Arkless Electronics
Trade: Amp design and repairs.
The design of the core will effect things as will whether or not it's magnetically screened and how well. I couldn't comment on individual makes as I'm not familiar with them. I wouldn't use a TVC personally as they are theoretically inferior to a basic normal passive.
Arkless Electronics
Trade: Amp design and repairs.
Aha I think I have quite a few of these, maybe you can confirm.... the ones I have are re-branded "Marshall" and obviously came from guitar amps, they have long anodes which are bright silver colour and completely smooth and there is still the original etched identification on them which is, top line "2A1" and underneath this is what I can only describe as an "o" with a segment missing at the bottom and a dot in the centre followed by "5E"... so "O5E". Currently trying the smooth long grey anode EI's (real thing as does have "EI" on them!).
Tony L
Administrator
Sounds about right, though I don’t know either way on the Marshall branding. Basically if they look identical to the EI smooth grey plates but have bright silver plates instead they are what I’m on about. Based on my samples they are a lot better sounding too, the grey plates sounding rather bright and thin, the silvers big, warm and natural. IIRC they are based on a Telefunken design and maybe even some of the original tooling. Chances are some will be microphonic and/or noisy though, or even if they start off fine end up that way in a little time. They just don’t seem to have the lifespan of good vintage valves.
Stunsworth
pfm Member
I bought three new ECC83s for the phono amp that Jez fixed. One of them failed after a month or so. Could just be bad luck - though I wish I'd kept the invoice to get a refund. Luckily I had three Golden Dragons lying around to use instead.
Tony L
Administrator
A picture of a few ECC83s; Blackburn Mullards:‘59 F92 long-plate, ‘65 I63 short plate, ‘69 I63 short-plate (you may be just able to spot the former has copper rods rather than nickel, it sounds better!) and a Mitcham box-plate. Finally a silver-plate EI for Jez! It actually is taller its not just the picture. I’d likely not get the lid on my Verdier pre if I stuck it in the phono stage!
The short plate Mullards confuse me in that the early ‘60s I61 design (not pictured, they are in the amp!) and early I63 look identical, then later they moved to nickel rods and at that point to my ears the sound changed to something rather warmer and more compressed. The long-plates and box-plate are not stereotypically ‘Mullard’ at all, really quite forceful. For my ears/system/amp I seem to like the I61 & copper-rod I63 the best, though a long-plate in P1 can be very good and would likely be my choice downstairs with the huge Tannoys.
Arkless Electronics
Trade: Amp design and repairs.
A picture of a few ECC83s; Blackburn Mullards:‘59 F92 long-plate, ‘65 I63 short plate, ‘69 I63 short-plate (you may be just able to spot the former has copper rods rather than nickel, it sounds better!) and a Mitcham box-plate. Finally a silver-plate EI for Jez! It actually is taller its not just the picture. I’d likely not get the lid on my Verdier pre if I stuck it in the phono stage!
The short plate Mullards confuse me in that the early ‘60s I61 design (not pictured, they are in the amp!) and early I63 look identical, then later they moved to nickel rods and at that point to my ears the sound changed to something rather warmer and more compressed. The long-plates and box-plate are not stereotypically ‘Mullard’ at all, really quite forceful. For my ears/system/amp I seem to like the I61 & copper-rod I63 the best, though a long-plate in P1 can be very good and would likely be my choice downstairs with the huge Tannoys.
That's the one's yep! Thanks. I'll give them a go. Also been trying Brimar and have some "ERA" ones to try which are very short small anodes and look more like ECC81's.....
Groove Tubes GT-7025 I have appear to be EI grey smooth long anodes in reality..
Marchbanks
Hat and Beard member
On the subject of ECC83s please can someone help me with one I have just found? I don’t remember where it came from, although writing on the box suggests it may have been a gift. I can’t find any info regarding precisely these markings...
12AX7BP
SOVTEK(R)
REFLECTOR (sic)
made in russia (in caps)
98 12 (presumably date code)
It looks like it has never been used. I’ve only got one, so the only place I can try it is on the line stage of my 25R!
12AX7BP
SOVTEK(R)
REFLECTOR (sic)
made in russia (in caps)
98 12 (presumably date code)
It looks like it has never been used. I’ve only got one, so the only place I can try it is on the line stage of my 25R!
George J
Herefordshire member
This is such a nice thread! This and Mike's St20 threads have given me the greatest pleasure just for reading such informative and genial posts.
Thanks for the pleasure of it.
Best wishes from George.
[PS: Listening to R3 on the old Troughline, which is performing like an audio angel!].
Thanks for the pleasure of it.
Best wishes from George.
[PS: Listening to R3 on the old Troughline, which is performing like an audio angel!].
Tony L
Administrator
Russian tubes are a confusing topic. Sovtek re-badged a lot of ex-military stuff, so my guess is this is what you have here, though the date-code seems a little odd. I thought Reflector valves were USSR era or shortly after, but I may be wrong. I’d certainly give it a go, it may be quite decent!
toprepairman
pfm Member
Tony, the valve position 4 in post 507 looks like it could be an ECC82.
Tony L
Administrator
Definitely a ECC83, it has type code 641 etched on the glass. I was wrong about Mitcham though, looking at it again its the Whyteleaf factory (the square with a diagonal line through) and 1962. That valve really confused me at first as it was boxed as a NOS ECC81 in a trio I bought, but clearly wasn’t when I plugged it in! The etched type code is always far more accurate than the label print in these cases. I did ok as it is worth at least 3x the price of the ‘81s! I think there were box-plate ‘82s too, though I haven’t got any.
PS Pretty much everything I know about Mullard/Philips valves can be found in this .pdf (AudioTubes).
snowman_al
pfm Member
Better still, that ECC83 is the typical Mullard M8137 (CV4004) structure. Your code 64x confirms that.
Easier to read code list here: http://www.r-type.org/pdfs/ref4110.pdf
Easier to read code list here: http://www.r-type.org/pdfs/ref4110.pdf
toprepairman
pfm Member
Very nice indeed and a bit rare.
Arkless Electronics
Trade: Amp design and repairs.
When I saw the pic I thought it looked rather like the M8137 but thought "one of the Mullard plants must have made ones that look this way but probably for a short time as I can't personally recall seeing any normal ECC83's like this....". Hope it is the real McCoy!
Anyway, found 4 of EI nickel anodes and 2 of these looking like from same batch so used them in phase splitter position and luckily one of the remaining two is quiet enough for first stage. Best yet!
Anyway, found 4 of EI nickel anodes and 2 of these looking like from same batch so used them in phase splitter position and luckily one of the remaining two is quiet enough for first stage. Best yet!
Mike P
Trade: Pickwell Audio
If you're ever passing near Sheffield come and have a play with mine. I'm finding it to be absolutely ideal.
Tony L
Administrator
As I understand it the M8137 is just a military designation for the ECC83, i.e. it is a direct equivalent. I’m positive mine is an M8137 anyway, the etched codes don’t lie (unlike the label prints). It looks structurally identical to this M8137. I’ll stick it in my Orange valve tester at some point, it should be NOS. It certainly works well and is very quiet, just a little bright and forward for my system context so I’m running with early ‘60s type I61s.
PS I’ll stick it in for another listen too as I've made some changes since I last tried it!
Arkless Electronics
Trade: Amp design and repairs.
IIRC the M8137 is "special quality" (as Mullard called them. I have some E88CC-01's which are) and long life etc version of ECC83 rather than just another name for a standard one.
Arkless Electronics
Trade: Amp design and repairs.
Latest instalment of my St20 experiments... This a true night and day improvement and I'm chuffed to bits!
Phase splitter and first stage decoupling/reservoir caps (dual 32uF in one can) now have 1000uF caps in parallel. They're big and laying on the carpet a few inches to the side of the amp....
In conjunction with the other mods this is now sounding how I remember "THAT" St20 sounding. Absolutely stunning... "super amp" type stunning! You would never guess it was a valve amp unsighted. "Modern" sounding isn't in it, we're talking straight wire with gain subjectively!
Bass control, slam, extension and grip is now good even by SS standards and its transparency is jaw dropping!
Oh and of course no Leak's were harmed in these experiments! Everything can just be removed again and many of the mods consist of putting something in parallel with what is already there so very easy to do. It's a pity the choke mod is a little trickier and needs a slightly less easy to get part but they are available from many specialists these days so not all that difficult to get if anyone wants to try this.
Phase splitter and first stage decoupling/reservoir caps (dual 32uF in one can) now have 1000uF caps in parallel. They're big and laying on the carpet a few inches to the side of the amp....
In conjunction with the other mods this is now sounding how I remember "THAT" St20 sounding. Absolutely stunning... "super amp" type stunning! You would never guess it was a valve amp unsighted. "Modern" sounding isn't in it, we're talking straight wire with gain subjectively!
Bass control, slam, extension and grip is now good even by SS standards and its transparency is jaw dropping!
Oh and of course no Leak's were harmed in these experiments! Everything can just be removed again and many of the mods consist of putting something in parallel with what is already there so very easy to do. It's a pity the choke mod is a little trickier and needs a slightly less easy to get part but they are available from many specialists these days so not all that difficult to get if anyone wants to try this.Enfield boy
pfm Member
As George said above, a good read. I haven't got a clue about most of it but I have very fond memories of a Leak ST20, a dear friend of my Dad owned one, it was the first time I heard music reproduced in a convincing way.
It remains a cause of deep regret that, although he gave me the amp and pre 15 or so years later I never got it to sound anywhere near as good in my system, it was good with radio and cassette but less so with my TT which had a high output MC at the time so I tended to use my Rotel RA610. I returned it so my Dad's friend's son could use it, which I don't believe he ever did and I feel so ungrateful for that (30 odd years on).
At that time I had been won over by the LP12/Ittok/Trak which led me in a completely different direction, I'm a happy flat earther, but think it would've been nice to build my music around that lovely old amp.
It remains a cause of deep regret that, although he gave me the amp and pre 15 or so years later I never got it to sound anywhere near as good in my system, it was good with radio and cassette but less so with my TT which had a high output MC at the time so I tended to use my Rotel RA610. I returned it so my Dad's friend's son could use it, which I don't believe he ever did and I feel so ungrateful for that (30 odd years on).
At that time I had been won over by the LP12/Ittok/Trak which led me in a completely different direction, I'm a happy flat earther, but think it would've been nice to build my music around that lovely old amp.