PGA2500 Project Finally Finished

[zayance]

Hi guys, well nothing much, but i finally finished (well sort of) Igor's PGA2500 Project, i needed some clean preamp, i had some stupid rookie issues with this one  :, but all in all it went pretty good.
I could have done it a little more affordable at the end  , was not too expensive build tough but i could have choose to go cheap and still efficient.
But i wanted to test my skills actually, it was my first "real" project in a way (builded one GSSL before and some SCA kits), on this one i had to take care of space management, front design, not that much because Igor tought about it all but still some to not get caught into bad situations, had some metal work (a little) and SMD soldering etc..., but i'm really proud of the achievement.
I did a quick test of the preamp on Male vocals, and it was pretty damn good/clean, but still very musical, on the pictures you see different poly caps, because i wanted to try some different to see what's up (i remember Igor saying good poly caps on input, and good output stage, output beeing OPA2604) so i choosed Panasonic ECQ, Roederstein MKT and SCR Audio MKP, and the difference was subtile, but still there from one to another, really, my prefered one is the SCR caps, smooth clean sound and very defined, the others were good but different, Panasonic a little more blurry in a way but still good, Roederstein was crystal clear, but a little more agressive on the highs.
It was nice to compare a little from components to components, and hear the differences, and makes me realise how much components, and i believe caps, influence the sound, i can also compare with different OPA, maybe later?
The fourth preamp, is on standby, just to see what cap i use on four of them or on pair.
Anyway i still need to try these preamps on different sources and situations, to hear where they shine the most but it was a cool project and i learned a lot so what else?
A big big thanks to Igor for this project, and for his help and patience, thanks a lot Igor  

http://img811.imageshack.us/img811/1948/front.jpg

http://img37.imageshack.us/img37/2368/frontcloser.jpg

http://img267.imageshack.us/img267/2140/insides.jpg

http://img35.imageshack.us/img35/7321/backbc.jpg

 

[Hank Dussen]

Nice build!!
I like the little squares instead of numbers.

 

[SIXTYNINER]

well done ,
really "porn" !

 

[Igor]

YUMMY!!!
Very nice build. Interesting info about capacitors. My favorite was ERO, old stock, 10uf/63V.

 

[zayance]

Yes Ero new stock was not bad but on vocal was not what i liked, but depends also of the other components choice i believe, still have to try on different source...

 

[kibadachi]

Congratulations with this Beauty!
Remembers me that mine deserves a better box then the shoebox i use now ;D
Like the professional looks of the rear panel as well. Where do you connect the insert on this pre?
Did you use Schaefer for the front panel?
If so willing to share the fpd file?

 

[zayance]

The insert points are connected on the 7/8/9/10 Pins on INS, but they will be balanced -10dB, I asked Igor just to be sure, and he gave me this:
7 send+
9 send-
10 retn+
8 retn-

And i've used switching neutrik jacks, so when no jack it acts like the jumper that has to be on pins 7/8 9/10.

The frontpanel was made by Schaeffer (not cheap), but it was before i knew Franck NRG services, he's cheaper, and as good as Schaeffer, maybe even better.

Sure i can share fpd file, send me your email adress and i will give you that, nothing much here, since Igor tought about the layout and all, it's just a nice application.

 

[rob_gould]

Hi Zayance,

Very, very nice work.  It's taking me a while to get to my PGA2500 project, but you have just inspired me to get going on it!

I also would be interested in taking a look at your .fpd files if you don't mind sharing.  You panel layouts are clean and professional looking.  Good stuff.

Cheers,

Rob

 

[zayance]

Sure Rob, email your email 

 

[crisotop]

beautiful, congrats! love the clean panel and external psu solution!

christoph

 

[zayance]

Did some recordings of Acoustic guitar, and the preamp did great, i used C414BXLS in Cardioid (could have tried with different mics also, but i wanted a flat take on this one), the preamp with ERO new stock was a winner on this one, made the take very detailed and crystal clear, and the guitarist loved the clean sound, highs were nice as well, so i'm going to go with two preamps with the SCR caps, and two with ERO, will give some choice, Panasonic was still not good for my taste, made the sound blurry as on Vocals same same.

 

[warpie]

beautiful, congrats! love the clean panel and external psu solution!

christoph

same here. What's the PSU enclosure? modushop?

 

[drpat]

...

 

[Kingston]

http://www.modushop.biz/ecommerce/cat136_l2.php?n=1#1

Thanks for the tip. This just completely solved my tube mic PSU enclosure problems.

 

[zayance]

Yes Modushop Galaxy Maggiorato, but i used it in vertical position, with feets, and Aluminium handle added ( bought on RS), for my G7 project PSU, the handles are in leather with custom aluminium made feets, hope the small size of the PSU case i choose will not cause too much problems on the Mic, still learning here  :

 

[snipsnip]

This is very impressive. Super tidy build too!

 

[rob_gould]

Hi Zayance,

I came across these PCBs the other day.  I'm undecided whether to build or sell them. 

What are your impressions of these preamps now you've had a couple of years of use from them?  Do you still use them and like them?

Cheers

Rob

 

[zayance]

Hi there,

Yes it's been used when needed, a flat preamp overall.
There are maybe other "better" flat preamp options out there now, so up to you...
I guess if you already have some transparent preamps, then these are not needed.
I wanted to build some M1 some time ago, but not much time for now..., better than these from
what I remember when used them some time ago.


T.

Edit: don't get me wrong, they do their job well...

 

[Andy Peters]

Hi Zayance,

I came across these PCBs the other day.  I'm undecided whether to build or sell them. 

They only make sense if you have a need for remote control of preamp gain, or perhaps perfect recall of gain. In the context of a digital live-sound console, they're the solution. For a typical studio, I don't see the point.

-a

 

[delaymix]

And the quality? this should be a strong point of this project. I think this is an amplifier should distance themselves from the group of common preamps for recording. Otherwise, I think it would be a bit sad. What do you think?