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

[Winetree]

Is anybody willing to share their cart for this project?

 

[ding]

There's one on page 2.

 

[e.oelberg]

progress !

 

[mrdarwin]

Two questions:
What are the DOA added in rev4 relative older revision?
Can I use edcor xsm 10k:10k as xformer output 600:600? (I have spare xsm...) or Carnhill 600:600?

 

[anjing]

progress !

Are these input trafo from a studer tape deck?

 

[berkleystudios]

Can I use edcor xsm 10k:10k as xformer output 600:600? (I have spare xsm...) or Carnhill 600:600?

yes you can use the xsm. i am.

 

[berkleystudios]

heres my build progress / mock up. had built 6 gar1731s for this but i think ill just save them for another build and use abes pcbs will also be suing a 5k pot on the front panel for threshold control.  just got the edcors cuz they where cheap, may switch them out for cinemags...

able where is the ratio circuit at? i was thinking of putting a switch  in so i could have a compress an limit mode by changing the ratio resistor. think that would be possible?

 

[e.oelberg]

progress !

Are these input trafo from a studer tape deck?

yes A80

 

[prh]

Do we have a schematic / BOM for the supplied DOAs?

 

[mrdarwin]

Do we have a schematic / BOM for the supplied DOAs?

check on first post: "Build Butler" for the bom. But actually no schems

 

[johnnyscotch]

Hey Abe/guys, sorry, I read through the thread, but I would just like to clarify for certain:

If we build the included DOA according to the schem/layout/BOM, does it drop right in, or is there some futzing around that has to be done to mount it??

 

[ding]

The included DOAs drop right in.

 

[e.oelberg]

i.m a bit confused about the bd140 139 orientation.where goes the emitter ? Silver side facing out ?

 

[druu]

Can someone tell me how many DOA's we were supposed to receive?

 

[e.oelberg]

Can someone tell me how many DOA's we were supposed to receive?

6

while 2 are still on one pcb with the valve socket

 

[mrdarwin]

About 6BC8 tubes...
If you look on rev 4 pcb, pin 1 of tubes is on the left.

On 6bc8, pin 1 is on the right when you mount it like on rev 4 pcb...

But if you look on rev2 boards, pin 1 is on the right and it's ok  with  orientation of the tube!!!
After looking on rev4 schematic, my conclusion is that 6bc8 connectors are inversed and can't be mounted on board.
Are you ok with me???

 

[ilfungo]

Hi mrdarwin
I've  checked the schematics and I think you are right!!! :-\

another question:
I'm using output transformer
The components that I can omit are these?
R38-39-40-41-42-43-44-45-46-47-48-49-50
C15-16-17-18 and 5532
and same for other channel
Correct?
Something else?
If DOA are used all the 22pf must be omitted?
Thanks

 

[ding]

About 6BC8 tubes...
If you look on rev 4 pcb, pin 1 of tubes is on the left.

On 6bc8, pin 1 is on the right when you mount it like on rev 4 pcb...

But if you look on rev2 boards, pin 1 is on the right and it's ok  with  orientation of the tube!!!
After looking on rev4 schematic, my conclusion is that 6bc8 connectors are inversed and can't be mounted on board.
Are you ok with me???

What would be a good fix for this? Will reversing the tube pcb not work?

 

[ilfungo]

I think we can mount the tube socket behind
but since there is the transformer we can mount the valve in the vertical....
What do you think?

 

[berkleystudios]

This is how i plan to mount them. I will have headers giving me enough height to clear the resisters. and I can mount mine up becasue I will be using a 2u (maybe even 3u) case