Deluxe reverb crammed into Princeton reverb chassis.

Paul G.

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About the Pro Reverb in a Deluxe Reverb chassis...well it all fits, and works fine, only problem -- I miscalculated and the rectifier tube is touching the power transformer. I'll do something to get a tiny bit of clearance. Otherwise, it's a peach.
 

RetiredUnit1

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I'm a firm believer in head only amps and speaker only cabs. Whereas at 66 I still have some pretty good muscle left on me but the arthritis in my hands HURTS ALL NIGHT and I cannot sleep if I carry too much. Even with the Tramadol I get from the Doc. And of course there are casters on the bottom of those speaker cabs.....
 

slauson slim

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This:

1660704551596.jpeg
 

Peegoo

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Those amps had been massaged by Cesar Diaz to have a much tighter low end.

I wanted the clean low end and punch of a DR but in a Princeton-sized combo, so I followed Diaz's example and did a the following mods to a PR:

-Installed a Heyboer TO20 output transformer
-Built a beefier baffle to prevent baffle buzz from the flexible stock baffle
-Swapped in a Weber 10F150 on Ted Weber's advice
-Swapped in a Copper Cap SS rectifier to improve punch and reduce compression sag
-Installed JJ 6V6s and biased the amp; JJ 6V6s are closer to 6L6s than 6V6s

The amp is louder than stock, and there's very little breakup in the low end when the volume is between 8 and 10. It's clean and punchy; no typical PR farting out at high volumes. I've had this amp now for 10 years and it's been a beast of a devil box.
 

proaudioguy

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I'm old and tired. My gigging amp is an Allen Accomplice Jr. While it it pretty light at 38 lbs., but the cab is pretty bulky. I was thinking of putting a single-channel AB763 into a PR chassis and cab running Deluxe Reverb transformers. (I've owned PRs, I need a bit more power and a better phase inverter). Anybody done this? Any stumbling blocks? Was going to stick to the cap can to save space, unless having the preamp common to power amp ground causes a problem.

I'd need to punch one more 9-pin hole, and open up the PT hole, otherwise, it should be good, right?

I’ve been considering doing this for at least 15 years. Just a single channel, 5 tubes. I would actually like to keep the PR transformer to give the amp even more hair, particularly since that first tube being out would give a little back. Every time I post the idea, I get a lot of people telling me why its a bad idea. Once all my projects are done and 3 guitars and at least 2 amps are sold, I may finally build it. If you build it, I hope I see your build thread and where you end up with it.
 

schmee

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I’ve been considering doing this for at least 15 years. Just a single channel, 5 tubes. I would actually like to keep the PR transformer to give the amp even more hair, particularly since that first tube being out would give a little back. Every time I post the idea, I get a lot of people telling me why its a bad idea. Once all my projects are done and 3 guitars and at least 2 amps are sold, I may finally build it. If you build it, I hope I see your build thread and where you end up with it.
It would be pretty good. But I have upgrade advice on a Princeton Reverb that makes a BIG diference... that is a bigger Power Transformer and a Deluxe output transformer.
The voltages on a Vibrolux PT work great for a Princeton circuit... the bigger PT gives you more clean headroom, which a stock PR doesn't have a lot of.

So what you end up with is a Princeeton with slightly bigger transformers but keeping the Princeton phase invertor etc. Still has that Princeton grit but with enough power to use well in a band mix.

People probably advise not to use the Princeton transformer because it's traditionally a weak spot in that amp to start with. It's really just a little Champ power transformer really and many fail.
 

proaudioguy

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It would be pretty good. But I have upgrade advice on a Princeton Reverb that makes a BIG diference... that is a bigger Power Transformer and a Deluxe output transformer.
The voltages on a Vibrolux PT work great for a Princeton circuit... the bigger PT gives you more clean headroom, which a stock PR doesn't have a lot of.

So what you end up with is a Princeeton with slightly bigger transformers but keeping the Princeton phase invertor etc. Still has that Princeton grit but with enough power to use well in a band mix.

People probably advise not to use the Princeton transformer because it's traditionally a weak spot in that amp to start with. It's really just a little Champ power transformer really and many fail.
See you just don’t get it. LOL
That’s exactly what I was talking about. I don’t want more clean headroom. I want compression. I just want the TONE of the DR which the PR is lacking. The power levels of the PR are perfectly fine. Just adding the LTPI will give it more, but may also compress more so the overall clean volume may stay the same. The same or LESS is good with me. I like the amp to be grungy when I strum hard and clean when soft, and all the compression you get in between.
 

proaudioguy

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See you just don’t get it. LOL
That’s exactly what I was talking about. I don’t want more clean headroom. I want compression. I just want the TONE of the DR which the PR is lacking. The power levels of the PR are perfectly fine. Just adding the LTPI will give it more, but may also compress more so the overall clean volume may stay the same. The same or LESS is good with me. I like the amp to be grungy when I strum hard and clean when soft, and all the compression you get in between.
I should add, I have a very sensitive speaker in there. I go between an EVM-12L and a JBL D112F. Volume is not a problem.
 

schmee

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See you just don’t get it. LOL
That’s exactly what I was talking about. I don’t want more clean headroom. I want compression. I just want the TONE of the DR which the PR is lacking. The power levels of the PR are perfectly fine. Just adding the LTPI will give it more, but may also compress more so the overall clean volume may stay the same. The same or LESS is good with me. I like the amp to be grungy when I strum hard and clean when soft, and all the compression you get in between.
You should mod the Princeton to have the long tail PI then. You will be close to having a Deluxe with small trannys. Better yet, just build a Deluxe with Princeton trannies.
 

proaudioguy

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You should mod the Princeton to have the long tail PI then. You will be close to having a Deluxe with small trannys. Better yet, just build a Deluxe with Princeton trannies.
I have been seriously considering this!
I just need to add that tube. I saw a post earlier though that has me thinking. If you cn use a 12DW7 to drive AND recover the reverb, then 4 Tubes is enough assuming there is no feedback asscoiated with having that stuff so close together. I am unclear how such a low MU section will drive the reverb (unless I have it reversed). I’d love to see what people are doing with that. That being said, I’m not trying to hijack this thread.
 

Badside

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I know this is the DIY forum, but I'm really liking what I see with the 68 Pro Reverb RI. Barely bigger than a Princeton, but 40W and a single 12" of the neodymium variety, pine cab, making it only 35lbs and as loud you need.

Basically just the reverb/trem channel and SS rectified (they'll say the sag is simulated in the PT... Whatever that means, maybe a sag resistor, as making the PT voluntarily current limited is not great for long term reliability me thinks)

It's also a build someone could easily replicate.
 

proaudioguy

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I know this is the DIY forum, but I'm really liking what I see with the 68 Pro Reverb RI. Barely bigger than a Princeton, but 40W and a single 12" of the neodymium variety, pine cab, making it only 35lbs and as loud you need.

Basically just the reverb/trem channel and SS rectified (they'll say the sag is simulated in the PT... Whatever that means, maybe a sag resistor, as making the PT voluntarily current limited is not great for long term reliability me thinks)

It's also a build someone could easily replicate.
You’re right. I want that in a DR and I want it hand wired.
 

justusberlin

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what about Robs 6v6 Blackvibe? Do you need Tremolo? Reverb?

A slightly larger footprint would be the Brownface Deluxe 6G3 Combo 535 x 435 x 241 vs 505 x 406 x 241

Currently researching for a 6v6 Blackvibe built (without Tremolo and Reverb) and stumbled upon the Brownface Chassis and Cabinet at TAD.
 
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gabasa

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I was thinking of putting a single-channel AB763 into a PR chassis and cab running Deluxe Reverb transformers ... Anybody done this? ... I'd need to punch one more 9-pin hole, and open up the PT hole, otherwise, it should be good, right?
It would be amazing. I friend of mine has exactly what you described and it sounds really good! It's a one-channel BFDR in a PR chassis, with the extra preamp tube added. Everyone that's tried it loves it.
 

gabasa

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I’ve been reloading this page every day. LOL
Here's a pic of the rear. It's not my amp, nor my build, btw; it was built by someone in Toronto that tries to make affordable builds for college students. I managed to get the amp into my hands so I'll try to post gut shots in the next day or two.

It was advertised as a one-channel DR in a PR chassis.

PR Rear.jpg
 
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