Mark III+/++ impressions and a few questions

No clips/videos yet for reasons below, but there will be some high quality ones coming this week.

Lots and lots and lots and lots of gain. Controllable and tight - much better with EL34s in the outer pair. The ++ mod instantly gets you into Black Album territory. Compared to my half-modded Blue Stripe 60W it's a lot tighter, has a bit more low end going on, more in the amount of harmonics etc coming through maybe than pure low fundamental. It's simultaneously a bit noisier and a bit more musical.

I noticed a change in sound after I accidentally put a bit too much bass through the EQ in the fx loop but I've been playing around with different speaker installations and it could be my mind playing tricks on me. It would have been about +12db boost on 5 sliders from 30-100hz with a hipass around 50hz. Any idea if this can have any effect on components? Hopefully it would just mean swapping out a 12AX7 because I've literally just got this thing. :lol: It seems to have basically gone a bit fuzzy, lost a bit of its sharpness. Seemed to improve slightly but not entirely when I removed all the fx loop stuff.

Also seem to have wired in one of my speakers wrong, I was planning on doing a Standard V30/Marshall V30/G12T-75 comparison with two rack EQs to show some of the different tonal options this thing can do, but until I open the cab back up and recheck the wiring and make sure I've not blown something by feeding too much signal through the fx loop I'll be sorting these issues out. Once that's all sorted I'll be doing a more in depth post. Big up Jon for sorting this mod out too, he did a great job.

Be gentle don't break it too soon!!!

The one weak spot in the mod I should point out is on C505 which I reversed R113 and C505 as in the RP10 IIC+. Check this looks ok and nothing has moved and is really near any other components. I did a massive shake test of the amp which was fine but after the UPS gorillas have thrown it around in the flight case who knows... use a plastic chopstick to poke around that area if the valve swaps make no difference. The other weak bit is R116 with the orange wire but that's to power the reverb. I say 'weak' because only one pin of the component is connected to the board in those areas. This happens in the IIC to IIC+ conversion though and holds fine. If you ever find these do move around (they shouldn't but again this isn't a tried and tested mod) a bit of hot glue gun action in that area would do the trick and hold them.

I'd imagine it'd be a bad valve though as if C505/R113 were loose you would get no sound at all most likely.

This is for a red stripe but same board layout to see where I'm talking about:

https://drive.google.com/open?id=1kf7xBblJ6qY1ZdxjI8Ek6hC1fO-vkEAO

Looking forward to the comparison when you hopefully get things sorted!

Cheers,

Jon