Popping again.....Cap across channel switch?

[mlp-mx6]

Gil,

Thanks, that's cool info. But I was under the impression that the LDR-switching Boogie came out after the II-series Fenders. Is that incorrect?

Just curious, really.
Michael

[FUCHSAUDIO]

Diode and capacitor across the relay coil, very important.

Make sure any signal capacitors NOT being loaded have a small resistor on them (1-M, 2-M, 4.7-M) to ground.

Andy, evidently success changes people... You've made it big to where you even think of a 4.7Meg resistor as small now!

Gil

No Gil , I mean it, they are really tiny....maybe a 1/4 inch long, lol.
Success is truly subjective. I'm "making a living" and having fun.

[FUCHSAUDIO]

relays make noise optocouplers don't...fender soldano and boogie all use optocouplers the soldano lead 100 has a nice setup for 2 master volumes if i recall.... the optocouplers are always Vactec VTL5C1 and hey you can use the 6.3 volt supply to run them ...look at the slo 100 watt soldano at blue guitar. they are expensive though so now you know why ppl use relays...like 15$ each optocoupler.

\

Optocouplers have a sound. Relays are like actual switches. Optocouplers contribute to changes in tone. A properly built relay circuit can be made silent. The TDS uses 10 relays. One is reverb,one switches LED's, 4 switch mid and gain boosts and 4 switch channels. No pops, noplace.

Optocouplers are cool, and in production quantities are pretty cheap, but me like relays more gooder, with all due respect to Mesa and Soldano and others.

['67_Plexi]

Did you ever cure this problem on the dual master HRM? I have exactly the same deal going on. Tried everything suggested here and anywhere else I could find, nothing works, even different brands and voltages of relays. Global master - no noise, Dual master - Popping that is directly proporional in loudness to the corresponding channel level. I'm positive it's on the switching side, not the coil.....grrr

How did Dumble get around this ? Did he actually truly use seperate masters. I can't say I've seen any front panel pics of an HRM. All pics I've seen of modern Dumbles have the 'ratio' control, which signfies a global master with the ratio control being the overdrive level control.

[pedro]

in a word........no,
I tried everything suggested to me and still get popping - though mine doesnt increase with channel volumes.

Its annoying at room levels but not an issue at gigs when its masked completely.

Still bugs me though.......

sorry i cant help cure it

Pedro

[goyo]

Maybe your (film?) coupling cap is leaky.... if it is, the megohm pulldowns might not help a lot. Film caps aren't supposed to be leaky but a metallized film cap can become leaky if heavily soldered on. This can be "self healed" by applying a voltage with no resistor in series to burn it away. This is a big problem with SMD film caps, not so much with leaded caps.

[coco]

Diode and capacitor across the relay coil, very important.

Make sure any signal capacitors NOT being loaded have a small resistor on them (1-M, 2-M, 4.7-M) to ground.

Put a 22-M across the relay contacts as well. If you need a diagram, send me an e-mail. Assuming nothing is oscillating or unstable, you should acheive silent switching with the right tweaks.

Slightly different idea where to use relays - I want to switch the cathodes of two different tube pairs. But my relay POPs . Surprise.

I've tried many variations suggested here (not all tho) with no success yet and was looking for more suggestions & thoughts. My circuit is very basic, like the Weber, fed off the 6.3 VAC and Full wave rectified, diode across the relay coil etc.

I'm not sure a relay is a good thing in this particular application, but if I can make it work, that would be great.

Other ideas? FETs, etc?

Thanks,

[coco]

Diode and capacitor across the relay coil, very important.

Make sure any signal capacitors NOT being loaded have a small resistor on them (1-M, 2-M, 4.7-M) to ground.

Put a 22-M across the relay contacts as well. If you need a diagram, send me an e-mail. Assuming nothing is oscillating or unstable, you should acheive silent switching with the right tweaks.

Slightly different idea where to use relays - I want to switch the cathodes of two different tube pairs. But my relay POPs . Surprise.

I've tried many variations suggested here (not all tho) with no success yet and was looking for more suggestions & thoughts. My circuit is very basic, like the Weber, fed off the 6.3 VAC and Full wave rectified, diode across the relay coil etc.

I'm not sure a relay is a good thing in this particular application, but if I can make it work, that would be great.

Other ideas? FETs, etc?

Thanks,

[groovtubin]

Did you ever cure this problem on the dual master HRM? I have exactly the same deal going on. Tried everything suggested here and anywhere else I could find, nothing works, even different brands and voltages of relays. Global master - no noise, Dual master - Popping that is directly proporional in loudness to the corresponding channel level. I'm positive it's on the switching side, not the coil.....grrr

How did Dumble get around this ? Did he actually truly use seperate masters. I can't say I've seen any front panel pics of an HRM. All pics I've seen of modern Dumbles have the 'ratio' control, which signfies a global master with the ratio control being the overdrive level control.

Jim@Omegaamps here, i use NO caps across the coil, DUAL masters, and NO popping whatsoever, e-mail me at Omegaamps@wilkes.net, i`ll scan a hand drawn scizo of my set-up. It`s regulated, w/star ground for all of the supply, regulator and relays.

[coco]

email coming, thanks. I just tried caps across the contacts - no luck either.

[FUCHSAUDIO]

If the 6.3 Volts you are using is also the filament supply for the tubes, it cauld be part of your problem as well. Just a thought. A separate 6.3 V transformer can make a world of difference in reducing circuit noise from the relays.

Good luck.

[coco]

Yes it is the same supply as the filaments. I have a spare filament xfrmr I'll try & let you know how it goes.

What about using a 6Volt AC relay?

Thanks

[d95err]

Yes it is the same supply as the filaments. I have a spare filament xfrmr I'll try & let you know how it goes.

What about using a 6Volt AC relay?

Thanks

I haven't tried it, but having fairly high-current AC so close to the signal path sounds like a sure way to pickup 50/60Hz hum.

[FUCHSAUDIO]

A 6.3 volt supply will yield about 8 volts dc after rectification. A 5 or 6 volt relay in series with an LED will work well, and you get a curernt limiter and "free" indicator the relay is active. A separate transformer will certainly help reduce or eliminate the relay circuit from causing noise in the circuit.

Hope it works out.

[coco]

No luck. A separate 6.3V tranny for the relay didnt improve matters.

and a resistor or cap or both across the contacts didn't work.

So I think it's not the relay. I think it's the fact I'm switching the cathodes and that's the source of the POP - the tubes.

Besides, if I switch it by hand, it also POPS.

So...a different approach is required to get silent cathode switching on the power tubes.