JapanAxe

Yep, just a matter of working through it until I find the issue(s). I've done this enough times not to be worried about it. I could always add a silicon rectifier as an option but tbh I don't really think it will be an issue.

Well that was interesting! The mains transformer I bought and installed is not the one I intended to get - it has a secondary of 300-0-300V at 200mA, whereas I meant to buy one that gives 360-0-360V at 400mA. I discovered my error when I checked the B+ voltages, which are about 10% down on what I expected. I used this online calculator to confirm that 200mA should be more than adequate for this amp with a 300V supply voltage - if it gets a bit squashy and saggy, no problem, this is for home use after all. Otherwise I'll have to drop another £120 on a PT that weighs 1.6kg more than the present one! Plate dissipation in each 6L6 is 20W, or 67% of max - that should be fine. With all valves fitted, there is a buzz at the output through my bench speaker but no signal is getting through. I noticed a bad solder joint at the 4ohm speaker output to which the NFB resistor is connected but fixing that made no difference. The 6SL7 preamp valves are the only ones I couldn't test, but I bought them as tested and working, the filaments light up, and swapping them round did not change anything, so I think there's still a wiring error in there for me to find. I've got a busy weekend of gigs and a rehearsal coming up and I need to do some practice, so I'll have to leave it for tonight. In the meantime, here's the mighty valve line-up:

Only if my building goes on fire.

All the heaters are wired up now. Those pink and purple wires sit well above the audio connections to the valve sockets. I have elevated the heater centre tap by connecting it to the cathodes of the output valves - as I understand it (see Blencowe 3.17), this creates a DC leakage current that is saturated, and consequently unaffected by any AC component from the heaters. All the other bits are now fitted. Time to fire up and plug in - NOT. I'll put this aside and come back to it tomorrow, when I'll check all my connections against the schematic and layout, both visually and with a meter, before running through a staged start-up sequence. I may change my mind about the knobs - I've already done so several times!

As of last night, all the connections are now made apart form the 6.3V heater supply. The stray white wire is the heater centre tap.

I’d be interested to try a TE head into my Super Twin although I’m not a fan of graphics EQs.

Today I made more connections from the transformers to the panel-mounted hardware, added the remaining resistors to the valve sockets, and installed the eyelet board. I ran a copper bus through all the speaker ground connections to make it harder for them to work loose. I have to remember to run another cable from this to the main ground bus, otherwise there will be no ground reference for the NFB circuit. My box of bits is now looking somewhat empty - valves, knobs, feet, fuses, pilot bulb, and a few screws.

Yep, done that one - only scared myself though!

I'm always a bit fearful that, when I do my pre-checks and plug an instrument in, I'll be greeted by a tsunami of humming and buzzing.

I have now fitted both transformers and made the connections for the mains and HT. The OT primaries are above the chassis at present as they will pass through at a different point.

This is the fun part!

I've now installed the input jack, screened cables, and tone stack board.

Sorry, I would draw the line at the Scottish bagpipes! Quite fond of the Uillean pipes though.

Only joking! Over the years I have warmed to the sound of the accordion.

At this point it was obvious nothing good was going to happen.

The money laundering thing happens on Amazon as well. Someone lists a really boring book on, say, the statistics of left-handed spigot trunnions, for a way higher price than any genuine buyer would pay. The transaction is used to send criminal funds, making them look like a legitimate purchase. Alternatively, the seller is just inviting offers and doesn't want to put too low a ceiling on these.

And I think I know who that is too...

Yes, I've met him. I'm on guitar at an open mic, sax player turns to me to take a solo, during which he continues to honk away at full volume. Of course this was a fun event, no paying punters, but the same guy is known locally for his inability to stfu on his sax.

Personally I’ve had more grief with guitarists who don’t understand how music works, e.g.: - Assuming the first chord of a song is its key; - Coming in in the wrong place e.g. starting the lead part of Apache on beat 1 instead of beat 2; - Adding the sus4 to a D chord (easy move for the LH pinky) regardless of musical context; - Inappropriate use of the blues scale (and I do mean scale, played up then down); - Inability to stop playing in breakdowns (or indeed at all). I could go one but I think that’s depressing enough!

I re-checked my layout this afternoon and found a couple of silly mistakes (plus another after I took the photo). After that I had a bit of a solder session and finished populating both eyelet boards, as well as fitting most of the flying leads, except the connections to the ground bus, which will be made with the boards in place. It's always worth checking component values on a meter before installing them - I found a stray 1ohm resistor in my 220k bag!

You may have noticed there are no valve retainers fitted. I did buy ‘bear trap’ retainers but decided not to fit them - the valves will stand above the chassis and the head is for home use only, plus it is a pain to remove valves from bear trap retainers.

I finally drilled the small guide holes that I will eventually widen for the self-tapping screws which will secure the cover to the chassis. I have ordered what I hope will be suitable screws. I also drilled a hole for the safety earth bolt and exposed bare metal around this and the input socket hole using a Dremel-type tool. All the panel hardware is now firmly mounted except for the input socket. It's always satisfying when the valve sockets are in. Next up, a load of soldering.

While I wasn't gigging I thought I might as well enjoy my smaller stage rig at home, so this has been my practice rig for several months. All being well, the Demeter is soon to be displaced from this role by my home-build B15 clone.

This makes perfect sense - prepare an encore but only play it if the audience demands it. Of course the word ‘demands’ is open to interpretation - do you wait for them to scream for more (genuine encore) or are you content for them just to stay in the room (fake encore). Perhaps Gibson should put out a video urging bands to ‘encore authentic’…

Thank you! This time I used a 30mm panel cutter for the valve socket holes instead of a step drill.