part of the filter network at the input stage.

Is the type of capacitor critical here, or will I be able to get away with an easily available substitute?

Thanks in advance.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 04, 2018, 10:06:53 PM
Hi all.

My kit arrived with only one component missing. Since I live pretty far away, (Southern most tip of africa) and don't necessarily want to wait for a single replacement cap to be sent, I'd like to know if I can substitute the part locally without compromising the preamp.

The missing component is C500 which has a value of 680pf and is part of the filter network at the input stage.

Is the type of capacitor critical here, or will I be able to get away with an easily available substitute?

Thanks in advance.

Hi,

Yes any ceramic cap +/- 100pF will be just fine.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Bendo on January 08, 2018, 07:15:21 AM
Thanks Mike.

Completed the build, and all works great except the DI input.

Reading above, seems another builder had a similar problem. (DI sounds very distorted and very low in volume) I've tried re-flow, and can confirm all components are placed correctly with the right values. Any advice on how to troubleshoot?








Title: Re: [BUILD] Hairball Audio - Elements
Post by: Bendo on January 09, 2018, 04:48:34 AM
Update - I've tried everything that I can think of - still no improvement.

I've swapped out the IC (was very difficult to remove from the board - gosh!) I noticed that the IC is getting quite warm. I assume this means there is a power issue? I'm not 100% sure - buy I think the relay was getting a little warm too.

The XLR input works flawlessly. Dead quiet and super clean. No issues anywhere else except for the DI input. Relay is switching when I plug the DI in.

Any advice? I can't read any voltages since I have no extender jig.

Thanks.

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Maggot Brain on January 10, 2018, 12:25:56 PM
Hey all. Just about to wrap up my 1st copper build. Just a quick question....

When I installed the TO220 style transistors, I pushed them until they stopped and soldered them assuming that they had gotten as close to the PCB as they could. Anyway, after looking at pictures, I can see that they are able to be flush to the PCB.

Just wondering if it matters that they stick up higher before I de-solder them, because that is a pain haha.

thanks
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 10, 2018, 12:46:37 PM
Hey all. Just about to wrap up my 1st copper build. Just a quick question....

When I installed the TO220 style transistors, I pushed them until they stopped and soldered them assuming that they had gotten as close to the PCB as they could. Anyway, after looking at pictures, I can see that they are able to be flush to the PCB.

Just wondering if it matters that they stick up higher before I de-solder them, because that is a pain haha.

thanks

You shouldn't mount those flush. There should be a little lead showing.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Maggot Brain on January 10, 2018, 01:04:14 PM
You shouldn't mount those flush. There should be a little lead showing.

Ok cool. There's probably a lot of lead showing, comparative to how you would build it, but it's soldered properly and all that. I tried to de-solder them to seat them a little lower and felt like I was going to damage the components from too much heat, so I stopped. I'll just leave em where they are for now.

Thanks!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: joepus on January 12, 2018, 02:42:04 PM
I got a Bronze Mic Pre for Christmas (awesome gift) and it came with  a 100k resistor instead of a 200k I presume. I put the 100k resistor in r301. At some point in  time should I change that out for a 200k?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 15, 2018, 12:21:36 PM
I got a Bronze Mic Pre for Christmas (awesome gift) and it came with  a 100k resistor instead of a 200k I presume. I put the 100k resistor in r301. At some point in  time should I change that out for a 200k?

My guess is the 100/200K may not matter in that spot.  If you want a 200K just fill out a missing parts form on the site.

Hairballaudio.com/missing

Thanks!

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: joepus on January 15, 2018, 11:40:56 PM
No worries
Just needed to ask
Having a blast with my Bronze pre
Thanks
Title: Re: [BUILD] Hairball Audio - Elements
Post by: gdayal9 on January 22, 2018, 01:21:12 PM
Hi guys , I just finished my elements bronze build. I have checked each resistor value and placement 3 times, and the build map, I'm pretty sure there are no errors on my part. Getting no output upon feeding an input signal from the regular 500 chassis I/O, but get some v v tiny output when i connect input source via the DI of the pre- amp, I can hear the flavor change as i do more input gain, but output is v v low..

I am attaching a pic.. can you please see if i have made any mistakes.. , or the reason for this not working..,

(https://image.ibb.co/iRmqEG/IMG_2902.jpg)
(https://image.ibb.co/kSuMMw/IMG_2903.jpg)
(https://image.ibb.co/fLV6ob/IMG_2908.jpg)
(https://image.ibb.co/gSsagw/IMG_2904.jpg)
(https://image.ibb.co/kWgCTb/IMG_2900.jpg)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 23, 2018, 12:12:57 AM
Soldering looks a little suspect.  It's hard to trace signal if you don't have an extender.  Look for any weird or lift pads.  Look for bad joints, particularity around large caps, they can be tricky.

Are you in the US?  We fix those for $50 flat.  It's a great deal.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: gdayal9 on January 23, 2018, 02:34:59 AM
ok , I re-heated and resoldered some points, still the problem persists... could it be that my 500 series rack has an issue, cause the output happens from the line out of the rack but no output from XLRs output ...

its an alctron 3 slot that  I bought used from reverb.com..., possible.. ?

Thanks

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 23, 2018, 01:24:52 PM
ok , I re-heated and resoldered some points, still the problem persists... could it be that my 500 series rack has an issue, cause the output happens from the line out of the rack but no output from XLRs output ...

its an alctron 3 slot that  I bought used from reverb.com..., possible.. ?

Thanks

Oh that's interesting.  Do you have another 500 series pre you can test in it?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: gdayal9 on January 24, 2018, 05:26:47 PM
Problem solved! works great!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: rdf on January 28, 2018, 07:02:56 PM
I'm having a hell of a time trying to mount my Grayhill knobs onto the shafts of my Bronze preamp.  They simply won't grab onto the shafts tightly enough to be acceptable.  The best I've done so far is somewhat stable but with still a decent amount of give.  Those eventually had to be re-tightened too as one fell off one day.   One of the set screw sort of feels locked in and the other seems to catch nothing at all really.

With both shafts turned as far counter-clockwise (gain all the way down), the flat side of the shaft points towards  roughly 4 o'clock.  Am i just missing something completely here?  Any idea what I could be doing wrong?  BTW, these are 1/8" shafts and knobs.

The preamp sounds damn good though.  Really happy with it otherwise.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on January 31, 2018, 12:33:53 AM
I'm having a hell of a time trying to mount my Grayhill knobs onto the shafts of my Bronze preamp.  They simply won't grab onto the shafts tightly enough to be acceptable.  The best I've done so far is somewhat stable but with still a decent amount of give.  Those eventually had to be re-tightened too as one fell off one day.   One of the set screw sort of feels locked in and the other seems to catch nothing at all really.

With both shafts turned as far counter-clockwise (gain all the way down), the flat side of the shaft points towards  roughly 4 o'clock.  Am i just missing something completely here?  Any idea what I could be doing wrong?  BTW, these are 1/8" shafts and knobs.

The preamp sounds damn good though.  Really happy with it otherwise.

Hmmm not sure.  Never run into that.  Some times you really have to get them as tight as you can.  Sure you got the right size hex key?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: rdf on January 31, 2018, 05:37:56 PM
Yeah i guess that was the case, one of the set screws isn't set quite properly but the whole thing is sturdy now.  I was using a hex key lying around my work bench that I thought was the right size,  and it was close but apparently not quite there.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on February 06, 2018, 06:09:15 PM
Small, but fairly annoying issue...

Input knob refuses to stay tight (I have the grayhill switch on the input). Am I just dumb and not figuring it out, or are these knobs just kind of a pain? It has 2 hex tighteners. I can get them to tighten for a  bit, but after just a few turns of the switch, the knob inevitably comes loose.

You have to tighten them VERY tight.  Both.  Make sure you're using the right size hex.  It should not slip.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 16, 2018, 04:13:16 PM
Hello,

So I just finished up a Copper and am getting signal through the mic and DI however when I put a condenser mic on the line and send phantom, I get no signal.  I do get a little bit of a buzz/noise, as well as a hefty thumping pop when I hit the pad and phase buttons. 

I've checked my resistors, polarity on the cap, solder joints, etc.  Nothing noticeably incorrect. 

Thoughts? 

Any help here is very much appreciated.  Thank you in advance.

-Terry

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 16, 2018, 07:59:11 PM
Hello,

So I just finished up a Copper and am getting signal through the mic and DI however when I put a condenser mic on the line and send phantom, I get no signal.  I do get a little bit of a buzz/noise, as well as a hefty thumping pop when I hit the pad and phase buttons. 

I've checked my resistors, polarity on the cap, solder joints, etc.  Nothing noticeably incorrect. 

Thoughts? 

Any help here is very much appreciated.  Thank you in advance.

-Terry

Does the LED illuminate when you turn on +48?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 16, 2018, 08:17:21 PM
Does the LED illuminate when you turn on +48?

Mike

Yes. 
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 16, 2018, 08:29:06 PM
Yes.

Hmmmmm. I would re-flow all of the joints on the +48 switch and the parts in that +48 box.  Try a different mic table and remove anything like a patch-bay from the equation.

Once you do all that see if you have and DC voltage between pin 2 and 1 of the pic cable, and then pin 3 and 1.

Mike

Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 16, 2018, 08:46:40 PM
Hmmmmm. I would re-flow all of the joints on the +48 switch and the parts in that +48 box.  Try a different mic table and remove anything like a patch-bay from the equation.

Once you do all that see if you have and DC voltage between pin 2 and 1 of the pic cable, and then pin 3 and 1.

Mike

Copy that. Ok, SO.... (this is a little embarrassing) - as I was doing the final assembly I realized I had put the LED on the wrong side of the board. I know, I know.. total bonehead.   So I then tried to unsolder the phantom switch to get at the LED and in doing so, I kinda hacked away at some of those solder points trying to de-solder it before realizing I could probably remove the LED with the switch still soldered on, which I did.  I then re-flowed the solder points on the switch.  They look OK but now I'm concerned I f**ked up one of the pads.. 

I checked the XLR cable with another unit in the rack so I know it's not that.

I'll check it out and post a couple photos when I get home. 

Thanks so much,

-Terry

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 16, 2018, 08:49:47 PM
Copy that. Ok, SO.... (this is a little embarrassing) - as I was doing the final assembly I realized I had put the LED on the wrong side of the board. I know, I know.. total bonehead.   So I then tried to unsolder the phantom switch to get at the LED and in doing so, I kinda hacked away at some of those solder points trying to de-solder it before realizing I could probably remove the LED with the switch still soldered on, which I did.  I then re-flowed the solder points on the switch.  They look OK but now I'm concerned I f**ked up one of the pads.. 

I checked the XLR cable with another unit in the rack so I know it's not that.

I'll check it out and post a couple photos when I get home. 

Thanks so much,

-Terry

If you look at the top and bottom of the PCB, you'll see traces....or you can refer to the schematic.

http://library.hairballaudio.com/images/2015/06/hba-elements-pcb-v1-3_schematic-production.pdf

Using that you can check the continuity between components to check for bad trace/pads.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 16, 2018, 08:57:13 PM
If you look at the top and bottom of the PCB, you'll see traces....or you can refer to the schematic.

http://library.hairballaudio.com/images/2015/06/hba-elements-pcb-v1-3_schematic-production.pdf

Using that you can check the continuity between components to check for bad trace/pads.

Mike

OK - So Im measuring 3.57v on xlr pins 1&2 and 1&3. 

Checked the other pre's in the rack and I'm getting 47.8v across those same pins. 

Going to re-check my resistor values...  :-\

Or could it be something else?

-Terry
Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 17, 2018, 04:44:49 PM
OK - So Im measuring 3.57v on xlr pins 1&2 and 1&3. 

Checked the other pre's in the rack and I'm getting 47.8v across those same pins. 

Going to re-check my resistor values...  :-\

Or could it be something else?

-Terry

I should mention I did check continuity and everything seems to be there.

-t

Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 17, 2018, 05:31:17 PM
I should mention I did check continuity and everything seems to be there.

-t

Resistors all match up.   

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 17, 2018, 05:39:37 PM
What is the DC resistance (ohm tester) between one of the greens on your input transformer and each of the other leads?

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 17, 2018, 06:26:57 PM
What is the DC resistance (ohm tester) between one of the greens on your input transformer and each of the other leads?

Mike


BRN:   9.5
R:   2 ... (fluctuates a little)
W:   9.5
BLK:   2
GRN:   0.4
V:   323
GRY:   167.8
Y:   168.4
O:   0.2

Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 18, 2018, 12:10:58 PM

BRN:   9.5
R:   2 ... (fluctuates a little)
W:   9.5
BLK:   2
GRN:   0.4
V:   323
GRY:   167.8
Y:   168.4
O:   0.2

I went back through the thread and read poster 'Darkus' had the exact same issue, same symptoms, and it turned out to be a bad input transformer...  Maybe?   

Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 18, 2018, 04:56:17 PM
I went back through the thread and read poster 'Darkus' had the exact same issue, same symptoms, and it turned out to be a bad input transformer...  Maybe?

Yes, you have a short in your primary.  Surprised you pass signal at all.

Email us: info(at)hairballaudio(dot)com
Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on April 18, 2018, 05:00:33 PM
Yes, you have a short in your primary.  Surprised you pass signal at all.

Email us: info(at)hairballaudio(dot)com

Emailed.  Thank you so much!! 

Can't wait to build the next one!! 

-Terry
Title: Re: [BUILD] Hairball Audio - Elements
Post by: terrydactyl on May 09, 2018, 01:20:08 PM
Emailed.  Thank you so much!! 

Can't wait to build the next one!! 

-Terry

Apollogies for not following up.  Put the new input transformer in and holy moly!!!  I was getting some signal before but now...NOW.... I've got some serious gain!  This thing sounds friggin AWESOME.  It actually sounds really, really good. I'm especially liking the DI on it.  Wow! Thank you!!  So stoked!!!! 

Title: C301 voltage
Post by: lofi_beatsci on September 15, 2018, 06:36:40 PM
Hi Mike -

I've got a silver build I'm piecing together. For C301, I've got a 100pF ceramic cap rated for 50V. I see the other cap in that series (c300) is rated for 63V. Do you think the 50V will be alright coming in off the DI?

Thanks in advance.

-Matt
Title: Re: [BUILD] Hairball Audio - Elements
Post by: charlievela on December 06, 2018, 12:33:04 PM
Hi.

I just completed a pair of Coppers. Channel 1 is working perfectly, on channel 2 I made a dumb mistake and flipped Q600 and 601 (which I know is highlighted in the build guide, but my distractibility knows no bounds)

At first it wasn't passing signal at all, once I desoldered and flipped the components, I got a signal that was occasionally interrupted by a clicking sound, that only got worse over the next few minutes. Now there's no output and a continuous clicking that's modulated by the buttons on the front panel. I'm assuming I fried one or both of the components when I desoldered. Is there a way to verify? I'm going to try and place a mouser order right now just in case. But I want to be sure I didn't mess anything else up.


Video of the noise: https://www.youtube.com/watch?v=S3I30AVvva8 (https://www.youtube.com/watch?v=S3I30AVvva8)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: OwenAudio on February 08, 2019, 09:43:19 PM
Hi!  Putting together my first gold preamp, and first build.  When populating my board today with resistors I got to R604-3R9 and R605-3R9.  The color code on the resistor matches my reference material but the reading I get from them when measuring with my multimeter is 4.5 ohms.  That’s way outside the stated tolerance.  Is it a bad resistor?  Do I go with it?

Thanks,
Nate
Title: Re: [BUILD] Hairball Audio - Elements
Post by: TillM on February 09, 2019, 03:05:49 AM
Use it, nothing will happen.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: OwenAudio on February 09, 2019, 07:18:26 AM
Use it, nothing will happen.

I figured that, but just wanted to be sure.  Thanks!!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on February 19, 2019, 01:12:12 PM
Posting an email question here about transformers.

GA80071 (PM1000) as an input:

I'm working under the assumption this post is correct:
Here's how I understand it:

Brown -- Primary Center Tap
Green and Blue -- Primary Leads
Yellow and White -- Secondary Leads (I've seen yellow labeled "cold" and white labeled "hot.")

Black must be an internal shield, but I've can't recall ever seeing it connected in any PM1000 channel I've racked and the black lead has always been cropped short.

Cheers,
--
Don

The PCB mount holes on the Elements are as follows Pin 1 (primary high) is the circled pad then down the line of 4 pins on that side it's 1-2-3-4 then pin 5 (primary high) is across from pin 4  then 5-6-7-8 with 8 being across from pin 1.

So white goes into pin 5 and yellow into pin 8.  On the primary side we don't know. Try green into 1 and blue into 4. Check your phase, if it's 180 swap those leads.

Brown unconnected and black to Pin 6 (ground).

Zobel network? No way of knowing, maybe start with the PM 1000 schematic zobel.

Output (EA2623):
Red primary high hole (either one)
Org primary low hole  (either one)

Blue/Brown Sec high holes
Green/Black Sec lo holes

Good luck.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: ECS on March 07, 2019, 10:05:59 PM
Just finished a Copper and it's working great!  I just wanted to confirm you've changed the heatsink setup on the BA512... all the photos I see are of a large black heatsink but my op-amp shipped with a plain metal standoff screwed to the transistors.  Is this how these op-amps are shipping now?

Thanks!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: useme2305 on March 08, 2019, 06:39:48 AM
ECS, that's interesting. i hope it's sufficient? can you post a pic of the new design?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: ECS on March 08, 2019, 09:46:39 AM
Like I said the pre did work fine in a quick 5 minute mic test... I didn't check to see if the transitors or standoff got hot because the unit was enclosed.  Here are a couple of pictures... just looks a bit odd to me.

(https://i.imgur.com/DCHdE9o.jpg?1)
(https://i.imgur.com/eIKPjQA.jpg)
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 08, 2019, 10:14:14 AM
Just finished a Copper and it's working great!  I just wanted to confirm you've changed the heatsink setup on the BA512... all the photos I see are of a large black heatsink but my op-amp shipped with a plain metal standoff screwed to the transistors.  Is this how these op-amps are shipping now?

Thanks!

Hi,

Yes this is a more common heatsink set up for this topology which generally runs a little cooler. If you look around many manufactures use this method (purple audio for one) or no heatsink at all.

The original heatsink was always more decorative, it was overkill. Rising material cost forced to either raise prices or use a more affordable method. Since it was more decorative we couldn't justify raising prices.

Jens the designer of this op-amp @ Eisen Audio has been running them with this set up in his console projects for years.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: ECS on March 08, 2019, 10:30:06 AM
Thanks for the clarification Mike! 

Just wanted to confirm it was correct... aesthetically I don't mind at all, not like I'm going to be looking at the thing.

Thanks again for all the great projects... I've got another 1176 build planned very soon!

~Eric
Title: Re: [BUILD] Hairball Audio - Elements
Post by: resilient on March 25, 2019, 10:23:40 AM
Hi Mike,

Built an Elements Gold last night.  It is unfortunately not working.  I haven't gone through the resistors to double check all of those yet, but wanted to check in with you here.  I get some noise when rotating the output knob, but that's it.  Nothing through the DI or XLR.

I should also have a 500 extender soon to take measurements.  I'll also try to find a way to post a pic of my soldering.  Currently the pic is too big.

Any thoughts on the noisy output knob?

Brandon
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 25, 2019, 10:50:38 PM
Hi Mike,

Built an Elements Gold last night.  It is unfortunately not working.  I haven't gone through the resistors to double check all of those yet, but wanted to check in with you here.  I get some noise when rotating the output knob, but that's it.  Nothing through the DI or XLR.

I should also have a 500 extender soon to take measurements.  I'll also try to find a way to post a pic of my soldering.  Currently the pic is too big.

Any thoughts on the noisy output knob?

Brandon

Well if it's not passing signal, you probably just have some DC in the output circuit you're amplifying.  Check all of your joints around those big caps by the input and output.  They can be tricky getting good flow into the ground plane pads.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: resilient on March 26, 2019, 05:28:23 PM
Thanks, Mike.  I'll double check them. 

I've got an extender coming tomorrow, so I'll be able to grab some measurements at that point, too.

Brandon
Title: Re: [BUILD] Hairball Audio - Elements
Post by: resilient on March 26, 2019, 06:28:25 PM
Ok, editing this thing for updates.

I have signal!  But it's low except in the highest position.  And it seems to be correct in that position... wide open and distorted (the distortion actually sounds kind of nice!).

I have reflowed all input control solder joints, including those on the Grayhill board.  Any thoughts on what might cause this low output until I get to the last setting?

Brandon
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on March 27, 2019, 01:30:40 PM
Ok, editing this thing for updates.

I have signal!  But it's low except in the highest position.  And it seems to be correct in that position... wide open and distorted (the distortion actually sounds kind of nice!).

I have reflowed all input control solder joints, including those on the Grayhill board.  Any thoughts on what might cause this low output until I get to the last setting?

Brandon

Check your gain switch resistor placement and soldering. At full gain you bypass those resistors. As you turn it down you start adding them from lowest value to highest value like a ladder.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: resilient on March 30, 2019, 01:38:58 PM
Found it!  I had mixed up R3 and R10.  Changed those around and all is well.  Thanks, Mike!

Brandon
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 01, 2019, 10:00:01 PM
Found it!  I had mixed up R3 and R10.  Changed those around and all is well.  Thanks, Mike!

Brandon

Nice!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: JOHN5 on April 28, 2019, 10:23:09 AM
Hi Mike -

I have two Copper units that I'm having some trouble with.  Here's where I'm at:

Unit #1 -

-No sound except for a significant humming - - I'd describe it as a ground-related noise due to its regularity and constant presence regardless of whether an input is present (mic or DI). 
-I checked resistivity w/ no op amp against my working unit (#2 - - see below)  All readings check out the same.  I have a spreadsheet of the readings I can send to you
-I swapped op amps with my working unit.  Both my op amps work in unit #2

Unit #2 -

-Works and sounds great except for the same humming as unit #1
-I've controlled for my 500 series rack slot:  I swapped another piece of 500 series gear (capi VP312DI) into the slots I had used for the hairball units.  No humming from the Capi unit when using same cabling and microphones for testing as the hairball unit. 

I've double-checked component placement on each and am not sure where to go next.  Any thoughts? 

Thanks,

John
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on April 28, 2019, 02:52:21 PM
Hi Mike -

I have two Copper units that I'm having some trouble with.  Here's where I'm at:

Unit #1 -

-No sound except for a significant humming - - I'd describe it as a ground-related noise due to its regularity and constant presence regardless of whether an input is present (mic or DI). 
-I checked resistivity w/ no op amp against my working unit (#2 - - see below)  All readings check out the same.  I have a spreadsheet of the readings I can send to you
-I swapped op amps with my working unit.  Both my op amps work in unit #2

Unit #2 -

-Works and sounds great except for the same humming as unit #1
-I've controlled for my 500 series rack slot:  I swapped another piece of 500 series gear (capi VP312DI) into the slots I had used for the hairball units.  No humming from the Capi unit when using same cabling and microphones for testing as the hairball unit. 

I've double-checked component placement on each and am not sure where to go next.  Any thoughts? 

Thanks,

John

Many repairs with coppers often boil down to the soldering around the larger vertically placed blue caps specifically cold joints on the ground pad.  There is a lot of heat sinking happening so you have to be patient with the heating of the pads.

Not sure about the hum.  Maybe the same stuffing error was made twice? 

Usual note:
We do $50 flat rate repair on those if that interest you.

***I will be traveling Wednesday April 24th through Monday April 29th and will be slower responding during that time***
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dp on June 11, 2019, 01:48:03 PM
Ordered-up a Copper and it should be here by Thursday. Really looking forward to this build. I've been really happy with the "Neve sound" I've been getting from the Softube Console 1 British Class A plugin but I think this thing will take that to a whole new level!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dp on June 12, 2019, 07:42:35 PM
Got the kit today... a day early... now that's serendipity!

Just started the build.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dp on June 12, 2019, 09:39:36 PM
Missing the 2N4401... it's just part of the relay circuit so I should be able to swap in a 2N3904 without any issues, correct?
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dp on June 17, 2019, 09:50:50 PM
Copper build update:

I got all the missing parts issues sorted out. I was missing the relay and its transistor and the 12k7 resistor in one of the Grayhill pots. Hairball got the transistor and relay shipped out quickly... thanks for that. The resistor I didn't discover until I was putting the Grayhill assembly together. I was easily able to put a couple resistors from my 1/2-watt MF set I use for my tube amps in series to get exactly 12k7. A little large but because of where it is on the board I was able to fit it in with no trouble.

Finished the build tonight and it works great straight-away... man that's a good feeling, isn't it?

This thing sounds fantastic. I re-tracked some vocals and was A/B'ing against some stuff I recently did with my modded-NT2 and the DIYRE CP5 with the Royal Blue colour module. They both sound really good, The CP5/Blue have a lot of high-end sparkle and some heft to it. Very clear and present. The Copper has the low-end and mid-range power you would expect from a "Neve" sound. Driven hard of course it will distort in a pleasing way. Set "on the edge" it sounds really good to my ears - the sweet spot. This thing is going to get used a lot. Have not tried the DI yet.
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on July 08, 2019, 10:20:26 PM
Copper build update:

I got all the missing parts issues sorted out. I was missing the relay and its transistor and the 12k7 resistor in one of the Grayhill pots. Hairball got the transistor and relay shipped out quickly... thanks for that. The resistor I didn't discover until I was putting the Grayhill assembly together. I was easily able to put a couple resistors from my 1/2-watt MF set I use for my tube amps in series to get exactly 12k7. A little large but because of where it is on the board I was able to fit it in with no trouble.

Finished the build tonight and it works great straight-away... man that's a good feeling, isn't it?

This thing sounds fantastic. I re-tracked some vocals and was A/B'ing against some stuff I recently did with my modded-NT2 and the DIYRE CP5 with the Royal Blue colour module. They both sound really good, The CP5/Blue have a lot of high-end sparkle and some heft to it. Very clear and present. The Copper has the low-end and mid-range power you would expect from a "Neve" sound. Driven hard of course it will distort in a pleasing way. Set "on the edge" it sounds really good to my ears - the sweet spot. This thing is going to get used a lot. Have not tried the DI yet.

Awesome! Sorry about the parts issues.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: dp on July 10, 2019, 06:19:24 PM
It's all good so no worries here. You make it painless to get the missing parts and since we are both on the West Coast they get here pretty quickly. I usually don't even bother when it's a resistor or a common-value capacitor since I have lots of those on-hand. But that transistor and relay aren't things I have spares of laying around.  8)

Really loving the Copper!
Title: Re: [BUILD] Hairball Audio - Elements
Post by: cmac on September 25, 2019, 06:45:27 PM
I have six copper Preamps all built by myself and have not had any problems until now. I can't say how old the unit that went bad is, because I have chipped away at building these two at time over the last several years. Its has to be at least a year old, and I do use them quite often for tracking drums. Anyway, I opened up the bad Preamp unit, and it was instantly obvious what the problem was! (figured I was going to have to hit the test points to narrow down the issue) Capacitor C505 has blown its top. I will attach a picture, I think that C506 just got some gunk on it when C505 exploded, but it may be worth replacing both. The 48V light on the front still works when plugged into my lunchbox, but the unit did not pass any audio. Which now is obviously due to the cap exploding.

Questions are:
- I have six of these, this is the only unit that this has happened to, is it something that I did? Because I want to take care not to damage my other Copper Preamps!
- I will probably replace both C505 and C506 Caps, should I be concerned about further damage to any of the other components due to this failure? 

As always, appreciate the insight!

Thanks much,

Clinton
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on September 25, 2019, 07:07:06 PM
I have six copper Preamps all built by myself and have not had any problems until now. I can't say how old the unit that went bad is, because I have chipped away at building these two at time over the last several years. Its has to be at least a year old, and I do use them quite often for tracking drums. Anyway, I opened up the bad Preamp unit, and it was instantly obvious what the problem was! (figured I was going to have to hit the test points to narrow down the issue) Capacitor C505 has blown its top. I will attach a picture, I think that C506 just got some gunk on it when C505 exploded, but it may be worth replacing both. The 48V light on the front still works when plugged into my lunchbox, but the unit did not pass any audio. Which now is obviously due to the cap exploding.

Questions are:
- I have six of these, this is the only unit that this has happened to, is it something that I did? Because I want to take care not to damage my other Copper Preamps!
- I will probably replace both C505 and C506 Caps, should I be concerned about further damage to any of the other components due to this failure? 

As always, appreciate the insight!

Thanks much,

Clinton

I would just replace those caps and see what happens.  Make sure you have the polarity correct.  The cap either exploded because of a 1) freak internal failure, or 2) or some crazy voltages around it that shouldn't be there.

I'd assume #1 one for now and replace and see what you get.

Mike
Title: Re: [BUILD] Hairball Audio - Elements
Post by: cmac on September 26, 2019, 10:57:34 AM
I would just replace those caps and see what happens.  Make sure you have the polarity correct.  The cap either exploded because of a 1) freak internal failure, or 2) or some crazy voltages around it that shouldn't be there.

I'd assume #1 one for now and replace and see what you get.

Mike

I have ordered replacement Caps for C505 and C506. I really think that will do the trick but will post back the results! Sounds like an odd thing that occurred. Thanks for the quick reply.

Clinton
Title: Re: [BUILD] Hairball Audio - Elements
Post by: cmac on October 04, 2019, 09:06:23 PM
I have ordered replacement Caps for C505 and C506. I really think that will do the trick but will post back the results! Sounds like an odd thing that occurred. Thanks for the quick reply.

Clinton

I received my replacement Caps for C505 and C506. I noticed instantly they appeared slightly smaller. When I removed the damaged caps from the PCB I see they are rated at 470uF/16V 105 celsius rated. The caps I ordered and Received are 470uF/16V  085 celsius rated.  Its always something! I referenced the BOM to order the caps, and had not yet removed the old caps to notice the 105 C rating. Is this a problem? I can get the higher C rated ones if its necessary. Thanks much.

Clinton
Title: Re: [BUILD] Hairball Audio - Elements
Post by: Hairball Audio on October 08, 2019, 02:36:08 PM
I received my replacement Caps for C505 and C506. I noticed instantly they appeared slightly smaller. When I removed the damaged caps from the PCB I see they are rated at 470uF/16V 105 celsius rated. The caps I ordered and Received are 470uF/16V  085 celsius rated.  Its always something! I referenced the BOM to order the caps, and had not yet removed the old caps to notice the 105 C rating. Is this a problem? I can get the higher C rated ones if its necessary. Thanks much.

Clinton

Those should be totally fine.