Tube amps and voltage….

Discussion in 'Amps and Cabs' started by pureoldsound, Sep 9, 2005.

  1. pureoldsound

    pureoldsound Member

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    Is not enough that we have to worry about getting the right amp, right speakers, tube, cab, cables, guitar, strings, pups to get the sound we want…We also have to worry about how much voltage runs in the place we’ll be playing in……

    Man it doesn’t get easier…..:D Anyway I noticed that my amp sounds completely different during the day than at night….During the day my amp sounds too harsh, no note definition, hard to tame, I have to re-set all the EQ and gain…Its frustrating.. Now at night is a whole different thing..I get a very articulate tone, I can dial in the EQ with ease, the amp gives a very warm tone…no complaints…..

    The other day my computer displayed a warning message saying that the voltage was too high....I assume that voltage as been screwing with my amp’s tone…..I might have to get one of those line regulators!!!!

    Anyone can share how likely this is?
     
  2. 908SSP

    908SSP Supporting Member

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    My guitar tech who only works a mile from me asked me approximately what time do I play so he could adjust my amp at that time of day. He says he has seen swings of between 108 and 128 volts. Enough to make a difference.
     
  3. 908SSP

    908SSP Supporting Member

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    Yea I never worry about the Ganesha it is built like an elephant and always sounds great. Some of the oldies around here I do and have a couple of variacs which I use when I play those.
     
  4. pureoldsound

    pureoldsound Member

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    I thought a power conditioner was different from a line regulator?
     
  5. 908SSP

    908SSP Supporting Member

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    Semantics and definitions what problem. Since the Ganesha controls all the voltages in the amp everywhere it is regulated since it uses a toroidal power transformer it is conditioned so I assume Dave used one term to include both processes.
     
  6. 908SSP

    908SSP Supporting Member

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    No just the Variac which I use to slowly bring stuff up to the voltage it was designed for back in 52 or 59. A power strip with surge protection probably doesn't help but I use that occasionally not always.
     
  7. hasserl

    hasserl Member

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    Funny, our voltage is usually lower in teh daytime while everyone is running their air conditioning, and gets higher at night when it cools off.

    I've seen voltages as low as 104 here! I've typically only see around 117 to 119 under the best conditions. Eh, that's California for you. :(
     
  8. drbob1

    drbob1 Silver Supporting Member

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    A variac would help tame high voltages, but isn't regulated so that it won't control variable voltages. There're two solutions to this-buy a power regulator (much more expensive than a conditioner, most of them are in the $300+ range) or use a multimeter to confirm the voltage coming out of your variac. If the minute to minute variations are fairly small, this will work-you can just adjust for day and nite differently.

    David, what sort of voltage swings can the Maven Peal power supply tolerate? How quickly does it react to voltage swings? What happens to an excessive overage? Props on an excellent "value added" feature there...
     
  9. pureoldsound

    pureoldsound Member

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    Ok I just bought a variac and I am going to get a line regulator to take care of the voltage differences…I talked to so someone who makes amps and explained what was going on with my amp. He suggested to get a line regulator and if I liked the sound at low voltages to get a variac and set the voltage on that. I talked to the guy that either fix or makes these variacs, and he told me that voltage does not affect the sound at all….he told me not to get any line regulator as residential voltages will only have about 5 volts difference between time and it will not affect the sound of the amp at all. Also that the variac will regulate the voltage just fine, and what it would do is just add more gain to the amp.....

    I don't know, I am kind of confused about this.....I thought voltage did change the sound of the amp???? I think voltage is running quite high during the day on my house as my computer displayed a warning about it. He told me that it could be a psychological thing but I don’t know I hear the amp different during the day than at night…..
     
  10. 908SSP

    908SSP Supporting Member

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    If he said that I wouldn't put much credence in anything else he said as this is just wrong. A variac will allow you to adjust your voltage mostly down maybe a little bit upward of what comes out of the wall. You test the output of the variac with your multimeter, do be careful, set the output at whatever you had when you biased the amp. Now at least you know that is constant. If the voltage varies while you play it will vary coming out of the variac as they don't have the brains to be self regulating and the reason they are so much cheaper then a full on regulated power supply which will self monitor. I also never run the variac at any other voltage then what the amp is set up for. I am not doing the "EVH" thing or increasing the voltage above the recommended voltage.
     
  11. pureoldsound

    pureoldsound Member

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    Well that's what I thought. I am not trying to do any EVH either I am trying to get the same sound I get at night every time I play. It made sense what a friend told me regarding this. He recommended getting a line regulator...that would tell me (as it has a meter) how much voltage I'll be getting during the night. If it is low or higher I will plug the line regulator from the wall then plug the variac to the line regulator set the variac to the voltage were I get the sound I like from my amp.
     
  12. aleclee

    aleclee TGP Tech Wrangler Staff Member

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    If the regulator isn't providing you with consistent voltage day in day out from venue to venue, it's doing a piss poor job of regulating. If you bias the amp at the voltage provided by the regulator, you should be able to leave the variac at home.
     
  13. pureoldsound

    pureoldsound Member

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    I have not gotten the line regulator yet....I have to get that first and see if my idea works if not I guess I'll move those toys....
     
  14. drbob1

    drbob1 Silver Supporting Member

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    The other use for a variac in addition to a regulated power supply is vintage amps. My JTM45 is happiest at 113V (when set for 110). Since wall voltage here runs up at 120+ I use the variac after the regulator to bring it down a bit. My Bassman is the same, but a little less sensitive. Anyway, at 120v the heater voltage is too high, there's a little more voltage on the power tubes, and bias is a little higher than the amp is happy with-so it sounds kind of compressed and rough.
     
  15. pureoldsound

    pureoldsound Member

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    So it does change the sound even 3-7 volts difference....I think in my case is the same thing...I just have to measure the voltage, but I am getting the Line regulator anyways.....I thought this was all in my head but my amp which is an exact replica of a 1968 plexi 100w...might like lower voltages as well..as I here it completely different when voltages are lower...When is high I get exactly the sound you described. It is harsh and extremely in your face....now when voltage comes down it is articulate, I can hear note definition, warm....
     
  16. jzguitar

    jzguitar Member

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    I'm so happy that I've got something else to worry about at gigs!

    For those of you with Variacs - where is the best place to get one, or do you have to find someone to build one for you?

    I do have an older Furman regulator that I may start bringing - I'm using a Dr. Z amp and I'm assuming it's not as finicky as some vintage amps. I do hear a difference from venue to venue, but I'm not sure how much of this is voltage and how much is other factors.

    Thanks for the info!

    jz
     
  17. pureoldsound

    pureoldsound Member

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  18. pureoldsound

    pureoldsound Member

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    I got a varic today and tried it. I don't know if it is all in my head but there was a change in the amps sound. From all in your face harshness by lowering the voltage on the variac it tamed the harshness and let the growl of the amp to come out. I max the gain and it was very pleasing. I still have to get a voltage regulator to make the correct assumptions. But so far I think voltage was a factor on my amps tone.....
     

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