Princeton Reverb Kit for an absolute Newbie?

[Structo]

Ooops!

This should do it.

[Richie]

Yes thats better. I used a shielded wire to the tube from that spot. So the shield ground went where you drew the 220k.Added some insulation or heat shrink will work cause it crosses a few things. I put the 220k attached to the shield ground.

The stock wire running to the tube in that section is a bit noisey

I'd be afraid that with the 220K in place you wouldn't have enough signal to overdrive the 6V6s

it works fine,and makes the amp cleaner.I'm sure someone could use a trim pot to tweak out a value that worked to their ear.

I guess we will await someone else or a few trying it in their amp and see what they think. Be even better to have someone try it in an amp that is having the problem most are having on alot of other forums.

You see alot of mods suggested on other forums.

[Deric]

Richie,

Thanks for the tips. Going to try this soon in a recently finished BFPR build.

May be a week or so but I'll try to post back with the results.

Be even better to have someone try it in an amp that is having the problem most are having on alot of other forums.

What problems *exaclty* are you referring to?

Thanks!

[Deric]

Tried this out last night. A couple observations....

-The 220k took the balls out of the amp. Really didn't seem to add any headroom - just less volume overall. You could turn the Volume up higher before it started to break up but it wasn't as loud. Took it out.

-Using a shielded wire here is a good call. My build was very quiet before but the Verb was a bit noisy as you turned it up. I can now crank the Verb with no added noise. Nice.

-Left the 500p cap in for now. Not a huge change but does take some of the fizzies out of the Verb.

**Disclaimer** I've got a SERIOUS head cold going right now. Can't see for shit but doesn't seem to be affecting my ears too much. I'll play with it some more over the next few days/weeks and report back if I hear something different.

[Richie]

Interesting. As i said above in the other post some amps with the same layout may not have problems, where some may have problems.
If you don't like the amp with the 220k leave it out.

Just be sure if you try the change, that the 220k does have the one end to ground on the other side of the 47ohm resistor,and not grounded on the FB side of the 47ohm.

But the other 2 things like the added 500pf cap and the shielded wire may be all you need to remove or cure the noise problem some of these amps have. One could also use a trim pot for the 220k to find the value that they like. Then just use that value resistor,or none if that is what you like.
And yes it should take some of the fizzy or highs from the reverb,or just take a little hair of the top of the reverb sound.

[Deric]

Richie

Thanks for the input. For the 220k - I just preferred it without. Maybe I'm just used to that since I've been playing it for a while. Definitely seemed to take away some "balls". By no means a bad sound - just different.

The shielded wire and cap made a very noticeable improvement. I previously had a very slight increase in noise when you turned up the 'Verb. Now it's dead quiet even when cranked. Gotta like that!

New question.....

Playing with the Reverb pot. Thinking about dropping it to 50k or even 25k..... Should I add a resistor to ground to keep the load the same? Like a 50k pot w/a 47k to ground? Will that effect the tone or should I just go with a smaller pot?

Thanks!

Deric

Edit: After looking at the schematic again.... I guess the resistor would go on the input side of the pot - not to ground??

[Firestorm]

New question.....

Playing with the Reverb pot. Thinking about dropping it to 50k or even 25k..... Should I add a resistor to ground to keep the load the same? Like a 50k pot w/a 47k to ground? Will that effect the tone or should I just go with a smaller pot?

Depends ... what are you trying to accomplish?

[Deric]

Depends ... what are you trying to accomplish?

Good point.

I've been playing with the value of the pot by tacking resistors across it to make the reverb more controllable. With the stock 100k it sounds fine but comes on way too fast. With a 100k across the pot (making the pot effectively 50k) it gets better - but - I "think" that I hear a difference (tone wise) in the reverb as the pot value gets smaller....

Was thinking about trying a 25k pot but then realized I "may" be changing more than just the "range" of the control.

So...my question is...

What effect does changing the total load have on the tone of the reverb (if any) and the "dry" tone of the amp (if any)?

Thanks!

[ChrisM]

Depends ... what are you trying to accomplish?

Good point.

I've been playing with the value of the pot by tacking resistors across it to make the reverb more controllable. With the stock 100k it sounds fine but comes on way too fast. With a 100k across the pot (making the pot effectively 50k) it gets better - but - I "think" that I hear a difference (tone wise) in the reverb as the pot value gets smaller....

Was thinking about trying a 25k pot but then realized I "may" be changing more than just the "range" of the control.

So...my question is...

What effect does changing the total load have on the tone of the reverb (if any) and the "dry" tone of the amp (if any)?

Thanks!

Use 100K(A).
Taper is more important than value here imo.
If still too much verb but a resistor in series with the pot, I'd start with 10K.