trinityamps.com

I actually use this thing, but the pop is pretty loud and probably not good for speakers.

I tried a 100k resistor in parallel, hoping enough current would leak across, but nope.

I don't think this is a good place for a cap.

Howzabout a 1M to ground as a "pull down"?

Anything else I can do besides soft switching? I'd like cheap and easy.

P

Try a shunt resistor 2.2M to ground --> across switch. 1 M may work as well.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I know its a while ago - but I have this pop and its driving me nuts.
Trinity S111, working perfectly EXCEPT,Loud pop when switching boost on/off either on the boost switch or on a footswitch.
I have tried a resistor across the boost switch, lots of various resistors from 100k to 1M, same across footswitch - nothing stops the pop.
Tried removing footswitch jack and just using boost switch - no change even when resistors added across boost switch.- still pops.
Boost switch is on/on with three terminals on the back. Tried two resistors, one between centre and lower terminal and one between centre and upper terminal - still pops. In this configuration tried earth wire to upper terminal (wire from valve to centre terminal, wire to boost circuit on lower terminal) = still pops.
Pop increases with tmb volume, as expected.

I know more about automotive electrics than amps, in the older points ignition circuits a capacitor is used to prevent arcing on the points - is there any way a small capacitor would work to stop the POP? maybe across the switch?

When you say "2.2M to ground - across switch," do you mean just across the switch terminals? or does it go across the terminals and then to earth?? or is one end across the terminals, then the resistor, then the other end of the resistor to earth?

Another thread you might try.

viewtopic.php?f=7&t=3044&p=24138&hilit=pop#p24138

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

OK so I have now built and installed the soft switch (using the diagram supplied on this forum). I STILL get a pop on the boost switch, and now also a HUM when the boost is switched on, which wasn't there before.
The pop volume is affected by the tmb Master Vol, but above 2 on the Master the pop is intrusive. I can use the amp and switch the boost quietly by turning the Ch Vol up and leaving the Master below 2 but its not ideal. Sort of defeats the object.
I am going to try re-routing the dc power supply wires to the soft switch to try to get rid of the hum.
I will also put the resistor back on the boost switch.

Why is it an option on the S111 if it is so much trouble to get it operating successfully?

The soft boost was not an option for a long time. We only set it up for builds for our customers, not in kit form.
Eventually, we did put it out there for more to use as it is a bit of a challenge. That is why we didn't put it out there in the beginning.
The real problem is we hit the cathode so hard with the boost on that circuit it is very hard to prevent a pop. You can always reconfigure for less boost.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I just noticed that with low'ish levels on the VRM, the boost doesn't have much impact, but it does near full voltage. Is that an expected result?

If you lower the plate and cathode voltages , there is less gain on tap. Just the math works out that way.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I thought so. I freaked out a first, thinking that I messed something up along the way. But I cranked up the VRM, a found that everything was normal again.