Split Load Switch

[Tim Hall]

I'm having trouble figuring out a good component rating for split-load (aka Fast/Gradual) switch. Since we're dealing with the B+ here, I figure you don't want use any old switch. Can anyone make a recommendation here? Thanks.

[Noel Grassy]

Tim, It looks like most folks use the mini toggles w/ 6A @125VAC rating.
I swung with Mouser's pt#690-123S1YZQ. IMO the Mountain Switch brand is garbage. But Alcoswitch, C&K, or NKK will give you a decent product for the money. I don't know what the actual current is at that position. I bet Skyboltone is furrowing his brow at such negligence. Maybe a more skilled individual will school us both.

[Tim Hall]

Actually I think I must have had a little brain fart on this one. I guess I'd really only be switching the signal off the plate, and not the B+ over the R. Is that right? If so, I could use a tiny switch.

[Richie]

you might ask Allyn or Ur12.. they have a fast gradulal switching board,so you can make it quiet footswitchable. If you use a manual switch,you'd have to set it to the position you wanted,or there would be a pop or thump sound when switched. Unless you used a different method,or modded the circut.
About any switch should work for that. Not much voltage or current in that section. Most switches are rated AC..so those would be about double rated for DC voltage.

[Allynmey]

you could run a cap off both spots to the switch and have the center connector go to the next stage. You will need 1M ground reference resistors on the switch to get rid of the pop.

[billyz]

Allyn,

Where do you attach the 1 m resistor to ground? I mean not the grounded side the switch side.

Thanks

[Allynmey]

at the switch after the cap

[Tim Hall]

Cool. Thanks for the replies.

[bnwitt]

What value caps? 0.1uf? should one eliminate the cap downstream then?

[Allynmey]

Yup!

[bnwitt]

Well with that setup one might as well put in a relay and make it foot switchable.

[billyz]

Since you guys are showing a .1uf coupling cap, am I to assume you are switching V2A and not V1A ? I have been using the V1A and really like the results, so much that I never got around to trying V2A. Also, when I grounded the 1 meg resistor after the cap (.002) I did pickup some hum. Possibly a ground loop.

[nee]

I've been playing around with the split load switch on V2a.

First of all I had the center lug of the switch connected to the .1uf cap, but there was a thump through the speakers when the switch was thrown, and I didn't like the idea of the B+ being on a front panel switch anyway.

So I did as Allynmey suggested above and used 2 x .1uf before the switch, rather than 1 after. While there was now no DC on the switch, there was still a speaker thump on switching, so I again did as Allynmey suggested and added a 1M resistor to ground from switch side of each cap to ground.

I'm certain everything is wired correctly, but with this configuration I get no signal at all. It's as if the entire signal is being shunted to ground.

[M Fowler]

Yeah my switch pops when engaging the gain, I left it that way.

Preamp gain center pin on switch to .1 uf/600v
Hard top of switch to junction of 82k/22k
soft bottom of switch to junction of pin 6/82k