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The Power Soak – just a load of hot air?


For a long time (we first encountered it in the early ‘80s), all was quiet on the Power Soak front. This is possibly because the system’s undoubted advantages – like giving the player the chance to enjoy fully saturated power amp distortion at bearable volumes, for example – were always accompanied by massive shortcomings that couldn’t just be explained away.

That classic phrase our parents and grandparents used to wheel out with regularity – “Everything was better in the old days!” – is not usually the case at all. It may sometimes be true, of course: back in the old days, rock ‘n’ roll felt louder, more genuine and authentic, and the electric guitar was the undisputed symbol of a generation of youth on the move. But the technology that first made the Rock ’n’ Roll Revolution possible was still in its infancy. The then-universal amp volume, a full tube 100-watt wall of sound, was not just responsible for epic rock moments. It was also accountable for countless cases of acute hearing loss and ringing in the ears and, above all, some of the most pathetically unbalanced band sounds imaginable. The guitar was simply too loud! And when you turned it down, it sounded s****. Or, to put it mildly, terrible.

Every guitarist has been privy to that well-used soundman’s old chestnut: “Turn the guitars down on stage!” To go some way towards solving this problem, the idea was hatched in the ‘70s and ‘80s to transform a portion of the power amp’s output into hot air. Or, more simply: to install a power resistor between the end stage of the amp and the guitar cab that would absorb a certain amount of the energy, turn it into heat, and only send a fraction of it on to the loudspeaker. In most cases, you could even select the amount of reduction yourself using a high power resistor network (also often referred to as a power attenuator). Finally, things quietened down and became a little more orderly on stage. And the best part: the amps were then made so that guitarists could rock them at the power limit – ‘til they were almost whimpering for mercy, in fact – and to such extravagant extents as they wished in order to get that sweet distortion they so loved and desired.

The Hughes & Kettner GrandMeister 36’s Power Soak in operation in 1-Watt mode. The jack lead in the shot will give you a nice impression of the unit’s diminutive size.

The Hughes & Kettner GrandMeister 36’s Power Soak in operation in 1-Watt mode. The jack lead in the shot will give you a nice impression of the unit’s diminutive size.

There was, however, still one key catch: most amp heads of the day featured a 100-watt output. They also often had no master volume knob, meaning that you could only truly enjoy that downright addictive distortion when you turned the gain control – in true Spinal Tap style – up to 11. However, the energy that this freed up would also invariably bring even the most sophisticated Power Soak system to its knees, meaning that guitarists would often end up irritated as their hi-tech “full throttle systems” developed highly individual and uncontrollable lives of their own. An incredible amount of compression crushed the sounds too, and that, coupled with the unwanted noise and the accompanying problem of microphonic pickups, meant that use of these early Power Soak systems was a highly suboptimal – not to mention not very satisfying – experience. One of the most well-known systems of the day, by the way, was the Tom Scholz Power Soak, developed by the guitarist of the well-known band Boston.

As the years wore on, things became quiet on the Power Soak front. Although it lived on as an oddball footnote in the minds of diehard old-school believers, the triumph of the tube amp master volume control almost finished it off for good. Recently, though, interest in the Power Soak has surged once again, thanks to the virtually overnight success of the so-called lunchbox amp, which has created a new performance category all its own. Nowadays, 50 or 100 Watts are no longer needed to blow our heads off. And sure, the power offerings of today might be laughable when compared to times of yore – but they’re certainly more manageable. And before you ask the question, the answer’s a resounding YES! Twenty watts, when cranked onstage, can be bloody loud!

This is an experimental build of a Power Soak unit for up to 100 Watts of power. On the front side of the unit are a series of small fans that guide the air through the heat sink. In some previously commercially available Power Soak units, power for the fan was partially generated from the loudspeaker signal itself.

This is an experimental build of a Power Soak unit for up to 100 Watts of power. On the front side of the unit are a series of small fans that guide the air through the heat sink. In some previously commercially available Power Soak units, power for the fan was partially generated from the loudspeaker signal itself.

These days it’s possible, with the clever use of circuit technology, to sacrifice a portion of these 20 Watts – thanks to a combination of tube shutdown and a resistor network – for the sake of impossibly delicious and saturated power amp sounds. And without any of the Power Soak’s earlier foibles, too. And there’s more: through the integration and connection of this Power Soak technology with MIDI, it’s now possible – for the first time ever – to store various channel and sound settings together with a Power Soak setting, which really helps extend the tonal ranges of these diminutive musical treasure chests in previously unimaginable ways. The first genuinely successful relaunch of the Power Soak came with the Hughes & Kettner TubeMeister 18. Still quasi-analog, it allowed the player to select various power levels. Its bigger brother, the TubeMeister 36, took things to another level, allowing Power Soak settings to be saved by MIDI – and then allocated to the amp’s various channels – for the first time ever. The system was so conspicuously inconspicuous in its operation that it quickly and quietly became an indispensable part of many a modern-day guitarist’s setup. The Power Soak truly had grown up. And of course, we’ve saved the best little detail ‘til last: external Power Soak units can easily cost hundreds of whatever your local currency is. On the Hughes & Kettner TubeMeister and GrandMeister series, though, it’s included as an essential standard…

For the physics buffs out there, this is the inductive part of that experimental Power Soak unit. As you can see, it’s not all done with power resistors…

For the physics buffs out there, this is the inductive part of that experimental Power Soak unit. As you can see, it’s not all done with power resistors…


First published: June 06 2014. Most recent update: October 30 2015.

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Leave a comment

Mike H. on May 17, 2020 Reply

I was wondering if anyone on this forum could help me diagnose a problem iv been having with my Hugh’s and Kettner grandmister 40… Recently whenever I use the power soak weather it’s at 1, 5 or 20W it cracks , hisses and pops non stop . But once I bring it back to full 40w the noise is gone and works fine. Anyone have any idea of what might be the problem? Thanks!

    Hughes & Kettner Hughes & Kettner on May 19, 2020 Reply

    Hi Mike, noises like this often represent a tube failing, but it seems something else might be going on here. It’s impossible to give you a 100% diagnosis without seeing the amp though, so we recommend you take it to the tech at the store where you bought it, and let them sort this out for you ASAP!

    All the best,

    Team H&K

Chris on September 20, 2019 Reply

Reading through these comments am I correct here.

I’ve set all my pre-sets to the footswitch with the power soak at 1watt, now if I want to record in silent and switch power soak to speaker off I won’t get those pre-sets?

What’s the easiest way around this, is the app the life saver here?

I’m guessing it’s a matter of saving your pre-sets on the app and once youve switch speaker to off you just recall your saved settings via the app and save them to back to the footswitch. Is this correct ??

I’m looking for the simples set up and the H&K leads the way by far and I’m one click from purchasing the GM 40

PS I like the blue lighting but a dimmer option would be nice


    Hughes & Kettner Hughes & Kettner on October 16, 2019 Reply

    Hi Kris,

    Well, if you’re always playing at 1 watt, and you then want to record silently, you can simply disconnect the speaker cable: then you’ll be able to record everything in silence, just by going straight through the Red Box!

    There are of course other things you can do, like creating all your presets at 1 watt and then duplicating them at 0 watts for recording, but you really don’t need to do that 🙂 It’s totally safe to run the GM40 head without a speaker cab connected, so that’s what we’d recommend you do!

    Hope that helps,

    Team H&K

Sven Blues on September 28, 2018 Reply

Good article.
I bought a 1970 Fender Twin in the early 80’s and immediately added a Tom Shultz power soak. Has always worked flawlessly, which is good since I keep my amp around 8, and drive it. I found a second one on eBay for my 1962 Princeton. Both amps have the attenuater permanently installed.
I couldn’t use these amazing amps all of the without them

    Hughes & Kettner Hughes & Kettner on October 17, 2018 Reply

    Sounds like a great setup you have there Sven! And yes, without an attenuator, many loud tube amps are simply unusable in most situations. We’re big Tom Shultz fans too 🙂 Rock on!

    Team H&K

John Danese on September 6, 2016 Reply

I have a 100 watt Switchblade. Recently I have been using my Blackstar HD Club 40- plenty loud enough and works well with my pedalboard.

Last week I hooked up my switchblade and fell in love again. But it is WAY too loud and goes from 0-100 on the smallest tweak of the master.

ANYWAY: I just purchased a Weber 200 Mass Attenuator- waiting for it to come- as someone suggested on Facebook. I am hoping that it does the trick ( I only need the amp calmed enough to still cut through the band – yet not draw blood from our ears).

Someone also suggested that I “pull” 2 outer power tubes ( or 2 inner) and that will in effect make it a 50 without killing tone?

Any advice on that?

    Hughes & Kettner Hughes & Kettner on October 28, 2016 Reply

    Hi John. No, you shouldn’t pull out power tubes from the amp, full stop. It’s not good for it. The attenuator should do the trick, although if you’re unlucky you’ll find it sucks out a bit of tone too. One other solution could be a volume pedal, but hopefully (fingers crossed!) you’Ve got your attenuator since you wrote this comment and we’vve done this answer and it’s doing the business for you 🙂

Eduard on June 22, 2015 Reply

oke great it was the midi cable! Now it switches channels also in powersoak mode.

    Hughes & Kettner Hughes & Kettner on June 22, 2015 Reply

    Aha, good to know, and glad you’re now sorted! Happy days 🙂

Eduard on June 18, 2015 Reply

Just to be sure if I understand you correctly: channel switching is possible while in POWER soak mode?

    Hughes & Kettner Hughes & Kettner on June 18, 2015 Reply

    OK, no worries, and let us know if you still have problems after checking with TC.

    Yes, you should be able to switch channels while in power soak mode. But don’t forget, in silent mode, all your stored power soak settings in your presets are ignored…

Eduard on June 18, 2015 Reply

okay good to know the channel switching should work in this situation so I will have to look elsewhere. I will check the midi cable and/or g-system. Thanks!

Eduard on June 18, 2015 Reply

The situation is as following:
I have my live presets dialed in with the different 1/5/18/36/reverb/fx loop/clean/crunch/lead
I switch those with my G-System combined with the G-system effects in de fx loop.
Now at home I don’t have the cabinets connected so the powersoak is automatically actived.
So I connect the redbox out to a mixer and play through my headphones.
So I want to practice with my live presets. But then the midiswitching does not work. So I have to switch manually from clean to crunch and or lead. Thats a bummer because this way I can’t practice my midi switching during a song.

    Hughes & Kettner Hughes & Kettner on June 18, 2015 Reply

    OK, well everything should be just fine if it is as you describe it: with the cabs disconnected, the amp stays in silent mode and IGNORES the power soak setting stored in your presets.

    So if the G-System is not switching in these circumstances, it seems like it must be a switch thing (this works just fine normally). Is the G-System working fine under normal circumstances, doing everything else you want it to do? If yes, we’d advise you ask TC directly (they know their pedals better than we do and might be able to solve this more easily!).

Eduard on June 18, 2015 Reply

I have a Tubemeister 36 which I control via MIDI by a g-system with the 4 cable method. Its great. There is one thing I find strange. I can’t switch channels via MIDI while being in powersoak mode. That’s a bummer because this way I can’t practice silent at night with the redbox using my channel switching presets!
Do you have an alternative solution for this?
Or is an ISO cab the only way to be able to do this?

    Hughes & Kettner Hughes & Kettner on June 18, 2015 Reply

    Hi Eduard, you mean you physically can’t switch channels? Or do you mean the power soak settings keep changing when you change channels? Because this second part is a feature of the amp that can’t be switched separately like that – you’d need to create a group of presets with the power soak settings you want, and use them to play with at home. Hope this helps!

Neville on October 22, 2014 Reply

Nice one, this extra cab load will not split the volume then? (Understand the impedance issues but not the wattage/loudness side of it)

Also, I’m guessing that this will just mean extra sound in another location (wherever the cab is situated) as opposed to a stereo rig? Which is what I would somehow like to achieve potentially in future – are there any workarounds for that if this is the case?

That’s why I went for the GM, that and the cost 😉

Neville on October 20, 2014 Reply

Just played in a rehearsal space scenario with my GM36 the other day… Gotta say I loved the size, weight and portability… I actually feel like it’s so near to being the ultimate amp! Just wondering why only one ‘speaker output’ and not two for 2 cabinets? (Is there a work-around for this? Well aware you can extend some cabs from their connection plates like Orange for example – but not sure if this is the same as potentially splitting the wattage?)

Aside from that, all I can think of now is it’s a shame it doesn’t have more FX (or at least the ability to update the unit/install with extra FX) – I feel like this is where you may lose out sales to AxeFX and Kemper (though they have their own drawbacks) – the extra cost for example, portability and lack of tubes is what sold me on the GM36 :)!

Well done on packaging everything you have into a box that size with such quality and thought though!!

    Hughes & Kettner Hughes & Kettner on October 22, 2014 Reply

    Yes, we agree on that. If you need more than standard FX, the AxeFX or the Kemper are indeed the better choice. But please note that both the AxeFX and Kemper are 100% modelling amps 😉 The GrandMeister is a 100% analog amp with three digital (but not modelling) FX processors, that are mixed to the analog signal in parallel to maintain 100% analog tube tone – from guitar input to speaker output. The disadvantage of this concept is that neither amp models nor FX algorhythms can be ‘updated’. And that’s why we put a fully integrated FX loop on GrandMeister. It’s up to guitarists to decide whichever system works for them 😉

    Hughes & Kettner Hughes & Kettner on October 22, 2014 Reply

    Oh yes, and of course you can connect two cabs to GrandMeister. Most cabs offer a parallel out, so if you use two cabs with 16 ohms each, it will result in 8 ohms. You can connect as many cabs at you want, as long the total impedance is in bewteen 8 and 16 ohms! We did a blog on Impedance too, which should help with this if you’re not too sure on what would match best…

Jason on June 16, 2014 Reply

I got a tube 36 and it kicks ass! 3 channels of tone. Maybe 2 pedals is all you need, maybe none. The TSC, auto bias and power soak what more could you ask for. This thing is freakin loud and the head comes with a styling bag the cab is solid. Got mine from MF. Was thinking of getting a F—–r or M——l, but after seeing the power soak, I was convinced. Unrelated to the amp, I wish they still made the rotosound MKII.

    Hughes & Kettner Hughes & Kettner on June 16, 2014 Reply

    Hi Jason,

    That’s great for us to hear, so thank you very much! We wanted to make an amp that could do everything a guitar player could need – Rock on Stage, Play at Home, Record at Night – and that’s what the TubeMeister range does. The TubeMeister 36 can be super loud or super quiet, depending on what you need to do with it, and the Power Soak means that you can push those tubes for the best tones at any volume setting.

    And on your unrelated wish, apologies. The best place to look for the Rotosound MKII is going to be at your local second hand music store…

    All the best!

Les Schunk on June 7, 2014 Reply

I live in Santa Ana California. Where can I go to actually Test Drive one of your Amps?????!!!!!!!!

    Hughes & Kettner on June 7, 2014 Reply

    Hi Les,

    please call Guitar Center

    18361 Euclid St, Fountain Valley

    If they don’t have all amps in stock, they can let you know another guitar center in Los Angeles area.

    Best regards