Can somebody explain to me what happens electronically with the FS?
I see the TRS jack, I see the REV connection from the ribbon cable, and I see the -36V connection from the relay. Can somebody guide me from there, what happens exactly as the switch is engaged?
Thank You
http://www.schematicheaven.com/newamps/ ... ssic30.pdf
Peavey C30 Footswitch
Moderators: pompeiisneaks, Colossal
Re: Peavey C30 Footswitch
On the jack tip is reverb, ring is boost and sleeve is ground.
The footswitches simply tie either the reverb or the boost connection of the jack to the sleeve (ground) to complete the connection.
In the case of the boost, the relay has -36V on one side, a dropping resistor on the other, but no connection to ground when switch S1B is in position 1 unless the boost footswitch is pressed which connects this resistor to ground, so the circuit ends up -36V -> relay coil -> dropping resistor -> ground.
The reverb is switched similarly except that it alters the voltage at the junction of resistors R33 and R35, pulling it closer to 0V.
The footswitches simply tie either the reverb or the boost connection of the jack to the sleeve (ground) to complete the connection.
In the case of the boost, the relay has -36V on one side, a dropping resistor on the other, but no connection to ground when switch S1B is in position 1 unless the boost footswitch is pressed which connects this resistor to ground, so the circuit ends up -36V -> relay coil -> dropping resistor -> ground.
The reverb is switched similarly except that it alters the voltage at the junction of resistors R33 and R35, pulling it closer to 0V.
Re: Peavey C30 Footswitch
Thanks Paulster -
I do not have the FS for this amp, and the reverb is "ON". So I imagine when the plug inserts the jack, it breaks the tip connection to ground and that would turn off the reverb. I guess engaging the switch would complete the connection to ground via the tip, and turn the reverb on.
Do I have this right?
Thanks
I do not have the FS for this amp, and the reverb is "ON". So I imagine when the plug inserts the jack, it breaks the tip connection to ground and that would turn off the reverb. I guess engaging the switch would complete the connection to ground via the tip, and turn the reverb on.
Do I have this right?
Thanks
Re: Peavey C30 Footswitch
With nothing plugged into the footswitch jack, both connections (reverb and boost) are tied to ground, so you could very easily stick a stereo plug in to switch off the reverb.
It looks like there's a user-accessible switch (S1) that will allow you to override the footswitch to manually choose channel or boost mode.
A 1/4"-1/8" headphone adaptor would suffice instead of a stereo plug if you don't have one lying around.
In fact, since the reverb is on the tip you could use a mono plug. The boost (ring) would still be tied to ground via the fact that the plug is mono but that switch should still let you choose your channel.
It looks like you could therefore also use a single-button footswitch if you wanted, just for reverb.
It looks like there's a user-accessible switch (S1) that will allow you to override the footswitch to manually choose channel or boost mode.
A 1/4"-1/8" headphone adaptor would suffice instead of a stereo plug if you don't have one lying around.
In fact, since the reverb is on the tip you could use a mono plug. The boost (ring) would still be tied to ground via the fact that the plug is mono but that switch should still let you choose your channel.
It looks like you could therefore also use a single-button footswitch if you wanted, just for reverb.
Re: Peavey C30 Footswitch
I think you tagged all the bases, thank you.paulster wrote:With nothing plugged into the footswitch jack, both connections (reverb and boost) are tied to ground, so you could very easily stick a stereo plug in to switch off the reverb.
It looks like there's a user-accessible switch (S1) that will allow you to override the footswitch to manually choose channel or boost mode.
A 1/4"-1/8" headphone adaptor would suffice instead of a stereo plug if you don't have one lying around.
In fact, since the reverb is on the tip you could use a mono plug. The boost (ring) would still be tied to ground via the fact that the plug is mono but that switch should still let you choose your channel.
It looks like you could therefore also use a single-button footswitch if you wanted, just for reverb.
This amp belongs to a friend of mine, and he was complaining about intermittent reverb. I am not really sure that problem really exists, but I told him I would look into it. I thought maybe the TRS jack might be getting corroded or have weak tension on the shorting contacts, so I just went ahead and replaced the jack. The IC/Op-Amp device was only 35 cents, so that got renewed also. The reverb has worked for me and another friend of ours, so like I said, I am not even sure if the amp has a problem.
Thanks
Re: Peavey C30 Footswitch
If he's using the footswitch and it has a captive cable then the cable is probably starting to fail where it enters the footswitch unit from being pulled tight at 90degrees when coiled round the switch after use.
That would be my guess if you've already replaced the jack.
It could be something internal to the amp but I'd look for the obvious external influences first.
That would be my guess if you've already replaced the jack.
It could be something internal to the amp but I'd look for the obvious external influences first.
Re: Peavey C30 Footswitch
Yes, the first thing I did was look at all the RCA connections, solder joints, etc. Everything looks "good", in fact I think this is the first time the board(s) have been out of the chassis. All the jumper wires are sound, cable connections were tight, solder all looks original, etc. The board is signed 7-31-98. All things considered, this PV has probably given good service for a long time.
This would be a topic fro another discussion, but with all the room that there is in this chassis, it seems like PV could have increased the price of the amp 100-200 dollars and made a much "better" and more serviceable amp. I realize PV has been doing this successfully for a long time. There is probably some magic number (in dollars) where PV figures the sales would start to drop off and the price increases would not keep up with the loss in sales (volume). This amp makes me think of the Fender HRDlx. They are both such popular amps, but you wonder how much better they could be made for (relatively) not a whole lot more money. Anyway.......
Thanks for the basic electronics lesson. I appreciate you dumbing down you knowledge to help me out. BTW, that is a good observation about the way guys tightly wrap a cable around a FS and the life of the cable. The INTERNET has been like a University for me......
Thanks Again.
This would be a topic fro another discussion, but with all the room that there is in this chassis, it seems like PV could have increased the price of the amp 100-200 dollars and made a much "better" and more serviceable amp. I realize PV has been doing this successfully for a long time. There is probably some magic number (in dollars) where PV figures the sales would start to drop off and the price increases would not keep up with the loss in sales (volume). This amp makes me think of the Fender HRDlx. They are both such popular amps, but you wonder how much better they could be made for (relatively) not a whole lot more money. Anyway.......
Thanks for the basic electronics lesson. I appreciate you dumbing down you knowledge to help me out. BTW, that is a good observation about the way guys tightly wrap a cable around a FS and the life of the cable. The INTERNET has been like a University for me......
Thanks Again.