375V asking too much from a 400V sozo?

[azatplayer]

Just measured a K60 clone up. At the mid of the divider forming the fast/gradual switch i got 375V. With a 5% wall voltage swing possible, i gotta think i should replace that cap huh? Got all sozos in there tho ;(

[David Root]

Maybe, maybe not. Depends if Sozo designed a service factor into their 400V rating. I would call them and ask, they might tell you over the phone but if you ask them on their website, they're likely not going to post that information.

I would be inclined to go with the Sozo, 375 X 1,05 is not quite 400V anyway. So long as the AC ripple content of the DC is low.

[guitarmike2107]

Should be fine, does the voltage drop when playing?

also you probably shouldn’t run the amp without power valves as the voltage will go up.

Is your switch rated to 375v DC switching?

[David Root]

I would doubt any switch we use is rated for 375VDC! I would be concerned if it were a miniature and/or a cheepo Chinese AC switch. Fortunately the current would be relatively tiny.

[azatplayer]

Its one of Danas lovely footswitch boards.
Ive been having trouble with this build from the getgo. Its a Concorde clone, all went really well, copied the layout very closely used the right trannies etc.
WOuld be the tidiest amp i have yet done. But have had issues ;(
Really hate having to touch a clean build!!
Ah well, luck of the draw.
I got some 600V styrene caps from Nebraska surplus this week in large values. I might drop one of them in there, i do like styrene!

[tictac]

I've never understood why people don't wire that switch like this...

There's no reason to put a large DC voltage on a dinky little switch not rated for it. With the addition of one capacitor you get the added value of not only switching the resistance from fast to gradual but also the capacitance...

TT

[azatplayer]

I've never understood why people don't wire that switch like this...

There's no reason to put a large DC voltage on a dinky little switch not rated for it. With the addition of one capacitor you get the added value of not only switching the resistance from fast to gradual but also the capacitance...

TT

Wow, simple but brilliant!

[Roe]

the sozo should handle it just fine. they test the caps at 800v

[M Fowler]

Tictac did you use a different/better switch as well?

Mark

[tictac]

Just a standard mini-switch, that's all you need....

If you really want to get creative you can use a DPDT and the un-used triode of V2 to switch the fast cap and the gradual cap to it's own triode which could be setup for it's own gain & tonal characteristics...

I treid this years ago but never really got into the Wreck thing...

I ended up turning the amp into a JTM45 style circuit.

I think if someone was willing to put in the time to tweak this circuit it could be very cool and open up some great tonal posibilities...

TT

[guitarmike2107]

Tictac, Thats the way I wire mine, and it is much better for the switch.

Nobody uses proper voltage rated switches on b+ lines, but if you can avoid it you should.

[tictac]

True enough...

Usually the DC voltage rating of a switch is about twice the AC rating which leaves many switches still underrated...

I just don't like the idea of high B+ so close to a metal actuator that's grounded... gives me the creeps....

[ChrisM]

The Fast/Gradual switch.
How does the different plate resistor size in conjunction with the coupling cap affect the sound?