Phil here, introducing myself and my plan`

[pjd3]

Because I've heard of many doing it, and heard clips of the results. I'm not talking about trying to fit a 60-100 watt amp into a Princeton footprint, just something a little more clean and bold than a Princeton Reverb. I wouldn't have picked up a Princeton chassis it i hadn't seen many put in some 6L6's, a bigger OT and step up the PT to meet the bigger tube.

A Princeton Reverb may have had just enough power if it was fine as it. I suppose a single channel Deluxe is close enough to what I'm hoping for, just maybe a little bolder.

Am I mistaken about that? I'm just looking for a low-medium power amp that holds together well though most of its volume range, a good pedal platform.,

Thanks,

Phil

[xtian]

No, you're good with the PR chassis and cabinet. I did something similar with my Monkeymatic Trinity amps (5e3 deluxe, 12" speaker, larger OT, 6L6s. Fun amp!

https://amps.monkeymatic.com/2015-monkeymatic-trinity/

https://ampgarage.com/forum/viewtopic.php?t=28653

[martin manning]

I have a Princeton Reverb chassis and eyelet board for starters. They just got delivered today. But, I don't really want a Princeton reverb... I want this amp to support the use of 6L6GC's and even KT66's. And this amp doesn't have to have the reverb circuit and maybe even not the tremelo circuit. I would like a long tail pair phase inverter... Really I need this amp to be pedal platform that is low to medium power and stays pretty clean through much of its volume range... I would like to use a reverb pedal and the end of my chain... ...a good platform for many kinds of overdrive, distortion and fuzz pedals, and reverb pedal.

Folks here including me are wondering why gather up a Princeton Reverb chassis, board, and components when a different amp (no reverb, no trem, LTP PI, 6L6) is planned?

[didit]

Hello -

I'll TAG up somewhat aligned with Aaron. A single channel "AB763" derived design that is ~30W (ie. 6L6 pair at healthy low dissipation) fits fine on a Princeton chassis. Add some inches in height & depth, and with right speaker it is a fine combo too. A Princeton layout is readily changeable to long-tail PI and a good tube-based effects loop would be cool build addition in gaps left by removing tremolo & reverb.

Best .. Ian

[Tony Bones]

I already said it once, but I'll repeat myself. I think the PR chassis is just about perfect for a simple single channel amp. Makes for a compact head and with a slightly taller cab it makes a good sized 1x12 combo. The eyelet board cam be repurposed, but I don't like fiber eyelet boards anyway...

[pjd3]

Thanks everyone for getting back.

A question. Should you use a couple of KT66's, what differences would you expect in perceived loudness and tone between a 4k primary OT and say, an 8K primary?
Would you choose one primary impedance or the other depending on what you were looking for in performance?

Thanks,

Phil

[pjd3]

Hey xtian,

Sweet job on those amps. Must be very rewarding. And its great to actually hear what folks are doing. I see that theres quite a bit that goes into getting something like this up and running. But I'm giving myself to July to have this head ready, for about 30 outdoor concerts that my band does every summer. I almost just bought a new amp but lost my mind and decided to build one. Got myself into some real hot water now. My amp tech just spend a good 30 minutes on the phone with me giving me some direction and advice, and I even ordered some more necessary stock for the amp, wiring, selections of typical value caps and resistors. Too late to turn back now. My tech is very confident that I can make what I need from what I have. So am I if I remain diligent and teachable. And as long as my wife lets us part with the cash to do so! Thats a bigger obstacle than my intellence!

Hey, thanks again for your input. I even have a dedicated notebook, taking everything down as it comes in.

Best,

Phil

[M Fowler]

I use blank PR chassis for many different types of amps, it's about perfect size.

Mark

[pjd3]

Thats what I reckoned Mark, and I don't mind opening a chassis port a few 1/8"'s or drilling a few new holes. Its all in the fun. Right now, I'm trying to get my head around about picking up the transformers. I'm just about there on the PT, how to determine that you are meeting the current requirements and making the Plate voltage you want for a particular rectifier and power tube set. I'm making OK bucks at the contract job I'm at now but that could change in a couple of months so, trying to get the more expensive components of the amp now while I can still win the battle with the wife! Hey, gigging is a self employed, self maintained side business, right? absolutely.

Thanks!

Phil

[martin manning]

I use blank PR chassis for many different types of amps, it's about perfect size.

Yes, I agree, if its blank! This project would leave a lot of empty holes if a pre-drilled PR chassis is the starting point.

[M Fowler]

Martin,

Yes I only use predrilled PR chassis for Princeton Reverb clone or similar projects using the large can cap hole and same size power transformer cutout.

Allen Amps has great larger PT's that fit the Princeton Reverb power transformer openings so you can make EL34 or 6L6 circuits for some fun projects.

Mark

[TUBEDUDE]

I used many Princeton chassis for prototyping and product. I drill out 2 more noval holes for 5 preamp tubes. You can do a lot before it gets too crowded.

[sluckey]

I used many Princeton chassis for prototyping and product. I drill out 2 more noval holes for 5 preamp tubes. You can do a lot before it gets too crowded.

4+2=6

[pjd3]

Thats good to know guys. I've lived 60 years with lots of holes in my head and am a still here. I'm only asking 10 or 20 years from this amp!

And I'm really interested in using KT66's for this project. I just like the clips I've heard and everything I've heard about them.

Are we on the right track when we say,

If we want Plate voltage (output tubes) of 430V while using a GZ34 rectifier tube we would need a Power Transformer that's 330v-0-330v
So, 330v x 1.3 = 429v?

I'd actually prefer 450v on the plates of a KT66 but, thats probably getting real voltage piggish. Also, the Current ratings we see on the high voltage tap specs I take as the maximum for delivered bias current to "all" the tubes? i don't see what else it could be, well, exept for the 5V tap for the rectifier tube. I see its usually 2 or 3 amps. I'd probably want a PT with 3amps just in case of using another rectifier one day. the GZ34 seems to use a bit less than 2 amps. Ah, get three. Keep it cool?

Thanks everyone!

Phil

[TUBEDUDE]

I used many Princeton chassis for prototyping and product. I drill out 2 more noval holes for 5 preamp tubes. You can do a lot before it gets too crowded.

4+2=6

I use PR chassis that come with 3 noval sockets.