Two Rock 10th anniversary schematic

[Arbutt]

Good afternoon
A bit of a long shot but has anyone a schematic for this model or indeed any two rock
customer stated that there is a loud pop on channel change.
I decided to order a couple of relays ( like for like). I asked tworock for a map and informed them of the fault
he gave me some pointers about lifting some of the wires from underneath the board to above, without pushing the wire through the eyelet . and changing a couple of ground points. they did say its can be common with a few of them to have this fault, But i believe that this is not what he referring too
did all what he asked and a few more, still no change. due to the amps age i decided to try some new filter caps
and tworock agreed. also fitted new LT rail cap
I emailed tworock again asking for a part copy or schematic and he has suddenly gone deaf and ignored my message
Too confirm i have swapped out the pre amp tubes still doing it. if you remove all but the pi its still there

This is a loud pop via switch or foot sw.I know you can get some popping noise but this is not that

Thoughts on fitting a Solid state relay
many thanks
Arbutt

[alexradium]

loud pops to me means there is some dc leakage,and that is mostly due to capacitors gone bad,check if you have some volts on the relay pins in various conditions

[Arbutt]

Thanks i have checked and double checked. Can't see any dc voltage on the pins
removed connections. all contacts are clear of any dc

I have tried just about everything, I am now at the point its standard for this model
I have drawn out the relay and its circuit.

The circuit below pins 1-2 connected (relay at rest ) Pins 1-3 connected when relay is s/w on ( switched on for lead channel)

could i down the route of solid state relay or any other idea
idea's on a post card please

Mr A

[pdf64]

Is the diode across the coil good? Suppressing inductive switching spikes is its job. May be worth trying a ‘points condensor’ cap across the switch too.

[Arbutt]

Diode tests OK . I forget if I changed it or not. But I will again. Never thought of a cap.
Thanks
Arbutt

[nickb]

Can we presume that it once was OK and this fault developed or not?

[Arbutt]

Hi nick. Yes it was OK. Then not used for abit. When powered up again
I've done all caps. In op I said how I moved all the wires as two rock stated and changed a few gnd points as instructed. No improvement.

[nickb]

A picture of the guts might help. Try the cap as suggested above. If you have meter look at the DCV on the pin 1's of the relay and see if there is any difference when you change channels,I see alex suggest this in post #2, but it needs to be done.

Does the noise stop if you set the lead and clean volume to zero?

[Arbutt]

Thanks nick. It's pretty much the same volume with the volume and gains on zero. What value / type of cap. I have metered the pins and can see no dc voltage on them. The relay is new. Same part no
I shall get on it tomorrow

[nickb]

Off the top of my head try a 100nF ceramic tightly across the relay terminal. I have no idea what the inductance of the coil is so this is just a WAG. It's interesting that the noise is still there with the masters at zero. That suggests the coil switching voltage or current is coupling into the power amp somehow. The cap might suppress the noise but I think there is another root cause. Since it wasn't there at first I can't give the wire proximity idea much credence. I'm thinking more a bad solder joint on a path that is common to the relay coil and power amp input.

[John G]

Hi,
Have you concidered adding a 22uF cap across the relay coil (observing correct polarity) or across the ch change switch.
Peavey do this in most of their amps I believe to suppress any switching noise (spikes)on the dc rail.
Just a thought.
John

[Arbutt]

Well it's now done. While I was playing with it this morning I saw something and had a thought.
I was spending too much time thinking its the relay and sound it bring caused by it.
Signal on leaving the relay went to send and return and onto the main. Board to decoupling cap to pi tube. It was the cable from the send and return to the decoupling cap.
I decided to wire the relay output directly to the cap. Very quite. Added some screened wire from fx loop to the decoupling cap. And for good measure screened wire from the relay to fx loop.

All I've got to do now is work out what I've done with reverb. Fecking thing
Thanks for the advice
Mr a