V8
I would love to dig through Gear Junkie's junk, but, will probably not get time to use any of it.
Transformers, always welcome...

From the relevant TGP thread...

I sometimes feel this is very accurate.

It looks as if the new AC4 Handwired is well received. Some gripes about lack of space to fit "better" Alnico speakers. I cannot say I understand why designers insist that the valves should hang down right behind the speaker. Pictures of the insides - it looks neat. There are transistors on the main turret board, and some debate about what they do. Probably reverb drive and return. The by-passable effects loop has its components and buffers on a separate board. I would like to have the Service Manuals of the new series, to see what the circuit is like. The pictures of the AC4 insides could be analyzed by someone who actually knows about circuits, but all the wiring is not clear there.
The happy new owners deem it to be a good price for the amplifier. From what I see, it sure is"better" than the old model. Of course, the inclusion of reverb and effects loops in these amplifiers has the "purists" up in arms...
I would think the new AC10 Handwired will sell well too, And immediately receive "better" speakers.

The history of this has been mentioned in my 2021 “Tone Zone Half Air Mod” post.
To recap, the guitar came fitted with a Tone Zone in the bridge, and an Air Norton in the neck – but, the former has no tone, and the latter has no air. I replaced the Air Norton (a Reverse Polarity pickup in this guitar) with a PAF PRO (DM151FBK), after doing the “Air Mod” to it, and fitting “Virtual Vintage” slugs. I half-aired the Tone Zone, but that did not do much to the tone issue – an overwound pickup (17.3 kOhm!) will be just that - dead. I fitted a Kinman style treble bleed (150 kOhm resistor and 0.001uF capacitor) in place of Ibanez’s 33 pF cap, and a 0.01uF tone cap, with new CTS pots.

The standard, very neat wiring:

Been a while, working up motivation to continue with this – I really do not enjoy soldering small wires into small places. But, I recently bought a long thin tip for the Magnum soldering station. Works a treat.

The tone control, with a 0.01 uF capacitor, was a bit vague. I fitted a 0.022 uF drop. The standard fitment was 0.022uF. The wiring is nowhere as compact as before, I did not cut the new pickup leads. Added Earth Bus strips, I am not a fan of soldering wires to the pot casings.

I decided to remove the six Virtual Vintage slugs from the PAF PRO, hoping to reduce output, increase clarity and shift the EQ a bit. I perceived it to be a bit thick(?) in the neck, as if it needs a bit of air. It is subtle.

(Reading posts by inquisitive pseudo-scientific people on the web, will indicate that these “Virtual Vintage” slugs apparently do not add much to a pickup’s inductance, well, not enough to “matter”. I was a physicist by trade, I like science, but, clinical numbers do not tell me why purple is such a nice colour. Or why these slugs do make a difference.)

The “Air Mod” spacers are Perspex. DiMarzio just use two plastic rings each side, to keep the magnet from touching the screws / poles.

Oh, yes, the polepiece screws are much shorter than standard, due to the pickup cavity not being able to accept anything below the baseplate. The standard screws go to the bottom of the legs, but here the legs go into deeper pockets.

Even after the airing modification, the Tone Zone was dead. No fun playing the guitar. I have debated which pickup might work best, but, I guess most lower wind pickups would be better for my purpose. I decided to try a Mo’Joe (DP216F).

The Paf Pro, fitted in the Neck position, is listed as having an output of “300” in standard form, the Mo’Joe is listed as “320”. The “Air” mod on the Paf Pro might reduce it’s output to about “270”, if I compare specs on DiMarzio’s site. OK, so, back in the old days, there was no “Matched Set”. But, going by DiMArzio specs for matched sets, the output difference should be about right.

(Take Note: There is not too much extra space in a pickup. I carefully assembled after removing the “Virtual Vintage” inserts, but, no output after I soldered in the new pickup. Dang? I did not mess with the neck pickup’s wires on the switch? It is earthing somewhere? I managed to pinch one wire against the magnet, not really visible. Took me a while to find that little pinch spot earthing the coils.)

Initial playing shows a much improved guitar. Amazing what pickup DCR does to"tone". These pickups are far from true “PAF” winds, but still has a lot of clarity - the Aired PAF PRO (measured 4.11 kOhm “North” coil, 4.3 kOhm “South” coil) and Mo’Joe (measured 4.81 kOhm “North” coil, 5.05 kOhm “south” coil) matches well in output and tone. All the potential I heard for the switch positions, but was afraid might be lost with another pickup, just got better. The guitar is much nicer now. The tone control rolls off very dark. I might try a 0.015uF capacitor in future, but with a 0.01 uF being very slight, 0.015 uF might again be “not enough”.

Now, I still have that RG570 with the lifeless Ibanez pickups to do…

V8
Thanks!
As mentioned, the chassis is not really deep enough, but it was free. The advantages of machine tools, chassis punches, I guess in the end the workshop becomes it's own hobby, costing much more than the hobbies one supports with it. The better option would, of course, be to CAD out the chassis (confident in your layout!) and have a CNC sheet metal place just cut punch and bend it up.
My future work (if ever) will use existing donor amps. I was planning to build this year, but, it is April already, and the plans are still just ideas. I really do not "need" another guitar amplifier, a small Stereo would make more sense, but, yah.

My post of 2August 2020 referred: After all this time, I read you get directly and indirectly heated rectifier tubes. Using the 5U4GB rectifier, a directly heater type, explains my measuring a voltage spike at startup. The voltage spike is probably not good for the other two valves. Or the first filter capacitor, although the dropper resistor should help there. In the interests of valve life, I should use a 5AR4 rectifier, but then I start all over with the B+ that is too high.

I at long last obtained 560 Ohm resistors for the 6V6 bias resistor. I fitted one measuring 540 Ohm.
I have previously lifted the cathode bypass capacitor on the first stage, not an improvement. I was under the impression I ordered smaller capacitors to use here, but, dang, I did not?
I rigged in an old 10 uF capacitor, while I look for a selection of capacitors. I was thinking 4.7 uF, to tighten up the flab, but may want smaller.
I fitted the 5AR4 rectifier again, and probed the following, with a JJ 12AY7 and JJ 6V6s:

AC at switch 217 VAC
Drop over Rectifier – B+
dropper Resistor 38 V
B+1 350 V
B+2 304 V
B+3 250 V

6V6 valve:
Heaters 6.06 VAC
Plate Voltage 341 V
Grid Voltage 304 V
Cathode Voltage 19.4 V

So, a drop of 19.4 V over the 6V6 Cathode resistor, giving me an idle dissipation of 11.6 Watt. I am happy. The amplifier is still a bit “congested”, but, that is the nature of the beast. Ideally I need an AC supply of 220 - 222 VAC, to lift the heater Voltage a bit, but as is now, it is within the 5% variation.

I guess we will have to wait for some real-world opinions. And some "gut shots".
Still only two pre-amp valves, so, the purists will still compain about the MOSFET(s?).
Does it really have spring reverb, or still digital as before?
The cabinet should work better. Effects loop, better. Still no cut control.
Better transformers?
The price sure is in a different league to our old C1 models.

I have been wasting time trying to read up on all this stuff.
It would seem the early THR 5 and 10 are loved. The bigger Cube's get some love. The Artist line is revered.
The Mini Katana or similar small Cube might be nice, when used with a better speaker. Need a Line Out to jack into the Hi Fi, and enjoy FRFR speakers, clinical clean tones...
The ideal unit will have enough knobs and switches to play with the presets, to avoid having to use any App to set up sounds you like. Initially, at least.

As a matter of fact, something I can jack into my little hi-fi system (well, it was 40 years ago) would probably be ideal.

My only exposure to modelling type amplifiers was a listen to some Line 6 amplifier long ago. I never bought into the concept.
I can see how such a multi-voice amplifier can be convenient for home playing as well as non-serious live playing, but I have no desire to sit and tweak settings and sounds on a PC. I am over-invested in valve amplifiers, do not play out, and rarely use anything but reverb. I struggle to gel with any overdrive or fuzz, probably because I have no idea how to tweak an amplifier.
The Yamaha is expensive, looks rather handy, and I am sure a good demo of that or the Katana line would sway me to consider one as my main bedroom amplifier. I guess for my situation, I really need nothing more. Would free up a lot of space. Better avoid that demo...

Arune5
This is easy. You can stretch open the crack a bit, mix up some 30 min epoxy, heat it to flow easy, work it into the crack, "clamp" the neck, wipe off excess epoxy.
I do not think that will need a dowel as well.

Cerise
I have not played it much yet, cannot comment on the tone.

Cerise
I have changed the tubes to lower gain ones, as documented earlier on.
I am referring to adjusting the gain on the MOSFET itself - not the circuit after it. Altering the stage after the MOSFET (and gain pot) does not do anything to it's gain, or the effect of the gain pot. It merely reduces the signal to the inverter.
Just curious, if the pre-amp is set up "too hot" (?), and the master volume does not reduce the volume to your desired level, did that amp tech have any suggestions about how to solve your problem?

V8
I guess I did not notice before, due to being in the process of slowly sorting it out, or just accepted it as playing too hard. Low action, Fret buzz...
It does it with open string, as well as fretted at the last fret. Some opinions say nut problems can cause this, not sure how, but a quick peek at dip, action, and then running up over all the frets indicated the problem is not on the neck - I took a screwdriver and pressed it in front of the bridge as an artificial saddle, noise gone.
The shape of the saddle slots, the play on the posts, this thing asks for trouble. If I pluck the second string real hard, similar issue. Not planning to play like that.
One can hear a more "solid" tone from the other strings, as if the first string loses power? Damping itself.
I guess raising the action will mitigate it, but I have the action lekker low now. The long-term solution will be better posts, clamping the bridge, and re-profiling the slot slope angles, or tilting the bridge on the posts.
My one "presitge" Ibanez has a troublesome sound on the second string, and I know pressing the saddle around helps temporarily. But, shoving in a shim to stop sideways play of that saddle does not help. I shall now look at it with new ideas, it might be a similar break angle problem.
One PRS poster reported his issue was caused by a slight burr in the slot. Guess one should clean and check really well.
Cut your nut with enough slope at front, use string tees, cut your saddles with enough slope behind.

This bridge is probably not the best system out there, but, it works.
The guitar has developed a buzz on the first string, any fret. Action is high enough, dip is enough, pickups are low, so, bridge?
Fixing the slots will need a decent nut file, but, in the interim, this shim seems to help with the string break point.

FWIW, it seems the buzz is in the up/down vibration mode, so I suspect it is not merely the slot being too wide.

This is a recurring issue, even on the hi-fi groups.
I had a very unpleasant dealing experience, with a kit. It seems the person is apt to accept orders, take the money for it, and then not bother to fill it in "good time". Or, be bothered with the quality.
I have also read reports by very happy customers...

I had the time to work on this some more. Or, had new 120kOhm resistors on hand to replace the plate load resistors.
I also jumped a 10kOhm resistor at the input (it formed a voltage divider with the 1 MegOhm to ground), leaving only 27 kOhm as grid stopper R there, and cut a little capacitor that went from input to ground. That is probably meant to filter out high frequency noise. I decided to cut out the extra "thick" mode cathode resistor on the first valve, I am not interested in this "Thick" mode circuit.
So, if I have to say, the amplifier sounds brighter, or clearer, or louder, maybe. It has good sustain, but the overdrive is rather harsh, trebl-y unpleasant and thin.
What is noticeable, is a tremolo effect on note decay. I would guess about a 3 Hz variation, in volume, clearly some remnant of that initial decay "woosh". I should probably fit new valves again as a test.
I shall probably alter a coupling capacitor, maybe a cathode bypass capacitor, add a grid leak to the splitter, to see, but, the transformers might be of better use in a turret boarded DIY amp. I preder to not hack up the PCB traces too much, the splitter grid leak will already require cutting a trace.
I'd like to try a 6V6 cathode bias thing, with a reasonbably "clean" pre-amp.

Cerise
Playing the amplifier results in the top panel not being very hot to the touch, so, I have decided not to drill holes as yet. I might still do so at a later stage, when I have the chassis out.

TAMING THE FIRST GAIN STAGE

The first gain stage being via a LND150 FET, on surface mount PCB, it is not configurable by swapping tubes or components on the fly. Resistor R95 is the “Plate Load” resistor, 220 kOhm. Q4, below right of it, is the MOSFET, and the small surface mount resistors below it, R62 and R63, are the “Cathode” resistors.

I want to reduce gain on this amp, or, have the gain kick in more gradually and smoother. I decided to alter R95, lowering it’s value by parallelling on a 266 kOhm resistor to lower the Plate load to about 120 kOhm. Oh, yes, R100 is also in that circuit. I guess the original Plate load would then be 230 kOhm, and I reduced it to 130 kOhm.

Laboratory equipment would have been nice, but, I shall have to play a lot to evaluate the result.
Initial quick test was with a SE Tremonti neck humbucker at full volume, guitar tone turned down, amplifier gain full open, master volume full open, Bass full up and Treble full down – It was rather noisy, and proved the system still works.

Some sane playing indicates the Gain pot now needs to be open more before sound eminates from the speaker, and it might have a softer ramp-up to it?

I expect overall volume to be about the same: The Master Volume pot only increases volume up to half way, after that volume does not increase anymore. I would like to have an oscilloscope to see what the signal does here.
And from the Pre-Amp side, once the signal is clipped to whatever voltage swing is available in the Valves, more Gain will not increase volume either, just distort more. Which it does, at full gain…A scope would be nice.
If I have to say, after brief playing, I might want to use a 170 kOhm resistor here, but time with different guitars will tell.

So far so good.

Thank you. Any information is always welcome.