Songwriter Prototype

[passfan]

I have exchanged the #124 OD circuit for the #183 OD circuit with excellent results. I now have a harmonically rich clean sound and a dumble style OD to go with it. It seems it may be time to finish a cabinet and come up with a footswitch.

[passfan]

I have increased lower volume performance by adding a master volume in between the effects loop and the PI input. This allows me to keep the gain on full and attenuate later on in the chain. This amps magic seems to lie in the input tube being run at full tilt. I have also dropped the first cathodes bypass down to 25 uf to increase the treble response in the amp and can now play without using the bright switch all the time.

[dorrisant]

Great job man... I will have to try my hand at one of these. I appreciate your extended notes too.

Tony

[LeftyStrat]

I don't suppose there is a schematic floating around, is there?

If not, am I right in the following topology:

- Paralleled 12ax7, 220k plate, 1.5k cathode. Bypass to taste.

- Coupling cap is paralleled with another cap in series with a 3 Meg pot for the bass control.

- Treble control is a post PI hi cut as in the Rocket.
- Power amp as the rocket, with one variant (not used on the production version) using a 6sn7 in the PI.

I assume the coupling cap/bass control combo feeds a 1 meg volume control?

[passfan]

Right now on V1 it's a .022 coupling cap with a 500pf split off with a bass control of 1 meg (the only 3 meg I had was a reverse log and weird stuff happened). Bass control is almost like a mild gain adjustment between light bottom end to heavy bottom end. PI is a 6SL7 right off Aikens site. Sub a 6SN7 for no breakup. I believe I used 1 meg for volume. 3/4 bass and volume , light pick on higher strings , lots of harmonics. Let some guys play it down at the local GC and it's already sold. Haven't even finished the cabinet or the footswitch and they're fighting over it. When am I ever going to get to keep one. I'm a slut, I tell ya'

P.S. look to the dongbiter thread for what there is in the way of a schematic.

[Colossal]

I'm a slut, I tell ya'

Nothing wrong with getting paid for it. You're a slut in demand!

[passfan]

Having fiddled around with this thing now I feel like it's nothing special. Aside from a few choice spots on the neck I much prefer an octal Rocket to this amp and since my deal for a sale seems to be caving in, I may just convert her to a Rocket or given the pt I used and the relay based footswitch perhaps another Komet 60.

[Colossal]

Having fiddled around with this thing now I feel like it's nothing special.

Kind of a bummer how that works but I think it also demonstrates why the holy trinity of amp designs (In the name of the Fender, the Vox, and the Holy Marshall) continue to be the benchmark. I just finished what is basically a Rocket for someone and man, that amp smokes.

[passfan]

I hear you. I think I'm going to experiment with the komet 60 circuit at a lower b+. I have a guy who's looking for louder than 30 watts and clean and the gradual mode may fit the bill for him. I'll use this songwriter chassis and cabinet with updated boards. It already has a dumble style foot switch in it. I like that amp better anyway