PRR-176 Vari-Mu REV 2 - *Group Buy 7/13!*

[ding]

Ok black anodized with white looks bad ass. I am still searching for those switches.  :

 

[baadc0de]

Hello all!

I took PCC189 tubes

Are PCC189 compatible with this compressor?

It's a real pain to have matched pair of 6BC8.
I've bought 10 pairs and still have from 1 to 5db difference of level compression.

My comp is a stereo with just one set of knobs for both channels, no link and outboard threshold pot. All built with Vishay/dale precision resistors.

Best regards.

Yeah, they work really well re: compressor action. I have a bunch of 6bc8 (from quirky channel master japanese ones, to some RCA, WE..) and these sound just as good if not better. I really like my PRR176 on acoustic guitars, bass and vocals. Can be very nice and gentle GR or quite aggressive.

 

[Spencerleehorton]

HI Guys,

i have been reliable informed that ECC180, 6BZ7, 6BZ8 are all equivalents for the 6BC8.
Can anyone verify that they will be ok?

regards

Spence.

 

[berkleystudios]

IM still waiting on the rev 4 pcbs to get in but can anyone tell me.......

1)what the compression ratio is on this guy and where in the schematic can I change it? I want to have a compress (1:5) and limit mode (1:15) if possible

2) would also like to know what tubes work the best and are easiest to find match pairs of, I have 4 6bc8s I bought in preparation of this but they are un-matched and I doubt they are very close...

3) has anyone not had and issue with Edcor Transformers and noise? I want this to be a really awesome build but the price just seems to keep climbing haha

4) I cant seem to find a lot of info on calibration. And I definitely cant find any procedure steps
never mind found them
5) Abe can the IC's (ne5524, TL072, INA134) you have on the rev 2( assuming they are still in the  rev4) can they be replaced with your discrete dip 8 kits? I think it would be awesome to make mine all discrete.

 

[ding]

Got my panel finished. In case anyone wants to in on it and get one also I started a black market thread.
http://groupdiy.com/index.php?topic=54476.0

 

[JeromeMason]

Hey guys, I know this is an older thread, but I've just built a Rev 2 and I'm getting a major ground buzz. I'm using all Edcor for input/interstage/output but the entire board is populated in case I want to switch at some point. I saw in the Rev 4 that there was some jumpers that had to be made to the board regardless of what types of transformers, just wanted to see if anyone might have a build doc describing any details on this or can help me out with tracking this down.

I have the wiring diagram, I have to admit I'm a little confused on the orientation of the pots, meaning which legs in the diagram are 1,2,3 so I can make sure I've got that right on my end. I want to believe this is something very simple. You can tap on the tubes and hear it over the hum plain as day. I'd love to get this up and running, so, if anyone has any documentation, or can point me to where it could be hiding in this thread I would be insanely appreciative.

 

[JeromeMason]

I know it's old... but.... anyone?

 

[SIXTYNINER]

Just for ask if this project thread is still open or closed (links at first page do not work)
thanks

 

[scott2000]

The version 4???  has a recently finished project and some recent pdfs for that build if it helps....
https://groupdiy.com/index.php?topic=54563.msg871586#msg871586

 

[SIXTYNINER]

The version 4???  has a recently finished project and some recent pdfs for that build if it helps....
https://groupdiy.com/index.php?topic=54563.msg871586#msg871586

Thanks for post !
started from the rev1 , then found the rev2 (docs - broken links) , now thanks to scott2000 the rev4 ,
after checked found  also there broken links ….. hmmm….little odyssey….
please any chance for the rev4 docs ?
thanks

 

[scott2000]

Thanks for post !
started from the rev1 , then found the rev2 (docs - broken links) , now thanks to scott2000 the rev4 ,
after checked found  also there broken links ….. hmmm….little odyssey….
please any chance for the rev4 docs ?
thanks

Just click the link and scroll up ...All of the pdf files are there.....ilfungo posted them

 

[jordan s]

Does anyone have the docs from this project? I was able to find the schematics from the REV 4 thread but nothing from REV 2 and especially not a wiring guide.

 

[shot]

Here's what I have on Rev2
Just rename .txt to .zip and unpack the archive
There's a wiring diagram, schematic and BOM inside

cheers!



Luka

 

[jordan s]

Thank you shot! You're a life saver.

 

[jordan s]

Does anyone have the details on the PSU board and transformer wiring? Everyone says to use a dual 18v transformer but the board has only 3 inputs for the 18v side which would make me thing they’re wired in series. I found a wiring diagram for the rev4 boards which have 4 18v inputs, 2 per each 18v secondary which makes sense to me. How does it work with the rev2 boards?

 

[bernatvm]

Anyone know where to find pcb today?

 

[evil grill]

HI Guys,

i have been reliable informed that ECC180, 6BZ7, 6BZ8 are all equivalents for the 6BC8.
Can anyone verify that they will be ok?

regards

Spence.

Did you try any of those tubes?

 

[rankot]

Here's what I have on Rev2
Just rename .txt to .zip and unpack the archive
There's a wiring diagram, schematic and BOM inside

cheers!



Luka

I'm looking for complete schematics for REV 2 (or later). Anyone???

 

[turnerk6]

Does anyone still have a live link to the schematic for this?

 

[living sounds]

Does anyone still have a live link to the schematic for this?

https://www.dropbox.com/s/sv5rnxk5nf6fvtt/PRR_176.jpg?dl=0