1. Wire I used is very thin, looks tacky and will break easier than the correct TWreck Wire. Also I doubt the thin insulation helps with the feedback in this amp, although with good pre amp valves its not been too bad. I want to replace this with the correct wire from RJ.
2. Output Transformer is wrong. I used a Danbury JTM45 6.6K OT which is ok but sounds very hifi to me (makes sense as its a copy of the Marshall RS OT I believe), whereas the Pacific Express OT I believe mainly focuses on the mid range. I want to replace this with the Pacific 6.6K OT.
3. 1K 25W Resistor isn't right. I used a chassis mount resistor which isn't mounted to the chassis and thus gets very hot. I want to replace with a 20W Wirewound Resistor as I don't have enough room for the 25W Cement but I think a 20W should be fine (current resistor rated at 12.5W when not chassis mounted).
4. Turret Board used for main component board is a generic board so there are a lot of unused turrets, looks untidy to me. Power Supply Board is made of soft material and looks untidy to me. I wish to make my own component board and Power Supply Board up (found same generic turret board from Tube-Town but without turrets).
5. Bias Trim Pot is a bit big and using that knob near the fuse holders has always worried me. Going to replace this with the trim pot from the Express BOM.
At the same time I may replace remove the ground buss from the back of the pots and install a few ground lugs for the Pre Amp grounds. The amp is quietish anyway but I found on full volume it hums a bit. I think this is partly the valve in V1 but also partly a ground hum issue. Plus installing ground lugs will mean the ground wire runs will be shorter.
So what do you guys think? My reasons for doing this are to bring the amp closer to the original spec wise and to ensure the amp is reliable. I know its in the wrong chassis and headcab but unfortunately I'm just too much of a fan of the old Marshall heads
.Also the bright cap wiring is now different to this photo, I used the method that I believe Colossal came up with (think it was Colossal) where you glue both caps to the switch. That made a HUGE difference to the noise level. Also the silver micas in the amp have been replaced and the 715p Caps I used are now 6PS Caps.
