Can i substitute two .022 capacitors for a .047?

Discussion in 'Tube Audio' started by HiFi-Stereo, Jan 11, 2019 at 4:10 PM.

  1. HiFi-Stereo

    HiFi-Stereo Active Member

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    I'm working on a Voice of Music 6V6 mono amplifier, and there are two .047 capacitors coming off of the 6V6 tubes... I replaced them with one new .047 on one tube, and put together two .022 capacitors for the other tube since i ran out of .047's. The twin .022 caps measured .043 together...
    Will that affect anything being slightly different values on the tubes?
     

     

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  2. gadget73

    gadget73 junk junkie Subscriber

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    parallel them, yes.

    In a perfect world they'd be very closely matched, but in reality you're within 10%, which is likely better than the original part's tolerance anyway.
     
  3. savatage1973

    savatage1973 AK Subscriber Subscriber

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    Did you measure the 0.047 cap?--how close is it to the measured .043 of the twin (paralleled, I assume)? If within +/- 10%, I wouldn't expect much/if any difference--that is a "normal" tolerance range.
     
  4. HiFi-Stereo

    HiFi-Stereo Active Member

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    Thanks, good to know! I'll leave them alone then...
    Also, the 2- 6V6 tubes and the 5Y3 are all close together and when i put my hand over the top of them, they seemed super hot after about 10 minutes of running... Is it normal for them to get really hot? The glow of them looks normal...
     
  5. savatage1973

    savatage1973 AK Subscriber Subscriber

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    Tubes (especially in close proximity of one another) can get hot. I don't know how much tube experience you have, as to what you consider to be "hot". If in doubt, check the bias of the output tubes to make sure it is within acceptable limits. Even different circuit configurations will make the same tube(s) run hotter in similar applications.
     
  6. primosounds

    primosounds Powered with pure tube sounds. Subscriber

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    In a pinch it is fine to do that, for example for testing, but really, you would want to have all the same brand and value coupling caps.
     

     

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  7. century tek

    century tek Super Member

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    You may or may not notice a difference in tonal quality between the channels, but yeah, its best to use the same for both channels.
     
  8. toxcrusadr

    toxcrusadr Omelette du Fromage Subscriber

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    Power output tubes are the hottest in the circuit, I think.
     

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