Hey! I've read the other posts on this but don't find quite what I'm looking for.
I would like your opinions on the following idea.
Push pull transformer. One side a 6L6 or similar, the other side a 10M90S.
Would this effectively make a single ended amplifier with a PP transformer with the CCS just balancing DC in the core? I read about similar ideas but don't know anyone who's built it. Except for the ridiculous heat sink it seems like it would work?
Cheers.
I would like your opinions on the following idea.
Push pull transformer. One side a 6L6 or similar, the other side a 10M90S.
Would this effectively make a single ended amplifier with a PP transformer with the CCS just balancing DC in the core? I read about similar ideas but don't know anyone who's built it. Except for the ridiculous heat sink it seems like it would work?
Cheers.
I built this one, or rather breadboarded it successfully: http://www.diyaudio.com/forums/tube...class-a2-set-secondary-flux-cancellation.html
I'm currently building two channels into a chassis for use in my listening room.
I'm currently building two channels into a chassis for use in my listening room.
Bias it for class A and use a power resistor for the inverted side Q-current.Hey! I've read the other posts on this but don't find quite what I'm looking for.
I would like your opinions on the following idea.
Push pull transformer. One side a 6L6 or similar, the other side a 10M90S.
Would this effectively make a single ended amplifier with a PP transformer with the CCS just balancing DC in the core? I read about similar ideas but don't know anyone who's built it. Except for the ridiculous heat sink it seems like it would work?
Cheers.
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Bias it for class A and use a power resistor for the inverted side Q-current.
Not a bad idea! And a power resistor doesn't need a $50 heat sink!
Suitable heatsinks are cheap enough and easily salvaged from dead amps. Even a power resistor will likely need a decent heatsink. However a suitable power resistor will be more expensive than a IXY chip and a salvaged heatsink.
Additionally the CCS brings the benefits of a high impedance which will lower overall distortion.
Shoog
Additionally the CCS brings the benefits of a high impedance which will lower overall distortion.
Shoog
Not a bad idea! And a power resistor doesn't need a $50 heat sink!
The problem with this idea is the total power needed from the PS. Are you going to do stereo? An SE amp and one tube per output is going to run @50ma x 2 and the PS tranny is going to be sized for that. If you go 50ma x 4 you need a bigger PS tranny. Too much wasted power.
Suitable heatsinks are cheap enough and easily salvaged from dead amps. Even a power resistor will likely need a decent heatsink. However a suitable power resistor will be more expensive than a IXY chip and a salvaged heatsink.
Additionally the CCS brings the benefits of a high impedance which will lower overall distortion.
Shoog
That was my first idea. I already have 10M90S. Even salvaged heatsinks are expensive in Toronto.
The problem with this idea is the total power needed from the PS. Are you going to do stereo? An SE amp and one tube per output is going to run @50ma x 2 and the PS tranny is going to be sized for that. If you go 50ma x 4 you need a bigger PS tranny. Too much wasted power.
Class A is a waste of power in the first place so I'm not concerned about the transformer...
You will need a power heat sink.
Just use a second 6L6 and don't drive it.
Once you get there you might as well tie it's grid to ground and use a common cathode resistor, but now it is PP and will partially cancel 2nd Harmonics.
Or how about making it switchable by having a switch that can tie the cathodes together through a big cap? Use a CCS in each cathode bypassed by large caps, and use the switch to go from PP to SE?
Active Surplus went out of business, A1 has salvages heatsinks but he wants too much for them, and the only other electronics surplus guy has virtually no heatsinks. I know I could use a CPU heatsink but I don't want to go fanless and they aren't big enough for that.
Scrap metal dealers here mainly deal with actually scrap like washing machines etc.
All the good electronics shops have closed down... The one close to me wants 25 cents for one 1/2W resistor. I get them for about 1 cent from China.
Scrap metal dealers here mainly deal with actually scrap like washing machines etc.
All the good electronics shops have closed down... The one close to me wants 25 cents for one 1/2W resistor. I get them for about 1 cent from China.
Class A is a waste of power in the first place so I'm not concerned about the transformer...
Are you starting with a PP amp, now, and just dropping the inverter side?
Correct. but I don't have/want 700V B+
I hear dat... Well, the resistors could be brought up top where the tubes would have been and sandwiched between two sinks with clips. It wouldn't look bad if you use some artistic vision. Paint them to look like hazardous warning signs... Have fun.
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You can use an incandescent bulb, or a pair for 240V to load 450V B+ for GU-50 SE.
I've heard about loading with an incandescent. How does it work?
I assume you need like 200W bulbs? And I'm assuming they change brightness with the music? I'm using 6P3S tubes BTW.
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