I finally got a SF Princeton!!!!!!!!!!!

[giogolf]

Well I sold some equipment I did not want any more and picked up a 70's SF Princeton. Man you guys are right, clean, clean, clean..... I went over to my local guitar center that has a pretty good collection of SF Fenders, and tried a bunch out. I really liked the DS Deluxe Reverb but they would not budge on the price. I also tried the Blues Junior, and at first I thought it was ok, but after playing the Deluxe and the Princeton, the BJ sounded very bland.

So, I picked up the Princeton for $700. I know its a bit more then some of you guys bought them for. But, online the best I have seen in good shape was in the mid $600, add shipping and I am close to where I bought mine for.

While I was there I also picked up a Bad Monkey, and am loving this combo. I have done some snooping around and have noticed some people doing some mods on their Princetons.
Hear is what seems to be some common mods: Replace the OT with a Deluxe Reverb OT, Increase the Phase inverter, and put in a more efficient speaker.

Have any of you done any of the above mods? If so did it increase your head room, make the amp louder? I am thinking of trying a Jensen C12, but do not know if I wanna try the Q or the R, any suggestions?

I just cant believe this thing stays clean up to 9!

[PhatTele]

I'm not a big fan of the phase inverter mod. The one I used (from Gerald Weber) really increases the gain. If you like that type of high gain drive it gives you, then it's fine. You will end up with a higher gain loud amp (they can be giant killers in this configuration). However, you end up loosing the tremolo and the sweet tone which are the big selling points for me regarding the non-reverb Princetons.

Swapping the stock OT is an easy mod but probably not necessary (unless you're doing the phase inverter mod in which case it's probably a good thing since it will tighten up the bass response). Getting a better speaker is always a plus and will increase the headroom...which the amp already has in spades...but the tone will be better.

Stay away from the Paul C and Stokes mods in these amps. They'll make the amp sound sterile.

If you want to warm the amp up and add some bluesy tones, I would recommend putting in a 25K midrange control in place of the ground switch (which you don't need). Just know that it will never sound as blusey as a Princeton Reverb....and no, that's not an easy mod (two additional tubes, reverb transformer, jacks, tank, rebuild the circuit board...don't do it).

So, unless you're a mod fanatic (which, I admit, I can be sometimes) a new speaker and a midrange control are all that I'd recommend for your amp.

[telel6s]

Congrats! I've had my '71 for about three years now and just love it. Have you tried hitting the front end with some wide-open P-90s yet? MMMmmmm...yum.

I would stay away from any mods on the Princeton to get more gain....sort of defeats the purpose of buying that amp in the first place. I think mine takes to pedals quite well so I would just get my dirt from a tap of the toe instead of changing the amp in a way that might get rid of some of it's nice clean tones.

As for a speaker, I've used:

• The original - blah and worn out
• A Carvin Vintage 10 - sort of a Celestion style. Better than the original in that it was louder and clearer but nothing great.
• A Weber alnico Blue Pup (30w). Don't think I'll ever be removing that speaker. It works especially well with the 2 & 4 positions on my Nashville-style Tele. In fact, I bought a strat-type guitar (PRS SE EG) just because of that. Ended up selling the guitar but that's how much I liked the tone of the Princeton + Blue Pup.
• I've thought about making a 12" baffle and trying either a Red Fang or Jensen Neo to get more volume for gigging without a mic but that's way down on my list of musical wants and dreams.

Have fun with your new toy.

[giogolf]

I did not realize moding the phase inverter would add more gain. Thats not what I am going for. I like the sparkle clean I get at such high volumes. The only thing I would like to achieve is to get this baby a little more louder so I would not have to mic it everywhere I go. I believe the amp is supposed to put out 12 -15 watts, and the Deluxe Reverb puts out 22 watts. I would like to get the volume some where in between there.

Does changing the OT with Deluxe reverb OT add head room? Some people say the 6V6's arent being pushed hard enough in the Princeton's, and for that reason they have untapped headroom.

[Kelsey]

I have a Weber 10F150T in my SF Princeton, but I think a Jensen Neo would kick it up a notch. I put a Neo 10 in my tweed Gibson GA-18T Explorer, and it is now much louder and clearer. The Neo 10 actually sounds quite similar to the Neo 12, so if you're thinking Neo you might not need to go through the hassle of a new baffle for a 12. I think some of the new Emi 10s would be a good choice for a boost in volume and good tone, too, given their efficiency ratings.

My favorite pedal to boost the Princeton is either the Bad Bob boost or the tube-based Damage Control Womanizer. The Womanizer adds a 12AX7 front end preamp that might make up the difference between a nonverb Princeton and a PR.

[Scott S]

My vote would be to mod the ground switch (after converting to a 3-prong cord of course) into a negative feedback on/off switch. Sonically, you'd either get "normal" or a louder, slightly rawer sound.

- Scott

[PhatTele]

It won't really get any louder with a Deluxe OT, but you will get tighter bass response...more snap in the bottom end. The circuit itself (especially in the power filtering section and phase inverter) is what's holding back (for the lack of a better term) the maximum potential of the 6V6s. You'll actually notice more of a difference by getting a better speaker or moving to a 12" speaker.

Meanwhile, the phase inverter mod is one of the main mods that would unlease the potential of the 6V6s and get you into the louder, 22 watt realm. The difference is pretty remarkable. The extra gain/drive the modded phase inverter adds can be tamed somewhat with some tinkering, but, like I said, it seems to wipe out the sweetness of the amp and you loose that cool tremolo.

Princetons are what they are. My favorite versions are ones that I've modded with larger power and output transformers (from Allen Amplification) so that they support 6L6s and a 12" speaker....now there's a gig-able version of that amp.

ps - I usually add a small trim pot as bias control (ala Hoffman Amps)....a very useful mod.

[Scott S]

IMO, mods are fun, but if what you really want is a blackface Deluxe, why not build one from scratch? After swapping transformers, adding a bigger speaker, changing to a long-tailed pair, etc, you've basically done a "total-body transplant."

- Scott

[giogolf]

There is 3 prong plug installed already. I guess before I decide to do anything, I will start trying 12" speakers for it.. Maybe even make an extension cab. Its gonna get mic'ed any place I play anyway so I am not going to do any phase modding at the expense of the original tone and tremolo.

What kind of tubes are you guys using in the Princeton, and have any of you installed a stand by switch (maybe in place of the ground switch)? Is stand by necessary?

[Scott S]

Not necessary if it's using a 5AR4, but not a bad idea if you've got one with a 5U4.

[giogolf]

i will check when I get home. BTY: are do they use the same size socket? Also i thought SF Princeton's only came with GZ34 or 5U4GB according to ampwares.com?

[Big Mike Simpson]

Put in a 12" speaker and play it for a while before you mod anything... a stock PR with a 12" speaker is a near perfect amp for a Tele...

[Paul G.]

I wouldn't mod the amp except for a speaker change.

This amp is a masterpiece of clean power. It is fond of pedals, so if you want "blues-y" (whatever that means), a quality OD pedal will give you that, while maintaining the pristine cleans and delicious tremelo of this amp.

I've done many of the suggested mods at one time or another to many Fender amps, eventually I pull them out as they don't really make the amp any better.

Plenty of nice speakers to take advantage of this amp's nice rich tone. The originals (almost all Oxfords, with extra flub) are not good.

Your 70s model will have a non-removable baffle board, so installing a 12" speaker is a hack. Plenty of efficient, full-sounding 10" speakers these days.

My favorite for Princeton/Princeton Reverbs is the Weber California 10" with a paper dust cap. Modelled after the JBL, it has a clear tight bass, is efficient and smooth.

P.

[J.Rodney]

I recently purchased a '79 sf princeton reverb,it sounds great,it came with a jensen c10r speaker, but I am going to try a Ragin Cajun speaker, that is the only mod I am planning to do.I hoping that it will sound even better.

[giogolf]

What does the black face mod do exactly? How does it change the sound? Is their a tutorial on how I can do it myself?

[Paul G.]

On a Princeton or Princeton Reverb, absolutely nothing.

Blackfacing on large Fender amps consist of 2 or 3 steps.

1. You change the bias scheme from "hum balance" to true bias.

2. You remove the 2,000 pF caps from the power tube Grids (pin 5) and remove the 150 ohm resistors and 5/25 cap from the power tube Cathodes (pin 8) and connect the Cathodes directly to ground.

3. You may need to change the feedback resistor.

On your Princeton or Princeton Reverb the bias is true bias already, you don't have the "Swampers" on your power tubes, and the feedback resistor value never changed. Nothing to be done.

The difference between early and late Princetons is basically construction and materials of the cabinet.

I like to put a bias pot in the place of the hard-wired resistor for the bias circuit so I can adjust the bias easily, but it doesn't affect the sound in any way.

If you want a Blackface Princeton, just squint.

P.