Forums - Viable rectifiers for UFO2

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Viable rectifiers for UFO2
02/09/25 at 22:16:57

I was wondering if something exotic like Valvo G4004, Telefunken RGN4004 or Telefunken RGN 2504 are viable rectifiers for the Zen?

RGN 4004 heaters require 4 amps at 4V, so it does stress the ps more than 5U4G

There are also more options to be considered - for example the RGN2004 - which is double the heater current and dc output of rng1064 - which I know is viable and has been used already in ufo

Anyways thought I'd bring these rectifiers up - might be interesting to hear what others think - perhaps it ends up similar to the thread of 80 rectifier types

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CAJames

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Re: Viable rectifiers for UFO2
Reply #1 - 02/10/25 at 19:30:05

Quote:

Posted by: whynotnothing Posted on: Yesterday at 14:16:57
I was wondering if something exotic like Valvo G4004, Telefunken RGN4004 or Telefunken RGN 2504 are viable rectifiers for the Zen?

RGN 4004 heaters require 4 amps at 4V, so it does stress the ps more than 5U4G...

For me, I wouldn't risk it but I guess the question is how bad do you want to try them? I'm pretty sure using the adapter is going to draw more than 4 amps from the power transformer and that isn't anything I'd want to do. But, I've seen adapters made with a connection for an external power supply which might be something to investigate if you really really want to run these rectifiers in the UFO2.

I've tried AZ[1|11|12] rectifiers in my UFOs, but they all use less power than a 5U4. FWIW they all sounded good, but not good enough to displace my favorite 5V rectifiers. There are so many 5V rectifiers out there I'm content sticking with them.

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[Volumio | Jay's CDT2 MRK3] -> Denafrips Terminator 2 + Gaia
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whynotnothing

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Re: Viable rectifiers for UFO2
Reply #2 - 02/11/25 at 09:47:44

Thanks.

Well, makes sense, I guess I won't risk it with an 4004, that'd be pushing it too far.

OTOH, since you've used AZ12 which should be an electrical equivalent to RGN2504 - I guess that one should be safe.

Reason I'm asking is I got the TFK RGN2504 globe with solid plates,
and another one I found for pocket change is Tungsram PV4200, which is an equivalent to RGN2004. Both look beautiful and would be a shame not to give them some run time

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whynotnothing

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Re: Viable rectifiers for UFO2
Reply #3 - 05/21/25 at 13:58:53

I went down this path and I have to say initial impressions are extremely positive. I guess the Zen minimalism and transparency are paying off here.

TFK RGN 2504 solid plates, globe shape. Impressive so far. Visually stunning as well, what more can one ask for.

Down the path - Tungsram PV4200, Valvo 2004 solid plate, TFK 2004 black mesh plates, U18 (basically a 4V version of the legendary u52) and a unicorn Rectron R0452 globe, supposedly electrically similar to 2504

It will take some time to go through this list, but with the way things started, quite excited to be honest.

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CAJames Seasoned Member "I've run every red light on memory lane." Posts: 3124	Re: Viable rectifiers for UFO2 Reply #4 - 05/21/25 at 21:52:50 Cool. Where did you get the adapter?
Back to top	[Volumio \| Jay's CDT2 MRK3] -> Denafrips Terminator 2 + Gaia Sumiko Pearwood -> Mapleknoll Athena -> Luxman SUT -> Mapletree Phono 3E STR-1002 -> Woo WA22 -> 2x UFO25s, balanced monos Omega SAM , Hifiman Arya, Audeze LCD-XC IP Logged

whynotnothing

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Posts: 16

Re: Viable rectifiers for UFO2
Reply #5 - 05/22/25 at 10:11:32

Deyan. He has already been recommended here. Looks good, works great, very happy. Unbothered to look further.

There are cheaper and more expensive options out there. Some exotic stuff on whatsbestforum, but a bit too pricey for me so not inclined to experiment in that direction.

If you hunt for auctions and/or deals, then most of these rectifiers add up to cost less than a single exotic adapter. So it was not worth it in my book. But YMMV ofc

Smiley

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astro-chris Seasoned Member Posts: 158	Re: Viable rectifiers for UFO2 Reply #6 - 03/04/26 at 15:05:43 Hi "whynotnothing", If I may ask, where did you find your Tungsram PV4200 "for pocket change"? I am seeking one for my LampizatOR Atlantic TRP DAC, but I cannot find one anywhere. Thanks so much, Chris
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whynotnothing

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Re: Viable rectifiers for UFO2
Reply #7 - 03/05/26 at 09:55:12

Hey Chris,

well, unfortunately, tube hunting business as usual, I won that Tungsram at an auction. Nowadays, I only buy tubes on auctions, or from locals. It's been a while since I've seen the pv4200 in the wild.

It's been almost a year since I've started this thread. There are a lot of great 4V rectifiers, and some are obtainable at way cheaper prices than their 5V counterparts.

Recent great find is the black mesh plates Osram globe U12.

Another is the Philips 1815, internal construction is supposedly identical to Rectron R0452. These rectifiers are heavy, big, with quite distinct internal construction, as if from a different planet altogether.

I think I like the black mesh plates 2004 the best so far with the Zen. I'll update on this when I get more time.

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astro-chris Seasoned Member Posts: 158	Re: Viable rectifiers for UFO2 Reply #8 - 03/05/26 at 12:41:42 Thanks so much for your response! I feared it was a lucky find. I shall keep searching
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