My Mkiii Don't Sound right

[roddyf]

Hi
I'm new to this forum and would like some feedback. I have just purchased a MKiii simulclass combo with EQ, Reverb & EV Blackshadow. It has had a voltage selector switch and a couple of extra footswitch jacks for the EQ & Reverb installed and appears to be in very good condition. The problem is the sound. I used to own a calibre 50 in the 80's and it was the sweetest amp I have ever owned. Beautiful tone and tight bottom end. The mkiii, which should be superior to the calibre sounds aweful. Sloppy bottom end and an undesirable fuzzy tone. I work in an enviroment where I cant crank it up to much, usually only about 2-3 on the master. Does this amp need to cranked to sound good. Would a power soak improve the overall sound or is there something wrong with the amp? I have put in the replacement valves that came with it but it has made little difference. I am just trying to get that smooth distortion that i used to get with the calibre and that I thought was the boogie trademark.
Any opinions here would be Appreciated

Thanx

 

[paleamberglow]

it takes a little while to dial in a good sound with boogies, they aren't always 'instant gratification' amps like Dr. Z or marshall, but this is an advantage because the boogies are so flexible. keep tweaking your sound for a few days before you consider the possibility that there might be something wrong with it. The Mark III sounds best at louder volumes, but still sounds great in the 1-3 range. I don't think an attenuator would make much difference with this amp. First I would replace the tubes (both preamp and power) and then if that doesn't improve it I would take it to a technician...

 

[DW]

What are your settings? For a nice singing lead sound, make sure Volume 1 (on the far left) and the Treble are both set to 8 (or higher).

As was just suggested, I would also install new tubes--both power amp and pre amp. I do that whenever I buy a used amp just so I know exactly how old the tubes are.

Also, make sure the Reverb cables coming from the reverb tank to the underside of the amp are plugged in all the way and perhaps try reversing the grey and white cables where they plug in to the amp. If they are plugged in backwards, the amp can produce a harsh fuzzy choked sound kind of like you describe. It is a bit tough to get your hand in there to swap them with the tubes and transformers in the way.

With the Master at "1" (or less) you should able to get a great sound. No Attenuator is needed.

 

[roddyf]

Thanx for the suggestions. Ihave checked the reverb leads and they are definately in th right way. The problem seems to be the lead channel. It just does not sound like other boogies I have played. I am a very experienced player and have owned and used many amps. With my 50 calibre I used to be able to dial in a great Steve Lukather type sound with eaze, clean and fat. Then go to a Santana or fusion sound just by switching pickups. The distortion on this amp will just not clean up, no matter how I tweak it. I can get a great clean tone but as soon as I switch channels, it turns to ****, and does not have the boogie tone that I know. Is this just the way this model was designed to sound? I just want a smooth breakup. not fuzzy
Do the mods for these amps have be done in the factory?
Does anyone here have the mod specs?

Thanx

 

[DW]

Every Mark III I've every played was superior to a 50 Cal. in the Lead Channel. Did you try another 12AX7 in the first position (the one under the silver can)? What are your settings?

I'm still thinking it might be a reverb problem. What happens if you unplug the grey & white cables going to the reverb tank?

 

[roddyf]

Did a few gigs on the weekend. Replaced 2 preamp tubes and tweeked the EQ alot. There it was. That tone I know and love. Thanks for your responses, I think I'm OK now. FOUND MY TONE!.