Soon I’ll be making my own heater circuit to use a few odd tubes as well. 2A3 being the first one.I vastly prefer the Marconi / Osram PX25 to RDs. I have a very good testing pair of both. But I am running the RDs one volt too low.
Sometime soon I will adjust the DAC to run the RDs and PX25 exactly at 4V. I think it will make a significant difference. I am very lucky to be able to run any valve at its precise voltage rating. But it is an effort to do so. Normally I run valves with approximate heater settings as I believe all Lampizators do, though they are optimised for one valve out of the factory. Mine was last done by Lampizator for PX4. But the DAC has been radically altered since.
Look at your test data sheets for what the DAC was optimised with out of the factory, as Al said.
Tesla AD1n is NOS so I don't know what you mean. Only a lot of valves sold as NOS have in fact been used I reckon. Not all, but a lot!
Soon I’ll be making my own heater circuit to use a few odd tubes as well. 2A3 being the first one.
Cool. Be interested to see what you think are the best 2A3s as mine will do them but I haven't got any decent 2A3s.
This has been my consensus on the AD1ns. I use the 300B setting, and if the tube's life is reduced, so be it. They are relatively affordable and sound terrific.Guys just a reminder. You cannot run AD1n, the Tesla tube, on 101D or PX4 setting and expect full output on both tubes.
Use the 300B setting. Just had someone else saying they thought they had a faulty AD1n. He was using low switch position in a GG1. It's a no go. You might get full output on both tubes if you are lucky but YOU WILL be lucky. Typically one or maybe both tubes won't give full output on low.
This has been my consensus on the AD1ns. I use the 300B setting, and if the tube's life is reduced, so be it. They are relatively affordable and sound terrific.
Correct, Low setting on GG1 is 4.5w, ie VxC. Even based on official spec, the AD1n is 8W. High even for high setting which maxes at about 7w.Guys just a reminder. You cannot run AD1n, the Tesla tube, on 101D or PX4 setting and expect full output on both tubes.
Use the 300B setting. Just had someone else saying they thought they had a faulty AD1n. He was using low switch position in a GG1. It's a no go. You might get full output on both tubes if you are lucky but YOU WILL be lucky. Typically one or maybe both tubes won't give full output on low.
Did U compare to ST bottle shape yet?I am glad Goran to spilled the beans. I have been listening to this tube for close to 2 weeks now and I have had no desire to take the tube out. It is very musical and doesn’t seem to have any real weaknesses. The bass is full and tight. The mids and highs are nicely balanced. So enjoyable.
Big thanks to Goran for introducing me to this.
That is the tube from Guenter's place. I am waiting on Sylvanias myself.Great stuff fellas. Thanks for exploring this tube and introducing it to us. I see a National Union version of the tube in one of the pictures. IME, They tend to sound better than most, especially RCAs, in other tube types. Have you guys given the National Unions a listen yet? If so, how do they compare to the RCAs?
Did U compare to ST bottle shape yet?
A big thank you to Goran the tube guru, for guiding me into the world of tube rolling fun. I was't really keen into tube rolling with my ARC Ref 3, until I have the Lampi, the cabriolet like design allow quick change of tubes, to alter the sound signatures in accordance to my mood. It is more fun than playing with cables and footers to be honest.C19 summer "fun" time is coming to an end, so it was a time to start thinking how to do something meaningful regarding HiFi and in my book tube rolling takes a quite high spot (financially better than rolling gear ).
Story about the tube I/We will talk/write here was ignited during a visit which @wisnon and myself had mid of August to Mr. Gunter Tobian to roll some LPs and listen to his nice products. During the time we've been there, I spotted few boxes of tubes which he uses in his DHT based preamps (SC12s, SC1) which instantly triggered my and Norms curiosity and seeing the tube spec, seed within me was planted and already started to grow. is
This particular tube has 5V heater with 0.25A and I've checked during the same day with Yoda if it can be used in Lampi and got his blessing to use 300b setting for Pacific/GG2.
Now finally let me name the tube I talk about - it is tube which started its life sort of century ago with the designation UX112A and later been named just 112A or 12A and having different shapes from globe to coke bottle.
More nice details you can find in the description from Thomas Mayer where it was also named a tube of the month back in 2017: http://vinylsavor.blogspot.com/2017/03/tube-of-month-ux112a.html.
With getting the approval from Yoda, I started to chase the tubes and as always eBay proved to be a nice destination and kind of immediately I got myself Cunningham RCA Globe UX112A version from early 20s of the last century (what a nice feeling to use 100 years old tube).
Comparing to previous times, this time I also wanted to check how the tube performs with several friends simultaneously to have several data points and opinions available before we write the findings. What was important to me is that we have a same base ie DAC and all three of us have Pacific SE with of course different rest of the systems, so overall it is a nice starting point.
With this said, I want to thank Ben from Singapore who is an often visitor of these pages but does not post a lot- if at all (Ben pls do it now ) and David aka @dminches who we all know well. Guys thanks a lot for jumping on the boat on my crazy hint
OK, to cut the crap - let me write my personal view on the tube.
Physically tube is a midget comparing to RD27 and even Elrog 300b but still looking very sturdy and well done. I would say that gain is higher vs 300b for 5-10%, maybe a tad more, but nothing close to RD/PX25/242. I didn't notice any microphonics and it plays dead silent (globe version i have). Now very interesting part is and goes hand in hand with old saying that poison is usually kept in small bottles and this is the case with this tube. It performs amazing by any means possible. Yes, its not the speed or details champion (and i'm comparing with RD27, PX25/242/ad1 which are for me monster tubes in Pac/GG2) and btw its not far from them in this regard but the entire package it gives its totally overwhelming and seductive and here i talk about staging, tone color, rendering of voices and one thing which for me kind of stands out is decay as with this tube it seems that tones last forever - just amazing. I have to mention I used ACME 274b rectifier during my listening tests and for example Ben much more preferred the pairing with RK 5u4g then ACME, while David I believe used different options.
I hope/I'm sure David and Ben will add up here and give their view on things, but for me this is one of the best tubes so far and a definitive must have in collection (ordered a second pair already but coke bottle shape ).
You want to hear best of the best things - if you score them (not to many out there) they are DIRT cheap - less then proper pentodes and I still can't wrap my head around why they are priced as they are (hope it stays like this).
Few pictures for illustration, and as always, happy rolling guys!
Cheers;
G
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What I have seen ux201a has the same 5V, 0.25A rating so i don’t see why they could not be usedNice find Goran. If 5v, .25amp tubes will work could 01a (201a, 301a) variations work?
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