Marshall PB-100 Power Brake

switchable between 8 and 16 ohms.variable attenuation level that goes up in stages.2 outputs for if you want to use 2 cabs.very strong and heavy.good build quality.

im not going to rate this at all becuase it doesnt colour the sound of the guitar and amp at all.i use it with my vox ac30 tbx ,there is a little loss of tone when its way down low but this is really due to the fact that the speakers aint really doing there proper job because its to quiet! also, as the volume decreases our ears become less sensitive to mid and high ranges so this is why it appears there is some loss of tone.

its never fried anything or even thought about breaking.
you MUST use proper unshielded speaker cable.make sure you set the ohm switch to the right setting.if you dont use the right cables you will fry your transformers and tubes.the fan works just fine

never had to deal with them for anything breaking but they replied to my emails pretty quick and they were helpful

very good piece of equipment,saves your ears and speakers.also it saves you from the risk of being evicted.does its job fine

this is a warning to other potential users
you all know what it does.....

it did make my amp sound excellent,i have a vox ac30 from around 1964 with blue speakers etc.

well after a few days i noticed a weird smell.thought it was just wearing in but then after a few weeks i turn on my lovely priceless original vox and pop boom.....nothing
turns out i blew my transformers and as some of you will know the original ones cant be purchased anymore,the re-issue ones only work if you install a solid state rectifier.so im left stuck with a broken vox.MY BABY it was.
the glue holding something on inside melted and the part fell off ,or so ive been told by my tech.this put a no load situation, as explained above.my amp just couldnt hack it.

they were not interested, they said that many others use them perfectly well.which is true.

i would never buy another, not ever.in fact if someone gave me one i would break into my own house and steal it! throw it into a river.
my vox is now dead.anybody selling transformers?

Simple device-simulates speaker load to allow amp natural tube breakup at lower volumes.

As has been mentioned before this is an intregal part of my rig.I am using this with a TSL100 head and a 4x12 cab.I have heard criticizm that these powerbrakes color the sound/tone of an amp, but the tone loss I see is minimal.

Have never had a problem with this workhorse and it gets used daily.I have noticed that mine doesnt get very hot (like I had been warned it would),the onboard fan seems to keep a handle on things.

No problems to report

This is a key piece of equipment.Either to save your bandmates(and yours)ears or to get the right sound at the smaller venues, it is a must.(full cranked Marshall sound/roar at lower volumes)That is all this device will do and it does it well....................................

Easy. Plug it in. Turn the one knob up or down to make it louder or quieter. Play your heart out.

I'm playing a Marshall TSL100 Head through two Marshall 1922 2x12's. Conventional though it might be, I use channel 1 as clean (rhythm or lead), 2 for dirty-ish bluesy crunch (rhythm or lead)and 3 for get-the-fuck-out-of-here wailing overdrive (lead only). Without the PowerBreak, the amp sounds pretty good - no prob's there at all. But it's what happens with the 'Break that's so damn good. If you've never heard the difference between a tube amp cranked and one that's not even breaking into a sweat, then you must stop reading now and go do it - this is something you have to hear to really understand. The reason is that output tubes don't sound like pre-amp tubes when they distort. And you don't have to push tubes all the way to full-on audible distortion to hear the benefit, either - put a lot more signal into the tube and, even without audible distortion, it will sound fuller with more harmonics.

Even played completely clean (my ch 1), shoving the master volume right up (I take it to about 7'ish on my clean channel) and cutting the overall volume via the 'Break yields a richer, fuller, smoother, more responsive sound that cuts through a mix effortlessly in a way that just doesn't happen simply by turning the master down to play at a similar volume without a PowerBreak. And for me this is the real acid test - the improvement of sound quality even played clean, rather than 'just' turning up the master to get 'nicer distortion.'

With the ch 2 bluesy/crunchy sound, I tend to use far less pre-amp gain than I used to and instead crank up the master to over-drive at the power amp end of things instead (the master is at 9 on this channel), which gets me a far more dynamic, less jagged overdrive that's infinitely nicer on the ear than anything I've ever got with just pre-amp overdrive alone.

And by balancing the pre-amp gain with the master gain for the ch 3 overdriven sound, I can get the kind of dynamic, lively, singing sound that can only come from output stage tube overdrive - the kind of EVH 'Brown Sound' or EJ 'violin-ish' tone that's simply not attainable unless you drive the output stage of the amp hard.

I noticed a few references to melting glue and stuff in other reviews, but like some other reviewers I don't generate all that much heat. Even flat out! I've used it in a couple of gigs and it was cool - in all senses of the word.

So no prob's so far.

Never had cause to call Marshall ever (and I've had stacks of their gear over many, many years).

I play lots of stuff, currently mainly soul/Acid Jazz/blues although recently I've been getting back into some fusion-ey instrumentally stuff. I've been playing since God was a boy and did a lot of session work back in the late Seventies/early Eighties.

Nowadays I play a '62 Strat through a mish-mash of pedals (Fulltone ChoralFlange, Electro Harmonic Small Stone, MXR Dynacomp, Line 6 Filter Modeller, Boss Harmonist & Aria Headrush) most of which are off at any one time (the only one that stays on constantly is a Z-Vex 'Super Hard On' I use as a pre-pre-amp at the beginning of my signal chain - FYI: I posted a review for this a while back in which I wet myself ...).

The PB100 has become an integral part of my sound, I simply couldn't get the tones I use without it.

this is a very simple devise, probably couldn't have many more features! i will say it does it's job and does it good. I use a marshall jcm-2000 100watt head and used to play on 1 or 2(very loud) with the powerbrake inline and the volumes cranked it sounds the way a marshall is supposed to! i read that the glue holding the inductor can melt but my powerbrake doesn't even get hot!!! a rackmount version would be nice!

i set my amp up with crunch on one channel, lead on the other with a little more volume. with the powerbrake my crunch sounds just like Black Crowes,or with more treble and no reverb just like AC/DC. put a tube screamer on this channel and it sounds like lead channel only with less volume.this setup can do it all, aerosmith,zep,G&R,Ozzy,ac/dc,skynyrd,clapton,crowes,crue(use deep switch). i use two different les pauls through this marshall and play stuff from pat benetar to G&R. and use an a/b to a clean amp. unless you play stadiums you should own a powerbrake there is no sense in owning a marshall if it isn't cranked!!!

i've only owned the powerbrake for over a month, just put new groovetubes in and replaced a fuse. other than that no problems. also i used to get alot of noise through my setup but found that going straight into the amp, through no effects or a wireless makes the amp sound like it is off.but unfortunatly i need a few effects. i found instead of running though effect such as delays,chorus's,phasers, i run them after the mike on my cabinet. this helps keep my sound noise free. also overdrives sound best after the preamp(in the effects loop).

marshall seems to make these to order or something.i waited two months for this.

ive been playing for only afew years but i'm now starting to gig with my band. the powerbrake is essential to my setup. it allows saturation,compression and the greatest thickest crunch possible.

I don't know if this should be called a effect or somthing for the amp. I decide that it is a thing for the amp and so that is way I leave this submission here anyway. It's a piece of cake. One big knob on the front where you can decrease the output volume between the amp and the speakers. One input and two output jack and one switch 16ohm/8ohm on the back.

For me it's sound good, I can have the filing and sound of my amp (Marshall Bluesbreaker combo) cranked at a bedroom level.

It seems like it's built like an amp. I have read that somthing inside it can come loose when it gets hot.

The warranty is one year. The only thing I have to say about the company that deliver it, they where slow, it took me 8 weeks to get it.

If it were stolen I would cry a bit, and then I would think of a way to get even with the bastard.

(Update to the review I submitted on 4/21/98)

(Update to the review I submitted on 4/21/98)
This happened with BOTH of my units... after playing my Sovtek Mig-100 through it continuously for 15 minutes I noticed a weird smell from it. Opening it up I found a capacitor was overheating: way too hot to touch and the plastic covering on it was melted. Also, another part (an inductor coil) was starting to melt the glue that was holding it to the board. My conclusion: not all of the parts in this thing can handle a 100-watt guitar amp cranked through it. Consider yourself warned.
It seems to handle a 50-watt amp with no problem.

Can't really be said to work reliably with 100-watt amps, should be called the PB-50.
It CAN be rewired to bypass the troublesome components, and I plan to upgrade them with more durable parts. But really, I shouldn't have to do this!

Switchable between 8 and 16 ohms, very handy for me. One knob on the front, 11 attenuation settings, each click to the left cuts the power approximately in half (I've measured this). Lowest setting cuts out the sound completely. No tone controls of any sort. Two speaker jacks on the back. Convenient handles on front for one-hand carrying.

It does just what I want: it takes the amp sound and cuts it down to size, at least in a quiet studio setting: haven't tried it live.

I am an amp tech and have inspected the insides of two PowerBrakes that I bought, one new and one used (I think about 2 years old). The level of construction inside is very good. However there was a problem in both units: the hot-melt glue they used to secure an inductor to the circuit board did not stick, so the inductor was held down only by its two soldered wires. Not hard to fix but if left the way it was I feel it would eventually break loose. This would be a disaster because the inductor is wired in series with the main load resistor: broken connection = no load = fried tube amp. Also, on the used unit one of the solder joints of the inductor was never correctly soldered; the enamel insulation wasn't cleaned off the inductor lead and was preventing the solder from attaching well. I'd say the guy who had it before me was lucky. Or he had a transistor amp, which wouldn't have cared.
A similar no-load situation will occur if the 8-16 ohm selector slide switch is not pushed all the way into one of its two positions. It really should be a toggle switch. The attenuation switch will also disconnect the load resistor when it's in between its click stops. I don't consider this to be poor design because I can see it's difficult to engineer this problem away. I mention it so that you'll appreciate that it's not a good idea to move the switches when you're pumping a lot of sound through this baby.
The jacks are plastic, probably about as sturdy as any other Marshall plastic jack.
Aside from this the thing is brick solid. It's got a big heavy transformer in it though, so falls from any real height will bend or break something.

Beats me.

I use these PowerBrakes with a Sovtek Mig-60 head and Sovtek Mig-100 head, both of which have been modified for more gain and smoother distortion. I have a 4x12 cabinet with Celestion Modern Leads and a Marshall 4x10 cabinet (1965A). For my sound I need a controlled and tailored blend of preamp and output-tube distortion, so for me the PowerBrakes are INDESPENSABLE for getting the sound I want without having to wake the dead.
At some point I'll probably replace the 8-16 ohm slide switch with a real toggle switch.