Was going to mention the powerbrake, but I always reply too soon.....sorry.

Mike

Thanks,
I just noticed that 50w marshall heads have only 2 power tubes. Is there a big difference beetwen pulling tubes out, and a made for 50w 2 power tubes amp?? maybe the impendance, cause you can use a 8 ohm cab with a 8 ohm output in your marshall.
also..what will be the wattage if I pull the tubes out? 50w?

Me, I got a li'l Gibson Goldtone, switchable between 6 and 15 watts. I'm a big believer in power amp and Celestion distortion. And of course most of the tone is in the hands of the player...
I turn this li'l lovely up to ten, and damn it sounds nice. I've made recordings with it that sound extremely reminiscent of Jimi's several suped-up vintage Marshalls. This done with a Les Paul Custom ca. 1980.
Worth a try! And you can always use your full-on Marshall with all tubes intact for those occasions where mind-numbing loudness in addition to killer fat tone is called for...
Ted

With a JCM 800 you can select the impedance of the output transformer using that pre-historic looking selector on the back.

One of the first ports of call would be to check out a cab with higher impedance if you're not already at the max.

You can also use less efficient speakers -- those classic Marshall 4x12 cabs were very, very efficient compared to a lot of modern designs.

For an alternative approach, I had the shop put in an effects loop into my 1977 JCM 800 head. The not particularly unexpected side effect was that I could take a line off the pre-amp. This definitely doesn't give the same sound as cranking up the volume, but it may well give the sound you're looking for.

Like the previous poster, I eventually chickened out and bought something smaller - a Mesa/Boogie combo. Sounds delicious. My JCM800 is still upstairs in the attic, rarely used... sniff.

Originally posted by Martin Turner:
[QB I eventually chickened out and bought something smaller - a Mesa/Boogie combo. Sounds delicious. [/QB]

Which one?

I went for the smallest one I could, as years of humping a Marshall stack around persuaded me to leave behind the kilos.

I went for the Subway Rocket (non-reverb version).

For a Boogie it's quite cheap. As a recording amp the non-reverb version is better, because it has presence which influences the other three tone controls instead of a spring reverb.

One nice feature is being able to switch off the speaker and record direct from the balanced recording out (which also doubles cunningly as a stereo headphone out). Very good for later night stuff at home.

The nominal power out is 15 watt RMS, but, seriously, its still way too loud to crank up anywhere outside of a gig environment.

It isn't 'portable' in the way of the Marshall valve-state combos, but I think its total weight including the Black Shadow speaker is less than my JCM 800 head.

Its hard to beat a marshall stack for almost all rock guitars, for me. I do also have a Mesa Mark 4. The is a very good sounding 1X12 combo but, It weighs about 500 pounds, and there about 1000 knobs and switches, not your everyday knobs and switches either, we're talking 3 ways and push pull shit.
Triode and pentode options, even the on off switch is 3way(Full power, and tweed power).

All that said, this amp takes discriptions like "crunch" and "in your face" to levels marshall will never know. But its still not what we have been hearing for the last 20+ years.

Why would you not want to try a power attenuator? I use one with my 72 Traynor (similar to Plexi) and it sounds great, much better than a master volume (especially the phase cancel type) Try Power Soak. It's much cheaper than the Marshall one.