Pro's and Con's of Attenuators

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GassageGassage Frets: 30826
edited April 2021 in Amps
So, in theory, attenuators are a great thing. However, I've absolutely concluded that in practice;

  1. They can bugger amps up and don't aid their smooth running- I believe they stress the internals of amps and cause issues
  2. The sound is nowhere near as good and whatever you do you lose parts of the high and mids
  3. You can use certain drive pedals (e.g. Kingsley Page) as a sort of reactive load/attenuation of input signal (my terminology is probably wrong here) that actually works far better.
  4. Re 1 above, the natural thing to do is crank the amp and fully attenuate rather than do it subtly, which surely must cause more stress on valves and OTs etc?
I also want to understand precisely what the difference is between a reactive load and attenuation.

I'd appreciate the wisdom of our amp fiends (yes you @icbm and others) regarding the points I've made.

*An Official Foo-Approved guitarist since Sept 2023.

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  • ecc83ecc83 Frets: 1589
    I am sure others will wade in with their experiences but, I have run  more valve amps into loads at full chat than probably most people on the forum? My results do not accord with "buggering " anything. Sometimes a valve arcs over and pops an HT fuse. More rarely a valve fails dramatically and has to be replaced but, SO LONG AS the fusing is correctly implemented and the rest of the design properly done, their should be no permanent bad effects on the rest of the circuit. We have know for a century that VALVES FAIL! It is up to amp designers to take account of that fact.

    I recall a test I did on a 15W EL84 amp where a new set of valves were fitted and a spec check done. The amp was then left on around half full power overnight into a resistive load. Next day all the voltages were the same and the response just 3dB down at 100Hz post the thrashing IIRC.

    But of course! NOT all amplifiers are THAT well designed!

    Dave.
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  • menamestommenamestom Frets: 4641

    I have never really seen the point in as much as you can get a decent sound with pedals into a clean amp.
    Power scaling is more attractive as it can be a relatively inexpensive mod to an amp, I may add it to my tweed deluxe with the ampmaker vvr kit.
    I suppose it depends on the sound you are after and amp you have in the first place.

    Attenuators are a rabbit hole I have steered clear of I probably best not look into it further! 

    Sorry not really answering the questions.....
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  • ICBMICBM Frets: 71957
    Gassage said:
    So, in theory, attenuators are a great thing. However, I've absolutely concluded that in practice;

    1. They can bugger amps up and don't aid their smooth running- I believe they stress the internals of amps and cause issues
    2. The sound is nowhere near as good and whatever you do you lose parts of the high and mids
    3. You can use certain drive pedals (e.g. Kingsley Page) as a sort of reactive load/attenuation of input signal (my terminology is probably wrong here) that actually works far better.
    4. Re 1 above, the natural thing to do is crank the amp and fully attenuate rather than do it subtly, which surely must cause more stress on valves and OTs etc?
    I also want to understand precisely what the difference is between a reactive load and attenuation.
    1. Not if both the amp and the attenuator are properly designed and well-built - no more stressful than simply running the amp at that volume into a cabinet.

    2. No, some attenuators do with some amps - some sound great with some amps. The difficulty sometimes is finding the right combination.

    3. You might get a good, or great, sound but it's not at all the same as running the amp loud and attenuating. You may prefer it though...

    4. Yes, true. The fact that you can run at full tilt all the time means that you're more likely to. That will definitely cause more stress than running it at lower volume, and will wear out the valves quicker - but is not a risk to a well-made OT.

    The difference between a reactive load and attenuation is that a load does not feed some of the power directly to the cab - it produces a signal-level output which you then have to re-amplify with another power amp (valve or solid-state). This can also sound very good, but it's also not quite the same as attenuating.

    Personally, I don't really like the sound of amps cranked to oblivion and then attenuated, even with combinations that work well - that makes them sound squashed and mushy, to me. I prefer getting the amp just up to the point where it starts to naturally overdrive rather than saturate completely, and I prefer master volume amps with attenuators so you can balance the power amp drive and final volume independently.

    Also personally, I don't like power scaling. I've never heard an implementation that sounds as good as a well-designed master volume, and it doesn't produce the same power stage dynamics as attenuation either.

    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski

    "Just because I don't care, doesn't mean I don't understand." - Homer Simpson

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  • Danny1969Danny1969 Frets: 10357
    Well the system physicals of it is you are converting watts of power into heat .... the amp is working harder but you don't get to hear the extra volume ... that's turned into heat. 

    So the valves will wear faster, other components like ceramic resistors may go faulty earlier. I used to run a Marshall Jubilee 100  on near full pelt into a home made load for gig'ing in the eighties. The valves needed changing a lot more often. 
    www.2020studios.co.uk 
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  • GassageGassage Frets: 30826
    Thanks all- this is really helpful.

    *An Official Foo-Approved guitarist since Sept 2023.

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  • Jonathanthomas83Jonathanthomas83 Frets: 3466
    edited April 2021
    @Gassage If I know you like I think I do...loading down an amp with a loadbox, then seeking out some IR's is not going to be your idea of fun. I love it personally but I don't think it's your thing. That said, if you did click with it, I'd be over the moon to hear that's the case. It's personally changed my outlook on things and made recording a hell of a sight easier!

    But loading an amp down with a Reactive Load is a lot different to attenuating it with a resistive load, for sure...as untechnical an opinion as that may be.
    Read my guitar/gear blog at medium.com/redchairriffs

    View my feedback at www.thefretboard.co.uk/discussion/comment/1201922
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  • ICBMICBM Frets: 71957

    But loading an amp down with a Reactive Load is a lot different to attenuating it with a resistive load like a Powerbrake, for sure...as untechnical an opinion as that may be.
    A Powerbrake is not a resistive load, it's highly inductive.

    It actually has an impedance curve closer to a real speaker than any other attenuator or load I know of.

    "Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski

    "Just because I don't care, doesn't mean I don't understand." - Homer Simpson

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  • LastMantraLastMantra Frets: 3822
    edited April 2021
    Weren't attenuators meant to just knock a touch of volume off in the studio? Not so much for cranking 100w'ers at bedroom friendly volume. 
    I think that if they're used sensibly they can sound perfectly decent. I like using mine anyway. 

    Personally I think that any amp has a volume where it just doesn't work well below. Which is usually around a neighbour bothering amount. Just where the speaker isn't moving enough and/or the internal components aren't working hard enough. Maybe your ears not being wobbled enough. At that point you're probably as well using headphones or something. 
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  • My bad. Removed powerbrake from my sentence, because the point still stands, I think.
    Read my guitar/gear blog at medium.com/redchairriffs

    View my feedback at www.thefretboard.co.uk/discussion/comment/1201922
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  • Modulus_AmpsModulus_Amps Frets: 2569
    tFB Trader
    I think the best options for cranking amps at quite volumes are currently the Fryette power stations type device, i.e. a reactive load that then re-amps the signal to drive a guitar cab or a reactive load that you then apply IR's to and then put through studio monitors or headphones.

    Most of the old resistive loads just don't work well for what most guitarists want, volumes at home levels. 

    @Gassage Have you tried the Fryette Power Station?
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  • GassageGassage Frets: 30826
    I think the best options for cranking amps at quite volumes are currently the Fryette power stations type device, i.e. a reactive load that then re-amps the signal to drive a guitar cab or a reactive load that you then apply IR's to and then put through studio monitors or headphones.

    Most of the old resistive loads just don't work well for what most guitarists want, volumes at home levels. 

    @Gassage Have you tried the Fryette Power Station?
    No and you're not the first person to suggest it...it appears to be excellent.

    *An Official Foo-Approved guitarist since Sept 2023.

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  • Modulus_AmpsModulus_Amps Frets: 2569
    tFB Trader
    Gassage said:
    I think the best options for cranking amps at quite volumes are currently the Fryette power stations type device, i.e. a reactive load that then re-amps the signal to drive a guitar cab or a reactive load that you then apply IR's to and then put through studio monitors or headphones.

    Most of the old resistive loads just don't work well for what most guitarists want, volumes at home levels. 

    @Gassage Have you tried the Fryette Power Station?
    No and you're not the first person to suggest it...it appears to be excellent.
    I would check it out, I have been messing with reactive loads lately and think they are a huge step forward from the old attenuator options. Its just how you re-amp them that is different. But if you want it to work like an attenuator then the Power Station appears to be the ticket.

    Only thing to watch out for is the power station can put out a lot more power than a lot of amps, so you need to watch the speaker power.
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  • xscaramangaxscaramanga Frets: 436
    Gassage said:
    So, in theory, attenuators are a great thing. However, I've absolutely concluded that in practice;

    1. They can bugger amps up and don't aid their smooth running- I believe they stress the internals of amps and cause issues
    2. The sound is nowhere near as good and whatever you do you lose parts of the high and mids
    3. You can use certain drive pedals (e.g. Kingsley Page) as a sort of reactive load/attenuation of input signal (my terminology is probably wrong here) that actually works far better.
    4. Re 1 above, the natural thing to do is crank the amp and fully attenuate rather than do it subtly, which surely must cause more stress on valves and OTs etc?
    On point 2: nowhere near as good compared to what?

    I assume you mean nowhere near as good as the sound of the unattenuated amp being run at full chat, which is probably true but a moot point, surely? If it were an option to just run the amp balls to the wall all the time we wouldn't be discussing attenuators.

    I used to have a Motherload and now I have a Two Notes Captor that I use as a load box, then reamp with a Matrix GT800FX power amp (with FX between the two if I fancy it). Neither of them sounds as good as the amp screaming, no. Physics and the Fletcher-Munsen curve make that impossible. But they both sound a lot better than the amp quietly without the attenuator, and for certain purposes I prefer them to modellers and definitely to clean amps with pedals.
    My YouTube channel, Half Speed Solos: classic guitar solos demonstrated at half speed with scrolling tab and no waffle.
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  • I think the best options for cranking amps at quite volumes are currently the Fryette power stations type device, i.e. a reactive load that then re-amps the signal to drive a guitar cab or a reactive load that you then apply IR's to and then put through studio monitors or headphones.


    That sounds hellishly complicated, and how is it going to sound anything like the real thing if it's re-amped?

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  • GassageGassage Frets: 30826

    On point 2: nowhere near as good compared to what?

    I assume you mean nowhere near as good as the sound of the unattenuated amp being run at full chat, which is probably true but a moot point, surely? If it were an option to just run the amp balls to the wall all the time we wouldn't be discussing attenuators.



    No, sorry, as good as simply turning the thing down via the vol knob!

    *An Official Foo-Approved guitarist since Sept 2023.

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  • PhiltrePhiltre Frets: 4164
    Amp makers should add a reverse volume control that has a minus amount. So then you can make your amp "1 quieter".
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  • Said it before on many identical threads - A Marshall Powerbrake (for a Marshall amp)  was the best thing I ever bought for my sound, and that includes all guitars & amps I've bought too.  Even on the heaviest attenuation settings it still sounds like proper power amp valve distortion should do - it's sublime.
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  • John_AJohn_A Frets: 3775
    edited April 2021
    They are a tool that fit specific tasks

    what to run a plexi without waking the kids? Powerstation or similar 

    what to gig a jrm45 wound up to crunch with a quiet band? Powerbrake or similar

    The only alternative to the above is pedals or modellers which is what I do these days but if you love your non MV valve amps and have volume restrictions you have to use something 
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  • Modulus_AmpsModulus_Amps Frets: 2569
    tFB Trader

    I think the best options for cranking amps at quite volumes are currently the Fryette power stations type device, i.e. a reactive load that then re-amps the signal to drive a guitar cab or a reactive load that you then apply IR's to and then put through studio monitors or headphones.


    That sounds hellishly complicated, and how is it going to sound anything like the real thing if it's re-amped?

    No its not really, Using the Power Station is very simple and works in the same way as an attenuator, between the amp and cab. Van Halen ran his amps into a load and then re-amped them, it is not really a new thing

    https://youtu.be/gKwJv2BQ-jw
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  • GoldenEraGuitarsGoldenEraGuitars Frets: 8820
    tFB Trader
    My last experience with an attenuated amp was a Marshall 2061 and Rivera Rockcrusher. No loss of tone, sounded incredible. 

    So much so I’m going back to that type of setup. 
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