Re: Tube recommendation for JCM-800 / Dr Z Airbrake question



"markd" <markd234@xxxxxxxxxxxxxxx> wrote in message news:h3ots6hpur8idkgska2ldp922s8j58e4cj@xxxxxxxxxx
I bought a 1987 JCM-800 combo a couple years ago, and during shipping
a couple preamp and one power tube got damaged. An amp tech (who has
since moved) replaced all preamp tubes with new Sovtek 12AX7LPS and
power tubes with Mullard EL34s. Everything else in the amp checked out
to be in good shape, and it plays fine after the work was done.

I bought it on eBay, so I never got to hear the amp prior to the tubes
being replaced since it was broke when it arrived. The preamp gain has
always sounded much more brittle/harsh compared to other amps I
own/have owned, almost similar to having a distortion (vs. overdrive)
pedal in front of the amp. Are the Sovteks the likely culprit, and if
so can someone recommend a different set?

On a separate topic... I'm also considering a Dr Z Air Brake
attenuator. I realize some people are really against using them, but
it seems if used judiciously I could stay out of trouble. The JCM-800
is so freaking loud that there's no way I can push the power tubes to
get the tone that the amp is supposedly capable of when the power
tubes are saturated... and as I understand, the master volume does NOT
act as an attenuator. I'm curious/confused why the Air Brake isn't
readily available from the usual online guitar sources when it
generally gets better reviews (and costs the same) as the THD Hot
Plate?

My understanding is that the later JCM-800s are more harsh/brittle sounding than the earlier ones. I don't know why, however. It's the nature of the beast, I suppose.

I've got a 1981 800 2204. Even with that one, I've got to dial it in carefully for any given guitar to avoid the brittle thing. Mine has 6550 power tubes, which seem to give it a tighter and a bit more pronounced low end compared with 2204s that I've heard that are running EL34s.

As far as attenuators are concerned, I wouldn't hesitate to recommend a Hot Plate. I've got the 16-ohm version, which I can use with the 2204 and 1960a cabinet that I have, and also with my Vox AC30. If you're playing primarily at home or at small venues, some sort of attenuator is practically a necessity, and I wouldn't get hung up too much on what the reviews say. Also, whether you realize it or not, attenuating the amp's output won't give you the same *feel* as playing the thing at full volume unattenuated. The factor of the guitar's interaction with the amplified sound won't be the same.

.



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