Speaker load box "power soak LITE"? (schematic)

[Steben]

16 ohm circuit.
Load based on Aiken's schematic, yet with a 8 ohm as base resistor.
I made some calculations and all positions should be similar to a speaker load line.

This is for 5 positions (-0dB, -6dB, -12dB, -18dB, 0), yet a 6th is easy to add.

[Dai H.]

shouldn't the 1mH and 50mH be switched?

[Steben]

shouldn't the 1mH and 50mH be switched?

cr*p. You're absolutely right.

[Pushtone]

I did something similar with three attenuation settings on a rotary switch.
I'm assuming the switch in your schem is also a rotary.

The rotary switch I have is an open frame break-before-make type.
I'm not sure if there is another type.


Anyway, my question is....

Is it safe to use this type of switch with a tube amp?
To be on the safe side I have been turning off the amp before changing atten levels.

I was going to include a bypass DPDT switch but I though that even more risky than the rotary.

So what about mechanical switches on an amplifier output?

Dave S

[Steben]

I did something similar with three attenuation settings on a rotary switch.
I'm assuming the switch in your schem is also a rotary.

The rotary switch I have is an open frame break-before-make type.
I'm not sure if there is another type.


Anyway, my question is....

Is it safe to use this type of switch with a tube amp?
To be on the safe side I have been turning off the amp before changing atten levels.

I was going to include a bypass DPDT switch but I though that even more risky than the rotary.

So what about mechanical switches on an amplifier output?
Dave S

I suppose you refer to the pause when switching, where the amp "sees" no load?
I think that is quite exagerated, we are talking milliseconds here and unless you intend to switch more than you play the guitar, the wear will be smaller than the heater. I think the amp can do the switch more harm than otherwise, if you choose a "wimpy" one.