Stalemate

Time and energy haven't permitted the continuance of my single-ended 6V6 marvel, so I figured I would tear into something I alluded to in the last post.

The Pignose G40V Combo amp.

I sort of picked this up on a "researched whim".
What web-scribes I could find on it indicated that it had some very old-school "brown" grit to it, and in fact, was almost hard to play clean.
Well I had been eyeing this puppy in the pawn shop for several months. Bigger rigs came and went, but this lingered. After it had gathered enough dust, the proprietor decide to reduce it to well South of 100 clams, so I was on-board for a 100% tube amp.

Topology of this little guy indicates a 6L6 Push Pull (presumably biased AB1) power section with a rather busy 3 stage front end, driver section, cathode follower tone (bass, mid,treble) and gain/master volume controls. It also sports a presence knob to de-bleed some of the negative feedback. so I would call it a hot rodded Plexi front-end (12AX7's) firing into a Fender Vibrolux.
Bear in mind, I am talking circuit topology, not build quality.

Indeed, even with single-coils this thing was hot, fat and wet. Anything over 9 o'clock on the gain started some serious compression and loose vintage grit. Even playing modestly clean it would compress and sing for what seemed like hours.
Only problem was it also received WEW out of Del Rio Texas (and any other station that was strong enough). Further schematic rooting indicated that indeed, like very antique Fenders this thing had no buffer resister up to the grid of V1a, the input was wired directly to the grid.
I figured a little buffer would kill some of the RFI and leave the crush, so I wired a salvaged 15K carbon resister in series and sure enough, no more del rio.
Most of the compression and mushy overload stayed intact.

I am currently using it as my practice amp, and I continue to be amused at:
. How loud it can get (I'm guessing an honest 35 watts through a 10" generic speaker).
. How much old-Fender crush it can build on the front end (Fenders did it out back).
. How tactile it is, you can pull-back and be sensitive or tear-in and sound really PO'ed, without ever turning a knob.

More later

A single-end to my search?

Been a long lonely-lonely time.

Still being in search of the perfect tone has taken through many, very creaky doors and down more than one detour.
(no wonder people do these side-turns with their faith too)

Additional roads traveled have been:

• Digital guitar modeling (a now antique Digitech RP-50, cool reverb and delay effects).
• The organic Tube Screamer TS-9 (mine dates to the early 1980's) force-feeding the front-end of various small amps such as an Estey Magnatone 104 ($2 at a yard sale some years back) and the Prince-tone.
• Most recently blowing through a Pignose G40V tube amp (the ultimate Brown-Soun machine, but that's another post).

The one I start to chronicle today centers around a Voice of Music reel-reel chassis I acquired and promptly gutted to start a new project.
Some guy had boxed this puppy up into a homade cabinet with a very vintage Bogen ceramic magnet tiny-wattage 12" speaker. What I could reverse-deduce of the schematic indicated a two-stage preamp (plus driver) via 2-12AX7's force-feeding a 6V6GT which was (uniquely?) cathode biased through an axillary winding on the secondary of the output transformer.

Little guy sounded pretty good, tight and chimey with lots of gristle cranked up to pat. pend.. Since we are talking a single-ended 6V6 machine (at likely reduced voltages) I would be surprised if it was kicking 4 watts, so this was at almost "have a conversation" volumes.
I wanted to build my own thang though so I came up with a hybrid schematic with 3-preamp stages plus a driver, with the last preamp stage having a cathode-follower tone stack w/ 3-band EQ. As an FYI, this is a cash restricted R&D project, so I am even salvaging tube sockets from the old unit. I did treat it to new pots and switches though.

Here is the start of the project:

Tiny box doesn't leave a lot of room, so I've burnt a knuckle or two so far.

I'm getting ready to finish out the power supply currently, and then to the preamp section, so it will get quite a bit busier in here.

More to come.