With adapters, they work as a power tube option in B7, GG and Pac. So they take the place of the usual DHT suspects (242, PX25, PX4, 101d, 300b, etc.).
Uses the PX4 heater setting.
For what it is worth, I believe Rob of LampiNA is using them currently in a Pacific.
The Aqua II is a very good tube, but I decided to stick with the Tele AZ1 while I look at other possibilities that improve on the latter's characteristics. The thought that came to mind during the final appraisal of the Aqua II at 302 hours was that if one wanted to show off their system to non audiophile friends or ones with a lower end system, this would be a tube to use. It does most everything very well and gives a very dynamic, articulate and delicate sound with lots of presence. It’s entertaining and easy to listen to. I think it’s a good option for those that don't want to or can't afford to pay the big bucks of the more precious NOS tubes.
Sophia told me the Aqua II is "neutral," just like live music, as they advertise ("life like"). That's not my taste, but after a reply, they offered me 14 days, so I bit. It sounded very decent right out of the box, and at about 150 hours in the sound did turn neutral, that is, clean and to my ears dry. That lasted until around 260 hours, when a touch of warmth appeared, and then became two touches over the next day and a half (I left the tube on the whole time, with an occasional short break). Btw, once again I found that it's necessary to wait until around 300 hours to give a call.
I think the biggest revelation I had in the comparison with the AZ1 was that some tubes have a thinner (not thin), clearer and more precise sound, something more like live music, while others have a relatively "thicker" or heavier sound. Until I heard the AZ1, I was unaware of the difference. With a touch of warmth to go along with its great transparency, I had not come across a tube of the kind that wasn't all cool or dray all the time. I take it from some of the descriptions over on the Horizon tube thread there are some other NOS that do so as well and sound even better.
A few months ago, Blake passed along two Telefunken AZ1 mesh plate tubes, one from the 1950's and the other identified as 1938. I don't know his source. Each has over 350 hours with me now, so FYI here's a short report:
The 1938 AZ1 is very different from the 1950's one. The 1938 is lower-end dominant and modestly rich and dark. The 1950's one is more mid-up balanced and light, clear and open. The 1950's one has a touch of warmth, which I like, while the older one has maybe 1/8 of a touch in that direction, which I find less satisfying over the long run. With regards to the latter category, if you remember back to TAS founder Harry Pearson's Yin-Yang descriptors, these two defy his categorization.
It is all a balancing act. Whilst there are winners and losers at any particular time in your system, any change of components anywhere in the chain will change your list of winning and losing tubes or valves.
With three power amp choices, I find the character of various Lampi tubes seems to change between power amp swaps far more than I expected.
There's a number that work well with the DAC without issues like hum, output level and microphony, and within that subset the best choice or better choices depending on material being played back alters quite a bit.
The Sylvania VT-25 sounds so different via my 211 based monos versus a decent Luxman solid state effort it beggars belief to me, at least. The thoriated tungsten filament chain really works well together. VT-25 with solid state not so much.
Was the 1950 Telefunken a true AZ1/WE54/WE55? If it was manufactured in the 50s, then it was more likely a AZ4/WE56 tube. The filament current of the AZ1 (circa 1930) is 1.1 amperes, which may explain it's warmth relative to a 1950 Telefunken rectifier tube. If the 1950 tube is an AZ4, then its filament current is 2.2 amperes. The Telefunken RGN2004, which is still my favourite, in the Horizon, is 2A. The Valvo G2504, which is preferred by many is 2.5A.
I suspect the filament amperage of the rectifier tube in the Horizon is more relevant to the wattage of the chosen pentode (output) tubes. Lukasz assigns the following relative sonic impact of the Horizon's 3 tube types: Rectifier - 10%, dual triodes - 40%, the pentodes - 20%, and synergy between pentodes and dual triodes - 30%. However, many of the Lampi DAC owners found, as I have, that the rectifier tube appears to have a bigger than 10% impact on the overall sound. So what's perhaps missing from the proportionality equation is the synergy between the Rectifier and Output tubes.
Good question. Have to let Blake answer that, since he was the source. I have an early1930's Telefunken RGN2004 soon to come, when the custom adapter is built. (edited to correct dates)
Good question. Have to let Blake answer that, since he was the source. I couldn't find any model markings on either. I assume you mean lack of warmth, since the 1950's one does have a touch of warmth that the 1938 one doesn't, or at least just barely. I have a 1930's Telefunken RGN2004 soon to come, when the custom adapter is built.
Looking back, you did tell me that. I put the adapters on right away and didn’t think to look on the tube bottoms. I can’t recall another tube of my many that had ID markings there. Previous post corrected.
After hearing of others success by using ECC40 tubes, I acquired a pair of Tungsrams.
I also went on Fleabay to VIC-Audio and purchased a pair of adapters.
They are listed as ECC40 to 12AX7 6.3V
After receiving the tubes and adapters I thought I would test them.
I put them in my DIY tube "warmer" which I use to preheat the tubes prior to inserting them into the tester. (allows for reduced time when testing a bunch of tubes).
They blew a fuse in the warmer. I then checked continuity of the wiring of the adapter and found pins 4 & 5 are tied together.
This would indicate that the machine that they are to be inserted in must be wired 6.3 volts in parallel.
For those that have tried ECC40 tubes in your Lampi, is your adapter wired like this?
And or, does anyone know if the wiring of the 9 pin Lampizator socket on a BALTIC 3/4 is series or parallel?
I am very leery of installing these adapters in my B4.
Any help would be appreciated.
Thanks Gene. So the1939 RGN1064 has 4V filament rated at 1A. The 1944 AZ1 cathode is rated at 1.1A. If my theory holds, on which I would defer to Lukasz, those rectifier tubes would pair nicely with lower wattage pentodes.
Based on my Horizon trials, the KT170 (85W) sounded thinner and flatter with my Tele RGN2004 (4V/2A) and the 274B (5V/2A) than with my Ken Rad 5U4G (5V/3A). The Ken Rad paired far better with KT170 and Telsa EL51 (45W). Better bass (in slam and articulation), dynamics, tonality, air and overall realism. As noted above, my favourite pairing is the SFR P.17C (25W) with my most recently acquired black-mesh plate Tele RGN2004 Klangfilm rectifier tube (4V/2A). Like Goldilocks - not to hard and not too soft!
Given that Lukasz doesn't place a full load on the pentodes with his design (~25% of nomial output), big power tubes may be overkill. However, some Lampi owners prefer big wattage valves in the output seats of their DACs to capture a big dynamic sound. I have found that I'm getting as much from the 25W P17Cs as the 85W KT170s - with the right rectifier pairing.
I recognize that performance pairing will also be influenced by speaker impedance and its upstream impacts on source and linestage components. Accordingly, my general experience-based observations here are also system specific.
Ray, This is informative. Helpful for understanding the electrical interaction between tubes, circuits and sound, instead of seeing them singularly. Since I have a GG 2/3, I will be looking at the PT 14 vs. my current production WE 300B's in conjunction with the rectis.
Ray, This is informative. Helpful for understanding the electrical interaction between tubes, circuits and sound, instead of seeing them singularly. Since I have a GG 2/3, I will be looking at the PT 14 vs. my current production WE 300B's in conjunction with the rectis.
Hi. I'm not familiar with the PT14. Is it an equivalent to an EL34/6L6? I look forward to your findings. This is a great sharing community. Keep enjoying that GG 2/3. I'm sure it sounds great!
Hi. I'm not familiar with the PT14. Is it an equivalent to an EL34/6L6? I look forward to your findings. This is a great sharing community. Keep enjoying that GG 2/3. I'm sure it sounds great!
Hi. I'm not familiar with the PT14. Is it an equivalent to an EL34/6L6? I look forward to your findings. This is a great sharing community. Keep enjoying that GG 2/3. I'm sure it sounds great!