that’s what I suspected, but apparently he didn’t go all in on yours 
Small blessings I suppose 
not sure why he used a 12au7/e80cc and some great lump of an oil filled cap though.
Have seen some M77 DIY schematics that use the e80cc though so he may have tried to copy that.
I might be wrong but I’m not sure Kondo himself ever used many Black Gate caps. Cerafine maybe.
I think he did in the power amps (going by some photos I’ve found) but trying to find 4x Elna 100+100 caps is probably going to be much harder than finding one BG wkz
Can’t make out what these are???
I’ve seen them in M7s, though the Ongakus I’ve seen have cerafines.
I actually have a 220uF+220uF 350V Black agate on a shelf which belongs to a friend and is for sale and could possibly substitute.
That M7 has Nipon Chemicon electrolytics,
the current Kondo amps use Unicom, which can be bought from Acoustic Dimensions in NL
The really old ones have Black Gates, then a lot have Cerafines, probably after Rubycon stopped the BGs, then Nipon Chemicon and now Unicom
Overall I think I generally prefer the Cerafine
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I have a couple of 100uF 500v BGs, a couple of 47+47uf 500v Cerafine a few 220+220uf 350v Cerafine.
If we cant find a 100+100 BG I would probably go for the 47+47 cerafine as first cap after the 6x4 rather than a 220+220, then have the 3 BGs as the last caps in the psu connected to the valves
If 47+47 would work I found a 500v BG heart of muse one?
I used to have some 100+100 500V BGs, but sold them - they’re crack money these days. Wish I had bought more at the time!
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I couldn’t afford the HV BGs at the time so that wasnt an option 
Even HV Cerafines are now crazy money on thief bay
I think I first came across Black Gates when visiting Akihabara in 1988 or thereabouts. Many of the little stalls there were selling them as well as Shinkoh resistors. We brought quite a lot back with us. But I was amused to learn that much of the well rated Rotel gear of the time (even down to their fairly cheap ‘audiophile’ integrateds) were already using them fairly liberally.
If Kondo started using them after that I suspect it was because PQ asked him to fit them to some of the amps he was importing. But he wasn’t using them in the electronics he was making in the late 80’s early 90’s. Besides Cerafine & Nippon Chemicon they’d also use Audio Professor (Morikawa) caps which were possibly re-branded Elna or Rubycon. Looked similar.
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Yeah, I’d rather use polypropylene types anyway. Last forever, sound good, etc.
Modern electros are so much better these days anyway, is it really worth springing for black gates? Not so sure.
I get it for replacing them in old amps, though.
Digging into the nearly 40 years of Audio Note / Kondo M7 history has been somewhat challenging, but this is currently the best I have been able to bring together based on the various sources I have found across the web.
1980 - 1984, original M7
FET (by Shigeru Trerada and Shindengen) pre-amplifier with a tube power supply
1987 - 1998, M7 Tube
Tube - full facility MM phono pre-amplifier - 5 x 6072, 1 x 6X4
Tube Silver - silver caps in the line stage as well in the phono
(Note: there appear to be many sub-variants, including use of 13D3 in the phono, and using a 6072 as a tape buffer, and very early ones may have used 2 x 6072 & 1 x 5687 in the phono stage & then 2 x 6072 & 1 x 5687 in the line stage)
Phono - MM stand alone phono stage - silver caps - valves not known
Came in two versions, first ones were in a quite small chassis with no tube rectifier, later ones came in same chassis as M7 Tube
Line - line stage pre . - 1 x 5687, 1 x 6X4
Line Silver - silver caps
Early versions came in small chassis similar to early M7Phonos and did not have tube rectification.
2000 - 2005 M7 IIK
Standard - a full facility MM phono pre-amplifier - it appears earlier versions used 2 x 12AX7, 2 x 5687 and 1 x 6X4, and later versions used 2 x 12AX7, 2 x 6072, 1 x 6X4
Signature version - had 2 more valves (but I haven’t found out why), better quality valves and materials including a large Alps RK50 potentiometer
Line - 2 x 5687, 2 x 12AT7 and 1 x 6X4
Phono - MM stand alone phono stage - 2 x 12AX7/5751/ECC83, 2 x 12AU7/ECC82/ECC802S and 1 x 6X4
2006 - to date: KSL-M7
Standard - a full facility MM phono pre-amplifier - 2 x 12AX7, 2 x 12AU7, 1 x 6X4
Line - 2 x 12AU7, 1 x 6X4
Phono - MM stand alone phono stage - 2 x 12AX7, 2 x 12AU7, 1 x 6X4
As Chris has an “M7 TUBE Silver Sound”, this suggests it is from the 1990s (the presence of Black Gates also indicate this) and it has silver coupling caps in the phono and line stages, following this it should “probably” have 5 x 6072 and 1 x 6X4, as per the classic circuit diagram from 1991, as seen here:
https://www.diyaudio.com/forums/attachments/tubes-valves/292487d1342874069-audio-note-m7-line-preamp-audionote-m7-pre-sch_01-pdf
Now to track down some of the components the previous owner considered surplus to requirements 
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1997 I believe, Guy emailed Kondo and they looked up the serial number.
It’s good to hear it fits with the timeline 
It would be nice to get the custom mains transformer N0-10982 shown in the picture that Guy posted, it was probably made for them by Tango, but isnt a standard model and has dual primaries so it can be used with 110 to 240V mains by wiring it up suitably.
The unit currently installed has a single 220V primary
The first M7 Tube was with 2x 6072 & 1 x 5687 in the phono stage & the same in the line stage. SS rectifiers and definitely didn’t have silver coupling caps but some orange coloured block type with twisted multistrand lead outs. It also had a bare copper cover which hastily attracted fingerprints & rapidly turned green/black.
As you have probably seen, @thebiglebowski has his M7 Silver preamp back following Covid lockdown
It has a 220V mains transformer, and after considering a few options I decided to go for an external step-down isolating transformer
The linestage and phono were both rather noisy, so to help address this I created a star earth for the psu, another for the phono, a third for the linestage and a star of stars at the chassis connection. It was also necessary to add bypass caps to the heaters on the phono input valves, and sort out the earth continuity between the different chassis panels.
The circuit was brought back as closely as possible to the original circuit using 2 x 6072A in the line stage, and 3 x 6072A in the phono stage. The linestage had 25 dB gain, but the MM phono only had about 20 dB of gain. To increase the MM gain I added Black Gate bypass caps to the cascode input stage and common cathode second stage, bringing it up to about 44 dB, or just about right for an MM phono stage. Finally, the riaa eq wasn’t that accurate, so a couple of resistor tweaks were installed using some old Shinkoh tantalum films to match the rest of the amp.
At the end it was nice and quiet, and sounded like a lovely musical M7 Silver preamp.
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