The Fender Silverface Princeton Reverb

In Amps by admin

In 2019 it seems that the 12 watt Princeton Reverb has attained a level of desirability and popularity that may eclipse that of any other Fender amp ever built. As volume levels have come down on stage, at home and on recordings, the Princeton sits squarely in the wheel house of many guitarists today who hold the Princeton Reverb in high regard for its beautiful clean and overdriven tone, lush reverb and solid tremolo. Fifty six years after its introduction, this amp has once again arrived, and the prices of vintage blackface models reflect its broad desirability. In the interest of saving a significant amount of your hard-earned cash, we acquired a much less expensive silverface ’74 model for review, optimized with you in mind. How good can a silverface Princeton Reverb get? You are about to find out, in the true spirit of the Quest. Enjoy…

By 1974 Leo Fender’s former company had changed dramatically under the ownership of CBS. The sprawling manufacturing facility that CBS built in Fullerton was producing clunky boat anchor guitars encased in plastic finishes that were guaranteed to age badly, and Fender amplifiers had undergone significant changes since the pre-1968 blackface era. Depending on what you read about the silverface era today, you might be led to believe that all the silverface amps were deeply flawed, compromised by questionable circuit ‘upgrades’, inferior component choices, shoddy cabinets made with dead particle board, and thin, lifeless tone. The truth isn’t so easy to grasp, depending on the actual year the amp was built, the specific Fender model, and how the amp may have been affected by component drift or modifications. Most of the people that bash silverface Fenders the hardest are the ones that own blackfaces… Don’t listen to them. In the case of the ‘74 Princeton Reverb model AB1270 we acquired, only a very minor change was made to a resistor value in the reverb circuit from blackface specs. Of course the familiar blue molded Sprague capacitors present in the blackface amps were substituted with Paktrons and white Mallory caps, and the wire used was also changed from cloth-covered to plastic coated. Most significant, however, was the change from a 5AR4 rectifier tube to a 5U4, and this is where some confusion exists surrounding the existence of an AA764 Princeton Reverb schematic and the subsequent AA1164 circuit.

While a AA764 schematic can be found on the web, it clearly does not appear to have been produced by Fender, yet most blackface Princeton Reverb tube charts and some from early silverface Princetons show the AA764 circuit that specifies a 5AR4 rectifier. The AA1164 schematic reflects the change to a 5U4 rectifier with a 340 V power transformer, while the ‘unofficial’ AA764 schematic specifies a 5AR4 with a 330V power tranny. Jeff Bakos confirmed the existence of the 330V transformers in blackface Princeton Reverbs as well. Whether Fender ever produced a AA764 schematic isn’t as important as understanding whether your amp was intended to use a 5AR4 or 5U4. You can follow the schematic as indicated on the tube chart, but be sure to check the bias on your output tubes. Prospective Princeton Reverb buyers will pay a premium for a blackface ‘transitional’ amp like the ‘68 model with drip edge grille. While we were trolling eBay a drip edge Princeton Reverb was listed as a late ‘67 model, complete with the desirable “AA764” blackface circuit indicated on the tube chart. Forty five bids were placed and the amp sold for $1,549. As far as schematics go, what you need to know is that the first blackface circuit can be identified as the mysterious AA764 (July, 1964), followed by the AA1164 and AB1270 circuits.

We found our ‘74 Princeton on eBay listed by a seller in New York for $975— a price that reflects the average paid for a silverface Princeton in good condition with an AB1270 circuit. The circuit board components in our amp were completely original with the exception of one replaced resistor. The electrolytic can cap had been replaced with a new cap from CE Distribution, and the power transformer had been replaced with a correct, high quality blackface era tranny labeled Mojotone built by Heyboer. The replaced speaker was an equally fine Eminence Legend 10. The output transformer and choke were original, as well as the heavy duty AC cord.

The ‘74 cabinet is made from pine boards painted black, although 2-3 pieces appear to have been glued together to achieve the width of one board from the blackface era. The baffle is particle board, and the cabinets were no longer built with finger joints, but rabbet joints where the side, top and bottom boards are glued together using locking grooves in each board. In a lightweight and portable amp like the Princeton Reverb we do not consider this construction to be detrimental to sound or durability in the least, and we owned and reviewed a big silverface Super Reverb amp (‘73) years ago that sounded fantastic.

We were floored by how gloriously Fendery good the ‘74 sounded right off the UPS truck. Equipped with JJ 6V6s, an old GE 5U4 and assorted American preamp tubes, the Princeton sounded full, lush and bright with brilliantly deep reverb, and unusually strong and vibacious tremolo. The amp was dead quiet, classic Fender clean up to about ‘5’ on the Volume control, and it gradually slipped into a greasy overdriven tone with the typical squishiness of a 5U4 all the way to ‘10’. We were more than pleased, thrilled, really, but of course, we were hardly done…

We called Jeff Bakos and he gave us a list of blue molded SoZo caps we would use to replace the Paktrons in the tone circuit. We would leave the reverb and tremolo circuits alone, but we wanted to see how the SoZos might change the character of the amp. Meanwhile, we bought a pair of matched vintage NOS RCA 6V6s from a very conscientious and helpful guy named Dave Baldwin in Seattle for $85. A week later we brought the Princeton to Jeff’s shop in Little 5 Points and got to work. Curious, we first checked the values of the components on the board against the specs in the schematic. They were all rated at +/- 10% and they all remained spot on after 40 years. Installing the SoZos took about 20 minutes. Jeff tightened a few tube sockets and jacks, and he also installed a bias pot, biased the RCAs at just under 30 mA and we were done. Before we proceed to speakers, here’s Jim Campilongo’s interesting take on silverface Princeton Reverb amps…

I think the silverface amps are not as bright, and even when I’ve done the blackface mod for $40, for $600 less I’ve gotten essentially the same sound. I love the silverfaces because they are just way cheaper and you’ve still got something that you love. They just seem like there is a little less high-end, and throatier. I’ve put the Jensen C10 speakers in them and they still sound mellower to me. They are both (black and silverface) great amps, and I couldn’t imagine playing through a silverface and being bummed out about it, and if you are… perhaps you should reassess your priorities (laughing). It’s kind of like staring at the moon… you’re standing there taking in the moon with someone and you’re thinking, “Well, I’ve seen better…” At that point you’re not enjoying something for the miracle it is (still laughing).

TQR:  You’ve also said that you always use great NOS tubes in your amps…

Oh yeah… definitely, and I bias them really hot… in the 30s (mA). Enter at your own risk, and some people don’t like it, but they are friggin’ loud, and in a way, that’s the secret. I mean, some people can’t imagine playing in a band with a Princeton, but if you bias that thing in the 30s and play the amp on ‘10’ with a Telecaster, it’s gonna cut like a knife. And if you play Woodstock, just mic it.

The combined effect of the RCAs and SoZos produced a slightly rounder, fuller tone with the mids filled in nicely, yet the Princeton retained the brilliant clarity, sparkle and deep fidelity we had noted the first time we played through it. Fender at its utterly classic best. The low end held together better with the volume cranked, and the overdriven tone of the Princeton was every bit as lush and pure as its clean tones. We liked the sound and feel of the amp with both rectifier tubes— it just depends on what you want— the looser jangle and squish of the 5U4 that saturates a little faster at high volume levels, or the slightly tougher sound and feel of the 5AR4. Now we were ready to try a few different tens…

This is the second silverface Princeton Reverb we have bought and reviewed, along with two blackface reverb models, a brown and a non-reverb blackface, and every one of them sounded different. The ‘74 may be the best yet. No… honestly, it is the best, beyond a doubt. You can ponder why some amps sound better than others, but given all the variables in play, it’s best to simply enjoy them and resist the urge to struggle with ‘why’? Aside from installing the best tubes you can find and perhaps tweaking tone a little bit with some good new caps in the right places (or not), speaker swaps remain the simplest and most effective potential improvement you can make to an amp. When changing speakers it is common to find loose speaker mounting screws in old Fender amps that turn in the baffle board when you try to tighten the nut down on the speaker frame. That had happened with the ‘74 and someone decided to just remove one of the fours screws that was loose. Since we have pulled a lot of screws out of Fender baffles with 8 screws to fit a Celestion speaker that can only accommodate 4, we had plenty of spares, so we replaced the missing screw and permanently seated it in the hole in the baffle with a couple of drops of Super glue. Twenty minutes later we were good to go and ready to begin testing speakers.

Eminence Legend speakers remain among the best and most overlooked replacement speakers, including the ceramic 1058, Alnico 1028, Legend GB128, 1258, and the Legend 15. The Legend 1058 that was mounted in the ‘74 is an excellent speaker rated at 75 watts with a 16 oz. magnet and 1.5 inch voice coil. The tone is big and warm, fuller than the Alnico 1028 and very well balanced across the full frequency range of the guitar. For some it might seem a little too vanilla, perhaps too balanced, culminating in a final impression that is, for lack of a better term, unremarkable in a 1×10 application. But we thought the Legend sounded really good in the Princeton— very transparent and pure, basically delivering what the amp was giving. We have used 1058s with great success in Super Reverb amps with a pair of brighter Alnico 1028s, and it sounded very good in the silverface Princeton— particularly with the brighter, original Paktron caps we replaced. As always, the key is to find the best match between the amp and speaker.

Eminence Ragin’ Cajun

In the Princeton Reverb the 75 watt Ragin’ Cajun produced bold low end and midrange tones with subdued brightness and rolled off treble presence compared to the other speakers we tried. For single coil Fender players this could be a great speaker that effectively fattens up a trebly Strat or Telecaster if that’s what you need, but in the ‘74 we missed the sparkle and clarity on the top. With its 1.5 inch voice coil and 30 oz. magnet, the Ragin’ Cajun might also sound better in a more powerful amp that can really move the motor in comparison to the 12 watt Princeton Reverb.

Eminence Copperhead

The 75 watt Copperhead with 1.5 inch voice coil and 20 oz. magnet immediately impressed us with great clarity, rich, solid bass, and midrange response that was neither overbearing or too scooped. The treble tones were beautifully musical, pure and pleasing— not in the least bit sharp or brittle, but vividly clear, and rich in harmonic overtones. The Cooperhead was absolutely one of our favorites among the speakers reviewed here, and we loved the dynamic touch-sensitivity we experienced with the Princeton. We suspect the lighter 20 oz. magnet might have something to do with that. The Copperhead is definitely worth considering as a 1×10 or in other combo configurations.

Celestion G10 Greenback

Our Made in England 30 watt Greenback was spectacular in the Princeton— responsive, dynamic and lively. With a big 1.75 inch copper voice coil and 14 oz. magnet, the Greenback was the most dynamically pleasing speaker we tried, with outstanding bass response, vivid upper mids, smooth and rich treble tones and lush harmonic textures throughout. This speaker just seemed best suited for the 12 watt Princeton Reverb, an impression that was confirmed in Celestion’s own online description that references “adding class” to small combos. If you should be inspired to follow our lead in acquiring a silverface Princeton Reverb, we can recommend the Greenback without reservation. Again, it seems that the smaller magnet and lower power handling characteristics matched up particularly well with the Princeton.

We have been playing through the ‘74 Princeton now for nearly two weeks, and yes, even after acquiring amps for review for 14 years and decades more simply playing them, this amplifier has inspired music, tones and a refreshing new perceptive mindset that we wouldn’t have experienced without it. The sound it produces is just so deep, 3-dimensional, touch-sensitive and clear that the slightest change in the way you touch the strings with your fingertips can be heard altering the layers of harmonics present in single notes and chords. The notes are vibrant and alive with rich, clear sustain, and the vivid reverb and tremolo effects add mystery, weight and a dramatic edge to everything we play. The Princeton urges you to slow down and milk it for all its worth, and its worth is incalculable. While we may have been inspired again by Jim Campilongo to find this amp, the point is really not about sounding like Jim, but about encouraging discovery. We can’t promise that if you hunt down another ‘74 Princeton Reverb, the one you choose will sound like ours, but with some good tubes and a good speaker, we’ll bet you can get close. Closer than any reissue Princeton, definitely, and the silverface amps have a unique tone that is different from the earlier blackface amps. If there is a trick to successfully finding your own Princeton, it is attitude. Avoid approaching your search in fear expecting the worst— as if the odds are against you, that you’ll buy a dog, or wind up spending a fortune fixing something you should never have bought in the first place. If you shop online, read descriptions very carefully, ask questions, and verify that the seller is knowledgeable, conscientious, and has the feedback to back it up. Many dealers won’t divulge important details unless you ask. For a $900-$1,000 sale they can send you clear jpeg images of the circuit board and transformers, and plan on replacing all the tubes and the speaker. On the other hand, if you really connect with amps with multiple overdrive and distortion circuits, don’t buy a Princeton Reverb. It isn’t you. But if the kind of lush and vivid purity of tone we have described here sounds appealing, you can do this. Simply Quest forth with confidence, and Enjoy… TQ