[BUILD] Hairball Audio - Elements

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resilient

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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
 

Echo North

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resilient said:
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
 

JOHN5

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Jan 21, 2019
Messages
7
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
 

Echo North

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JOHN5 said:
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***
 

dp

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Mar 30, 2019
Messages
56
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!
 

dp

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Mar 30, 2019
Messages
56
Got the kit today... a day early... now that's serendipity!

Just started the build.
 

dp

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Mar 30, 2019
Messages
56
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?
 

dp

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Joined
Mar 30, 2019
Messages
56
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.
 

Echo North

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dp said:
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
 

dp

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Joined
Mar 30, 2019
Messages
56
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!
 

cmac

Member
Joined
Jan 13, 2016
Messages
12
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
 

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Echo North

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Messages
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Seattle, WA
cmac said:
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
 

cmac

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Jan 13, 2016
Messages
12
Hairball Audio said:
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
 

cmac

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Jan 13, 2016
Messages
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cmac said:
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
 

Echo North

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cmac said:
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.
 

cmac

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Jan 13, 2016
Messages
12
Hairball Audio said:
Those should be totally fine.

I replaced the caps for C505 and C506, the 48V light will light up, which tells me it is getting power. Still no signal will pass.. Any further thoughts? I am willing to hit the test points and report back. Thanks much.

Clinton
 

Echo North

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Messages
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Location
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cmac said:
I replaced the caps for C505 and C506, the 48V light will light up, which tells me it is getting power. Still no signal will pass.. Any further thoughts? I am willing to hit the test points and report back. Thanks much.

Clinton

Do you have another op-amp you can swap in to rule out a bad op-amp?
 

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