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Lamm schematics

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#1
Does anyone have schematics for Lamm M2 amp? Is there any way to get the schematics? If not, could anyone recommend a different amp, with readily available schematics, that is on the same quality level more or less?

Thanks
 
#5
Konnichiwa,

eitanwaks said:
Does anyone have schematics for Lamm M2 amp? Is there any way to get the schematics? If not, could anyone recommend a different amp, with readily available schematics, that is on the same quality level more or less?
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I doubt you can get the exatc schematic, but quite frankly, what Vladimir Shushurin does is easy enough to decode.

The signal circuit uses a 2-Stage driver with 12AX7 & 6N6. You can find similar circuits in 6S33 Amplifiers from Audio Professor Japan (they have schematics on their website) among others. Some such Schemes use SRPP -> DC couled Amplifier Stage -> AC couled to Cathodefollower which drives directly the 6S33, like this:

An externally hosted image should be here but it was not working when we last tested it.


I suspect Vladimir Shushurin uses a simple RC coupled 2-Stage variant of this, no cathode follower. You find the same sort of thing also in the 300B & 211 SE Amp from Air Tight.

6S33 is fixed bias run with a lot of current and low anode voltage. I think I mentioned the values in another thread on the 6S33 (175V/300mA - I just checked).

PSU is regulated with a very classic valve regulator circuit Neon reference, Pentode Error Amp and 6S33 Regulator. I call such circuits generica simplicima.

The transformers are claimed to be rather unusual and custom, so you'll be out of luck on exact copies.

But from the damping factor/output impedance of the Amp (2R @ 16 Ohm Load) and the 6S33's anode impedance (80R) you can work out the ratio as 640R primary, so any really good, big and high primary inductance OPT with 600R Primary and 300mA DC current handling will do.

Sayonara
 
#7
analog_sa said:
Anyone knows why this thing is so expensive? Hammond chokes?!
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The amps possibly have a silver wire OPT, but I'm guessing saying that. Any amp that can claim the title "best" by reference to published reviews can basically set its price, even if that amp betters the competition by only a hair. I don't doubt the amp is by some measure good, and that it probably betters its competition. I do doubt it approaches the actual existing state of the art.
 
#9
Anyone knows why this thing is so expensive? Hammond chokes?!
Click to expand...

$29,000+ for 6C33C amps is ridiculous. One of the funniest things I've ever read read in Stereophile - when asked if there were any way to improve the amplifier, Shushurin said he would like to add a vacuum tube rectifier, but it would be too expensive.

Actually it wasn't that funny, it made me angry.


John
 
#15
:cop:

Comrades, let's not get into racial generalizations.

(/cop off)

The price charged here is more related to fashion than to bill of materials or actual quality (or location- there's lots of well-priced product coming out of NYC). There are still suckers in this world, and when that is the case, there's always Stereophile to turn their cranks.
 
#20
Little doubt Romy The Cat has nice pics. Plus he's a professional photographer. Have you got any cute kittens to trade?
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He reminds me a little too much of David Berkowitz, so I'm not going to send him any cats. I don't want to feel responsible if they start giving him orders.🙂

John
 
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