PRR-176 REV 4 Build Thread ***Manual up!***1/16/14 - (chk 1st post)

[Script]

Fuse type is 'slow blow'

 

[emx]

What about the amps rating on the fuse? does anyone have any approximate number for that for it?

 

[duantro]

Hey all, I’ve picked up a non working unit and have brought it back to life and it sounds great. Have ll1540’s on both input and interstage, and using 1731 opamos on the outputs. Rev 2 boards, but I thought there might be more replies here. The only issue I’m having is channel 1 release is fast regardless of where the pot is. I’ve double checked c2 and r9 and they seem correct and no solder bridges. Any thoughts on where to look? There was a broken wire that I fixed on the center tap/resistor switch for control voltage. Could that have zapped the c2?
Edit: replaced C2 and it works like a champ. Never mind!

 

[Kingston]

How long has it been, a decade? Anyway, I had a maintenance issue with this. Left channel would lose input volume every once in a while, a nasty intermittent issue.

My build has modifications that make it run hotter than the stock. It has a MOSFET based B+ PSU for absolute stability and the tubes are 6N5P running on 110V B+ rails. I might have detailed these in this thread long a go.

But those tubes run HOT! For the 1U unit it was apparently too much. I traced the issue to an overheating input DOA right next to the tubes.

I had to get some ventilation in there. So I punched four holes on the top cover right on top of the tubes. Same hole punch I use for XLR back panel I/O's everywhere, practically the same hole spacing on top of the tubes as well. It's happy now.

But I can't place another piece of gear right on top of it anymore - it needs that space to breathe. Kind of made that compact 1U size pointless.

 

[emx]

Curious what everyone else used in their PRR-176 compressors for transformers. And maybe which transformers of the ones I have available they would use in each position. I currently have the recommended Lundahl LL1540 soldered in before the tubes but might de solder it to use it after. I have available to me the following and but if anything else might be a better fit I'm game to get it...

2 Lundahl LL1540 (The recommended one for this build, I've already soldered it in before the tubes but might consider using it after the tubes)

2 Jensen JT 11SSP-6M (Nice higher steel content, 70's hifi vibe I'm told. Was considering using it as a balancing input but not set 100% on that. also
too wide for the 1U collective cases enclosure so I'm going to need to externally mount them on the back)
https://www.jensen-transformers.com/wp-content/uploads/2014/08/jt-11ssp-6m.pdf

2 Jensen JT-11-FLCF (I might need to create some shielding for this one as it's not cased.)
https://www.jensen-transformers.com/wp-content/uploads/2014/08/jt-11-flcf.pdf

2 Hammond 1140-LN-B (Was considering this as input or output balancing)
1140-LN-B


So curious what the consensus was for this, what would who use where is the question I guess?

 

[living sounds]

BOM and Schematics Rev 4

 

[Waadka]

Hi guys
Where can I buy PRR-176 rev 4 ?

 

[living sounds]

Hi guys
Where can I buy PRR-176 rev 4 ?

Used, if you can find a seller.

 

[flyingeyepro]

well, I guess I should check this forum more often......