Search results

  1. triode17

    Filter cap question

    40uf is fine. SS rectifiers generally have a high surge rating, although vintage rectifiers may not. Try looking up their specs. and compare to a modern rectifier like a 1N4007.
  2. triode17

    Dynakit ST70 Bias Question

    Johnny- I would be concerned about this. The bias control may have gotten dirty inside, causing the erratic changes. This can cause an overload condition. Try a simple solution, turn the amp. off, note the approximate control position and rotate the control from end to end about ten times. Reset...
  3. triode17

    Phono Dropout on my PAS 3

    This could be as simple as a dirty tube socket. Remove each phono tube, by wiggling it out one at a time then reinserting it a few times. Try the preamp again to hear if the problem has stopped. If so, clean the pins of each tube with DeOxit or an equivalent contact cleaner.
  4. triode17

    Vinyl vs. CD vs. Streaming. Which do you prefer and why?

    Vinyl. It has an infinite sampling rate. It's a reproduction struck from the original source. Anything else is only a blueprint of the original.
  5. triode17

    Is 20 Watts per channel enough?

    How DO you know?
  6. triode17

    Tube Amp Newbie

    No, I ran the phono stage into the CD recorder to do a transfer. I have since built a stand alone PAS phono stage but added an Aikido output buffer which alleviated the problem. Sounds great, full Bass.
  7. triode17

    Tube socket glue....

    Nothing bad will happen. I have used those tubes that were glued without any problems.
  8. triode17

    Tube socket glue....

    I use RTV (silicone glue) and it works fine. A bit messy though ,be careful.
  9. triode17

    JFET vs tube buffers

    I recommend the Aikido Cathode Follower from Glassware audio. I have used them in a few hand built preamps and they work very well. Excellent sound and it can drive down to about a 20k Ohm load, so you can hook anything to it. Available as a kit or you can breadboard it from their schematic...
  10. triode17

    Build Thread - Modern Power EL84 P-P amp

    Another note, I just built an experimental, split load phase inverter and and it oscillated coming out of the driver. Try a 100pf in series with 22k ohms from the plate of the driver to ground if this occurs.
  11. triode17

    Dynaco ST70 Distortion.

    It's something common to both channels. What are the 'biaset' voltages on the front panel?
  12. triode17

    What would be the sound of a failing coupling cap?

    you mentioned loose sockets once. Be sure there are no connections from a tube pin to ground through the base. I chased one like this in an ST-70 for hours once. If in doubt, connect a wire from the pin to the main cap. ground.
  13. triode17

    What were your first set of headphones, and let's hear the story behind them.

    Karl, these were modern phones for 1970. Who else remembers the 414's? I still have them. My only other complaint was I had to squeeze the phones on my head to get any decent bass. Studios used them. Eventually, I bought a Radio Shack output transformer that converted 1000 ohms to 8 ohms and...
  14. triode17

    Welborne ST-70 has arrived w pics

    What are the "model numbers" of the preamp tubes? In what positions?
  15. triode17

    I think I just destroyed a Scott 222c. Should I give up trying to learn how restore audio gear?

    Are you sure you didn't have the meter leads connected for a current reading? The high scale 10 or 20 amps. places a very low resistance shunt across the leads. That could have caused the damage. Also, you don't measure the voltage 'across' the transformer, you measure it across the input side...
  16. triode17

    First time buyer

    Are you sure about this? 15 sq. ft. is equal to a 3x5 foot room. I think a jail cell is bigger! Do you mean 15 foot square?
  17. triode17

    can different tubes make amp "shine"??

    I have found that the driver tubes (just before the output tubes) have the largest influence on the sound. They do the heaviest lifting.
  18. triode17

    Sherwood S-8000 IV pilot lights

    Yes. I have one and the lamp is located on the edge of the dial glass.
  19. triode17

    Filter cap buzz....should I worry?

    The cap may have loose foil windings. What you are hearing is probably an upper harmonic of the 120Hz. power supply ripple. It may not cause any trouble but you can replace it if it bothers you. Talk to the parts vendor about it, you may get a free replacement.
  20. triode17

    How to Repair Rubber Speaker Surround Puncture

    Lucky- I did the same thing once and (also) used RTV to repair the puncture. I smeared on a light layer of it with a wet finger and its been fine for years. I even checked it with the manufacturer and they agreed it was a good fix.
  21. triode17

    question about tube warmup while testing

    The answer here is yes and no. Although both sections are warmed up , heater -wise, in my Heath TT-1A tester, only one section at a time is actually loaded. So, when I switch sections to test, I do wait about a minute to assure its warmed up properly. I can't speak for the TV7.
  22. triode17

    Heathkit W5M rebuild problem

    These were kits. Is it possible that the transformer taps were misconnected? Double-check this.
  23. triode17

    Is an hour playing music equal to an hour warming up?

    According to Morgan Jones, the heaters take one minute to get to full temperature, the cathodes take 5 mins. I have measured the plate currents of power tubes and they take 10 mins. to get to full current. So, I like to give 15 mins. for serious listening. But after an hour or so, the whole amp...
  24. triode17

    "Properly" charging SLA battery

    Unitrode makes a charging IC for this purpose. I don't know the part number, you'll have to look it up.
  25. triode17

    Any Lafayette LA 350 experts (or just tube amp noise issues)

    I wouldn't pull the 6AN8s' while it's on. That can cause an instability which could damage the amp. Turn it off first.
Back
Top Bottom