The Mysterious Attenuator

Discussion in 'Effects, Pedals, Strings & Things' started by IluvRock&Roll, Oct 2, 2006.

  1. IluvRock&Roll

    IluvRock&Roll Member

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    :puh

    Need some help with the Attenuator. I have only read minimal info on these 'gadets' and I like the idea of what they do. The thoughts of my amp driven to pure od sounds like a great idea. I play a Fender Deluxe Reverb RI which, of course, has no od channel. Currently am satisfied with the Java Boost and OCD for od needs; but I wonder as I wonder what the amp would sound like with the attenuator. It's just a mystery to me.

    Can you tell me if running one would shorten tube life dramatically as I cannot afford to replace tubes on a monthly basis?

    Which 'brand' would you recommend?

    I know nothing of what I would need here, but am willing to give it a try so what do I need to know BEFORE BUYING?

    Thanks alot!
     
  2. e-z

    e-z Member

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    You are going to get opinions ranging from "use 'em all the time" to "never!". Definitely do a search on "attenuator" and you'll find lots of info. My personal experience is with the THD Hotplate which I would recommend trying. Remember that you will need to adjust your amp's tone controls when using an attenuator to really dial in the desired sound, whatever that may be.
     
  3. g3rmanium

    g3rmanium Member

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    It's different, but with my HotPlate, quite acceptable. You lose the sound pressure and maybe the energy, but you can run your amp flat out without disturbing anyone.

    No, probably not.

    I use a THD HotPlate together with a 69 Super Lead 100 W. That amp had some problems so it sounded like a broken Fuzz Face until I had it repaired. I'm still working on dialing in the sound though.
     
  4. StompBoxBlues

    StompBoxBlues Member

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    It would be good for you to try it anyway. I also recommend the HotPlate (you have to buy the one that is designed for the right impedance, the same as your speakers and output impedance on the amp).

    Not sure from your post if you know how they work, or not. Mainly, they put a resistance (not pure resistor though...since impedance changes with frequency) impedance in line, breaking in between your output transformer and the speakers.

    The HotPlate, personally I like a LOT...it even has switches for getting back some lost frequencies when attenuated.

    I don't think you will go through tubes more often (though there is a discussion about this...where some people I really respect said that in fact there is some possibility that the tubes get some kind of arc or lose their charge ability...not sure exactly why) mainly...the idea mostly came about maybe because it is, to your amp, exactly like turning up the amp way more often...so in that respect it can seem like you go through tubes more often, but even without the attenuator if you had cranked up that high you still would have gone through the same tubes, same rate.

    One thing though to keep in mind...your amps OD sound is only partly the overdriven output tubes....it is also the speakers getting and playing the signal, and MOVING AIR...that is part of the overall OD sound...so if you move less air that aspect is going to be absent.

    Compared though to Od's (which are working on the input signal) probably get you in the same boat.

    There are a couple other benefits of having an attenuator. One is, when the soundman frowns on your amp...saying you MUST turn down, this gives you a nice option for keeping it cooking, but less volume.

    Another thing, if you service your own amp, it is fantastic to be able to turn way down the output (or even not hook up the speaker cab, using the HotPlate to it's "Dummy load" setting) so when you are measuring voltages for example, you don't get that startling "crack" sound when you touch the voltage probe to the tube pin...that crack can sometimes ake you slip and is definitely unnerving.

    I trust the HotPlate, but am not sure I would ever buy one used. Not knowing what abuse has been done to one before, you have to keep in mind, the HotPlate (or any attenuator) in line like that...IF it fails is going to probably wreck your output transformer. That could be costly. It is putting one more thing in line that CAN go wrong.

    Have to weigh the plusses and minuses.
     
  5. IluvRock&Roll

    IluvRock&Roll Member

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  6. StompBoxBlues

    StompBoxBlues Member

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    Yeah, that should be it. It's one 8-ohm speaker right? AND the owners manual also calls for 8 ohm impedance total? IF so then yeah.
     
  7. IluvRock&Roll

    IluvRock&Roll Member

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    Yes, It's a 1X12" Celestion Greenback Speaker @ 8 ohms. The manual says:

    Output: 22W at 8 ohm (speaker Jacks)
    Inputs 2: 136K ohm (both channels

    Almost forgot to ask. Can you turn the Attenuator on\off with a footswitch to use it like a Stomp Box?
     
  8. StompBoxBlues

    StompBoxBlues Member

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    No, you can't really (as far as I know) turn it on and off like that. I think the "shock" of rapidly changing the output impedance (even briefly like that) would be way too dangerous to the Output Transformer.

    Keep in mind too, always have the amplifier off when you hook up, or remove, the attenuator. Make sure the cable is connected all the way (unless using "dummy load", in which case no sound is output).
     
  9. StompBoxBlues

    StompBoxBlues Member

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    In fact, you might want to ask the moderator to move this to "Amps and Cabs" forum here....there are a lot of really knowledgeable folk there...in fact, do a search in there on attenuator and check out some of the discussions (there have been a LOT of them).

    Some heated discussions, but it would be good for you to read, and again, some very wise folk wrote about these things. Attenuators are not the perfect solution...but they can be useful. I am glad I have one, and have used it on gigs.

    Other options, more costly, are "power scaling" which you might also search on in there...this is a more intrusive mod on the actual amp, that I have no direct experience with but it sounds like it is a great option. It is "sort of" (reallt not looking to get stomped here, I mean only generally) like having a master volume, but one that adjusts the whole amp instead of just one gain stage. A few people have been amazed at their results with power scaling.

    But you mentioned not having enough to be changing tubes so often, so this might be out of reach for you right now. Need a good amp tech to install it too.

    The HotPlate is not a bas option...you'll have to judge yourself if it gives you any more than the OD on input signal way.

    Good luck!
     
  10. AndreasG

    AndreasG Member

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    Attenuators are IMHO the best way to get overdriven tones from a tube-amp on rehearsal/stage-settings (if you need bedroom settings, better get a headphone amp). You might loose some (very little) tone, but how much tone you loose with your amp on "2" and a chain of OD-Boxes? I heard the Marshall Power Brake works well with Fender amps (strangely enough) and maybe you get one cheap as they're considered somewhat lesser attenuators.
     
  11. Doug H

    Doug H Senior Member

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    Agreed. Attenuators can be effective for knocking a few db off, but running a 100 watter at bedroom volume will basically turn your amp into a fuzz box- not enough air moving plus the apparent bass loss at low volume. May as well get a fuzz pedal and run your amp at a lower volume for that situation. For stage volume though, an attenuator or combination of attenuator and post-PI master volume can be effective.
     
  12. Jacobpaul81

    Jacobpaul81 Member

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    As others have mentioned, the point of the atteunator is not to save tubes, but to push them properly, to get amp gain, without all that crazy unecessary volume. I have a 16 ohm hotplate setup for my AC30 which is paint falling off the walls loud, when Im not using the atteunator. The atteunator lets me get the volume down enough that my house isn't falling to pieces, but I still get a nice gain.

    I don't recommend setting a hotplate to it's minimum setting. That seems to add alot of unecessesary compression, so plan on having it still set to have some volume, even if its the setting one from the bottom.
     
  13. StompBoxBlues

    StompBoxBlues Member

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    Your post...for some reason, made me realize something about attenuators that I actually hadn't thought of and never seen mentioned before.

    When you mentioned the "unnecessary compression" my first thought, cause I think like this is, "compression? How come? Is that true, cause the HotPlate doesn't add compression...oh, he must mean tube compression!"
    which led me to think....

    Because you can attenuate so much, it is very possible to be playing your amp at "volumes" (as seen by the amp circuitry) that you would NEVER be setting your amp to, even in a stadium. I know it might not sound SO low with the attenuator, but at the highest attenuation (lowest volume) you can easily get your amp to a volume that if you turn the attenuator up to zero attenuation, you'd realize it just is TOO high.

    Made me wonder if some of the complaints from folks that have to do with loss of frequencies, might be the result of their amp just plain driving TOO hard?
     

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