anything that can be done to sweeten up the reverb?

[pine]

Are there any parts that can be changed in a standard reverb pan (one that doesn't have the dwell controls, etc.) that will allow me to change how it sounds, and its attack, and its brightness? What does the dwell control and the other controls actually do, and can that be adjusted in a standard one knob reverb via parts substitutions?

[Bruce / Mission Amps]

Are there any parts that can be changed in a standard reverb pan (one that doesn't have the dwell controls, etc.) that will allow me to change how it sounds, and its attack, and its brightness? What does the dwell control and the other controls actually do, and can that be adjusted in a standard one knob reverb via parts substitutions?

Yes and no.
Just not enough info in your question there... what kind of reverb, what amp.... tube reverb, solid state reverb, stand alone reverb?
Standard, as in black face or silver face Fender combo amp reverb?
A clone of a Mesa Boogie Reverb, which is different too.

etc.

[pine]

It's a Vibroverb Blackface (not a reissue) but the reverb doesn't sound very good, OEM reverb

[pdf64]

Is your amp well maintained with good tubes and filter caps, bias adjusted?
Have you spare spare known good 12AT7 and 12AX7 tubes?
The V3 reverb driver application is very demanding on a 12AT7, need a very tough one in there, best is a mullard CV4024.
Checked connectors and cabling to pan?
Substitute in the known good tubes - any improvement?
The amount of reverb drive can be reduced by removing the V3 (reverb driver) cathode bypass cap - like turning a dwell control down a bit. But double check all the basics are correct before tinkering. Peter.

[cbarrow7625]

Can you describe what it is about the reverb that you don't like? Making it "sweeter" is a bit vague.

Is it too bright? Too dark? Not enough mid-range or "body" in it? Too loud in relative level? Too soft? Not enough "depth"? Too much "depth"......you get the idea.

With some more detail I bet you'll have a bunch of guys weigh in with their $.02

[Gtr_tech]

The V3 reverb driver application is very demanding on a 12AT7, need a very tough one in there, best is a mullard CV4024.

Ya got that right.....they should've used a more robust tube like a 6CG7.

[pine]

It is too bright and a little metallic sounding, a friend of mine called it "too fast", not enough depth or body. I barely turn it on and it's almost too much

[cbarrow7625]

On the later Fender Reverb amps they started putting a .002uF cap from the return input to ground. The schematic for yours doesn't show that cap. That would be a good place to start (and easy to do).

That will bleed off a little bit of the high frequencies in the reverb.

I would check that the reverb driver tube is good as well, like PDF suggested. That may help with some of the depth & body issues.

If it is still "too much" even with the .002uF cap fitted, try removing the driver tube bypass cap to reduce the drive level some, as PDF suggested.

[pine]

Before this goes any further, my thanks to all of you for your time and expertise, I really appreciate it

[Chuck H]

Pine,

You can "soften" the reverb a bit by reducing drive to the 12at7 input. This is what the "dwell" control on a stand alone reverb does. It makes it so you can get "boing-g-g-g" instead of "BWANG-G-G-G" if that makes sense. Since you say you have too much reverb on tap anyhow, here's something you can try:

Find the 1M resistor that has one end attached to ground and the other attached to the grid of the 12at7 and the 500pf decoupling cap. Replace that resistor with a 1M pot. One outer lug of the pot goes to ground and the other outer lug to the 500pf decoupling cap. Then connect the grid of the 12at7 to the wiper of the pot. You can use the pot to adjust the drive to the tube. I would turn the reverb up full and then adjust the new pot so you get a bit more reverb than you think you'll ever need. Then, without turning the pot, remove it and measure resistance from each end to the wiper. Then use fixed resistors of those values in series where the pot was and connect the 12at7 grid to the junction of the two resistors. The junction of these resistors would be the same as the wiper on the pot. Be sure to install the new resistors so the resistances are in the same order as when the pot was in place.

If you like where this is going, but you want a fuller reverb sound, you can experiment with bigger capacitor than the 500pf in the circuit now. 1000pf or 2200pf should be more than enough. If the reverb distorts with the bigger cap you must reduce the size of the cap or the drive to 12at7. A "bleeder" cap, mentioned in a previous post, on the grid of the return stage may also be a good idea. You can try values from 220pf to .01uf.

HTH

Chuck

[pine]

Thank you Chuck H; that's what I think I'm looking for; Since I already get much more than I need, I'm guessing I'll be turning the reverb down some with the pot. I'll give that a try, and thanks again for your time and trouble everyone.

[pdf64]

To expand on my earlier post, try the known good 12AT7 (preferably CV4024) in V3, known good 12AX7 in V4 (preferably a warm tone type like old GE or RCA).
The reverb level is made much more controllable, with better resolution for low reverb levels, by replacing the reverb level 100k linear pot with a 100k audio pot. Peter.

[Chuck H]

The reverb level is made much more controllable

I agree.

with better resolution for low reverb levels, by replacing the reverb level 100k linear pot with a 100k audio pot. Peter.

How is this possible. Linear or audio taper, you still have the exact same resistance, via a carbon track, on either side of the wiper. The circuit is identical. Just the knob settings will change. So how does this provide better resolution at low reverb levels? I'm just trying to keep it real. I wouldn't want pine to change the reverb pot taper in the hope of making it sound any better. That simply won't happen.

Chuck

[ncboy654]

I just found a little trick to take out some of the "springiness" high frequency slinky type of sound by adding a 4700 ohm resistor across the output of the tank.

[Chevy]

Yet another possibility...

You can try increasing the value of the .003uF coupling cap at the reverb output stage. I've tried this, and it can darken the sound quite a bit.

So many options.....