Fender 65 Princeton Reverb RI rattling sound

[Jared Purdy]

Ha Ha!! That's hillarius!! Right you are mate! It does start from 1.

[MWJB]

A friend of mine has just reported back regarding the "tube rattle" in his PRRI, a GE 5751 in V1 seems to have cured it. Amp sounds a little "softer" but hi pitched rattle is gone at least at moderate drive.

So thanks Jared, I stand corrected, looks like the baffle/cab wasn't totally to blame after all. Maybe worth investigating a moderate drop in preamp voltage (via B+ dropping resistor), or some other way to curb highs, to tame highs/gain for those that still want to be able to use a 12AX7? Should point out that the amp in question is running 425vdc on the plates with a NOS 5Y3 (expect anything up to 470vdc with GZ34), but still rattled with the 12AX7 & 5Y3.

[Jared Purdy]

Someone on this site mentioned the 5751 as an alternative to the 12AY7 (was it you?). On another site, or maybe it was this one, someone was complaining about the lack of difference bewteen it and the 12AX7, and he claims to have tried several different manufacturer's tubes! I don't know, I'm no expert. I'll likely just stay with the 12AY7. I did a little experiment the other day (to see if maybe it wasn't my ears!) so I put three different 12AX7s back in V1. They all sounded horibble compared to the 12AY7. Not only did the speaker fart out at higher volumes (6-7, with the treble and bass at 5), but the 12AX7 is definately a more shrill/raspy sounding tube.

[Liamjrtc]

Someone on this site mentioned the 5751 as an alternative to the 12AY7 (was it you?). On another site, or maybe it was this one, someone was complaining about the lack of difference bewteen it and the 12AX7, and he claims to have tried several different manufacturer's tubes! I don't know, I'm no expert. I'll likely just stay with the 12AY7. I did a little experiment the other day (to see if maybe it wasn't my ears!) so I put three different 12AX7s back in V1. They all sounded horibble compared to the 12AY7. Not only did the speaker fart out at higher volumes (6-7, with the treble and bass at 5), but the 12AX7 is definately a more shrill/raspy sounding tube.

This amp is driving me nuts. Mine doesn't sound farty. More like an irritating rattle on the E and A strings past a certain volume. At my wits end. Did you put one 12AY7 in there? If you would kindly let me know what glass you put in I will give it a try. Anything to make it stop. I even made a 3/4 baffle out of ply (which does make a pleasant tonal different) but still the bloody irritating rattle. I can't use this thing to record in its current configuration.

Ps I can also attest to the celestion gold.

[Jared Purdy]

resurrected from the dead!!!

This amp is driving me nuts. Mine doesn't sound farty. More like an irritating rattle on the E and A strings past a certain volume. At my wits end. Did you put one 12AY7 in there? If you would kindly let me know what glass you put in I will give it a try. Anything to make it stop. I even made a 3/4 baffle out of ply (which does make a pleasant tonal different) but still the bloody irritating rattle. I can't use this thing to record in its current configuration.

Ps I can also attest to the celestion gold.

I fixed mine. I sold it!! Seriously nothing worked, and I'm not sure the money that I spent on the Gold was worth it. Nice looking and sounding speaker though. The AY7 just drops the volume, that's all it does, nothing more. I'm not sure what brand I used, possibly as Tung Sol. I've long moved on from the PRRI. After that amp, I messed around with a Mesa Boogie Lone Star Special for a year or so. Great amp. Love the sound of it, and versatile to boot. For the last three years I've been playing a Swart AST Master MkII 112 combo with a 12" Gold in it. Sublime amp. Best of luck.

[Liamjrtc]

That right there is pretty depressing I have to say. Fender have a lot to answer for.

[Jared Purdy]

That right there is pretty depressing I have to say. Fender have a lot to answer for.

And to be fair, the problem goes back years, not just in the PRRI series. It's the design of the amp, the circuit layout and or the combination of resistors, capacitors, transformers, etc. I'm not sure if it can be isolated to one single item. I use to have a stock 74' Silverface. It had the same problem. I gave up on it too. Go for a Headstrong, or one by Rick Hayes over at Vintage Sound amps. I've played the Headstrong, and it was clean all the way to the top. I've only ready excellent things about Hayes' amps.

[Liamjrtc]

And to be fair, the problem goes back years, not just in the PRRI series. It's the design of the amp, the circuit layout and or the combination of resistors, capacitors, transformers, etc. I'm not sure if it can be isolated to one single item. I use to have a stock 74' Silverface. It had the same problem. I gave up on it too. Go for a Headstrong, or one by Rick Hayes over at Vintage Sound amps. I've played the Headstrong, and it was clean all the way to the top. I've only ready excellent things about Hayes' amps.

Well I might give a tech free reign to try and fix it. It can't be sold as it is.

[Jazz P Bass]

If the volume control is set at 4/5, then the amp is maxed out, as far as 'clean' goes.
The lower register notes are distorting.
That is what you are hearing.
Turn the volume to 3/4 & if the noise goes away then that is what is happening.

Fender amps usually clip the bass notes long before the mids & trebles.
That is why a 'quick fix' is to change out V1's cathode bypass capacitor to a lower value.
The lower value cap limits some of the lower frequencies, which allows the other frequencies to reach clipping at the same time.

My 2 pence.