5e3/AC15 mod

[afm_380]

Tubenit's schematic in this thread got me thinking of a mod I'd like to attempt to my recent 5e3 clone build.

I've split the cathode bias of the input tube sections so that each channel has a completely different voicing. But, now I'm thinking of adding another preamp tube into the circuit so that one channel can have the tradition two gain stages befor the PI, and the other channel three gain stages along with a cathode follower pushing the tone stack. Along with a master volume just prior to the PI (the volume pots just behind the first gain stage become gain controls). I have a pair of Yellow Jackets so I'll build it for 6v6/6L6's with the ability to run el84's easily.

Here's my mod'd 5e3 schematic stealing pieces from Tubenit's reference. What-cha think? Worth the effort?

[booj]

I'm leary of the Yellow Jackets ability to match EL84's up to a 6L6 type output tranny. I tried a pair on the output of a Peavey 100 series Classic 50 watt combo, and got 10 watts and all the crossover distortion I could hope for. (bad mismatch)

[HBamps]

IMO, I think your VOX channel is going to have way too much gain and mush out pretty quickly. The 5E3 channel has alot of gain as is but the VOX one you have 3 gain stages and a cathode follower with no attenuation.

[afm_380]

If I have enough realestate I may add a second pair of power tube sockets for the el84's ... gotta do some more chassis design work for that.

I can lose a gain stage by turning v3 into a longtail phase inverter, but then my tweed channel would only have one gain stage (I wonder how that will sound ... ;o).

Thanks for the suggestions ... this new obsession with tube amp design is AWESOME.

[HBamps]

you could experiment with the VOX side and try it with or without V2a.

[tubeswell]

Originally Posted by afm_380

I can lose a gain stage by turning v3 into a longtail phase inverter, but then my tweed channel would only have one gain stage (I wonder how that will sound ... ;o).

Thanks for the suggestions ... this new obsession with tube amp design is AWESOME.

FWIW the 5G9 has a LTP straight after the VA input stage and has a typical tweed vol-vol-tone stack in between. It makes about 12W and sounds gr8 with a 20W greenback if you use 2.2uF on the first cathode bypass cap and .047uf as the first coupling cap. (So that's an idea for your tweed channel)