Fender Princeton 65 Reissue spring reverb.

**Teddyfm** · 05-23-2015, 03:05 PM

So first thing first. Got a new Princeton 65 Resissue. Changed the speaker to a Lil´Buddy and put in a 12AU7 in the preamp slot, V1. Like it alot.

Tried the reverb. Nice until I went over 5. Starts humming and increases all the way to 10. Changed reverb tube, 12AY7. Still humming. Pulled out the reverb cables. That produced a more distinct white noisey hum. Moved it to other rooms. Changed power cable. All this without a guitar plugged in.

Ok, its not that loud but its there and it starts to annoy me. Any suggestions to would be very appreicated.
Any other PRRI user experience the same?

Ted

**Stringswinger** · 05-23-2015, 03:28 PM

Ted, I owned one of those reissues and tried a bunch of mods to dial in a good, quiet jazz sound. I changed the speaker to a 50 Watt Weber, the transformer to an American made unit, the tubes to JJS and even had diodes wired in for solid state rectification.

All to no avail, the amp never delivered the warmth of an actual blackface Princeton so I sold it and bought a 1964 non reverb Princeton with a factory JBL. I use a Tone Candy Spring Fever pedal for reverb and it sounds fantastic.

I think the reissues are for rock players who don't mind the harshness of the PCB tube amps. IIRC, the reverb on the reissue maxed out pretty fast. Perhaps at 5 on the pot, the circuit may be overloading?

Good luck getting it figured out!

**Teddyfm** · 05-23-2015, 03:34 PM

Hi String

Been looking for an easy fix. Does´nt seem to be one. Bad soldering perhaps.
I really like the sound I´m getting out of it though.

Is it possible for a spring reverb to be dead silent at all?

**spiral** · 05-23-2015, 03:47 PM

Originally Posted by Teddyfm

Is it possible for a spring reverb to be dead silent at all?

Not really. At least not in a Fender. A spring tank is essentially a big pickup that gets massively amplified. You can try to shield the bottom (and make sure the shell is grounded) and wrap it in foil, but there will be hum when you turn up the reverb. Is it there when the reverb is at 0? Try different locations for the amp too.

**Teddyfm** · 05-23-2015, 03:56 PM

Originally Posted by spiral

Not really. At least not in a Fender. A spring tank is essentially a big pickup that gets massively amplified. You can try to shield the bottom (and make sure the shell is grounded) and wrap it in foil, but there will be hum when you turn up the reverb. Is it there when the reverb is at 0? Try different locations for the amp too.

Thanks for your suggestions. Tried it out in another room. Still humming. At 0 no hum at all. Have not tried the tin foil method, did put a towel in under it though. Also no difference. The thing is its humming with the reverb cables pulled out, albeit at a higher frequence.

**Stringswinger** · 05-23-2015, 04:42 PM

It could be the pot...

**Teddyfm** · 05-23-2015, 04:57 PM

Originally Posted by Stringswinger

It could be the pot...

I guess that could be on of the culprits. Soldering aswell I guess.
Will do a last tube test tomorrow and if that does not yield any good results then I guess I have to send it back and hope they have a good technician at their place.

**spiral** · 05-23-2015, 11:10 PM

Originally Posted by Teddyfm

Thanks for your suggestions. Tried it out in another room. Still humming. At 0 no hum at all. Have not tried the tin foil method, did put a towel in under it though. Also no difference. The thing is its humming with the reverb cables pulled out, albeit at a higher frequence.

Typically a reverb tank is open on the bottom, and if you are getting magnetic fields from under the amp, you could get hum, so putting a metal plate under the reverb that makes ground contact with the tank can help. Wrapping it tinfoil may also help. They also may not help at all. A towel is magnetically transparent so it won't do anything (unless you have lead towels). Spring reverb is noisy: it picks up any magnetic fields around it, and there is one directly above it (the transformer in your amp). It could also be a bad component (like a capacitor or tube).

Are you able to compare your noise to another Princeton? It's always hard to say what is out of character since one man's noisy is another man's quiet.

**Teddyfm** · 05-24-2015, 06:42 AM

Originally Posted by spiral

Are you able to compare your noise to another Princeton? It's always hard to say what is out of character since one man's noisy is another man's quiet.

Yeah, will going to have a listen at a store. See how it sounds compared to another one.

**Franz 1997** · 05-24-2015, 08:21 AM

In all the hard wired Fender amps I have owned ( a lot) turning up the reverb past 1 or 2 substantially increases hum, as Spiral explained very clearly and accurately. Can't speak for re-issues.

With the reverb leads pulled out, it will hum a LOT more; that's normal.

**Keira Witherkay** · 05-24-2015, 08:32 AM

i think we spoilt with dead quiet solid state gear and digital effects....tube amps and vintage pickups are just noisy by nature and do hum/buzz have earthing issues in some rooms

but i see that as part of the charm

so yeah check it out against some other models of the princeton RI before you think it's a problem

**Teddyfm** · 05-24-2015, 08:59 AM

And the minute you go to the forums to research, you only find horror stories. Its like when you check online for some pain you have. It always to be last stages of cancer or you will be needing a liver transplant in the next 24 hours.

So, I will continue to enjoy this amp and take it easy. I also like the idiosyncrasies of a tube amp, having played SS amp for the last year and a half.

Thanks all for chiming in.

Ted

**monkmiles** · 05-24-2015, 09:33 AM

Anything past 3 on the reverb knob on my PRRI is too much reverb. Though I hadn't noticed noise in mine.

Mine has been a great jazz and rock amp for me. I just do a 5751 in the v1 one spot and then got a 12" baffle and an eminence lil texas speaker which is loud and light weight. I used it on a private party jazz gig last weekend at some ritzy house and it was more than enough. I also use it occasionally in an organ trio but we do keep our volume under control, its not a loud funky type of organ trio but more straight ahead. That said I have 40~ watters tube amps for louder gigs. But the PRRI has been my most used for the situations I play in over the years and probably my favorite. Works well for me.

**Longways to Go** · 05-24-2015, 11:56 AM

I love my PRRI. 5751 in V1 & Celestion Gold speaker. Very nice, and a very quiet amp.

When I first got it, the reverb cut out from time to time. Turned out to be a loose wire at the reverb tank.

Have you taken out your tank to inspect it? Easy to do -- no tools required. the tank sits in a bag held in with Velcro straps. I suggest popping it open to inspect the springs & connections -- make sure everything looks OK.

**Teddyfm** · 05-24-2015, 01:25 PM

It sounds better now. Think it was a bad tube. Changed the reverb one with the vibrato one. The vibrato started to sound like a chopper at 5. Same valuue as when it was in the reverb position. Still hums but definatley a lot less. Otherwise its very quiet.

Thanks for the input all.

Ted

**jgmouton** · 05-25-2015, 04:30 AM

Teddyfm, do you mean you just swapped the reverb and trem tubes to cure the problem?

**Teddyfm** · 05-25-2015, 04:51 AM

Originally Posted by jgmouton

Teddyfm, do you mean you just swapped the reverb and trem tubes to cure the problem?

Nope. Did play with the stock ones first. Sounded good. Switch the preamp one to a 12AU7 to get a cleaner sound.
Sounded nice. Thought why not get some more control over the reverb aswell. Put in a Electro Harmonix 12AY7. Noticed that it started to hum after playing sometime. Changed it to a JJ 12AU7. Not humming so much but almost no reverb. Changed back to another Electro 12AY7. Humming louder now. On a whim I changed position on the Electro, in position V1 and V4, and it sounded pretty bad. Both of them. Using the Vibrato, got me a chopper sound at speed 5 without a guitar plugged in. Tried them on a Vox amp in the preamp channel, lots of humming. I think I got a bad batch of Electro Harmonix tubes. Went back to the stock reverb tube, and now it sounds OK.

I think there are two factors involved. Bad tubes and underpowered tubes. And also being a total amateur regarding tube amps.

Moral of this story is.
If it aint broke, dont fix it.

Ted

EDIT: Hopefully I am making some sense.
EDIT: My god, shouldnt be writing and cooking at the same time.

**SamBooka** · 05-25-2015, 08:36 AM

I would respectfully suggest you put the 12AT7 back in the reverb driver tube.. 12AY7 cant handle the current required to drive the reverb tank .. you will burn the tube out.. make take a couple of years but if it is a new issue tube it will cook. If it is an older tube (70s or prior) it will also cook.. but take 3 times as long.. if you put in a 12at7 from the 70s you will probably cook before the tube does

If you are using at 12AU7 I cant answer.. I forget the current ratings on those.. better than the 12AY IIRC but I cant say if it is safe or not.

**Teddyfm** · 05-25-2015, 09:04 AM

Already did it. 12AT7 in reverb channel. This is a learning experience for me. Also, I´m learning to trust my own ears and not random Youtube clips. Thanks for your suggestion Sam.

Ted

**Longways to Go** · 05-25-2015, 09:47 AM

try an old NOS 5751 in V1 -- hard to beat.

12AU7 is too sterile for me.

**Teddyfm** · 05-25-2015, 09:57 AM

i was thinking the same thing actually. Very clean with a 12AU7, almost as you said sterile. What would a 5751 bring?

**Kelly77** · 05-25-2015, 10:13 AM

Well...maybe I am the exception...but...I've had a bone stock PRRi for the last 2 years....and didn't do a thing. Still have the original tubes...and the speaker is very well broken in. It is quiet, sounds great...and no issues. I've gone the Princeton search route...Vintage Sound, Allessandro PTP Princeton, even a Carr Sportsman. This amp was the keeper. Go figure?!?!?!?

**Teddyfm** · 05-25-2015, 10:21 AM

Originally Posted by Kelly77

Well...maybe I am the exception...but...I've had a bone stock PRRi for the last 2 years....and didn't do a thing. Still have the original tubes...and the speaker is very well broken in. It is quiet, sounds great...and no issues. I've gone the Princeton search route...Vintage Sound, Allessandro PTP Princeton, even a Carr Sportsman. This amp was the keeper. Go figure?!?!?!?

Great! More power to you. I mean it. I tried the stock speaker at a friends first. Great sound with a tele. At home it was very brittle. Had to turn the treble down to 1 to get it somewhat pleasant sounding to my ears. That was with a guitar with a Bare Knuckle Mule PU. Pretty dark PU. Not a fan of the "blanket over speaker" tone mind you. Maybe I should have given it some more time to break in.

**Longways to Go** · 05-25-2015, 11:30 AM

I think the stock PRRI sounds absolutely great out the box too. When I got mine, I was deep into tube amp fiddling mode, so I messed around. The stock speaker is very nice -- the celestion gold is deeper, clearer & louder. It is also heavier! Worth the change? probably not, but still fun!

I have a little stash of old tubes, so trying them out was great fun. 5751 has proven to be my favorite V1 in every tube amp I've tried. Less gain than a 12AX7, a little mushy richness on the treble end that helps tame the Fender sparkle. At least that's how I hear it. Great for jazz -- maybe not for rockabilly twang?

I should also add that I think the PRRI has fantastic sounding reverb & tremolo. I didn't even know I liked tremolo until I got the Princeton!