Hello, I'm new to diyAudio and am currently working on a project for school that involves building a guitar tube amplifier.
We have decided on trying to emulate a Matchless Lightning and Spitfire and blend them into one amp where they would share a single volume but the Tone control for the Spitfire and Treble and Bass for the Lightning would be separate.
This leads me to my question which is while my group is trying to accomplish switching between the different tone controls. We figure this can be accomplished through mechanical relays but are still unsure if there are alternative approaches that may be easier.
Has anyone attempted this sort of design before?
We have decided on trying to emulate a Matchless Lightning and Spitfire and blend them into one amp where they would share a single volume but the Tone control for the Spitfire and Treble and Bass for the Lightning would be separate.
This leads me to my question which is while my group is trying to accomplish switching between the different tone controls. We figure this can be accomplished through mechanical relays but are still unsure if there are alternative approaches that may be easier.
Has anyone attempted this sort of design before?
a relay for sure is simple and doesn't add anything you do not want. An other approach I used consists out of two triodes with a common anode resistor as output. The two signals that you want to swith AC coupled to the grids. This mixes the signals. If you want to swith-off a signal, just put a negative voltage to the grid of the triode you want to swith-off, e.g. at the low side of the grid leak. If you want a spdt switch, swith the negative from one to the other. This approach also amplifies so you may need a stage less.
But, take care not to swith the negative voltage very abrubt, otherwise you get a click or bang at the moment of switching. Switch slower using a RC lowpass, the impedance at the low side of the grid leak is high, so no problem at all.
But, take care not to swith the negative voltage very abrubt, otherwise you get a click or bang at the moment of switching. Switch slower using a RC lowpass, the impedance at the low side of the grid leak is high, so no problem at all.
- Status
- Not open for further replies.