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Baldwin 6L6 organ amplifier


Erik Mandaville

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I forgot to mention this in our elongated discussion of subwoofers and whether they can be effectively used in Klipschorn based systems. I've heard from so many who really like them, I am looking very forward to investing in one for us -- it's going to be an SVS, though the model hasn't been decided upon yet. It's going to be a post-holiday expense anyway, so there is time to discuss and investigate that.

So, to the Baldwin. This was a $250 purchase that another forum member sent to me to look over, test the tubes, capacitors, etc. The twist lock caps loosened in shipping, four solder connections were improved, and one of the four 6L6s tested very low and was thrown away. A Brand new set of matched Electro Harmonix 6L6s were set into position, and I was simply amazed. This is (now) a stereo amplifier, having had some changes made to the circuit for operating as a stereo amp. The OPTs are very high quality, and the power transformer is the largest PT I have ever seen.

I did not know what to expect, but what this amp provided in the way of music for $250 was almost ludicrous. It was that good! On top of everything, it is probably more quiet than my own amps AND the current SE OTL now in the system. The DRDs have everything beat as far as residual noise goes, though. After hearing the pair I worked on and modified for Wolfram, I am determined to either get a pair for myself sometime, or more probably build one from scratch. The 45, 1 watt triode is terrific sounding.

This battleship like Baldwin amp operates in self-bias mode, and is totally user friendly. In the few days I had it here, I will say that it sounded nearly as good to me as any of the best amps I have had in our system. What a great deal this was.

This is to illustrate that one can find exceptional performance for a very modest cost. There are some other vintage amp companies, such as Heathkit, that used this particular tube, but I'm more familiar with it for musical instrument amplification. For home music making, though, this amplifier was something I think you all would really have liked.

I'm going to be installing a pair of variable L-pads on of the type A crossovers I built, and will let you all know how it works for attenuating and balancing the mid horn. It's being done on my networks first for a test, and then will be installed on a friend's if it works out. For those of you who think your midranges are too hot and want an easy way to balance it, this may be at least one answer. I'm going to be using a notch filter on my own K-55s, but don't have the parts yet. I think this has been discussed in the past, but it should even out a peak at about 9kHz. I have still yet to hear any honking with the AL network. It has been sounding fine.

...I think I'm going to start keeping an eye out for Baldwin tube amplifiers.

Erik

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Sounds interesting as always, Erik. I'm a believer, eventhough I personally never heard an electronic organ's amp used for stereo use, I used my bro's '62 Magnavox 6QB5/EL84-based console amp for a short while in my system and was literally blown away by its sonics! And I'm always hearing about an old organ find at a local Goodwill and its hidden treasure full of vintage tubes, power trannies, and speakers tucked neatly inside. Seems Baldwin organs aren't the only finds out there...look for old Allen, Conn, WurliTzer, and Hammond to name just a few. I'm sure their amps are just as fascinating as the Baldwin's.4.gif

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Mike,

Big iron on that Allen.

Erik,

Very cool. One of the guys at diytube took the EL84 amp they sell the boards for and changed a few parts (power transformer for one). Ran jumpers off the PCB to octal sockets and ran 6L6s with it. He says it kicks pretty well.

Marvel

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You guys have posted really great finds like this in the past, and I have always thought they were really neat. It just reminds me that much of the current technology we now enjoy in modern designs is a pretty close reflection of things already done, ground already traveled, and so forth. And this amp really did sound incredibly good. It was pure 'function' in appearance, and there was something about that that really appealed to me.

Dee: I don't know all of the history of this particular amp, but you ask a good question. The amp is equipped with two identical OPTs, one for each channel. During its earlier life (it is a functioning antique, after all...)I believe each of the two sections (now the right and left channels of stereo)was dedicated to different frequency ranges -- one low, and one high. whatever was done internally, which I would like to get a schematic for (that might be hard to do), split those sections equally between the two outputs; thus allowing for full frequency response from each channel. Gosh, this sounds awfully vague to me, but that's the best info. I can give you on it. I've been in touch with the seller, but he doubts a schematic can be found. It's really very much of a dual mono design with dual rectifiers and ripple filters, and I was just blown away by how good it sounded -- for $250. There was not even the least bit of hum. There was at first, but I think that was caused by a loose ground connection on one of the twist-lock multi-caps. Either that, or the new tubes cured it. In any case it, it is a wonderful amp.

time for bed...

Erik

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Erik,

There are resources for Baldwin organs and repairs. We got a full repair manual for an early solid state model that our church has. I'll see if I can rustle up the info where I got the manual and they had most everything available.

Was there any part number or model number on the amp? That would help to get the right paperwork.

Marvel

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