Give Me Suggestions for an Attenuator!

Discussion in 'Amp Central Station' started by Fiesta Red, Sep 3, 2019.

  1. nocastermike

    nocastermike Tele-Meister

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    I have used several thru the years. Boston strangler, scholtz power soak,Dr Z mass,marshall power brake and Webber Mass. The Webber covers any impedence and sounds the best. I would like to have a freyette.
     
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  2. PCollen

    PCollen Friend of Leo's

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    I also use mine when working on and biasing tube amp heads...no need to have a speaker connected as the attenuator with the voice coil is a true substitute when set to the required speaker load.
     
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  3. Tim S

    Tim S Tele-Holic

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  4. MikeG74

    MikeG74 TDPRI Member

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    I was wanting to do the same thing and got a Weber MiniMass. To me, it sounded better just to use a light overdrive pedal at low volumes. now...when you crank the amp up and start driving the speakers too, it sounds glorious;) I tried mine on a few amps and it just didn't work like I wanted it to, so I sold it... Just my two cents:)
     
  5. Guran

    Guran Friend of Leo's

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    I have the current Harley Benton PA-100 version and I just agree with everything you said. I just use it to shave off a few dB, and it works great for that. Sure, you have to tweak EQ a bit, as mentioned, but I can't see that as a problem.

    I would put it this way. No, it doesn't sound as good as the amp alone. It does sound better than if you turn the amp's master volume down to the same level.

    I have ran it without a speaker while trying the speaker emulated line out for recording. I wasn't that impressed, but it could be that I didn't experiment enough. It was just a 10 minutes quick test.

    At €69 the price is hard to beat!
     
  6. graybeard65

    graybeard65 Tele-Meister

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    Many have shared positive thoughts on the Weber Mini Mass - add my praise to the pile.

    I’ve got a ‘68 Custom Deluxe Reverb reissue, and the WMM opened that up for me - no more need for OD or distortions to get a cranked sound at home volumes - an amp that needs some juice to sound fantastic has plenty of room to make magic!

    Can’t say enough good things about the Weber!
     
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  7. J-Flanders

    J-Flanders Tele-Meister

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    I have the current Harley Benton PA-100 as well. I use it with a Fender Champion 600 to play late at night. I put the amp's volume at 11 and then attenuate it to a whisper quiet volume. You loose quite a bit of treble at that point but I'm fine with that.
    However, it (mine?) has a noisy fan. The fan is part of the load/attenuation, it's not powered by mains but by the audio signal itself.
    Once up and running it's inaudible but when the fan starts or stops it makes this Zzzzzzz Zzzzzzzzz sound.

    The Fender Champion 600 is only 5 watts or so, which isn't enough to make the fan run constantly, even at full attenuation.
    So, every time I hit a chord the fan starts up with a Zzzzzzzzz and stop right away with Zzzzzzzzzz.
    If I reduce the attenuation it doesn't run at all but then the amp is too loud.
    If I attenuate until it's quiet enough I hear the Zzzzzzz Zzzzzzzzzz all the time. :(

    Those who're using this attenuator, are you experiencing the same thing (under the same circumstances)?
    Would it be ok to unplug the fan as it's not doing anything but make start and stop noises with a 5 watt amp?
     
  8. johnDH

    johnDH TDPRI Member

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    Id suggest that for a 5W input, it shouldn't really need the fan. If you can open it up enough to reach the parts that get hot, you could check that. If after playing, there's nothing so hot that you cant comfortably touch it for 5 seconds then id say its ok.
     
  9. J-Flanders

    J-Flanders Tele-Meister

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    This is supposedly an 'improved' version of the jettenuator which didn't have a fan, so I'm pretty certain it will work fine without the additional cooling by the fan.
    What I'm afraid of for example is that if the fan is in series with the load resistors and I unplug the fan there will be no load for the amp and I'll damage the OT.
     
  10. Stewtech

    Stewtech TDPRI Member

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    If you have a effects loop the JHS little black amp box is a option
     
  11. johnDH

    johnDH TDPRI Member

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    Good point. Best to investigate how the fan is wired. There may be other components involved too, such as diodes. If you figure it out, test the resulting ohms seen by the amp with a multimeter first, to see what changes!
     
  12. matrix

    matrix Tele-Meister

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  13. Guran

    Guran Friend of Leo's

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    As I use mine to shave a few dB off a Marshall half stack, that isn't an issue for me. :D

    5 W should be easily dissipated by the resistor heatsinks alone.
     
  14. VintageSG

    VintageSG Friend of Leo's Ad Free Member

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    Mine's the first, closest to the Jet City version. No fan.

    It has handled a Cub 10 running flat out ( circa 15 Watts-ish? ) for hours at a time and it barely got warm. Amp --> D.I --> Attenuator ( no speaker, just a backup load resistor )
    It has handled my Champ-a-like in a similar fashion ( 5 Watts-ish )
    It has recently had a Jet City JCA20H doing its best to get some heat from it, and no deal. Barely warm after a couple of hours. 5 Watts ain't going to trouble it. You -could- switch the fan out for a 21 Watt, 12 V light bulb for squits, giggles and a night light. Just pinch the indicator lamp from your car ( don't! )

    I can't see the fan being in series, so wouldn't lose sleep over it.
     
  15. Ziggy587

    Ziggy587 Tele-Meister

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    I got the Bugera PS1 Power Soak earlier this year and have been loving it. I can't speak to how the the line out or emulated mic outputs sound because I've never used them, but otherwise I've had a blast using it.

    PS, I just noticed AMS has an open box unit right now for $10 off the regular retail price. https://www.americanmusical.com/Item--i-NFS-BUGPS1
     
  16. J-Flanders

    J-Flanders Tele-Meister

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    Great idea! Thanks.
    I tried to trace the circuit (it's mostly smd):
    [​IMG]

    I left out the XLR out and line and it probably contains errors so don't use it to build your own. (At around 65 euro from Thomann it's not worth the effort anyway)
    I found only one schematic of an attenuator using a self powered fan:
    [​IMG]

    Judging on my crudely traced circuit and the similarities to the other schematic it looks to be safe to disconnect the fan. I added a switch to turn the fan on/off just in case I want to have the fan later on with higher wattage amps.

    Here's a picture of the inside and the circuit:
    [​IMG]
     
  17. johnDH

    johnDH TDPRI Member

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    Id agree those do indeed look like you could unplug the fan.

    But that very simple L-pad arrangement for doing the attenuation is entry-level circuitry from class 101! All fine if you are happy with the tonal effects.
     
  18. Festofish

    Festofish Tele-Meister

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    Not really an attenuator but jhs black amp top box works for me.
     
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