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Tube Audio Amp question

Back in the 60's I built a pair of amplifiers using four 6L6 output tubes in push pull parallel mode. These were actually designed using schematics from guitar amplifiers, and I used the output transformers made for guitar amps. I ran these tubes to their limits by running the highest power supply voltage as these tubes could handle. I ended up with an extremely loud stereo, and was putting out enough power that I once blew the glass out of a window. The sound was clear as a bell too. I used some of the best and largest speakers I could get.

Well, these days I am old, retired now, and have had the urge to design some tube amplifiers again. To me, they always sounded better than semiconductor amps.

The 6L6 tubes were always my favorite tube. They were easy to get, powerful and had a nice sound. But here's my question. Is it possible to run EIGHT, or TWELVE, SIXTEEN of them together? I'd assume the circuit would be to push pull parallel / Series. In other words, run 2, 3, or more tubes in series TIMES FOUR (the push pull parallel part of it). Is this possible?

I once figured that I was getting 140 watts RMS out of those four

6L6s, running everything at it's maximum. This time I'd like to go for 280 watts or maybe 560 watts....... Yeah, I already know getting an output transformer will be tough. Probably need something custom made.

I might be old, but I still want to see if I can blow ALL the windows out of the house, just to do it !!!! I guess those of us who became adults during the 60's will never quite give up the dreams. Somehow, a 1200 watt RMS system powered by a total of 32 6L6 tubes and a wall of 18" woofers and horns just seems groovy. (After I add another 200 Amp Breaker panel in the house), I should be able to power these amps, along with a full spectrum, 10KW color organ, strobes, blacklights, lava lamps, mirored balls, and of course the original floating colored oil film kaleidoscope projection system, while listening to the Woodstock soundtrack album on 12" vinyl.

This could just be way farout, heavy, trippin, and totally groovy.

Mark

Reply to
maradcliff
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try using 833 tubes. they are about 500 W each and the plates glow orange in normal operation.

Reply to
TimPerry

On Fri, 03 Nov 2006 05:24:31 -0600, maradcliff Has Frothed:

You'd want to switch tubes to maybe a higher power pentode like a 6146. There was someone experimenting with a 6 tube 1500 watt amp but I don't remember what tubes he used just that the filiment current was around 10 amps.

--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794
Reply to
Meat Plow

Just run all your pairs in parallel. You can get them to current share well enough with some uncoupled cathode resistance.

There are higher power tubes of course. 6L6=KT66, which iirc have a bigger brother in KT88. Then there are serious power tubes.

Its quite possible to make your own. In fact if you're prepared to use a bell jar and pump, its quite easy. Those valves could be funky as well as groovy. Not many amps have to pump down to operate. Using bulb filaments for emitters will make it very visual.

NT

Reply to
meow2222

Why so much power? Sounds like overkill to me. Build 50w monoblocks and use a set of effecient horn type speakers (Klipsch or the like). That'll be plenty loud. If you want to run a bazillion pairs of output tubes in parallel....good luck finding an output transformer to match the total plate impedance.

Reply to
boardjunkie

You hand wind one using the motor lams from an old 1 HP motor, and bus bar copper hand insulated with cloth tape.

Reply to
Homer J Simpson

...during the peak of a lunar eclipse.

Reply to
Allodoxaphobia

Sure.

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Reply to
Homer J Simpson

I guess I missed this part reading too fast. If that's all you want to do...use dynamite. It'll be cheaper, more efficient, and a real

*blast*.

Your post smacks of troll, but in the event you're serious, there's always these:

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Schematic:

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Reply to
boardjunkie

Looks like the motor controller for a streetcar!

Reply to
Homer J Simpson

Trix used to make a cinema amplifier in the 50's. A pair of 813's with nearly a Kv on the plate. If I recall they produced about 600 watts into 100 volt line. The output trany was a toroid about 9 or 10 inches in diameter, potted in a cast alloy case.

--
Baron:
Reply to
Baron

Use a pair of 4CX1500 (or larger) tubes. ;-)

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prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

Heh....yea. Transmitting tubes. I was gonna say a pair of 250TH.

Reply to
boardjunkie

Not that any of this is a repair issue, but if you're going to use those, you might as well go for watercooled tubes. Get rid of that fan noise, and why not be out of the ordinary.

Michael

Reply to
Michael Black

Real men use 200 amp SCRs.

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Reply to
Homer J Simpson

Homer J Simpson spake thus:

Water-cooled?

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Reply to
David Nebenzahl

Mercury!

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Reply to
Homer J Simpson

A higher power tube does seem to make more sense than combining 36 smaller ones. But unless I'm mistaken, the 6146 is rated for 25 watt plate dissipation, the same as the 6L6.

Reply to
Blake

3CX2500F3 even?... problem is the forced air cooling is so noisy.
Reply to
TimPerry

On Sat, 04 Nov 2006 19:03:16 -0800, Blake Has Frothed:

Must have read the tube data wrong or the data I was reading was a typo.

Some else suggested using an 813. I can't recall the site but someone built a 1kw audio amp using them. This guy was a bit on eccentric side if I recall correctly.

--
Pierre Salinger Memorial Hook, Line & Sinker, June 2004

COOSN-266-06-25794
Reply to
Meat Plow

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