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O.k I had a good chance to crank the heck out of my 30 watt tonight.
And whilst I mentioned in the other post it didn't sound fuzzy or flabby, I actually take those words back.
I was able to open up the amp by cranking the master and yes I found all the inconsistencies of a dc-30 amp.
On the clean channel, anything past 6-7 on volume knob things got flabby particularly on single coil pickups on the tele.
On the EF86 side, I got major flabbiness with the gain past 11 o'clock and things got fuzzy and loose at higher gain.
High inputs was unuseable for high output humbuckers, major flab and fuzz. On low inputs much nicer!!

Don't get me wrong, there are some numerous beautiful tones to be had at lower gain gain on both channels, that transparent chimey cleans and slight grit that can't be beat. beautifully transparent. But it simply can't hold even medium gain tones.

Some people may shrug their shoulders and say "Well that's part of the matchless design" but why have a range on your controls which are unusable? I think that any well designed amp should be usuable throughout a good part of it's range.

Hence now I'm on a quest to see how I can improve on this thing.
I know Dirty amps has done exploration in this area. If there's any way to tighten up the sound of the ef86 and make it less fuzzy and more tighter sounding, I'm all ears. I guess the first step is to play around with the amount of gain on the channel.

Tweaking is all part of the fun!

I performed some of the clean lightning mods which helped give more headroom on the clean channel and made overdrive a bit smoother.

I think the main cuplrit of the flabby fuzziness of the ef86 side is the rotary toneswitch. It's very gainy! I think it needs some value changes to tame the gain. Any suggestions?

the voltage going to ef86 affects the tone significantly. I think the stock dc-30 has too much (measured about 350v) making it fuzzy, buzzy and flabby. decreasing the voltage seems to smooth things out.

The 18 watt message board has a pdf or jpg in the files/downloads section with various component values in an EF-86 topology. You might mess around with those. Also, if you can get your hands on any schematics of a famously anti-DIY amp maker who isn't a medical doctor but plays one in his advertising literature, people opine that his EF-86 builds are less gainy than what Matchless does.

Bear

Thanks - yeah I've played around with values to something I pretty much like. Good thought I'll visit the "doctor" see what he's done..

Well I've discovered that this amp likes open back cabs with smaller opening - for tighter bottom end.