6L6 Beginnings

[Daddy Dee]

Very cool Erik.

More pics as you progress in the project, please!

[mike stehr]

Sure, the power transformer could be rotated, as could the OPTs, actually. The chassis is just a little small for the job IMO, but might work out okay. This design was inspired by the Baldwin organ amp I had here for awhile, and the power transformer shown in the picture is sort of coincidentally also from an organ. It's as large as it is because of the 50 or so 12 volt dual triodes in the tone control circuitry. The only thing I'll use the 12 volt winding for on these things is for a single pilot light -- which really isn't even needed since the tubes essentially do the same thing. Light up.

Erik

A buddie and I were looking at those PS xformers last night. Those things are enormous.......

[jt1stcav]

IMHO I also find Erik's 6L6 project fascinating (and I'm no solder-slinging DIYer either). The fact that he can take a 6 or 7 decade's old approach (like Mark, Craig, and others have) and design a pair of modern-day monoblocks from it is truely awe inspiring. I'm not electrically inclined like Erik (and my dad), so I'm always intrigued at how people with these skills go about the design process and build their own tube amps from scratch.

[Erik Mandaville]

Mike:

"A buddie and I were looking at those PS xformers last night. Those things are enormous......."

They sure are, and bigger than I had expected. They are very well made vintage transformers, though, and should work well. They sort of came my way unexpectedly from a friend who had them on hand, as did the chassis, and I have always thought it was kind of neat to make something work well with what is nearby or available that will work. I don't need a P-former with an enormous 6.3 volt current rating, but that's okay with me. Shawn had an interesting idea in possibly using it as the supply for a regulated heater supply. I did the same thing with a preamp I made a couple of years ago, and have been happy with the performance.

I may try to do some 'light' chassis work today, but hefting those transformers is probably something that's going to have to wait for a week.

Jim, Dee: Thanks! Jim: I've got a couple of books if you'd like!

Erik

[Coytee]

Looks like you're copying Mark's Pcats where one can see the circuits from above?

[6] []

Flew right over his head.................

Indeed, it might seem so [:$]. Perhaps he'll read this thread about the pCAT (not Pcat) and see that I wasn't trying to be a hiney hole.

http://forums.klipsch.com/forums/1/698067/ShowThread.aspx

I was inspired by the vertical wires.

Eric, in case I rubbed ya wrong, I've got nothing but admiration for those of you that can weild a soldering iron like a scalpel.

[]

[Erik Mandaville]

Coytee:

Thanks for the link. I missed that thread.

Erik

[DRBILL]

Erik,

If this is going to be a "Williamson" design, let me know and I can send you some interesting reads. You might want to consider using 6BG6s instead of 6L6s. The 6BG6 is a 6L6 with a plate cap and NOS Phillips is $6!

DRBILL

[Daddy Dee]

Here's another example of the good will and collegiality typical of the PWK legacy on this forum.

Is this a great place or what!

[3dzapper]

I'm keeping an eye on you too Erik. Love those huge PTs and welded steel chassis.

Our friend and forum member dmitry gave me some Russian 6n3c's ( 6L6 equiv.) to build an amp around. I'll not be as fancy as you with hard wired drivers though. I'm thinking Eico ST-40 7591 iron driven by a DIYtube Dynaclone driver board.

Rick

[Erik Mandaville]

Dee:

"Here's another example of the good will and collegiality typical of the PWK legacy on this forum.

Is this a great place or what!"

It sure can be. I agree with you!

Bill: There are certainly some similarities to the Williamson. One part of this design comes from a fairly old schematic I have that incorporates varying amounts of negative feedback, including none, and I will be using that aspect in this project. I'm doing a couple of experiments on my own, which may or may not be workable -- although I think so. Final tuning is going to be done by ear, of course, so there's just no telling for sure until I hear the results. I do appreciate the offer on that reading material!

Rick: Those transformers are pretty hefty, for sure. I may try to begin punching holes for stuff tomorrow, but it just depends on how I feel. Working some more with placement of the P-xformer and OPTs, I've decided that a longitudinal orientation (the long way!) will probably work better with placement of filter caps, as well as get all AC components and leads even further away from the input. I had kind of an uexpected idea of having the chassis blued in the way one does in gunsmithing restoration; but, as interesting as that seemed to meat first, I remember what a hassle it was when I tried it a couple of times using cold-blue methods. When punched and drilled and filed and sanded, they will be sent out for powder coating for a much more durable finish. Anyway, I'm curious about your project, as well. I hope you have fun with it.

Erik

[Erik Mandaville]

Like this:

The filter choke and OPT will look flush/even from the front view, although the choke is not quite as deep, front-to-back. It leaves a good space for the power switch and/or fuse. This chassis orientation also IMO provides a better stage, so to speak, for the input/driver and output tubes. The rectifier will still be centered in front of the power T.

Erik