Exercise in Crammage---70s 50W ODS in Princeton Rvb. Chassis

[ChrisM]

Thanx Tony, I remember the bypass from my #124 build.

I already wired the relay old-style, just for comparison I'll try it like that then rewire it.

Now all I have to do is get a faceplate and backplate made up.

Where/how are you getting that done?
I am doing a very similar project with a Mojo PR chassis right now, also looking into faceplates.

[David Root]

rj of rjguitars.net says he can get it done, I just have to take the time to draw up the templates.

I have also used Joe Vallina of amplates.com in the past, he is very good. I'll see if I can get some pix of what he has done for me.

[ChrisM]

David, what reverb circuit are you using?

[glasman]

Here are a few pics of my take on the same thing. This is a prototype I built in a Mojo princeton reverb chassis.

When I had my commercial chassis made, I went for a more "comfortable" 8.25" chassis .

[Structo]

Hi Gary,
Nice clean looking build.

Can I ask what shielded cable that is and where do you get it?

Also, what are the IC's on the main board for?

[Zippy]

Also, what are the IC's on the main board for?

I was coming up short on the tube count, considering that the amp has both reverb AND an active effects loop.

May I enter a guess that the IC's are for reverb?

[M Fowler]

Nice amp Gary.

Its funny how so many of us are working with those PR chassis. They have the correct tube count for my Rocket Reverb four 9 pin and 3 octal so that works out great.

Mark

[Structo]

Also, what are the IC's on the main board for?

I was coming up short on the tube count, considering that the amp has both reverb AND an active effects loop.

May I enter a guess that the IC's are for reverb?

Now that I think about it, you are probably right.

[David Root]

Chris, there is no reverb circuit in mine. It would have to solid state to fit in, I think.

Gary, that's very nice indeed! Those PCBs allow you to put so much more on one board, no need for the side mounted PS and bias board. Except you have to use an X-mount PT, not a Z-mount. No FET input on it though, or is that on the board too?

[glasman]

Correct the ICs are reverb drive and return. No FET.

[glasman]

The coax I use is RG319 that I normally source from Apex Jr. Last time I ordered he just got a 1000' roll in and I bought the whole thing so I am set for a while. The 319 is a nice compromise between size and center conductor diameter. Much better than the 187 and 188 coax.

[David Root]

Finished it today. Minor problem with the FET, one wire too many between the jacks.

442 plates/screens, 292/292 PI, 124 PI ground (12AT7), 163/333 on the loop plates (also 12AT7), 194/192 OD, 194/194 clean, 20.1/11.2/2.25 FET.

Clean is very nice, I like it better than my #124 in some ways, even with the PI perfectly balanced it is harmonically pleasing, although it lacks bass compared with my #124. This on my 2x15 JBLs. Have not tried it yet on the Altecs yet.

OD--NO FIZZ!!-- much shorter wires this time, single bias pot. Nice OD thru Normal input, FET turned up the gain, super sustain, haven't taken a slide to it yet but I will.

Old matched RCA blackplates, NOS Mullard CV4024 PI, old Sylvania 12AT7 in loop, old Amperex 12AX7 in V2 and RCA long blackplate 12AX7 in V1.

[Sonny ReVerb]

The coax I use is RG319 that I normally source from Apex Jr...

RG-what? RG319 has on OD of 2"

[UltraHookedOnPhonix]

Glasman, is the reverb power supply bipolar, like +15V/-15V? If so, how did you ground it?

Very cool build! Neatly designed PCBs.