60's Vintage TNT Bass Amp

[Archie Speed]

OK, now think about the screens. Pin 6 is not used by the tube, it is a handy point to solder something. If all the pins 6 are wired together, that means they are all on one line, then at each tube socket, a 500 ohm resistor goes from that lone over to pin 4, the screen grid. Your schematic does not have the pins 6 daisy chained. Your drawing has a resistor from pin 4 of V1 to pin 4 of V2, where another resistor joins to go to pin 4 of V2, and so on. Your description sounds correct, your drawing does not seem to agree with your description nor does it seem correct.


And it sure looks like half of a Bassman 100:
http://bmamps.com/Schematics/fender/..._100_schem.pdf

Note in your drawing the unecessary 0.1 cap from the plate of the second triode to ".22" resistor, I assume .22Meg, or 220k. That is left over from when they eliminated the master volume. And they used the 12AX7 version of the phase inverter, but those are details. This butresses my thought that it is a Bassman clone. Or once was.

Sorry, but having just opened this cad app for the 1st time today I wasn't able to master the art of designing a socket or finding a means to add a pin, etc. I took my best shot using the available library images. My schematic does indeed show pin 4 multipled and doesn't indicate pin 6. Pin 6 is unused by the tube and is just a tie point. Resistors span 6 to 4 and all 6's are multiples. When I get a chance to understand the app better, I'll add the 4-to-6 points. Sorry. I thought this better than a pencil sketch.

Thanks all for the time & comments/corrections/help.

[Enzo]

Hey, the criticism is entirely meant constructively, no pointing fingers or anything. Better drawing than my own pencil work, I assure you.

[Archie Speed]

Enzo, understood. Tired & a bit frustrated & it shows.

Last gasp for today. Revised schem attempting to reflect EL34 4-6 resistor multiple & corrected valur of '0.22' res to what appears to be coded 2.2M (R-R-G-S), but I might need to take it out & measure it. Pretty faded bands.

Thank you.

[J M Fahey]

Hi Archie.
CONGRATULATIONS on the tracing and drawing effort and doubly so for masterung Tiny CAD or whatever.

That said, I guess it's quite clear now that it's 90% of a Bassman , converted to EL34 .... which changes nothing beyond different biasing and pin 1-8 wiring, so as a practical option I'd straight follow a Bassman schematic and simply check/confirm/mod/rewire your TNT so it complies with it.

So print a nice large copy, probably in 2 taped sheets so as to make it easier on the eyes, and check pin by pin, socket by socket, part by part, wire by wire so they match.

Can't go wrong

Of course, in case of doubt, follow the original schematic and not what you have there.

[Archie Speed]

Hi Archie.
CONGRATULATIONS on the tracing and drawing effort and doubly so for masterung Tiny CAD or whatever.

That said, I guess it's quite clear now that it's 90% of a Bassman , converted to EL34 .... which changes nothing beyond different biasing and pin 1-8 wiring, so as a practical option I'd straight follow a Bassman schematic and simply check/confirm/mod/rewire your TNT so it complies with it.

So print a nice large copy, probably in 2 taped sheets so as to make it easier on the eyes, and check pin by pin, socket by socket, part by part, wire by wire so they match.

Can't go wrong

Of course, in case of doubt, follow the original schematic and not what you have there.

Nothing mastered, particularly TinyCad. But a step forward. More to follow as project evolves.

Thanks, JMF.

[potatofarmer]

Just a heads-up: that bias cap is backwards!

[Enzo]

Ooops, yep, you reversed ALL the caps instead of just the B+ ones.

[Archie Speed]

Ah. Corrected. Thank you, sirs.

[Deadear]

Any more update's on this interesting amp. What is the status ?

[Archie Speed]

Still a work on progress that has taken somewhat of a back seat. Plan is a rebuild of the basic original, which is amounting to a Fender Bassman 100. Assuming I live long enough, I'll post restoration info.

[CannedHeat]

These TNT Amp's were custom made by an exterminator from Venice , CA Named Frank Cooley he made these AMP's for people in the LA area in the 60s and for the band Canned Heat! Would you sell this cabinet to me?

[Deadear]

Got to be worth at least $20 000.00 bucks given the heritage. Might have been at Woodstock ?

[Archie Speed]

This amp is an interesting project (to me) from an interesting era (one that I remember...mostly). I have no desire to part with at the moment. From what I know of its history, it never left the West coast. Kinda like me.

[CannedHeat]

This amp is an interesting project (to me) from an interesting era (one that I remember...mostly). I have no desire to part with at the moment. From what I know of its history, it never left the West coast. Kinda like me.

I sent you a message

[Archie Speed]

I sent you a message

I answered. Amp is not for sale.