Building the perfect Princeton Reverb

kmcguitars

GuitarArtologist
For those of you who know me from the Forum know that I absolutely adore Princeton reverbs. Unlike all it's big brothers from the Deluxe to the Twin. The Princeton circuit differs from all the other BF/SF
Amps, By using a Split load Phase Inverter opposed to the Long tail PI in most other models.The Split load PI to my ears seems to drive the power tubes into a smooth but yet dynamic overdrive. The Tremolo is also unique to the Princeton using power tube bias modulated tremolo which produces a more pleasing effect IMO. Although the Princeton in it's stock form has many short comings that keep it form being the Ideal Club/bar amp, My PR surprisingly held it's own,But was always lacking in one way or another. So instead of hacking up a now collectible amp with B.S. mods, I've decided to build my own amp based on the Princeton AA1164 circuit and address it's short comings. I imagine this is not a new Idea? But here or my specs. It will be a 1 x12" combo w/t Deluxe style transformers. This should put me in the 25 watt range.The Bias will be Fixed/Adjustable with the option of running 6V6's or 6L6's.My PT has taps to run either a 5U4G or GZ34 Rectifier.A standby switch will be added,Plus a tremolo OUT switch.(Even w/t the trem off it still remains in the circuit stealing some gain) This switch will effectively remove the trem from the circuit giving you back some gain.My OT has 8 & 4 ohm taps. It will be wired with a Switchcraft 13a ext. jack, This way when a 2nd 8 ohm load is plugged into the ext. speaker out it will automatically shunt the 8 ohm tap and run safely at 4 ohms.Lastly I will use the JJ multi section cap 40uFx20uFx20uFx20uF. This should help tame some of the flabby bass. I had a 1/2 dozen Chassis's made up to my specs. laser cut.Along with that I had stainless steel faceplate's made up that I plan to have laser engraved. So what I'm I going to call this Lil' monster?... The CHARMINGTON Reverb-Amp . Here;s some pics of my progress so far.Gotta Go... Go a lot of soldering to do.
BTW, If anyone is interested in a chassis, Or a build like this? Shoot me a PM
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Re: Building the perfect Princeton Reverb

You have me SOOOOOOOOOOOOOOOO CURIOUS about this...

I feel about PRs exactly the way you do!
 
Re: Building the perfect Princeton Reverb

I've been intrigued by princeton reverbs ever since I found out that Barry Melton of Country Joe and the Fish used one. Would it be possible to get clips when you finish?
 
Re: Building the perfect Princeton Reverb

It's a fun design. I'm about finished with mine, but I've not modded it with the cathode/fixed bias switch. Let us know how that works out for you. I love that option on my bigger tweed. Good luck!
 
Re: Building the perfect Princeton Reverb

They are one of the few amps that you can plug into with nothing else and it gives you what you need. Great little amps
 
Re: Building the perfect Princeton Reverb

Very cool project. I'm very interested to hear what the cathode/fixed bias switch does too. I'm also intrigued by the trem out switch. I'm thinking of building the Allen single channel brown vibrolux-based project (no trem or verb) and now I'm wondering what kind of gain it might have...
 
Re: Building the perfect Princeton Reverb

If I can make a suggestion, Ted Weber used to make a 10" speaker called a C10NQ. He still makes it but it has a different model number. It's his version of a '66 Jensen C10N but with a lighter cone from a C10Q. I use that speaker in both of my Princeton Reverbs and it's the best 10 for those amps I've tried. Makes them louder and clearer but at the same time deeper, fuller and ballsier. Makes them sound like a 25 watt amp. I have a'74 silverface and a '66 blackface. Bruce went through the silverface and turned it into a fabulous amp. He made a few changes to the circuit but one thing that really helped was using a .02 cap in the tone stack. Lew
 
Re: Building the perfect Princeton Reverb

WOW!!! I want a PR someday! I cant wait to follow your progress bro!
 
Re: Building the perfect Princeton Reverb

im working on a sorta similar project for a friend of mine. bf princeton without the trem, bigger trannys, 1x12" combo, 6l6 option etc...
it should be a great amp, love to hear clips when its done
 
Re: Building the perfect Princeton Reverb

Man bro I have amp GAS again. I havent had that for a long time. This would be the perfect gigging amp for me.
 
Re: Building the perfect Princeton Reverb

If I can make a suggestion, Ted Weber used to make a 10" speaker called a C10NQ. He still makes it but it has a different model number. It's his version of a '66 Jensen C10N but with a lighter cone from a C10Q. I use that speaker in both of my Princeton Reverbs and it's the best 10 for those amps I've tried. Makes them louder and clearer but at the same time deeper, fuller and ballsier. Makes them sound like a 25 watt amp. I have a'74 silverface and a '66 blackface. Bruce went through the silverface and turned it into a fabulous amp. He made a few changes to the circuit but one thing that really helped was using a .02 cap in the tone stack. Lew

Lew, I asked Ted what speaker to put in mine for vintage tone and this is the one he sent me. I'm looking forward to hearing it soon.
 
Re: Building the perfect Princeton Reverb

Lew, I asked Ted what speaker to put in mine for vintage tone and this is the one he sent me. I'm looking forward to hearing it soon.

My guess is you'll love it Scott. I have an older model but it should be the same speaker. IMO, Ted Weber makes the best sounding new 10" guitar speakers I've used. Lew
 
Re: Building the perfect Princeton Reverb

My guess is you'll love it Scott. I have an older model but it should be the same speaker. IMO, Ted Weber makes the best sounding new 10" guitar speakers I've used. Lew

I agree 100% Lew. You and Christian suggested his 10s back when I needed speakers for my Vibrolux. If you recall I went with 10F125s. I still to this day think that was the very best enhancement made to that amp hands down.
 
Re: Building the perfect Princeton Reverb

does any one know what that speaker lew and scott are talking about is called now?
 
Re: Building the perfect Princeton Reverb

looking at teds site im guessing you are right, thanks
 
Re: Building the perfect Princeton Reverb

looking at teds site im guessing you are right, thanks

Im really thinking thats it...I tried the plain 10F150 once and really didn;t care for it...it was just too dark sounding and stiff no matter whatm plus in a small amp like a PR it would never "breath" good however this 10F150T thing might be the ticket however Im so in love with the tone of my 10F125 I can't see whating to change it!
 
Re: Building the perfect Princeton Reverb

Im really thinking thats it...I tried the plain 10F150 once and really didn;t care for it...it was just too dark sounding and stiff no matter whatm plus in a small amp like a PR it would never "breath" good however this 10F150T thing might be the ticket however Im so in love with the tone of my 10F125 I can't see whating to change it!

Exactly. The lighter "Q" cone brightens it up. Ted's copy of the original Jensen C10N doesn't really sound like an original C10N...it's just as you say: to dark sounding. But when he uses the lighter "Q" cone with that same speaker it picks up treble and adds a lot of toothy texture.

I tend to like the ceramic magnet speakers in blackface amps and the alnico magnet speakers in the tweed amps. Or a combo.

Lew
 
Re: Building the perfect Princeton Reverb

Ted strongly recommended his 10F150T with light doping for my Blackface Princeton Reverb project. He also told me to spec it as "well broken in" by him. didn't know Weber offered that for their speakers.

The amp is almost done and I'll report back when it's complete.

Chip
 
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