Fender 65 Princeton Resissue Mods

[timmerel]

I'm thinking about one of the new 65 Princeton Reissues, and would like any thoughts from those who have tried the following mods:

- New speaker (10 or 12, and which one?)
- Higher quality tubes (new or NOS - and which ones for each position?)
- Paul C mod
- Stokes mod
- Blueprinting the components
- Adding two 470 ohm resistors to the screen grids of the 6V6 power tubes (a la David Boze)

The sound in my head is the Hendrix/SRV clean with a strat (and I know they had completely different rigs and were themselves). Overdrive is a secondary consideration (although would be nice if it still sounded good).

[brad347]

Not for nothing, and I don't usually say things like this, but IMO the best "mod" would probably be to not buy one and to buy a silverface Princeton Reverb instead.

I think the Musician's Friend price for the RI is about $899 IIRC. MSRP is over a grand.

You can find a nice silverface Princeton Reverb for that, or usually less. Blackface and silverface princetons are very similar... there weren't many changes made to that particular amp. The silverface with its tagboard construction will be easier to service down the line and more durable, and also has the same Schumacher transformers as the blackface amps. If you are buying it to immediately mod, why not go for an original which is the same price and easier to mod/service, and of which you don't destroy the resale value immediately. This is one reissue that truly doesn't make much sense to me, as the original Princetons (particularly the silverface ones and the non-reverb ones) are still affordable. Maybe they know something I don't.

Short of that, the first places to look would be the speaker and tubes and maybe the output transformer, as you have said. If overdrive is not your goal, I really like the clean sound of the Princeton Reverb in its stock configuration. But that's just my opinion.

[mbratch]

If you need more volume and 12-inch speaker, why not just get a DRRI? ;)

[SatelliteAmps]

Agreed. That's a lot of effort to modify an amp that you could probably already get that sound out of somewhere else.

[timmerel]

I like the Princeton because of its light weight and sound, and am interested in hearing from anyone who has done any of these mods.

[teleman1]

timmerel,

Leo designed this cabinet for a 10". Thats what it is voiced for. I don't recommend a 12. Its too big and rattles the cabinet even more. Besides, I have heard a 68 with the orignal 10" in there and it sounds fine. Nothing wrong with trying out other 10" for your particular sound.

Of Course the amp benifets from NOS. You can get the currently built recommened 6v6's. But you might try a Mullard in the v1 12ax7 slot and perhaps a NOS rectifier tube.

This amp sounds pretty dang good stock. A couple of the mods you spoke of increase the volume. Do you need that?. I also wonder about the Stokes mod cause it was for the PTP models. Has it been coverted for circuit boards?

[timmerel]

Sounds like a good Weber 10" might be the way to go then.

I'm using a Mullard in another amp, and that sounds a good idea for V1.

On the volume focused mods, I was really thinking in terms of higher headroom to keep it clean. I don't know about the Stokes mod for circuit boards, just read about it for Princetons in general.

[SatelliteAmps]

You will have a lot of difficulties doing any of the circuit mods, due to the fact that this is a circuit board based amplifier. Those mods are easy on any of the other Princetons because they are point to point wired. The mods you are asking about would entail cutting traces, and a bit of buggering to try and get everything to fit and work well together.

Any of the mods can be done, but if you want to have those mods, there are cheaper, better ways to get them. Having done them to some SF Princetons, there are some benefits to them. There isn't a great change in overall volume, but there is a difference in clean headroom.

The easy way to get more headroom out of any amp is to change the tubes to different types if you can. Going with a 12AT7, 12AY7, or 12AU7 will all alter the gain characteristics dramatically. Changing the rectifier and the power tubes to different types will also alter the clean headroom.

[mbratch]

You will have a lot of difficulties doing any of the circuit mods, due to the fact that this is a circuit board based amplifier. Those mods are easy on any of the other Princetons because they are point to point wired. The mods you are asking about would entail cutting traces, and a bit of buggering to try and get everything to fit and work well together.

Any of the mods can be done, but if you want to have those mods, there are cheaper, better ways to get them. Having done them to some SF Princetons, there are some benefits to them. There isn't a great change in overall volume, but there is a difference in clean headroom.Not to mention that such changes may have reliability issues if not done carefully and expertly.

And, thus, brad347's suggestion to check out SF Princeton Reverbs is a good one. :)

[timmerel]

So if I stick with the reissue (without the circuit mods, but with the speaker and tube changes), what specific tubes would you recommend?

[brad347]

Not to mention that such changes may have reliability issues if not done carefully and expertly.


...and are non-reversible, permanently damaging resale value. :)

[brad347]

So if I stick with the reissue (without the circuit mods, but with the speaker and tube changes), what specific tubes would you recommend?

What is your tube budget?

Ideally, blackplate RCA (original to the Princeton) and Brimar are very nice. Both are very expensive by now.

For cheap tubes, JJ 6V6 is very robust and good sounding for the money.

[timmerel]

I've been down the NOS route before, so know they aren't cheap.

I think the amp has the following tubes:

3 X 12AX7
1 X 12AT7
2 X 6V6
1 X 5AR4 Rectifier

Are you suggesting RCA blackplate for the 12AX7s? And what would you suggest for the other tubes?

[brad347]

I've been down the NOS route before, so know they aren't cheap.

I think the amp has the following tubes:

3 X 12AX7
1 X 12AT7
2 X 6V6
1 X 5AR4 Rectifier

Are you suggesting RCA blackplate for the 12AX7s? And what would you suggest for the other tubes?

I was speaking strictly about the 6V6s.

I thought the Princeton used a 5U4 but it's been a long time since I've been inside one.

The best 5AR4 by far is the old Mullard/Philips/Amperex. You will pay for them.

My favorite 12AX7 in Fender amps are blackplate longplate RCA and longplate Amperex Bugle Boys. Shortplate Mullards are what I use because I have a bunch of them around. They're actually not as nice sounding for guitar use as the other two, IMO. Of those, the RCA is probably the most economical.

I don't know if Mike K has any of those Marconi coke bottle 6V6s left, but those were great for the price.

Other guys here know more about tube snobbery than me, so listen to them. Those are just my personal experiences. ;)

[mbratch]

So if I stick with the reissue (without the circuit mods, but with the speaker and tube changes), what specific tubes would you recommend?
Honestly, I'd consider speaker first. A speaker is arguably the biggest impact on the tone of the amp, outside of the circuit design and cabinet. You might actually like the stock speaker. :) If you don't, then consider a couple of highly recommended ones, including (but not limited to):

Weber 10F150T
Weber 10F125
Eminence Ragin Cajun
Eminence Copperhead
Jensen C10Q re-issue
Reverend All-Tone 1030 [no longer in production]
Vintage Jensen C10Q
Vintage Jensen C10NS
...
(And the list goes ohn, deeeeeee deet deet deet.....
the list goes ohn.... deeeeeee deet deet deet.....
drums keep poundin' the rhythm to the brain....)

BTW, the BF Princeton and Princeton Reverbs used 5AR4 (GZ34) rectifiers. :)

[timmerel]

I agree - Ted Weber recommended the first speaker on your list, lightly doped and broken in by them.

So guess its that plus paying silly prices for a bunch of NOS tubes.

I'll try the amp stock first, but my previous experience with good NOS tubes has made me encouraged to give them a try with any amp.

[brad347]

so what are the advantages, in your mind, of buying the reissue amp versus an original or silverface?

[SatelliteAmps]

The speaker will make a huge difference. If that still isn't enough, have someone plop in some 5881's, and maybe a 12AT7 in the V1.

[timmerel]

What is the difference with 5881s? I've used an 12AT7 in another amp, and it worked well.

[SatelliteAmps]

I may have spoken too soon. The reissue Princeton Reverb PT won't work well with 5881s. Apparently it just won't keep up.

If it had worked, the difference would have been a bit more bass response, and a bit more clean headroom.

[BuddyGuit]

I put a Eminence Lil' Buddy in my '77 Princeton Reverb and now there is sometimes TOO MUCH bass response.

[Tomo]

Why do you (not you)have to mod thing right away!

Don't suck into mods too much? You can work on how you play and change to how you want sound.... Mod your playing... touch..???

Just a thought.

Tomo

[karmadave]

I suspect you void your warranty, once you start mucking around with a PRRI. I'd try and find a clean Silverface, or better yet an Allen Sweet Spot. I've own both a BFPR and a Sweet Spot and the SS is simply more versatile...

That's my $.02.

-KD

[Rhizopus]

Why do you (not you)have to mod thing right away!

Don't suck into mods too much? You can work on how you play and change to how you want sound.... Mod your playing... touch..???

Just a thought.

Tomo


because this is thegearpage.net :D

[timmerel]

Of course I'll try it stock first, but I've only had good experiences with retubing with NOS.

Haven't replaced speakers before, but many folks seem to think it is worth the trouble in these amps. I'm happy to give it a try, as it is easily reversible if I stick with a 10.

And on original BF or SF + mod to BF specs, here in the UK they don't seem like cheaper options. On more boutique options like the Allen, there is something I quite like about Fenders - I used to have a Twin Reissue which sounded great.

[Tomo]

because this is thegearpage.net :D

That's right! It's good to try other tubes, speakers... and how you play it.. how you enjoy it... that's key!

Tomo

[brad347]

Why do you (not you)have to mod thing right away!

Don't suck into mods too much? You can work on how you play and change to how you want sound.... Mod your playing... touch..???

Just a thought.

Tomo

This is hardly a new sentiment on this board.

For what it's worth, I feel that anything that brings a musician enjoyment-- whether it be practicing, listening, amp-modding, etc-- is a positive thing.

I'd much rather someone follow their heart and mod their amp, if that interests them, than to feel some sort of 'pressure' to practice their instrument instead, if they don't really want to.

Because in the long run, that pressure will turn into anxiety, and that anxiety will impede progress. Musicians achieve greatness through love of the art form and the inspiration that follows; they seldom, in my experience, achieve greatness by practicing from the zone of pressure/anxiety/fear. I have learned that people are like plants. You can overwater them with force-fed knowledge and kill their love/curiosity. I think it's great to learn while you're curious, and take a rest when you feel 'full.' When you are 'full,' your ability to learn/assimilate slows considerably, anyway.

And should someone discover that they like modding/building amps more than practicing guitar, then the world will have one more happy, successful amp tech/builder. Which is a lot better than one more frustrated musician, which the world hardly needs.

But more likely, they'll get to the point where they feel 'full' with that amp-modding knowledge eventually, and find that they're curious about searching out some other things to play over altered dominant chords again. To everything there is a season.

This is all, of course, just one person's opinion.

All the best! :AOK

[mbratch]

For what it's worth, I feel that anything that brings a musician enjoyment-- whether it be practicing, listening, amp-modding, etc-- is a positive thing.

I'd much rather someone follow their heart and mod their amp, if that interests them, than to feel some sort of 'pressure' to practice their instrument instead, if they don't really want to.That is a very good point.

On the other hand, it's also good for us to challenge each other to think in terms of what we're trying to achieve, and map that into a sensible action that might progress toward that goal, rather than just assume we should do something because we read about others doing it so much. Following the heart is good. Following the hype is not always so good. ;)

On the other hand (let's see... that makes... 3 hands?), I have to admit that what happens all too frequently to a poster (and I get annoyed when it happens to me) is they ask, "What do you all think of X and Y" and a common reply is, "Why don't you do Z". But then again, when "Z" is offered, sometimes it's enlightening to the poster.

Ah, another day in the life of a TGP thread. :D

[brad347]

On the other hand, it's also good for us to challenge each other to think in terms of what we're trying to achieve, and map that into a sensible action that might progress toward that goal, rather than just assume we should do something because we read about others doing it so much. Following the heart is good. Following the hype is not always so good. ;)


That's true!

But on the fourth hand, while it's easy to get all pedantic on a forum, it's sometimes good to remember that for some, music is not a career but rather a diversion.

For instance, my dad likes old muscle cars, but has no aspirations to be a professional race car driver. If he wants to, say, install some high-performance parts on his car to get a few more horsepower, he would probably do better in one sense by going instead to a track and practicing some racing skills. But that's not really the point of what he's doing, you know? He's not a professional driver, he just makes a hobby of having a cool, fast old car.

There are many many people who are not professional musicians or even semi-pro musicians, but rather just make a hobby out of having good-sounding gear. If that's what brings them joy out of music, then that's great!

[Bikedude]

Someone mentioned why don't you just by a DRRI if you want more clean headroom. I'll say here that the PRRI flat out smokes the DRRI tonewise! I've been chasing the PRRI tone with the DRRI for a year and a half. I've done, Marconi's, pre-amps, rectifier, rebias, CRex, clip, and out of the box the PRRI is hands down the tone winner here. Does it have the headroom of the DRRI, well no, but it will cut about 95% of the gigs I play, save for the few outside gigs, and big rooms over 350 cap. I always slap a 57 to FOH, and the PRRI will keep up with a clean boost, and OD's sound stellar thru this amp. Glorious overdrive tone, and sane levels. Got mine for $805 with footswitch, cover, and no rattle. BTW, I do have a set of Marconi's from my DRRI i may try with the PRRI., but I'm gonna prolly leave it stock, even leave the red pilot lite in it. I'ts a neat little, lightweight tone monster that rivals my Goodsell 17 booteek amp., at half the price.

[Lance]

Hmm, a friend of mine put a 12" Tone Tubby San Rafael 25 in his real '65 BF Princeton, and it sounds simply marvelous. It has all original tubes in it, so yeah the RCA 12AX7's, and the JAN Phillips 6v6's really give it that nice warm tone. I'll try to dig up a clip from the jam session I went to on Sunday, but it'll have to wait until later.

[stratdev]

I tend to agree with Tomo... just play it and take your cues from the amp and your ears. I play a '66 Pro Reverb, a '64 Deluxe Reverb, a '62 Brown Super, and a '57 low power tweed reissue. Each brings something UNIQUELY special to the table. Trying to make a DRRI sound like a PR is folly. Saying a PRRI "smokes a DRRI tonewise" is pure, unadulterated subjectivity. The difference is phase inverter topology sets the PR apart from the rest of the blackface line.

One of the jams we run in the Philly area is very sensitive to volume level (particularly for their dinner guests). Typically I bring the '64 DR, but guys would enevitably crank it only to have me run up and reel 'em in. So I went out and got a PRRI just for jammers to use. Well, the 10" Jensen was just out of it's league with the other amp on stage, a '65 DR. It could hang volume-wise, but it was clear that what it NEEDED in this application was a little more speaker wallop and girth. But first I tried an old Weber P10Q... better, but not there yet. So I grabbed one of Larry Rodgers' faded 12" baffle boards, a spare Texas Heat I had laying around, and went at it. Literally 15 minutes later a little flamethrower emerged. Re-tubed with Marconis, but the amp seemed to respond better with a set of newer Tung-Sols. Whatever works. ;)
http://img.photobucket.com/albums/v687/stratdev/57%20Twin%20Reissue/300_8477.jpg
http://img.photobucket.com/albums/v687/stratdev/57%20Twin%20Reissue/300_8480.jpg
http://img.photobucket.com/albums/v687/stratdev/57%20Twin%20Reissue/300_8482.jpg

For those of you who may actually want to see what's inside the PRRI chassis, here are a few chassis shots. Note the bias pot. The originals are very high resolution and I can zoom in if you want to see more detail in a particular section:
http://img.photobucket.com/albums/v687/stratdev/57%20Twin%20Reissue/web_8297.jpg
http://img.photobucket.com/albums/v687/stratdev/57%20Twin%20Reissue/web_8301.jpg
http://img.photobucket.com/albums/v687/stratdev/57%20Twin%20Reissue/web_8298.jpg

Now, here's the amazing part... I A/B'd the 12" PRRI with my Swart AST (loosely based on a PR). The nod goes to the AST for tremolo (no match for the '62 Super, but great on it's own merits), but on all MY usual tone criteria, I liked the PRRI as well (and at half the price). It's a solid little amp, testament to Fender's experience with PC boards in the vintage reissues.

Your mileage will SURELY vary! ;)

[timmerel]

I don't think I'm the next Randall Smith, I'm just after good tone.

And as my other (heavier) amp already has a 12 in it, I'll give this one a shot with a 10 and see how I like it. If for small gigs (which is why I'm thinking about it) it needs more bass, then I'll give a 12 a shot.

[teleman1]

I just a/b'd the prri with a stock and a little refurbished 68 pr. I think the 68 won by a hair. And truthfully, it was probably the 68's original speaker that gave the advantage. But really, these amps are VERY close in tone. I mean VVVVERY. And the prri is freakin quiet in comparison at idle, volume 0 or 10.

THe prri is the best amp to come out in a long time!

[brad347]

I just a/b'd the prri with a stock and a little refurbished 68 pr. I think the 68 won by a hair. And truthfully, it was probably the 68's original speaker that gave the advantage. But really, these amps are VERY close in tone. I mean VVVVERY. And the prri is freakin quiet in comparison at idle, volume 0 or 10.

THe prri is the best amp to come out in a long time!

How close were they in price? I'd assume they were probably about the same price?

[Fenderosa]

My favorite mod for a Princeton Reverb is to put in an Eminence Copperhead. It gives a great honking tone. I mean honking in a Honky Tonk Woman kind of way. This speaker rocks.

I have tried Weber C10Q, C10N, P10Q, P10RT, California 10, Mojo Tone Eminence 10, and an Eminence Ragin' Cajun. All of these speakers had advantages and disadvantages. I also really like the Ragin' Cajun and the Weber C10Q. I play clean rock and roll with strats and teles. The Ragin Cajin is great clean, and the Weber C10Q is great clean. I felt the C10N added too much bass and the California was too sterile with this amp. The Mojotone and generic eminence sounded good at low volumes (3 or 4), but sounded not so good at higher volumes. They got lossed in the mix when I play with a band. The Alnico speakers also seem to get lost in the mix. I don't care for the sound of alnico speakers in this amp because they lose the punchyness that I feel is necessary to cut through.

The Ragin Cajin is probably the best for playing with a band and not getting lost in the mix.

[timmerel]

Ted Weber suggested one of his Weber 10F150T - do you prefer the copperhead, and do you prefer a 10 over a 12?

[brad347]

I just a/b'd the prri with a stock and a little refurbished 68 pr. I think the 68 won by a hair. And truthfully, it was probably the 68's original speaker that gave the advantage.

Do you think that the solid-pine finger jointed cab of the original might have something to do with that too? I would think it probably would.

[Bikedude]

Stratdev, "the PRRI smokes the DRRI tonewise is pure unadulterated subjectivity", true, but I see your using a modded PRRI! You also state that the PRRI could hang with the DR volumewise. No way a PRRI can hand with a DRRI volumewise, but on the other hand, I still stand by my contention that the PRRI sounds better "tonewise" than a DR. IMO! , and in many other opinions that have heard, or played, or owned both amps. Maybe its the circuit, or maybe the 10, but it does sound better to me than the DRRI. Maybe your 65 DR sounds better than the DRRI, and that's still up for discussion around here, but you sure do rave about how good the PRRI sounds with that 12 in her. Happy Modding.

[stratdev]

I personally don't see swapping in a speaker as "modding" in the traditional sense. Modding in the traditional sense involves alterations to the circuitry. This is just a plain old speaker swap, not a mod. I do have an old RCA GZ34 in there which delivers substantionally more current than the lame stock Sovtek. The Sovtek only delivers about 80% of the juice, and like most currently available GZ34's, is way under GZ34 spec. Unless of course if you want to call replacing a tube a mod! :) Just a tube swap, no more, no less.

If you want to get techinical bout the PRRI, it's modded when you get it. The originals don't have bias control pots (though many old ones have been "modded"). Most originals have a 5U4 (some have GZ34's) rectifiers. If you compare a PRRI and PR head up, you'll find the PRRI a bit louder. Unlike the DRRI which is biased "cold" at the factory, the PRRI (at least mine) was drawing full schematic values.

When playing live, my '65 DR is usually about 5 on IT's dial...this roughly translates into about 10 or so watts (it's only getting to 22 watts wide open). The PRRI is pumping about 10 watts at about 7 on IT's dial (only hitting 15 watts wide open. Either way you're actually only pumping ten watts out of either. Assuming you have the same speaker in each, the PRRI is just as loud under those gigging conditions. When was the last time you ran either on "10?" This big difference is the slightly mismatched phase inverter values (what makes a PR or PRRI so cool actually) and headroom.

I think a lot of people haven't learned to critically listen to their amp's performance before rushing out to perform the latest and greatest internet-fueled "mod." Many hop on the bandwagon without fully realizing what the un-modded circuitry can really do. In other words, there's a lot of gratuituos modding simply for moddings sake.

But I reiterate, tube changing and speaker changing, at least for me, is certainly at the very lowest end of the modding spectrum, if at all. Tomo had the right idea... listen critically and assess before jumping in and modding things.

But hey, it's your amp! :)



Stratdev, "the PRRI smokes the DRRI tonewise is pure unadulterated subjectivity", true, but I see your using a modded PRRI! You also state that the PRRI could hang with the DR volumewise. No way a PRRI can hand with a DRRI volumewise, but on the other hand, I still stand by my contention that the PRRI sounds better "tonewise" than a DR. IMO! , and in many other opinions that have heard, or played, or owned both amps. Maybe its the circuit, or maybe the 10, but it does sound better to me than the DRRI. Maybe your 65 DR sounds better than the DRRI, and that's still up for discussion around here, but you sure do rave about how good the PRRI sounds with that 12 in her. Happy Modding.

[Bikedude]

PRRI--10in. Spkr=Stock, PRRI--12in. spkr.=MODIFIED. IMO. I played with my PRRI on 10 all nite last Sat., and yes I wished I had brought my DRRI, as it has more headroom and is louder than my PRRI-Stock. I may modify my PRRI at some point, by adding aftermarket NOS Marconi's that I pulled out of my DRRI. Even the Marconi's and all the other "mods", I did to my DRRI, never put it in the "subjective tone-range" of my totally Stock, Un-modified PRRI. But hey, who cares, I'm glad you modded your PRRI with a new baffle board, and a 12in. spkr. for more headroom. Lets start a poll on which amp sounds better,(unmodified), a bone stock PRRI, or a bone stock DRRI. I'll cast the first vote for the PRRI.

[teleman1]

Brad,

Good point, it probably does, but not as much as a good worn in speaker.

[stratdev]

Let me try again. ;) When you change tubes and speakers, you do nothing to modify the circuitry of the amp. Would you call it modding to run a PRRI into a 1x12 cab? Of course not.

Frankly, I got the PRRI for others to play in a jam we run with SEVERE volume restrictions. The call was made because I personally like to use the smallest amp that will hit it's zone (verge-of-breakup point) at the desired stage volume. This method has served me well since I got my '64 Deluxe Reverb in 1967. The size of the gig (room acoustics, physical venue features) determines what amp I bring. If I were to be getting a PR type amp FOR ME, I agree with Jim Soloway...I'd get a 'Lil King by Headstrong. Or a used Gomez "G" verb with it's accurate circuitry into a single 15" (sadly now discontinued).

The term "smokes" is far too overused. What's that mean? In what context? With what guitar? Using what pickups? At what volume? Clean or dirty? Too many variables, way too many variables. Examples: If I'm using humbuckers, in a medium room, I'll grab my Vibrolux reverb first. If I'm playing single coils, I'd grab my '66 Pro Reverb or '62 Brown Super. In smaller room, my DR for either. Without clarifying and delineating the variables for a controlled test, you may as well put on a Wizard's hat and try to turn lead into gold. As you may tell, I'm fully addicted to Fender amps. I have mostly vintage, but am not a vintage snob. But I know what I like and what I hear, and make my OPINIONS accordingly without resorting to impossible-to-substantiate profundities as "it's the best," "it smokes it," etc. The PRRI is a nice amp. Sounds great to me. But if you walk out into a crowded bar (as opposed to being on stage) you'll find that a 12" speaker offers much better dispersion than a single 10 and is far less beamy. YMMV (and obviously does). ;)

Why should a PRRI sound like a DRRI? Despite being both blackface copies, they have very different phase inverters. The DRRI's can be a bit harsh up top, but fixable without resorting to circuit mods. Swapping out new 6V6's for NOS 6V6's is not a mod...it's a mere tube swap resulting in your perception of better tone. The tubes that are stock are there for one reason...to meet a price point to get the amp out the door. They are at best middle of the road... they sound "good"; the amp makers, including Fender, know damn well they are subject to personal preference and will most likely be swapped out for those that meet individual preferences. Same with speakers...do you really think that the very average Jensen they use is the best choice for the PRRI? Neither do they. It's a business. But circuit-wise Fender has done a real nice job at capturing the "essence" of a PR.

I'll bail on the silly "what smokes what" poll. Too many uncontrolled variables, too much subjectivity, and lack of an operative definition of what ever the hell "smoking" is anyway. Those kinds of things just turn into unproductive pissing contests.

How did you bias your Marconis in the DRRI? That can have A LOT to do with the tone. I typically start cold at 45-50% dissipation and then work my way up until I get the singing tone I want (typically about 60-65% dissipation...varies with amp model and the actual tubes used). Final tweaks by ear. Or do you consider turning the bias pot another "mod?" ;) I had to ultimately pull the Marconis from the PRRI since I didn't have enough range in the bias pot to get it up to where I like it's performance best. Given that, I found that a set of regular Tung-Sol reissues, biased where I wanted them, actually sounded "better" (PURE OPINION) to me in the PRRI.

Don't mind me. I just marvel at folks who plan out their circuit mods before spending any time with an amp, whatever amp it is. Maybe they don't trust their ears or maybe they have bought into the whole "internet amp mod guru thing" lock, stock, and barrel. I see a lot of guys immediately ready to mod away. But if you ask them "what exactly is it you don't like and desire to improve?", they get all vague, and even worse, defensive. In other words, they mod because someone told them they should, and not in order to fix a particular issue perceived with their very own ears, with their own guitars, using their own pickups, and in the environment of typical use. In other words, wild wanton modding for modding's sake.



PRRI--10in. Spkr=Stock, PRRI--12in. spkr.=MODIFIED. IMO. I played with my PRRI on 10 all nite last Sat., and yes I wished I had brought my DRRI, as it has more headroom and is louder than my PRRI-Stock. I may modify my PRRI at some point, by adding aftermarket NOS Marconi's that I pulled out of my DRRI. Even the Marconi's and all the other "mods", I did to my DRRI, never put it in the "subjective tone-range" of my totally Stock, Un-modified PRRI. But hey, who cares, I'm glad you modded your PRRI with a new baffle board, and a 12in. spkr. for more headroom. Lets start a poll on which amp sounds better,(unmodified), a bone stock PRRI, or a bone stock DRRI. I'll cast the first vote for the PRRI.

[Webfoot]

Curious how well the PRRI handles a good distortion box like the BB preamp which has separate bass and treble knobs. How loud can you go with thick distortion into the PRRI and not have a ratty sound?

I have a modded Blues Jr (which I bought used and mod'ed) and it sounds great... probably rivals or surpasses most boutique amps at fifth of the price. But rather have 6v6s or 6L6s.

[timmerel]

So on speaker, what do folks think about:

10 versus 12?
At 10, Eminence Copperhead versus Weber 10F150T?
At 12, what speakers?

[Bikedude]

My "un-modded", PRRI handles my Crunch Box, BUEQ, and my OCD extremely well. Nothing "frizzy" here like with my "un-modded" DRRI. I've since "modded", my DRRI, with a bright-cap clip,(i guess that qualifies as a mod under Stratdev's rules), and added a CRex, Marconi's(biased at around 22mA). Still the PRRI, (stock), sounds better clean, and with OD's than the (modified) DRRI. The only thing lacking with the PRRI, as should be expected, is the clean headroom, which may be cured with a new baffle board and a 12in. spkr. I may do this since I have a CRex in my DRRI, and I think it will be comming out soon as I may be selling this amp. I have a Goodsell for the extra clean headroom I may need with a small amp, and I have a 73SFTR or a HRD 4X10 if I need more push. I've been trying to warm up to the DRRI since I got it in late 06, but it never seems to deliver like the PRRI has right out of the box. To completely throw a wrench in the gears, I'm playing a 350 seat club with a huge stage tonite, and I'm bringing my LSC 1X12 loaded with JJEL34's, JJ-Pre-amp tubes, and JJ Rectifier, going FOH with an SM57. I think I'll have the "clean headroom" issue solved tonite.

[stratdev]

"I've since "modded", my DRRI, with a bright-cap clip,(i guess that qualifies as a mod under Stratdev's rules)"

Yep, that's a circuit modification. Not my rules, just how it is! ;) And something, consequently to be relayed to prospective buyers. No one gives a crap about tube/speaker swaps (buyers will usually yank whatever we have in there and put their own favorites in)

The only thing lacking with the PRRI, as should be expected, is the clean headroom, which may be cured with a new baffle board and a 12in. spkr.

The Jensen in there stock is rated at 30 watts and isn't really contributung to any break-up. The PRRI will exhibit it's characteristic headroom level with a 12" as well...it's an amp thing, not so much a speaker thing. What it will do is give you and your audience better dispersion, less beaminess, and a "bigger" sound normally associated with 12's. I paid careful attention last night at the jam... the PRRI was starting to breakup nicely at 6 with the 12" Texas Heat...same as it did with the 10 Jensen reissue.

[stratdev]

Sorry, the reissue C10R is rated at 40 watts (not 30 as I said above), making it even less prone to add a little speaker juice to the equation. Someone mentioned the older C10R's in the originals... they were 15 watt rated, and when cranked, an older original (or a PRRI with an older C10R swapped in) will indeed get a "bit" of speaker breakup in the overall sound. Those older C10R's were great in these low powered applications. The reissues are reasonable well voiced for clean, but don't add the extra mojo that the older ones did cranked.

[~el gringo loco]

Gotta confess I haven't heard the PRRI so my opinion is probably about as worthless as a cup o' spit, but I have owned a PR with a 12" speaker mounted on a house-made replacement baffle for 25 years now.

Man, what a great package; if I were the OP I'd not hesitate to change the speaker to a 12 of some kind. I've had maybe a dozen in my amp over the years -- I've had it a long time and I like to tinker -- and all of 'em have sounded good.

Looking at the pictures of the amp along with the video Jim Campalingo demos it in makes me think that they got the essence of the amp right in the RI and that an investment in a 12" baffle and a speaker or two could give you some tonal options you'd have to do a whole lot of tweaking on to get through mods. Put another way, why mod the circuit to make more power or more grind when you could easily change the speaker alone and acheive the same goal?

Cool thing about it is that you can really change the character of the amp through your choice of speaker -- I really like the way my amp sounds with a late '50s P12R, and I really like it with an Oxford 12M6 that was OEM in a '63 Bassman 2x12 cab, reconed by Uncle Ted with a Jensen kit, I think. It's sort of "just right" -- it's strong enough to stand up to the amp but doesn't overwhelm it, and it can be gritty and chimy and clean all at the same time.

But I've liked it with a ToneTubby H1, with a Weber P12S, with a Kendrick Blackframe, a JBL D120F, a couple of different Celestions and with a Mesa that looked like it was built by Emi, and a few others I'm too lazy to mention. And they all sounded good; some were more efficent and clean and the amp got louder, and some were more inefficent and the amp had to work harder and it got gnarlier as a result. The architecture of the amp is sort of a hybrid of black, brown and tweed thinking, and if you put an old Jensen alnico in there it will sound like it belonged at Chess in 1958.

That may or may not be a good thing depending on what you want, but I actually like it just fine both ways. I keep a more efficent speaker in it, though, because every now and then I need to play a bar where I've gotta project a little -- and it sounds really damn good.

Oh yeah, far as tubes go, well, I went the first 20 years of ownership being obsessed with keeping my amp equipped with choice old tubes; I used to love RCA blackplate 6V6's -- the came stock in the amp and they sounded great. And mostly RCA 12AX7's and 7025's along with a RCA GZ-34, although I had one gained out Mullard 12AX7 that could help any Fender amp sound like a Marshall -- it had that EL34 thing happening, and it was very cool.

But the last few years I haven't much cared what I put in the amp, and it still sounds great. It sort of but just barely got wet in Katrina, and I lost my tube stash, too. I don't remember what I put in it now, nothing special, I seem to remember using Tung-Sol ri ax7's that sound great, but the amp sounds so good every time I gig it that I don't sweat it.

So yeah, man, if you want to get a lot more amp for not much more money, just buy a baffle and a speaker or two and sell what you don't like. I know you'll find something good, it's just a matter of taste . . .

Good luck,

~j

[timmerel]

That helps a lot - thank you!

So for out and out clear, articulate clean - which 12" do you like best?

[Bikedude]

Thanks, El Gringo, that's very helpful info. I have a CRex 12, that's begging to go in the PRRI. It's had a home in my DRRI for over a year, but the PRRI just sounds so sweet in comparison. Thanks again.

[timmerel]

So any favourites for 12" speaker for a Princeton?

[teleman1]

I have said this before. Leo Fender designed the size of these cabinets to be voiced for a 10". The cab shaking more and vibrating the tubes life away isn't exactly a good thing either. Use a separate 12" cabintet that is voice for a 12" and be happy and save the aggravation.

[mainstreetexile]

I have said this before. Leo Fender designed the size of these cabinets to be voiced for a 10". The cab shaking more and vibrating the tubes life away isn't exactly a good thing either.

Not disputing that, but there are plenty of people who have converted a PR to 12" and liked the results.

[mainstreetexile]

That helps a lot - thank you!

So for out and out clear, articulate clean - which 12" do you like best?

Not to say there aren't others, but the three I'm going to consider for this (same goal as you) are the Eminence Red White & Blue (used by David Allen in his Sweetspot), a Weber ceramic California (used by Vintage Sound Amplifiers in their Princeton clone) and the Jensen Neodymium 12".

[~el gringo loco]

I have said this before. Leo Fender designed the size of these cabinets to be voiced for a 10". The cab shaking more and vibrating the tubes life away isn't exactly a good thing either. Use a separate 12" cabintet that is voice for a 12" and be happy and save the aggravation.

Man, I don't know if you're describing your own experience, but I made a new baffle for my amp in 1984 and it's been righteous ever since. And I've played it in a whole bunch of settings, many of 'em with the amp nearly dimed for several sets a night.

Here's what my amp sounds like -- the guitar is a 2xP90 strat mongrel, the amp is a '65 Princeton Reverb with a Tone Tubby H1 alnico hempcone in a custom cut mahogany plywood baffle I made for it back when I got the amp.

http://www.funkytele.com/trash/talking%20shit%20blues.mp3

The player is a little toasted as there was a pretty good party going on that night, but you get the idea -- a PR with a 12" speaker doesn't suck, at all . . .

Try a PR with a ceramic speaker with a medium weight magnet and you might be amazed at how great they can sound.

~j

[~el gringo loco]

Not to say there aren't others, but the three I'm going to consider for this (same goal as you) are the Eminence Red White & Blue (used by David Allen in his Sweetspot), a Weber ceramic California (used by Vintage Sound Amplifiers in their Princeton clone) and the Jensen Neodymium 12".

To me, one of the secrets of running a 12" in a PR is that you don't want the magnet to be too heavy, and a Cali has a 60oz magnet, IRC. By comparison a C12N has a 30 oz mag, and it moves a lot easier. One of my absolute favorites was an old Kendrick Blackframe, the kind with the bell cone, and the Alltone 1250, I think, was another great one.

Just think mid-60s vintage Jensens like Fender would have used in a 2x12 Pro, for example, and you'll get there . . .

At least, that's been my experience. And FWIW, once I put a reconed '63 Oxford 12M60 in my amp I've not thought twice about speakers -- it's just right in every way -- it's right in the middle of clean and funky and snappy warm.

Good luck!

~j

[Lance]

I am quite happy with the Tone Tubby San Rafael 25 that is currently in the 65' that I borrowed frm a guitar buddy of mine. Warm, punchy, great cleans, good breakup, which is definitely more of the amp than the speaker, as stated above. This one seems to like 5 - 5 1/2 to keep it clean. You get just a smidge of BF grit characterstics, yet maintain the clean headroom. Haven't tried the reissue, but I did try one of those Princeton recording amps. The one with the silver mid section that has distortion & compression. Tried it with a new American Standard Tele, and I thought it sounded great! Really, I was having a good old time with this pair at my local Guitar Center equipment testing facility. I'm sure I'll pick one of those Teles up in the near future, when there are enough of them around to get one used for a much better price.

[250k]

I put an eminence red fang 12 in mine. Definitely worth it to my ears. Breaks up great and I can use it with a band in small clubs.

[Bikedude]

I think I've decided to keep my PRRI loaded with a 10in. spkr. like the way the amp was designed. I may put a different spkr, maybe one of the new C Gold 10's, or one of the Copperheads, or RJ"s, but I'm keepin it a 10. I have diff. amps, a 1X12, 2X12, 4X10, and a 2X10, so this amp will stay a 10in. It's the flavor of the amp that is so riteous and I think the 10in. spkr. has a lot to do with that "mojo".

[teleman1]

El Gringo! THe worse thing for tubes is to shake aggressively. A 12 inch speaker is going to shake and vibrate more than a 10. Now put a speaker in a underdesigned for a 12 inch cabinet. THe cabinet vibrates more than a 10 inch. Now say you want some better sound and you invest in NOS tubes. Its common knowlege that because of the expensive tubes, its a better situation for them in just a head, instead of a combo amp. I am not saying a 12 inch couldn't possibly sound better in a PR cabinet.

I have been around amps since the late 60's. And if I were playing out and looking for ultimate tone, I'd look into a separate cabinet. And it has been recent that I began to find out the variety and quality of tone one can achieve with a separate cabinet. Different size cabs, open back or closed, and construction quality can bring some extra tonal nirvanna. THe prices on the cabinets are what clued me in; they seem very expensive. But recently I have tried these cabs and have been quite surprized at the quality of tone. IF I were playing out and the PR was the amp, I'd put the chassie in a head and get an appropriate cabinet; this can also save your back and profuse sweating! ANd of course tube vibration.

[~el gringo loco]

El Gringo! THe worse thing for tubes is to shake aggressively. A 12 inch speaker is going to shake and vibrate more than a 10. Now put a speaker in a underdesigned for a 12 inch cabinet. THe cabinet vibrates more than a 10 inch. Now say you want some better sound and you invest in NOS tubes. Its common knowlege that because of the expensive tubes, its a better situation for them in just a head, instead of a combo amp. I am not saying a 12 inch couldn't possibly sound better in a PR cabinet.

I have been around amps since the late 60's. And if I were playing out and looking for ultimate tone, I'd look into a separate cabinet. And it has been recent that I began to find out the variety and quality of tone one can achieve with a separate cabinet. Different size cabs, open back or closed, and construction quality can bring some extra tonal nirvanna. THe prices on the cabinets are what clued me in; they seem very expensive. But recently I have tried these cabs and have been quite surprized at the quality of tone. IF I were playing out and the PR was the amp, I'd put the chassie in a head and get an appropriate cabinet; this can also save your back and profuse sweating! ANd of course tube vibration.


Everythng you write makes sense, Teleman, but it doesn't match my experience.

I've had the amp since early 1984, and I converted it to a 12" speaker not long after. When I bought the amp it was a pawnshop closet classic with the original tubes -- hell, I think the rectifier is still original. I've retubed it several times since then -- I used to play it a lot -- and other than a cracked carbon comp resistor and maintenance items like filter caps it's been trouble free and not particularly hard on tubes for all these years.

I don't want to brag, but the amp even got flooded with 12" of water in Katrina, and other than having to replace the speaker and reverb tank she's still sounding great. I've gigged her maybe a dozen times so far this year, most of 'em with the volume up in the 6-9 range, and she sounds better than most amps around here.

I had a Tone King Imperial for a few years so I understand the benefit of a bigger, tuned cabinet, but I've made choices about what I've kept and what I've sold and that little Princeton Reverb isn't going anywhere -- it's just a wonderful sounding, highly portable amp that, thanks to a reasonably efficient 12" speaker, is capable of keeping up with most any band I play with.

I know you're right and I know that I've abused my little amp more than anyone should, but I'm into it 24 years later and she's still going strong with no ill effects to show for it. In fact, I just ordered an amp cover as she's starting to age quickly, now, but that's cosmetic . . . Katrina was hard on her, that way.

And fwiw, a friend of mine, James Pennebaker, runs an old PR with a 12" Emi Red Fang that sounds great, too -- he could have used anything on Marcia Ball's last CD, but that's what he chose.

The right 12" speaker in a Princeton Reverb is a good thing, man, gotta try it before you knock it . . .

~j

[merkaba22]

One alternative that merits mentioning is the PR II -- it has a (birch?) plywood baffle attached on all four sides and a 12" from the get -- is PTP for modding, has an amazing clean channel with piles of headroom, 20 + watts (I have heard of examples having 26) that will out of the box, meet your requirements and can be had for various prices but somewhere around $600 would be the norm - and then there is the 10 "Super Champ, its famous younger brother. YMWV.

[teleman1]

EL Gringo! You used the Katrina factor. That right there puts you over the top. And them 24 years. It worked for you and it can work in other situations.

Question! Before it gets into all broken up, the top of the headroom, does the cabinet buzz & vibrate???

[TreyD0g]

i bought stratdev's prri with 12" speaker, and it does buzz and vibrate at high volumes. it was shipped with the tubes inside so there may have been a lil damage to the tubes but i don't think so. anyways, it's a great sounding amp but the buzz is noticable. i was told that tube dampeners could help with this problem.

[stratdev]

For the record, I did not sell the PRRI to this buyer. There is an owner in between. It NEVER had any issues. Unless you go through the tubes, methodically testing each in turn (like I outlined in a PM to you), you can't take bad tubes out of the possible cause list.

Also... is the noise a mechanical noise proper (such as cab rattle) *OR* is the noise amplified and actually coming through the speakers? Believe it or not I have come across rectifiers (not in the signal path) with clangy elements and that noise did actually get amplified. And what is "vibrating?" Are the chassis bolts tightened? Are the 4 speaker bolts tight? Is there stuff in the bottom of the amp like cables, etc?

At any rate, the first course of action is methodical tube testing. Then check back


i bought stratdev's prri with 12" speaker, and it does buzz and vibrate at high volumes. it was shipped with the tubes inside so there may have been a lil damage to the tubes but i don't think so. anyways, it's a great sounding amp but the buzz is noticable. i was told that tube dampeners could help with this problem.

[TreyD0g]

well, i don't have any replacement tubes right now, so is there any other way to test them? and i do believe the amp sounded great when in your hands, and it still does. im sure it just needs a little adjusting to rid of the rattling. this is my first tube amp so im gonna let someone with a lot more experience analyze the problem. it sounds to me like it's a cabinet rattle though.

[RedRock]

470 ohm screen grid resistors kill the high end in a PR.
If you want more power, install an upgraded Allen PR power transformer,
go to a Deluxe Reverb output transformer, and install JJ 6V6s, of even
5881s or 6L6s. The Allen Power transformer has more than enough heater current
to support them.
If you do the above, a 12 inch speaker would be nice.

[JDW3]

I am in the process of deciding between a Weber 10f150t and a Emi Copperhead. I have a SF Princeton non-reverb, with Stokes mod and Paul C mod. I did both mods at the same time and to be honest, it's a little gnarly cranked, or grainy maybe is the right term.

It has the original RCA blackplates. I was thinking about undoing one of the mods. Anyone do one or the other? What were your results.

[walterw]

what's the trick where you replace the 12at7 with that tube that has an ax7 triode on one side and an at7 triode on the other? something about giving the amp more gain with the 12ax7 side without overdriving the reverb with the at7 side?