gar2520 build thread

[ilfungo]

thanks helterbelter
Yes Both the same...
I'll try to recheck all
my problem is not just noise
but I have a very low output and a cut of low frequencies

 

[chunger]

Gonna try to redeem myself from bricking a GAR2520 a while ago. . . trying to up my batting average a bit.  This one went smoothly!

;D

Fun builds. . even for a novice.

 

[gar381]

chunger

Your builds look better and better ! 
They are looking almost as good as mine
and I have built over 150 of them !!!  One suggestion.....
Tuck the 5.6 ohm resistor lead (R11) behind the DB139.  It will help
you not to create a short between the resistor lead and the twist
at the top of D1 diode pair when you insert the DOA in the millmax socket.
This is based on a problem that turned up about a year ago.  Anyone who has
built one should do this mod when you have a chance.

BTW...  1 hr 10 min is a perfect time !

LOOKIN GOOD my friend !!   

GARY

 

[skal1]

is their a bom for this guys.

skal1

 

[gar381]

skal1

There is a complete BOM in the assembly manual that comes
with a PCB or kit purchase from classicapi.

GARY

 

[skal1]

ok nice i just wanted to source my own components before hand.

thanks GARY

 

[a zombie]

Hey, this is my first post here on prodigy-pro.

Anyways, I'd just like to say that I built my first gar2520 and it is working perfectly.  All around a great experience! thanks Jeff and Gary!

I will post a photo when i build my second, then you guys can comment on my build quality

-James

 

[jsteiger]

...I'd just like to say that I built my first gar2520 and it is working perfectly....

Welcome James and congrats!! 

Feels good doesn't it!  ;D

 

[a zombie]

It certainly does!  these things are quite an accomplishment sir 

 

[gar381]

Hey, this is my first post here on prodigy-pro.

Anyways, I'd just like to say that I built my first gar2520 and it is working perfectly.  All around a great experience! thanks Jeff and Gary!

I will post a photo when i build my second, then you guys can comment on my build quality

-James

James

Welcome to the lab you will love it here
This place is a wonderful BAD Habit ;D ;D

I'm glad the build was a great experience and looking forward to your photo.

GARY

 

[MikeClev]

I just finished soldering my first gar2520! She's a beaut! It took me about 2 hours whilst watching episodes of The Colbert Report. The instructions were clear and easy to follow. Tomorrow I'll put together its companion gar2520 who will join a pair of APP2050s in a brace of API 312 style preamps.

Thanks to Gary for all his hard work!

Viva la DIY!

 

[sam system-d]

I've been scared of those little things when I ordered them. PCB is so tiny! I've never done something like this.
But the pdf is so well done, the built was kind a easy. Too easy maybe. So I was supecting that something would go wrong when I would turn the unit on. NOPE!
Everythings working good!.
Thanks to GAry & Jeff for providing such a cool DOA!

 

[bigevil]

Just completed my first build! couldn't have been any more fun. It's not the easiest(and I'll find out if it actually works when I swap it into my VP25) but I had a blast. One thing I did mess up is that I broke off a lead Q6 so I've gotta order a replacement to finish up but other than that I think it should hopefully work.

Question, can I use a similar PNP TO-92 or do I need the exact one on the BOM? There are a few local electronic component stores with great selection but its unlikely they carry the brand name as listed in the documents.


In the meantime here are some pics. I know my soldering could use some work but I'm just glad I actually made it through the thing with no major screw ups.

 

[gar381]

bigevil..

Use the correct Part.

Check you PM.

GARY

 

[wimmy7986]

Has anyone ever had R12 burn up on you?  I'm putting this opamp in a VP312...  Without the opamp in the voltages are reading correctly on the 312.  Then when i put the opamp in, my R12 starts smoking.  I've checked visually for solder bridges and haven't seen anything    Could something be shorting to the case??  Thanks!!

 

[Siegfried Meier]

I just had R13 cook and was wondering a similar thing...

I've built up a load of these, and I've never had a bad one...any ideas?

Thanks!
Sig

EDIT - Looks like R9 as well, same value...any idea what would do that?

 

[Siegfried Meier]

Is it possible that the transistor are faulty?  Would that cause those resistors to burn?

Its probably faster and cheaper to just build up another one, rather than figure out what's wrong here...

 

[bruno2000]

Is it possible that the transistor are faulty?  Would that cause those resistors to burn?

Its probably faster and cheaper to just build up another one, rather than figure out what's wrong here...

Check the diodes.
Best,
Bruno2000

 

[Siegfried Meier]

Ya, diodes are fine.  Solder joints are nice and solid, no bridging, looks great.

 

[bigevil]

Well,
it took a long time but I finally was able to build my second Classic API VP25 and was excited to throw my gar2520 in there and see how it compared to the other opamps. Sadly, for whatever reason when I use the gar2520 it causes the whole rack to get a loss in power (the lights all dim, other modules don't work etc). Any idea where to begin? I've looked as close as possible for bridges and other issues but can't seem to find anything.  I swapped out the DOA on the VP25 and it works perfectly.

Thanks so much, here are the pics again.