Ultimate Attenuator?

Discussion in 'Amps and Cabs' started by John55, Jan 13, 2005.


  1. John55

    John55 Member

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  2. Joe

    Joe Senior Member

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    Don't know about current production models but the original ones were a disaster and they got horrid reviews. If buying used make sure you can confirm date of manufacture and talk to the builder to see when any major overhauls began. Or buy a THD Hot Plate.
     
  3. Roodboy

    Roodboy Supporting Member

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    Theres a nice review at legendarytones
     
  4. aortizjr

    aortizjr Member

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    Buy a Weber MASS or a THD Hotplate. You can get the Hotplates for pretty cheap from Avatar Speakers.
     
  5. begin_etienne

    begin_etienne Member

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    I have used one with a bogner ecstasy 101b and the output transformer was vibrating and generating a buzzing sound out of the speakers at a high attenuation setting. The UA itself was also vibrating using the plexi switch.

    I got the UA from the guitarist of the Black Crowes, maybe this was the first generation of the UA.

    I wish I could try it with a Marshall.

    I think there's an internal power amp in the UA. Also, you can use any impedance without changing jacks or turning a knob, nice !
     
  6. 908SSP

    908SSP Member

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    My Ultimate sounds great and doesn't buzz. I believe it is the latest version. Sounds better then my Mass or Allesandro of course it cost more.
     
  7. John Phillips

    John Phillips Member

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    Caveat: I've never seen or used one. But I have read about it, and it appears that it is NOT an 'attenuator' - it's a dummy-load/re-amp system.

    Quite different, and should not be marketed as something that it is not. (IMO)

    I also understand that it is a fixed impedance of something like 32 ohms. Do NOT assume that you can use this with any amp, especially a 4-ohm one and certainly not a 2-ohm (eg Super Reverb). Doing so could wreck your amp. There is no such thing as a 'universal impedance' attenuator (not without having an impedance selector on it, anyway). It's possible to make one which is usable with a range of impedances, providing you accept the mismatch caused - the Airbrake designs are like this - but if so, 32 ohms is not the right value to choose. It's well outside the safe mismatch range for a 4-ohm amp, even allowing for the rise in a normal speaker's impedance at high frequencies.

    If any of this information is wrong, I'll be glad to be corrected, but if not there's no way I would use one of these with any 4- or 2-ohm amp, and I'd even be careful with an 8-ohm one.

    Personally, I would buy an attenuator.
     
  8. grantster

    grantster Member

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    This device sounds like some take on the EVH trick of running into a dummy load and then sending signal thru solid state power amp. There is a guy in vancouver that has built something like this for years. He was selling them for about $200.
     
  9. pfrischmann

    pfrischmann Member

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    I heard (unconfirmed) that Magnus is importing that same canadian product.
     
  10. grantster

    grantster Member

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    I went to read the review at legendary tones after I just posted and was shocked to see that it looks exactly like the one that I have. Same box, knobs, switches etc, even the same concept. I have had mine since the late nineties. hmmm? When did the ultimate attenuator come out? The guy that built mine has some other cool inventions. He is not a guitarist himself but has been repairing amps for 30 years. He has quite a knack for listening to guitarists problems and coming up with solutions for their gear.
     
  11. The Whiz

    The Whiz Member

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    Is it a shop called Ho's? Or something like that? By Metrotown?

    taco
     
  12. grantster

    grantster Member

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    Maybe magnus is working with the guy that built mine? I don't know, I have not been by his shop now for several years.
     
  13. grantster

    grantster Member

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  14. begin_etienne

    begin_etienne Member

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    Thanks for clarifying !

    What is nice with the UA is that you can go below -32db (correct me here). This could be a useful feature for guys like me who run their SLP with channel 1 and 2 jumped and the normal and hi-treble at 10, with an overdrive... that's a lot of DBs. IMO

    E-
     
  15. John Phillips

    John Phillips Member

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    If you do prefer the sound of the Ultimate, and want to run it with a cranked Plexi, set the amp to 16 ohms BTW. That's the safest given the real impedance of the UA (assuming 32 ohms is the correct figure, but from what I've read I'm fairly sure it is).
     
  16. loverocker

    loverocker Member

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    Yup - it's like the back-end of the Guytron (although the Guytron has a valve power stage). It's a great idea, but I agree that calling it an attenuator ain't right - that's just bandwagon marketing off the success of THD/Weber/etc true attenuators.
     
  17. pluto

    pluto Member

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    Mark Gregg apparently is simply distributing Ho's attenuator. That's my understanding. This was surprising to me because when I spoke to Mark before buying the UA, he kind of made it like he designed the whole thing. Oh well.
     
  18. pluto

    pluto Member

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    As to the UA, it's pretty good if not on the expensive side. The thing looks pretty cheaply made, but as far as getting "true" bedroom volumes, the UA is IMO the best device (not sure whether to call it an attenuator!) I've heard with a non master volume amp and I've owned 2 Hotplates, a Koch Loadbox and a Dr Z Airbrake. However, given the expense of the UA and its build quality, I would definitely buy another Hotplate (or maybe a Weber since people rave about that one too) over it if I ever got another attenuator.
     
  19. 908SSP

    908SSP Member

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    Ok What is in there? The switch labeled in the upper left corner is stock I labled the wrong one in photoshop and I don't want to redo it. I added the one in the lower right hand corner because I didn't want to leave the fan running and I didn't want to unplug the thing. Like I said it sounds good way better then my Mass on my Bassman head. I did measure the ohm at the input and it is 32ohms.
    [​IMG]
     
  20. John Phillips

    John Phillips Member

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    It's a bit difficult to make it all out clearly, but what is in there appears to be:

    A dummy load resistor (the 'gold' thing). This is smaller than I expected, it looks like a 50W type. What's the black thing it's mounted on BTW? Is that another fan, or just a large heatsink? I also expected there to be more than one, since 32 ohms is not a 'standard' value, and I'd expect it to be made up from a 22-ohm and a 10-ohm in series. Is there another larger resistor underneath it where it can't be seen?

    A 2-transistor solid-state power amp that looks like about 100-150W capability.

    A power transformer for the SS power amp.

    A cooling fan for the SS power amp.

    A board with filter caps and maybe a power resistor or a few other components on it, for the SS power amp (the thing with small copper circles on it).

    What looks like a SS bridge rectifier, a switch, a control pot (with resistor tacked onto it) and possibly an inductor (all in the top right).

    A small switch on the back panel (with the white toggle) connected to the pot.

    Two things I can't identify to the lower left of the load resistor.

    And a whole lot of quite crude and home-assembly-style workmanship which would not pass EC regulations...


    908SSP - thanks for the pic. Running that with a Bassman (4 ohm output) could blow the OT, power tubes or other parts. Even if it sounds good. I've seen a couple of Bassmans fried when used with a standard Marshall 4x12" (16 ohm), 32 ohms is even more risky.
     

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