Schematic for AB 763 foot switches?

[zfiles1701]

The schem/layout from hoffman is easy until I look at the footswtiches.  On the final wiring of this build, and the foot switches have me stumped.  Can anybody post some scherms or pictures?  And, have alot of mods I'd like to try.  Could the foot switch jack be put right next to the input jack or would that make too much noise?  Thanks

[sluckey]

and the foot switches have me stumped.

Hoffman's layout doesn't actually show the footswitches. It only shows two RCA phono jacks and the pink wires connect to the center pin. The reverb jack is located next to the reverb return jack and simply has a jumper wire between them. The shell of the jacks are connected to chassis ground. You could easily use a 1/4" stereo phone plug instead of two separate phono plugs.

You must use shielded cable between the amp and the actual footswitch assembly for the reverb. The trem does not have to be shielded but I use shielded just because I have access to lot's of two pair STP cable. Mounting the footswitch jacks next to an input jack would be inviting trouble.

[zfiles1701]

Hard to imagine what that looks like.  Let me rephrase if you don't mind.  When you step on the switches, what do they connect or disconnect?  Reverb?  Trem?   Thanks Again

[sluckey]

Look at this schematic, pages 1 and 2.   http://home.comcast.net/~seluckey/amps/misc/Hoffman_AB763.pdf

Step on the reverb switch to put a ground on the output of the reverb tank, killing the reverb signal. Step on it again to remove the short and enable the reverb signal.

Step on the Trem switch to put a ground on the trem oscillator, killing the trem signal. Step on it again to remove the short and enable the trem signal.

[zfiles1701]

Can't thank you enough.  Did not see that schem when I first got the layout form Hoffman.  Simple and easy enough.
Once I get sound and debug it, I'd like to try a VVR but have heard that it won't work with the reverb or trem in the circuit.  (have heard-don't know)  Would turning the effects off help, or would I have to use a reverb/trem bypass toggle and get them completely out of the signal path when dialing the VVR down?  Thanks a bunch again sluckey

[PRR]

VVR won't affect the reverb. (Why would it?)

VVR won't affect opto-roach tremolo.

VVR _will_ mess up grid-bias tremolo. The grid swing is related to power tube plate and screen voltages. When VVR reduces those voltages, the trem swing must be reduced. You may turn-down Depth every time you touch VVR. You may feed the trem oscillator from the VVR suply; it will sorta-track to a point, but may quit working at low VRR setting.

The VVR suppliers have probably got answers.

[zfiles1701]

Does not affect reverb.  Very cool.  Will affect tremelo.  Well, when using the VVR I won't need or want tremelo.  So, when you switch the tremelo off, will it still have a negative affect when you dial the VVR all the way down?  If it has no impact when switched off I'm good.  But, if the VVR is dialed down, the tremelo is switched off, and the tremelo is still affecting the amp then I need to be able to toggle the tremelo out of the circuit for VVR use.  Would a DPDT toggle get the job done (if needed)?

[sluckey]

VVR won't affect opto-roach tremolo.

If you drop the voltage such that there's never enough to fire the ne-2 (approx 90v I think) then the opto-roach is dead.

But, if the VVR is dialed down, the tremelo is switched off, and the tremelo is still affecting the amp then I need to be able to toggle the tremelo out of the circuit for VVR use.  Would a DPDT toggle get the job done (if needed)?

When the trem is switched off with the footswitch it has zero effect on the amp. You don't need any additional switching.

[zfiles1701]

Really appreciate all the help, and will post results when I get there.....at a tortoise's pace.
Thanks again guys.