Bad idea to run indicator lamp this way?

[Gaz]

Gaz: As I posted a few nights ago (#6) you could use a 3PDT center-off toggle switch without changing any of the stock secondary wiring (assuming that you just need a single pole to switch off the main power- otherwise you would need a 4PDT switch.)

When they first came out with the progressive toggle switches 15 years ago I was really excited and picked up several from Allen Amps as I recall. But as Bruce Collins pointed out you could just as effectively use a regular center-off DPDT toggle switch although without the progressive feature. Just flip the switch one way for Standby and the other way for On. (During the short time while going from Standby to On the tube filaments should stay hot.)

Here is one eBay auction for a 3PDT switch which may or may not fit in the intended space for it. If not a rotary switch might work. IMO it is better to not change the original standby design unless absolutely necessary. (As someone else suggested you might want to incorporate some sort of mute function instead.)

Steve Ahola

Carling Technologies HM254 73 Toggle Switch 3PDT on Off On | eBay

Thanks for the thoughts, and the link, I will definitely consider going that route! I do have to disagree about altering the original design though if there is nothing harmful with the mod. As you know, lots of ways to implement a standby.

[Steve A.]

Thanks for the thoughts, and the link, I will definitely consider going that route! I do have to disagree about altering the original design though if there is nothing harmful with the mod. As you know, lots of ways to implement a standby.

Yes there are but not that many guitar amp schematics with a secondary like that one. I will borrow ideas from comparable designs left and right but there is not a lot of them comparable to THAT...

Theory is great but I like to look at real world examples. Especially with standby switches which might POP when you toggle them.

The big question to my mind is whether you actually need a standby switch or would a mute switch suffice.

BTW did you make a decision on the indicator light? I would go with a 6 volt light on the filament supply...

Good luck... you have definitely taken on an interesting project!

Steve Ahola

[Enzo]

Remember, this indicator lights when both B+ nodes are working. There already is a separate power on indicator, which is all a 6v light would be. Think of it like the green LED for "status" on a PV 5150 or related amp.

[mhuss]

Yes, only the 200 and 400 watt Hiwatts had both 'mains' and 'standby' indicators, because they were the only ones that had separate plate and screen (&etc.) supplies with a convenient 200-ish voltage difference between them.

[Steve A.]

Remember, this indicator lights when both B+ nodes are working. There already is a separate power on indicator, which is all a 6v light would be. Think of it like the green LED for "status" on a PV 5150 or related amp.

I was just thinking of the Mains indicator light... with this being a new build with limited front panel space I think I would eliminate the Standby indicator light. But that is me... YMMV

Steve A.