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    It seems unsafe with those big value resistors....

    It seems unsafe with those big value resistors. 12ax7 seems weak to can push the power tubes into grid current territory. For the moment it not work properly as it is, have to do a fresh recap. but...
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    Simms watts 200 question

    Hello. Got a Simms watts 200 to restore, 4xkt88 in UL mode supplied at ca. 650V arround. What is wondering is its poor 12ax7 driver into big 220k grid leaks. Thinking more to add a pair of...
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    Always I try to look and understand who have to...

    Always I try to look and understand who have to gain something from this
  4. Someone consider a hundred volts as a safe limit....

    Someone consider a hundred volts as a safe limit. For this reason a diode or neon bulb will work. As time the voltage drop below 90v it will be blocked so in fact is out of circuit.
  5. Isolation between grid and cathode is supposed to...

    Isolation between grid and cathode is supposed to be passed through. When cold we have whole HT voltage on the grid whilst cathode stay at 0 potential. ( cold heaters meant no current flow, no...
  6. Can You post a picture how you tone stack is...

    Can You post a picture how you tone stack is wired ?
  7. Actually there are two separate secondaries in...

    Actually there are two separate secondaries in parallel think they did it for interleaving reasons .
  8. Eminent is not a guitar amp. Get full...

    Eminent is not a guitar amp. Get full documentation here, from Mr.Peter Andersen effort. Many Thanks!
    http://www.peel.dk/Dynacord/

    Almost forgot: Get first check to bias trimmers. This is very...
  9. ...Let see the donor...TG9375, right ? 56886...

    ...Let see the donor...TG9375, right ?


    56886

    Have some scope screenshots by my tests. You can get 120w at 480V with a quad of EL34.
    This trannies runs pretty hot I remember. Don't worry to...
  10. Think it was. I don't remember precisely. I...

    Think it was. I don't remember precisely. I recovered a bunch of good Partridges from SC scrap but had care to carefully notice its specs. What I remember precisely after I did some tests it was this...
  11. These are the specs of my tranny: 4 ohm -...

    These are the specs of my tranny:

    4 ohm - green
    8 ohm - brown
    16 ohm - yellow
    100V - blue
    Common - black
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    Hi, Yes, is ringing also without nfb connected,...

    Hi,
    Yes, is ringing also without nfb connected, same manifestation. Time to look for a Zobel alternative. Thanks for support.
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    Similar arrangements into a Grommes amp, not...

    Similar arrangements into a Grommes amp, not quite same paraphase aplication.

    56606
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    So what are substantial diferences between those...

    So what are substantial diferences between those two variants pls?
    Why classical arrangement with the shunt resistor in the bottom is preferred?
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    56604 The original circuit was modified to...

    56604

    The original circuit was modified to allow the whole bias over nfb resistor
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    Thanks for You answers..The circuit comes from an...

    Thanks for You answers..The circuit comes from an old schematic relative to applying nfb into a paraphase inverter, I remember. In any nfb circuits some bias is developed over nfb resistor, I just...
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    Well, I have to keep those 1.5k resistor as bias...

    Well, I have to keep those 1.5k resistor as bias resistor for cathode. I will play with the value of shunt resistor till desired nfb amount. Thanks
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    Hey, thanks for input. The bias for first stage...

    Hey, thanks for input.
    The bias for first stage is made over 1,5k resistor which is relative to ground through secondary winding. The feedback ratio is determined by 1,5k / 47ohm resistor which is...
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    NFB network compensation help pls.

    Hello,
    I trying to implement some (6db arround) nfb into my project. For some reason testing at 1 kcps with square wave is ringing a little bit too much. I tried to compensate with a capacitor...
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    Those MV is not "transparent" and think no one...

    Those MV is not "transparent" and think no one will be. But is great useful tool even for bedroom levels. Put it into max position and restore the amp in factory condition. I installed tens in...
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    Thank You

    Thank You
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    Thank You. How accurate this method is, please ?

    Thank You. How accurate this method is, please ?
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    Trying to dampen impedance peaks at resonant...

    Trying to dampen impedance peaks at resonant frequency using different methods. I wonder how effective are? I have a good signal generator and the 2k OT will help to drive the speaker. But have no...
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    Impedance measuring jig

    Hallo. How can I measure the impedance peaks of a speaker at resonant frequency, please ?
    I have an 600ohm output audio generator. A hefty 100w 2k output transformer and a multimeter. Thanks
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    It works pretty well like in post #3. Shielded...

    It works pretty well like in post #3. Shielded wires are not necessary but twist wires well. At minimum settings the effect of presence pot will be none.
  26. I.m even worst. I smoke two packs of cigarettes...

    I.m even worst. I smoke two packs of cigarettes per day (not quite, but close) but don't recommend to anyone.


    Just kidding...:tape:
  27. It looks like as time any builder looking for...

    It looks like as time any builder looking for neaty wiring, keeping wires as shortest or as close to ground mass or orthogonal posing, twisted or whatever...to claim to have not care about cap...
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    Alles klar!Kann night spreche in gutte Deutsch...

    Alles klar!Kann night spreche in gutte Deutsch auch. Tut mir leid.
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