Hi all,
I am looking at buying some ECC801S valves for my RH84 project .
I have come across Tronix / Brimar ECC891S CV4024 black plate valves
and ZI / Brimar black plate valves.
Has any used these or can say how they compare to other brands.
Thanks
I am looking at buying some ECC801S valves for my RH84 project .
I have come across Tronix / Brimar ECC891S CV4024 black plate valves
and ZI / Brimar black plate valves.
Has any used these or can say how they compare to other brands.
Thanks
Both are restamped USA production plain ECC81. Send me a PM if you need some real 801s /6201
You can recognize Philips organisation(Incl mullard which was 100% owned by the Dutch) ECC81 by the seams on the top, and etched code near the bottom. Telefunken by the diamond in the bottom, but during the shut down of TFK production there where quantities made with TFK materials by Tesla i dont know how this applies to ECC801S
Your best bet for a quality ECC81 is a PHILIPS 6201.
Your best bet for a affordable ECC81 is a Tungsgram or RFT.
You can recognize Philips organisation(Incl mullard which was 100% owned by the Dutch) ECC81 by the seams on the top, and etched code near the bottom. Telefunken by the diamond in the bottom, but during the shut down of TFK production there where quantities made with TFK materials by Tesla i dont know how this applies to ECC801S
Your best bet for a quality ECC81 is a PHILIPS 6201.
Your best bet for a affordable ECC81 is a Tungsgram or RFT.
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I'm not sure you can say for sure they are just bog standard ECC81 re-stamped, but they are unlikely to be ECC801S, which was just a Telefunken tube, AFAIK.
CV4024 is a special quality ECC81, maybe just selected by testing standard tubes, but closer tolerances anyway. They are sourced from Brimar and Mullard (mainly Mitcham works). Those tubes above were probably CV4024 rebadged.
6201 has 3 micas, I think, and is another level of quality.
I bought a bulk load of CV4024 thinking that it would be fun to match pairs and pass them on. The ones I have, have signs of previous markings, then were cleaned and just stamped CV4024 by Mullards when they were bulk tested in the 80's, as part of an MOD contract (there were 100.000 tested). It is amazing how much variation can exist between the tubes, but generally the halves are close. I group them by manufacturer, construction and close curves, but struggle to break even ;-/
CV4024 is a special quality ECC81, maybe just selected by testing standard tubes, but closer tolerances anyway. They are sourced from Brimar and Mullard (mainly Mitcham works). Those tubes above were probably CV4024 rebadged.
6201 has 3 micas, I think, and is another level of quality.
I bought a bulk load of CV4024 thinking that it would be fun to match pairs and pass them on. The ones I have, have signs of previous markings, then were cleaned and just stamped CV4024 by Mullards when they were bulk tested in the 80's, as part of an MOD contract (there were 100.000 tested). It is amazing how much variation can exist between the tubes, but generally the halves are close. I group them by manufacturer, construction and close curves, but struggle to break even ;-/
FWIW, I use Brimar 6060/CV4024's in my DAC's output stage. Hands down the best 12AT7 I've ever heard. None on the typical hardness on top, very airy and sweet.