Fender Princeton head

[ibanez48]

I got lucky and a buddy of mine gave me a fender Princeton non reverb  head and cab. I don't know if the cab is original but it's old it has one 15 inch speaker. Are these heads worth any thing I really can't find any info on the head just the combo amp. I looked up the serial # off the transformers and it's a 1966 year model. It said the non reverb are more rare the head is in pretty good condition for its age. It's all original eccept some one relocated the on/off switch to the front by the pilot light. Don't know why they did that if I move it to the back were it goes then they will be a hole by the pilot light
 Now. And one of the instruments input someone put a toggle switch in it and if u turn it off it kills the input. And right bye the toggle someone put a little light it's not hooked up I guess it was at one time I guess it came on when u killed the input. Other than that Totally stock no mods. So I was little scared to plug it in after looking at the original power cord. I did take the chassis out before I plugged it in the only thing I found was one of the ceramic capacitors for the tremolo was broke off it just barely had enough to solder it back on. So plugged it in and fired right up everything works even the tremolo and what's crazy on my squire strat this thing has hardly any hum to it. Accept using humbucker gets a little more hum. Does anybody think it's needs a recap there is only five caps. They still look brand new. Oh and this thing still has the original tubes in it.

[Travis]

First off, we want to geek out on some pics!!

Sounds like a really cool find! Congrats. I have never heard of that amp as a head before.

Mojotone sells a blackface Princeton Reverb style faceplate but not the non-reverb model. I was thinking maybe you could use something like that to cover up the mods

My friend is a Princeton freak and what he tells me is that the non-reverb model is much cleaner sounding than the reverb model. The one with reverb is hotter because of the recovery stage for the reverb

The switch really just literally cuts the input? Sounds like a different way of doing "standby" maybe? Seems kinda dumb to me.

About changing the caps, pretty much every amp tech will tell you to at least change the filter caps. They have a lifespan and they play a critical role in the amp. In some cases where you have a super rare vintage amp with perfectly functional original caps, you might want to leave them original. In this case, even though they're currently looking good and you don't have noise issues, it wouldn't be a bad idea to replace the filter caps with some high quality new caps just to avoid potential trouble

I would love to see photos inside and out head and cab if possible

[ibanez48]

I will get you some pics

[ibanez48]

Travis.   Man I can't find any info on a Princeton head. I have searched everywhere can't find anything I can't even find a pic of one. One guy on a forum I was reading he said he has never known fender to make a low wattage Princeton head. All I can say is I have one right here in front of me lol. This must be like a super rare head then I can't believe I can't find even a pic of one. I will get some pics up tomorrow.

[Travis]

Maybe someone made a head and speaker cab for the amp?

[ibanez48]

Here is some pics

[Frank_NH]

Very cool!  Here's another picture from the internet (below) and a link to a reissue sold on Reverb.com:

https://reverb.com/item/535428-fender-princeton-reverb-head

[Travis]

The speaker cab definitely does not look like anything Fender made in that time period. Looking at the head it seems very likely that someone cut down the original cab to convert it to a head

You can buy the chassis straps and replacement knob and a cap can from mojotone if you wanted to fix it up a little

[ibanez48]

You know I was looking at the bottom of the head and it looks like someone maybe did cut it down. That sucks if they did should left it a combo. It plays great I tried out couple of distortion pedals through it plugged in to my 4x12 cab it sounded good except it was what I call a little woofy on the low end even with the bass on the amp and pedal dialed back. The treble sounds good wish it had more gain though. Im more of hard rock and metal guy don't use clean that much. Might look into modding it getting rid of the tremolo. Add another 12ax7 in it and replacing the out put transformer for more volume. If someone did cut it down to a head I guess the value of the amp is gone. I might go ahead and mod it any thoughts.

[Travis]

Yeah I was going to ask if the tolex is cut around the bottom. Seems that there's little doubt that it's a modification unfortunately, but I'd still be thrilled to get that amp so hopefully you're not upset.

Before you tear into the amp with more mods I would recommend doing some basic maintenance and trying out some different speakers to see if that gets you where you want to be. I know this sounds weird if you're used to working on pedals where the filter cap usually has little to no effect on the sound but with amps the filter amps do influence the sound of the amp particularly the "stiffness" of the low end.

Think of it this way. Your amp has to work extra hard to pump out the bass frequencies. When the amp is working harder it sucks more juice from those filter caps. When the amp is trying to work hard but doesn't have enough juice at the moment it wants to crank out the bass, you hear a slowed response of the bass frequencies which makes the amp feel mushy.

The filter caps are in that silver metal can between the transformers. Looking at the schematic, it should be 4x 20uf 450V.

The speaker will be the easiest way to get more volume. If you really wanted to go crazy you could modify this to run a pair of 6L6 but that would be a pretty intense mod. You'd need a bigger PT, OT, and more

If you don't want the tremolo but you want more gain you could repurpose that half of the 12AX7 that's being used for the tremolo.

Take all necessary precautions if you work on this thing, it can kill you.

[ibanez48]

I here u on working on tube amps i have built 3. I don't care for the tremolo its a cool effect but don't never use it. I will into modding the other half of 12ax7 tube fore more gain.

[moda]

I was going to suggest it had been modded to a head as well. I had a Jazz Chorus 60 head that i could never find any info on. I always thought the previous owner must have pulled the chassis out of the combo and made it into a head.

[BetterOffShred]

There's a cool mod for the Bassman circuits that could easily be adapted to the Princeton preamp section, that adds a stage of gain.  It's called the "Hyperon" if memory serves.  It's typically done to the Bass channel on AB165's since the silverface stuff isn't worth as much as the blackface stuff yet.   I agree with Travis.. The filter caps in this bad boy are probably leaky and not operating at peak capacity. I think most of the older electrolytic will only last 10 years or so, but as he said THESE CAPS HAVE LETHAL Voltage on them, so be careful, which you probably are having built 3 tube amps.  I think the Princeton is a pretty cool pedal platform personally as it handles just about anything well, and it isn't ear bleeding wattage.

I'd recap the B+ filter section and replace any electrolytic cathode caps too, and then see how it sounds.  Tubes alone can change the sound greatly, and most of the Princeton amps were Tube rectified.  I prefer Solid State rectification myself in most amps, tightens up the bass and sounds better overall IMO!   But that's an easy mod too.  

-Brett

[ibanez48]

Thanks for the info Brett. I would like to mod it get rid of the tremolo I never use it. I'll look up and see if can find the mod your talking about. I don't really ever play clean mostly high gain stuff.

[BetterOffShred]

Sure.  Well You're never going to get it to sound like a Triple Rectifier, because it isn't, but you can get more gain out of it for sure with another half a 12AX7.  There's a cool Merlin Blencowe high gain Single End amp schematic out there, which has a nice preamp that could be strapped onto a Princeton in theory.  It's a lot of work IMO and you might be better off just letting it be what it is and building a Dark Terror clone or something similar.  Fender amps from this time period do what they do, and in my opinion do it best.  I love the Vibro Champ, the 5G9 Tremolux, The Bassman.. The Deluxe Reverb.. oh my!  All such excellent sounding amps, but not particularly high gain.  

I mainly play through a '68 Bassman AB165 I modded to have the AA864 normal channel, and A Triple Rectifier.  They both handle pedals well, but my SG plugged straight into the Bassman is still one of my favorite sounds ever.     I'm not trying to be weird and sound like I'm lecturing, but the Princeton is not a JCM800 that can be modded to even more gain, if you get my meaning.  It'll basically always be a low wattage, early breakup type amp.  
-Brett

[ibanez48]

Hey Brett do have a link to the Merlin's high gain Single End amp schematic cant find anything on it. Would like to look at it. Could u help me with using the other half of the 7025 tube for more gain and how to layout it out. I have and idea how to do it just looking for some help thanks.