reduce bass in princeton reverb

[Reimer]

Hey

What is the best way to reduce the bass in a Fender Princeton Reverb.

[hasserl]

Turn down the control.

OK, OK, I'm sorry, just having some fun.

I'd swap the first stage cathode bypass cap to 4.7uf, then if you want further reduction swap the PI to power tube coupling caps down to .047 to .022uf.

[Mandopicker]

Sorry to raise an additional question, but...

How much does the cabinet/speaker size combination weigh in relative to bass response? I am of the opinion that has a noticeable effect.

Thanks in advance for comments.

Good luck Reimer...let us know how the experiment goes.

[chipaudette]

If you're using humbuckers in your guitar, I'd actually drop the cathode bypass cap even more. The Mesa Boogie Mark IIc through Mark IV use a cathode bypass cap of only 0.47 uF. I think that I've got 0.68 uF (of something like that) in my amp. It works pretty well for me. It might be too much bass cut for some people, though.

Actually, on my amp, I've got the cathode bypass cap on a switch so that I toggle between the standard Fender value (22 uF) and my 0.68uF value. Look at the Mesa Mk IV schematic to see how I use a 22K resistor to keep the switch from making a "popping" sound when I go back and forth between the two.

On single coils, I always go for the full Fender value (22uF). I only use the lower value on my humbuckers.

Chip

[Reimer]

Thanx for the postīs

Is it the two .1 capasitors going to the output tubes from the PI that can be changes to reduce bass?

The trick with the switch changing the cathode bypass cap, have I though of before, I make that one, it look as this is a good one. ;o)

[Steve A.]

Another approach would be to replace the 0.02uF cap going to the cathodyne phase inverter with something smaller (like .001uF or .005uF). Is this a reissue amp with pcb's or does it have an eyelet board? It is very easy to experiment with different values on an eyelet- much harder on the reissues.

Are you running overdrive pedals into this amp for a dirty sound or just plugging in? I ask because IMO reducing the Ck cap on the initial stage down to 0.68uF or 0.47uF will cause it to lose much of the classic blackface PR tone. I think that 25uF is overkill but you might find a happy medium between 2.2uF and 5uF.

For higher gain amps 0.68uF works great. If you can add switches to your amp toggling between 2 or 3 values for this cap can be really slick: you can have the fuller Blackface tone with a 2.2uF to 5uF cap and a more Marshall-like tone with a 0.47uF to 0.68uF cap. Or use no Ck cap at all for a cleaner sound with more headroom (I believe that the Blues Junior does this with their Fat switch in the "weight watcher" mode).

Steve Ahola