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Baldwin 6550 amps


3dzapper

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What do you think, do these have a future? All triode input and should be about 60 Watts or maybe 30 in triode mode. Dynaco iron and what looks like a veery hefty power tranny. By comparing the size of a tape dispenser like that in the picture tape against one, the output tranny it is about the size of a Mark III output.

The price seemed right. LINK.

http://forums.klipsch.com/idealbb/files/baldwinamp.jpg

I envision cleaning up those chassis, adding some black walnut to the sides. An RCA jack on top near the input and a set of gold binding posts.

Rick

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Yeah, the caps are a given Tom. I was studying the schematic trying to figure what I have "in stock" that will work.

I'd like to stick a choke in there somewhere. Any ideas or will I need 2 per amp? George Wright uses one on the "ground' side of the Mono Tens power supply caps which are split like that. That seems to put it replacing the 1K resistor. I have a pair of 3 Henry 300mA chokes coming from the far east that might be perfect.

Rick

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Hey guys.

I see we have some Baldwin fans here.

Here is a picture of my Baldwin behind my new MC-30's.

I have the Baldwin bridged in MONO

and am using it w/ my LaScala center channel.

SWEEEEEEEET !!!

I will never sell my Baldwin.

If anyone can ever here the sound of this...you won't forget it.

Congrats on the purchase.

They don't look the same as mine,

but if they sound anything like what I have ,

then you are in store for a huge treat !!!

Please report back to me, when ya get those "bad-boys" up and pumpin' !!!

download.asp?mode=download&fileID=36091&

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Have you bench tested the OPT's for bandwidth response, and figure up the primary impedance? The schematic indicates various taps on the outputs, that's a plus.

Hopefully you'll have some power down at 30 Hz, you should...

That driver circuit is different, I wonder how balanced phase would be. Fixed bias on the inverter, a million resistors, 3 tubes, it should be balanced. Cathodes drive the output tubes.

What would be the name of that driver circuit topology?

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"What would be the name of that driver circuit topology?"

The outputs themselves are Ultralinear tapped. I have no idea what the driver circuit would be called Mike.

These are Manual organ amps or the keyboard. I found the following at Theaterorgans.com:

"By the way, musical pitches on the organ range from 32.692 Hz in the bass to 5919.85 Hz in the treble, a span of seven and a half octaves. The frequencies of the Solo Unit for the pedals range from 16 to 3136 cycles per second."

I take that to mean 30 Hz to be no problem as well as the overtones of a 5919KHz fundemental. Hopefully with a design requirement of a clean 32.7 Hz tone it will go even lower.

Rick

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"The outputs themselves are Ultralinear tapped. I have no idea what the driver circuit would be called Mike."

That's ok...

1.gif

I visited my retired EE audio freind today and was going to bring that baldwin driver circuit up, but forgot.

I may send him the schematic and ask, after I switch it over to JPEG.

I have my Lowery 6550 PP mono organ amplifiers, and have decided to go EL-34 PP for various reasons.

I think we finally pondered out a driver circuit, it's been going back and forth over emails for some time.

I'm gonna try the Eico HF-22/35 driver circuit, EF-86/6SN7.

Can't swing the cash for some nice EF-86, plus I would have to change a octal socket over to mini-pin.

I pondered out a couple triode octals that may work, and he came up with 6SJ7, a sharp cutoff pentode.

I wasn't too sure if I had 6SJ7 stashed at home, so he digs up a pair of Tung-Sol JAN-CTL-6SJ7GT/VT-116A's.

They tested at 120%. That saved some time and cash.

The inverter circuit is a little different with kind of the Magnavox paraphase divider idea.

I more than likely will go fixed bias on the outputs, or self-bias with pots.

This is been a real challenge.

Ol' Dan isn't one to say just copy a circuit, it's gotta be different, better.

But I'm finally to the point of soldering up the stripped mono amp for breadboarding.

I got wood sides and front panel planned, I want something burled and marbled looking. But for a reasonable price.

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"got wood sides and front panel planned, I want something burled and marbled looking. But for a reasonable price."

The thing to do there is to use burl veneer on MDF or birch plywood. There is a lot of wild burl around in the small quantities needed for a chassis.

This is cool:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=67234&item=7505621490&rd=1

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Man, that walnut burl looks cool!

"The thing to do there is to use burl veneer on MDF or birch plywood. There is a lot of wild burl around in the small quantities needed for a chassis."

Sounds great to me, but my chassis height is only 2 inches, and I only want the thickness of the side and faceplates not much more than a quarter inch, three eighths max.

It would seem like a real chore to veneer a 1/4", 3/8" strip to the sides.

Maybe use hardwood of some sort to veneer to, then use the same type of veneer just for the facing, and leave the sides alone.

I work around quite a few tile guys who do bathrooms and counters and all that crap. They use quarter inch thick and better granite and other types of tile.

It would be interesting to use granite or marble for side and faceplates, they could cut them to size.

The only bummer would be trying to polish the cut sides, and I'd kinda like the edges rounded a tad.

Then affixing the panels to the amp, if you could mount threaded studs to the granite and then bolt them to the amp sides and front....

It would weigh a ton, but it would look cool.

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