[BUILD] Hairball Audio - Elements

[martinswain]

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.

 

[brandonsullivan]

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.

 

[josephdhemphill]

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.

 

[Echo North]

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

 

[josephdhemphill]

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...

 

[Echo North]

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

 

[josephdhemphill]

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!

 

[josephdhemphill]

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?

 

[Echo North]

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

 

[josephdhemphill]

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!

 

[josephdhemphill]

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

 

[Echo North]

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

 

[area8]

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

 

[Echo North]

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

 

[area8]

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

 

[Echo North]

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

 

[area8]

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

 

[Echo North]

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.

 

[area8]

Secondary reads > 2M resistance. That's different.
Frank

 

[Echo North]

Secondary reads > 2M resistance. That's different.
Frank

That ain't right.