Ampeg Reverberocket GS 12

[M Fowler]

Yeh ok what?

[goldenmonkeycolor]

Yeh ok what?

all you said was add a 1M pot for tone control. after you posted that I went and looked up how i might wire this and what cap to use- etc etc, but I'm pretty unsure in this circuit.

also
can anyone answer this?

I was told to make my reverb less bright and filled with treble content I should reduce the value of the 10uf cathode bypass cap on the reverb driver tube. I know this would decrease the gain a bit- but from what I've understood it will decrease the gain of the low frequencies mostly and leave the high frequencies higher.

I'm about to just try it. But am I completely misunderstanding this? I thought I was pretty aware of how cathode bypass caps and resistors affected sound in gain stages... but maybe I totally fumbled it? Sorry for my newbie questions- sometimes I think I know some stuff then I read conflicting information from what I ***thought*** i know, and it screws me up. So i just wanted to clarify why this would lower treble in this circuit. maybe something about it makes it different- i used the cathode cap calculator found here https://www.ampbooks.com/mobile/amplifi ... capacitor/ but I wasnt sure of Rg.

[M Fowler]

Take a look at this reverb.

2007 Old flame Reverb Section Schematic.jpg

[TUBEDUDE]

A small cap across the reverb transformer output, or across the recovery amp input to ground will attenuate treble, but didn't you say the treble content of the main signal was too bright also? If so, treble should be reduced in an earlier stage.

[goldenmonkeycolor]

Take a look at this reverb.

2007 Old flame Reverb Section Schematic.jpg

Isnt this quite a bit different style of reverb? the ampeg is capacitance driven

to everyone else:

now when I turn the reverb up- certain notes get really distorted- is my tank just going bad? or maybe the rubber I put between it and the cabinet wood are vibrating more somehow?

Now most importantly- before I try adding a reverb tone control I would like to just take off some of the super high frequency treble of this amp. I feel like either just lowering its max frequency response- or shelving a chunk of the upper frequencies would work. Where should I try this? In the tone stack? or maybe just the early cathode bypass stages?
Lower gain in first gain stage?

If you could throw me your first two options I would really appreciate it!

Also I need some new reading on tube amps- anyone got a recommendation for a book that really helped them out in all this. I felt like I was really close to putting it all together on fender blackface amps- but this one is throwing me around and I'm realizing how little I know- Thanks!

[goldenmonkeycolor]

A small cap across the reverb transformer output, or across the recovery amp input to ground will attenuate treble, but didn't you say the treble content of the main signal was too bright also? If so, treble should be reduced in an earlier stage.

Yeh I think id really just like to attenuate the treble early on in the first gain stages- What would be the best way to do that?

[pompeiisneaks]

That's just your typical 'tone' pot type setup, or you can test a few values of capacitor through a resistor to ground in the path. you could temporarily wire in a pot with a few different cap's and try dialing it down just enough to get it where you like and then just measure the resistor and hard wire it into the amp, or add a pot that's the 'tone' pot for that purpose. also you could play with a tool like this if you know the frequency you want to cut out:

https://www.electronicproducts.com/RC_F ... lator.aspx

~Phil

[goldenmonkeycolor]

I've never worked with the style tone stack in the ampeg. Couldn't taking out some treble be as simple as changing the .00025uf cap in the treble part of the tone stack? or maybe its the .002uf cap.

Or should I just do a low pass filter in between the volume pot and the pin 2 of the second gain stage? or would another spot work good for a low pass filter. I guess I could make it adjustable... I'm not even sure what would be an effective low pass... Like somewhere around 2-3khz?