Hey guys. I'm having some trouble getting a decent sound out of my Marshall and I could really use some help with a few questions.

To start things off, the two outside power tubes are pulled in the amp, I guess dropping it down to 50 watts. Ive heard mixed answers on this being damaging to the power section on the amp, but I live in an apartment now so lower volumes are required sadly. Assuming this is relatively safe for the time being, should I leave the amp bias set to 90 mV or drop it down to 45 mV?

The tone I'm getting right now is a combination of buzzy highs and muddy lows. Ive had the amp for about a year and never changed the tubes, but it was only used in a band setting for maybe 3 months and then put in the closet or just played quietly. Would new tubes fix any of this?

Lastly, my cab is a left over Randall R412CX cab from an old solid state Randall RH200 halfstack. Link to the specs. I'm looking at getting a new cab in the future, but for now how should I be connecting this amp to my Marshall? I've been running out of the 4 ohm output on my amp into the 4 ohm input on the cab, but it has this switch to toggle between 150 watts stereo or 300 watts mono that confuses me a bit. I'm only using one input, but would it be better to leave it on stereo to match the wattage closer to my Marshall's?

When I was still jamming with my band I could never find this amazing volume that 100 watts of tube power is supposed to have and was always getting lost in the mix. We were EQed pretty well and were playing at a pretty average volume, but my amp would never keep up. Could this have been a tube problem or just the byproduct of a mismatched cab?

I'm a bit of a newbie when it comes to tube amps so I'm expecting a few flames, but thanks in advance to all you nice individuals that decide to help out.
Last edited by wyplash at Dec 9, 2007,
Having any tubes pulled out while running it is a BIG no no as far as I know and cannot be good for the tube amp, thats also why your tone sucks.

yes your right about the ohms but keep the cabinet running in mono, you use stereo when you have two cabinets hooked up the to the head.

Also if you are planning on playing at low volume with your 100 watt head the only way to do that is to get a power attuenator or a marshall powerbrake which both are kind of pricey and both still change the tone of the amp somewhat along with making the tubes wearout as if the amp was cranked to 10 on the master.

Also just to make sure you know.. NEVER EVER turn the head on without having a cab plugged in or you are going to fry your amp.
Originally Posted by slatsmania
I'd rather plug my guitar into my dog's ass.

yes... the marshall mg series < dog's ass