[BUILD] Hairball Audio - Elements

[Echo North]

Yah ok, so i did just that. Im having slight issues here, if anyone knows whats going on please, help 

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

 

[darkus]

Yah ok, so i did just that. Im having slight issues here, if anyone knows whats going on please, help 

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.

 

[yourdudeness]

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?

 

[Echo North]

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.

 

[cmac]

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. 

 

[cmac]

This is a better quality picture for zooming in.

 

[Echo North]

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

 

[okdaniel]

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.

 

[Echo North]

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

 

[okdaniel]

Thanks! I'll rig it up.

 

[cmac]

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!

 

[Ataraxia]

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,

 

[Echo North]

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

 

[Ataraxia]

Ok, thank you for the Quick reply,

cheers

 

[pethell]

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

 

[Echo North]

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

 

[Sinkia]

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

 

[Echo North]

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

 

[Sinkia]

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

 

[Sinkia]

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