How to power the reverb

[dogears]

After reading about Keiths amp problems, as well as looking at several of the layouts, I was wondering what you all felt about powering the reverb.

My thought would be to decouple the powering from the amp as much as possible. Would I not want to have seperate filter caps for both the reverb tranny and recovery amp plate? Isolated from the B+2 by resistors?

I was thinking of 24k to 56k for the tranny and maybe 100k for the plate of the recovery amp. 33uf caps for both.

Any ideas?

I think powering the reverb recovery from B+5 is not good. Especially without isolation and a dedicated cap.

[Normster]

Scott,

After our chat, I did a little research looking at Fender Deluxe Reverb, Reverend Kingsnake, and Mesa Mk III. Looks like they all tap into B+5 (or B+4 in the Mesa) without any additional filtering. The Deluxe is running 3 preamp tubes from one 16uF filter tap!

On the transformer side, Mesa uses a 33k resistor, Reverend uses 56k, and Fender goes directly to B+2. My Bassman runs directly to B+2 but I think it's probably a good idea to throw a 24k-56k in there just for the hell of it.

[dogears]

Powering the recovery plate from the B+5 with no isolation is not good IMO.... Maybe ok for some generic Fender, not for these pups....

Scott,

After our chat, I did a little research looking at Fender Deluxe Reverb, Reverend Kingsnake, and Mesa Mk III. Looks like they all tap into B+5 (or B+4 in the Mesa) without any additional filtering. The Deluxe is running 3 preamp tubes from one 16uF filter tap!

On the transformer side, Mesa uses a 33k resistor, Reverend uses 56k, and Fender goes directly to B+2. My Bassman runs directly to B+2 but I think it's probably a good idea to throw a 24k-56k in there just for the hell of it.

[keithrick]

FYI: Here is what Gary said in a previous thread titled "Reverb Transformer Voltages," regarding isolating the reverb transformer:

As far as the reverb tranny, the 450 is fine. Look at the Fender Super reverb and Twin schematics. The tranny was feed from the Screen grid. I would suggest adding a 27K to 47K resistor in series to the transformer to help isolate it a bit from the screen grids. You could also add a 10 to 20uf cap after the resistor for the final touch.

Gary

[dogears]

Until Gary responds here, I'll add, based on my conversation with him this afternoon, that you also definately want to pull the reverb recovery B+ from the B+2 using a dropping resistor and seperate cap. Not isolating it from V1 is really bad.

FYI: Here is what Gary said in a previous thread titled "Reverb Transformer Voltages," regarding isolating the reverb transformer:

As far as the reverb tranny, the 450 is fine. Look at the Fender Super reverb and Twin schematics. The tranny was feed from the Screen grid. I would suggest adding a 27K to 47K resistor in series to the transformer to help isolate it a bit from the screen grids. You could also add a 10 to 20uf cap after the resistor for the final touch.

Gary

[BobW]

Until Gary responds here, I'll add, based on my conversation with him this afternoon, that you also definately want to pull the reverb recovery B+ from the B+2 using a dropping resistor and seperate cap. Not isolating it from V1 is really bad.

That is a good idea for the reason you stated Scott, also it current limits the B+2 if the reverb xfmr ever goes bad.

[Normster]

Powering the recovery plate from the B+5 with no isolation is not good IMO.... Maybe ok for some generic Fender, not for these pups....

No argument here. That's why I designed my latest power supply with an additional cap and dropping resistor. Of course now I'll have to modify the dropping string to take the reverb transformer off of "B3" as well.