Underpowering a cab

StormCrow

Hi all,

I have a Trace Elliot AH200 (GP12 Preamp) that I bought second hand today. I have connected it to a Marshall MBC410 cab. The TE is rated at 200w, 4ohm. The MBC is 600w.

I get a terrible distortion when I play through this combination. The sound is fuzzy, and there is an odd distortion that almost sounds like a torn speaker. The louder I play my bass, the worse the sound.

The higher I turn the gain and volume on the TE the better the sound, but even at max on both it sounds bad.

Both Icecreamman and I tested it.

I used my Kustom 80w 8ohm to test the MBC, and it sounded quite sweet, but I kept the volume low and played only for 10 seconds or so. Worried about doing damage to the cab because of the ohm mismatch.

So, am I underpowering the cab, or is the TE faulty? Or perhaps both? Any advice appreciated.

Stormie

AlanRatcliffe

I shouldn't help - I wanted that amp... ?

Under powering a cab is OK. With solid-state amps, the only thing you have to be careful of is using a lower than rated impedance or shorting the output. If it's rated at 200W into 4 Ohm, then you'll only get 100W into an 8 ohm cab, but that won't do any damage.

Things to check:

Make sure you are using a speaker cable, not an instrument cable
Turn gain down low and volume up. If you crank the gain, it will distort - it's made to
Clean out the effects loop sockets (if it has them) and also try a cable from send to return
Rotate/move all the pots/faders a few times to see if you get any noise and to clean any dirt off the tracks

If you still have the problem, it's likely going to need a pro to look see. Quite likely to be dry joints from the symptoms.

StormCrow

1 Make sure you are using a speaker cable, not an instrument cable
2 Turn gain down low and volume up. If you crank the gain, it will distort - it's made to
3 Clean out the effects loop sockets (if it has them) and also try a cable from send to return
4 Rotate/move all the pots/faders a few times to see if you get any noise and to clean any dirt off the tracks

I have tried everything but using a speaker cable. I have used 7 different instrument cables, and they all sound exactly the same.

Hey... it might be in the market again soon...

StormCrow

Seems as if the head is broken and unrepairable...