Here is a photo of one of the M2 amplifiers that First Watt sold to customers, for money. You can just barely read the logo on its front panel. {Click on the image to see it full size, and also click on the white X in the corner of the image}
What are those things at the bottom of the picture, below the toroidal transformer? The one on the right has blue and gray wires, the one on the left has yellow and red-orange wires. What ARE those mysterious doo-dads that Nelson Pass put into the original M2?
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What are those things at the bottom of the picture, below the toroidal transformer? The one on the right has blue and gray wires, the one on the left has yellow and red-orange wires. What ARE those mysterious doo-dads that Nelson Pass put into the original M2?
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ok, i get it. i'll use the bridge rectifiers you suggested and ask no further questions
Generally I use a bridge rectifier in the GBPC "square block" package, when the transformer rating is more than 150-200 VA, and the diodes are going to dissipate significant amounts of heat. Bolting the bridge rectifier assembly to the chassis solves the heat problem quickly and easily -- and the bridge occupies less room on the heatsink / chassis floor, than four individual power diodes.
Below is a link to a power supply I designed, that uses four individual Soft Recovery diodes rather than one bridge rectifier. It's for a stereo pair of LM3886 "chip amps", using a 200VA mains transformer. Notice how puny the individual heatsinks are; you can't get away with something this scrawny in a First Watt amplifier running Class A!!
Below is a link to a power supply I designed, that uses four individual Soft Recovery diodes rather than one bridge rectifier. It's for a stereo pair of LM3886 "chip amps", using a 200VA mains transformer. Notice how puny the individual heatsinks are; you can't get away with something this scrawny in a First Watt amplifier running Class A!!
Ok.....I use four individual Sic Cree diodes for the ACA (4 for each channel). That is without heatsink. They reach about 70 degree C. That is probably the limit where they can be used without heatsink. You can't call the ACA a FirstWatt amp......or can you? …..all the other amps needs more power. I agree that it is much easier with a bridge which can be mounted using only one screw. I wonder why you can't get Schottky diodes in such a package…….
That would be great, but you have to let me send something in return. If I generate a model I will post it here.
Sounds like a fair trade! Send me your shipping address via PM and I'll mail them on Friday.
edit: readers may wish to study the datasheet of the input IC used in the M2x Norwood input stage: (link to pdf). What do you see in the figure on page 3? {upper left}
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Those are "node names" not part IDs. I put them on the schematic to make it easier to discuss the circuit. Instead of saying "the output of chip U4" we can now say "Bob".
And by the way, member GOR previously chastised me for naming the last one "Dave" instead of the more cinematic name "Ted". link to IMDB
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And by the way, member GOR previously chastised me for naming the last one "Dave" instead of the more cinematic name "Ted". link to IMDB
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I would have gone with the more obscure, but much funnier Hansel & Gretel & Ted & Alice...
(From my very mostest favoriteist Peter Schickele album; )
Music: ‘Hansel Gretel, Ted & Alice’ - The New York Times
The Intimate P. D. Q. Bach - Wikipedia
(From my very mostest favoriteist Peter Schickele album; )
Music: ‘Hansel Gretel, Ted & Alice’ - The New York Times
The Intimate P. D. Q. Bach - Wikipedia
I had wondered about GOR's comment, thanks for finally letting us in. Now I'm wondering about the HiFi components in your cinematic link - Bob & Carol & Ted & Alice (1969)
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My wife did the graded gate on the FET's which killed the impact ionization on our bi-FET's. That's how we met.
I would have gone with the more obscure, but much funnier Hansel & Gretel & Ted & Alice...
(From my very mostest favoriteist Peter Schickele album; )
Music: ‘Hansel Gretel, Ted & Alice’ - The New York Times
The Intimate P. D. Q. Bach - Wikipedia
I saw him in concert in Toledo Ohio in the 1980s. He was a riot. In high school, our choir director had us sing some of his music....Please kind sir that portrait I see, if that's your daughter, present her to meeeeeeeee.... Look her face could launch a thousand ships......
In the 1970s, it was audacious stuff.