5f2 but with two channel

[Mikante]

Hey guys,
This is just an idea form my next project.
I d like to build a 5f2 amp, but i want to have to independent channels, both with volume and tone control.
What schematic could help me put this together beside the 5f2 of course.
I don t want the two channel to be cascaded but individual even tough they should share the same input. Adding a valve and double the pre amp circuit would do?
Looking forward to hear your thoughts.

[Phil_S]

You don't say what you are looking for. The 5F2 has a volume and a "tone" control. The tone control is a cut control. I like the sound of the 5F2 circuit, so I'm not saying otherwise. This is your typical 15W-ish amp. Maybe you can build a Fender or Marshall style TMB tone stack for the other channnel? Take a look at the Marshall 18W TMB schematic and layout. I'm guessing it will work with a 5F2. I think what works for a pair of EL84 also works for a pair of 6V6's without modification.

[echuta13]

The first thing that came to mind is the preamp from a 5F6a Bassman as an example. Split the cathode on it for different bias & bypass cap/voicing, and use mixers. More or less what Phil is showing in his schematics.

[Mikante]

Hello,
I had a look at the tweed bassman 5f6 schematic right before to ask here
I want it to be a 5 watt champ. For me is the perfect wattage for an amp.
I play at home and record a lot. I don t gig anymore
Do you guys think it is possible to have one normal input only for both channels?
My goal is to have two channel going at the same time, one almost clean and the other playing around with distortion.
@Phil_s: what is v3 there for, does any two channel amp need a phase inverter tube?

[LOUDthud]

The first stage of a tube amp does not create significant distortion or clipping unless you run a pedal into it. So, to do what you want to do, you would take the front end of a 5F6A, then instead of the two Volume controls have two of the 5F2 Vol/Tone networks, then mix the signals for the back end of the 5F2. I think what you'll end up with is basically a 3 Watt version of the 5E3. The differences of the two channels will be very subtle. The distortion of one channel will bury the clean signal from the other channel. You would do better with two 5F2s.

[Mikante]

This one looks interesting, i wonder how the two channels interacts with each other in this particular design.

4FCC954A-1141-40EB-A289-3F32F55ADDCF.png

[Mikante]

The first stage of a tube amp does not create significant distortion or clipping unless you run a pedal into it. So, to do what you want to do, you would take the front end of a 5F6A, then instead of the two Volume controls have two of the 5F2 Vol/Tone networks, then mix the signals for the back end of the 5F2. I think what you'll end up with is basically a 3 Watt version of the 5E3. The differences of the two channels will be very subtle. The distortion of one channel will bury the clean signal from the other channel. You would do better with two 5F2s.

What if you only double the second stage and the into the power tube?
V1 for both and then v2 for the first channel and v3 for the second? In this way they should not interact or even bury one another?
I could use a 6l6.

[LOUDthud]

What if you only double the second stage and the into the power tube?
V1 for both and then v2 for the first channel and v3 for the second? In this way they should not interact or even bury one another?
I could use a 6l6.

If you try to double the second stage into the power tube, you have to figure out what to do with the feedback loop. It might work to join the two tubes at the cathodes and connect the feedback there.

I was thinking the thing to do would be to add two second stages (one 12AX7), then mix the two signals to a Master Volume control, then to the power amp of a 5F2 (the 2nd triode and 6V6). That gives you an odd number of triodes, but may be closer to what you want.

[Mikante]

The feedback can be added to one channel only, let s say the one that i would use for clean or crunch.
I could then let the signal into the power stage after the phase inverting.
I don t know enough about phase inverting circuit and design so my ideas might be wrong.

[LOUDthud]

If you try to inject a signal inside a feedback loop, the feedback loop will fight the injected signal and try to cancel it. Because the loop gain of tube amps is low, cancellation will not be complete. Won't hurt anything to try, might sound cool