Any luck with Mercury Magnetics tone clone OT?

[TheHandsomeOrk]

Their blackface Twin Reverb tone clone series. Using one at the moment for a 100w high plate build along with the power transformer. Voltages are perfect all around. Correct caps, resistors, pots etc. lead dress looks tidy, nothing looks out of place but I can't get the OD channel to sound any good.
Clean channel is nice sounding, quiet with plenty of headroom and very happy with it. I've been chasing my tail for days tweaking the OD and front end with no luck. Tried different caps, pots, tubes, speakers, resistors, even wire and end up no better off. Re did all the grounds, re-flow all solder joints, double check components etc. I can get the OD to sustain and break into feedback ( in a nice way) at low levels on single notes but double stops and chords sound crap. The only thing that I can think of is the OT or steel chassis (never used one before) will have to be changed. Before I gut it and build a 50w with bassman OT I thought I would check here and see if anyone has had any success with these transformers. Thanks for any help.

[wjdunham]

I have used their Blackface Twin in a couple of builds, a 100W #102 (high plate skyliner) and a 100W 70's - both sounded wonderful, no problems with the OT's. Mercury's tend to be pretty consistent and while it's always possible to get a clunker, it's not the first thing I would suspect.
If you post a gut shot of your amp I'm sure you'll get lots of help from forum members here with suggestions on what to try.
Bill

[wjdunham]

What brand power and preamp tubes are you using? If you believe everything else is in order I'd try a couple of different tubes in the overdrive and PI sockets to see if that will open things up.
Bill

[TheHandsomeOrk]

Thanks Bill
It's good to know that others have used these OTs with success. I do have another which I can sub in but it means pulling boards to get at bolts/nuts.
I'm not 100% sure on the steel chassis as I've always used aluminium, I've read it makes no diff but I'm not convinced. As for tubes I'll keep plugging away and see if there's any improvement.