Ok, I've got a couple of C3Gs knocking about, and the 6550 pp I built a while ago. Will they go together? I've drawn up the front end of DTB's C3G/2A3 feeding the 6550 o/p stage which is wired with one grid earthed to preform the phase-splitting function.
Will it work? Will the c3g drive the 6550s? I've removed the feedback loop from the 6550s. Will they object?
Schematic here: http://www.thepippin.plus.com/Misc/6550-c3g.pdf
Just fooling about.
#2
You would need to change the output stage to use a shared cathode resistor with no bipass cap, or even better a CCS, otherwsie it wont work as a phase splitter.
It will work though, only one valve will be driven with a signal, the other will just provide the standing current to prevent the OP TX from saturating.
It would be interesting to see what it sounded like, as its half way between a SE and PP amp.
It will work though, only one valve will be driven with a signal, the other will just provide the standing current to prevent the OP TX from saturating.
It would be interesting to see what it sounded like, as its half way between a SE and PP amp.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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shane
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#3
Like this? How would I set the value of the CCS resistor?
http://www.thepippin.plus.com/Misc/6550-c3g-2.pdf
http://www.thepippin.plus.com/Misc/6550-c3g-2.pdf
#4
Set the resistor so that at the required current, the voltage across the resistor is the target value for the regulator. I think it s1.25v, check the the spec for the reg. So if you wanted 120ma, use ohms law
R = E / I
R = 1.25 / .12
R = 10.4
R = E / I
R = 1.25 / .12
R = 10.4
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andrew Ivimey
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#5
Hello Shane, could I remind you that you must bear in mind that an LM317 can only take 40volts across it before it fails. The (only) weak spot to the Lazy'mans constant current source, as I remember its called, is this voltage limit.
Your output valves are prob. within limits but it might be worth checking.
Your output valves are prob. within limits but it might be worth checking.
#6
good point, though with that voltage you have a lot of other options, A c4s would work, It will be dissapating about 5w so some heatsinking will be needed..
Actually, a c4s would be a problem as its a better source, the LED string voltage would be a problem. There are some sinks in MJ that would do the job.
Actually, a c4s would be a problem as its a better source, the LED string voltage would be a problem. There are some sinks in MJ that would do the job.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.