Watkins Dominator extra stage?

[nosaj]

This is the junk box amp I built I gave up on the tremelo just couldn't get it to oscillate but since I'd never use it nor would my son. I have some questions. To turn the tremelo tube into an extra gain stage, would I just duplicate the first channel?

Thanks,
nosaj

[Chuck H]

Sort of. You obviously don't need an extra tone control. And you'll likely run into the possibility of needing to add a grid stop to the extra stage and/or some voltage division before or after to control drive levels. Because this is an unknown it would become an exercise in design with listening tests as your only real marker for relative goodness. Since it's a "junk box" build you might also consider whether the layout and lead dress can handle the added gain without instability. Just set it up like a normal gain stage and allow for the probability of a voltage divider before and/or after that stage.

[nosaj]

Sort of. You obviously don't need an extra tone control. And you'll likely run into the possibility of needing to add a grid stop to the extra stage and/or some voltage division before or after to control drive levels. Because this is an unknown it would become an exercise in design with listening tests as your only real marker for relative goodness. Since it's a "junk box" build you might also consider whether the layout and lead dress can handle the added gain without instability. Just set it up like a normal gain stage and allow for the probability of a voltage divider before and/or after that stage.

So would the trainwreck Universal gain stage be an ok model to follow?
Any idea why the trainwreck name was used?Was it because it was nothing like a trainwreck at all?
Thanks,
Jason

[Chuck H]

Well it's just a gain stage. And I can't say why some would allocate it to TW originality. Yes, that model will work fine. Just be sure to allow for a voltage divider before that stage in case you need to tune it.

[nosaj]

Well it's just a gain stage. And I can't say why some would allocate it to TW originality. Yes, that model will work fine. Just be sure to allow for a voltage divider before that stage in case you need to tune it.

Voltage divider being a gain pot?

Thanks,
nosaj

[Chuck H]

A gain pot would be a variable voltage divider. And that would be fine too. If you don't want to add another gain adjustment though you can used fixed resistors. Just a series resistor and a load resistor. Same as what the pot would do, but at fixed values.

If the gain stage model includes a 1M grid load (as it should) then all you need to do is include a place for a series resistor behind that grid load. The series resistor and the grid load constitute a voltage divider. You may even choose to use a jumper rather than a series resistor. But probably not. So you'll want to include a place for it to make the additional stage easier to tune in to the rest of the circuits.