LampizatOr Golden Atlantic + TRP
- Thread starter Golum
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Todays Test- The TRP with 6AQ5 Miniature 7 pin
I’ve been wondering for some time how these smaller 7 pin pentodes would sound so I did some reading, spoke with a couple of tube rollers and made the decision that I would start out with the 6AQ5. This seemed to be a good start as the pin out is shared with many other 7 pin base pentodes (I hadn’t done the triode test when planning for this) and hopefully I’ll come across a couple of indirectly heated triodes that work with the adapters I ordered for these. Due to the holidays and customs it took 5 weeks to get the adapters so this test was way overdue.
As I didn’t want to burn a bunch of $$$ on a test I looked for an old set of 6AQ5’s on EBay. My search netted 5 Sylvania JAN tubes from 1953. The seller said they had not seen any use as they were spares and they looked great once unboxed.
I popped these into their adapters and installed them into the dac for a 4 hour warm up this morning. As these are much older than I am I know they deserve a proper burn in as they will loosen up after a few days of use but I’m growing impatient and have music to listen to so off it went!
I started out with some heavy rock music from Alice In Chains before moving onto more instrumental plays as I’m familiar with it. At first I was surprised by the sound, it was complimentary with the dac and system but wasn’t providing a lot of drive. I believe the plate dissipation with these is almost half of that when compared to the larger octal pentodes. I continued listening at a low volume for about 20 minutes before increasing the volume to “normal” listening levels and beyond. That’s when the truth came out.
Although these little guys seemed to hold their own at first pushing them harder brought out the weaknesses fairly quickly. While distortion definitely came into play I think most of the harshness I experienced had to do with the lack of use (no burn in time). I listened to various artists for a period of just over an hour- below are the notes I typed while listening.
6AQ5
1) These are low output- need to increase volume to get the same drive.
Needs to be driven harder to produce results of 6L6- needs at least an increase of 4-6 on preamp to equal 6L6.
2) Stage is set back compared to others. Stage is good though- wide, good separation / placement of instruments but busy passages or high amplitude peaks things get congested and blurry.
3) Treble- The highs are more crisp than the 6J5. Highs get a little crispy, sharp and ringy in what seems an un-natural way (may have been the recording) also more sibilant than I’ve noticed before. Not really fatigued though.
4) Mids punch on vocals. Mids are good but can be a little challenging on really busy parts. A little blurry in upper mid/treble regions in busy passages but higher frequencies ring through. Excels in midrange overall but can sound a little harsh.
5) Bass is definitely not as big or impactful as with the 6j5 or 6L6 but obviously seems better with more highly compressed recordings (brick wall). Bass most impactful in upper to low midrange. Lacks the usual punch and doesn’t dig as deep.
I will definitely have to let these sit in the dac and cook a little longer before expecting much more from these. The last pair of new adapters/tubes I worked into did take a good 4-5 days before they performed their best. My only issue is that I’m so impressed with the 6J5‘s I don’t really want to have to wait. I may do off listening burn in while doing other things just to get the time on them.
That’s all for now!
I’ve been wondering for some time how these smaller 7 pin pentodes would sound so I did some reading, spoke with a couple of tube rollers and made the decision that I would start out with the 6AQ5. This seemed to be a good start as the pin out is shared with many other 7 pin base pentodes (I hadn’t done the triode test when planning for this) and hopefully I’ll come across a couple of indirectly heated triodes that work with the adapters I ordered for these. Due to the holidays and customs it took 5 weeks to get the adapters so this test was way overdue.
As I didn’t want to burn a bunch of $$$ on a test I looked for an old set of 6AQ5’s on EBay. My search netted 5 Sylvania JAN tubes from 1953. The seller said they had not seen any use as they were spares and they looked great once unboxed.
I popped these into their adapters and installed them into the dac for a 4 hour warm up this morning. As these are much older than I am I know they deserve a proper burn in as they will loosen up after a few days of use but I’m growing impatient and have music to listen to so off it went!
I started out with some heavy rock music from Alice In Chains before moving onto more instrumental plays as I’m familiar with it. At first I was surprised by the sound, it was complimentary with the dac and system but wasn’t providing a lot of drive. I believe the plate dissipation with these is almost half of that when compared to the larger octal pentodes. I continued listening at a low volume for about 20 minutes before increasing the volume to “normal” listening levels and beyond. That’s when the truth came out.
Although these little guys seemed to hold their own at first pushing them harder brought out the weaknesses fairly quickly. While distortion definitely came into play I think most of the harshness I experienced had to do with the lack of use (no burn in time). I listened to various artists for a period of just over an hour- below are the notes I typed while listening.
6AQ5
1) These are low output- need to increase volume to get the same drive.
Needs to be driven harder to produce results of 6L6- needs at least an increase of 4-6 on preamp to equal 6L6.
2) Stage is set back compared to others. Stage is good though- wide, good separation / placement of instruments but busy passages or high amplitude peaks things get congested and blurry.
3) Treble- The highs are more crisp than the 6J5. Highs get a little crispy, sharp and ringy in what seems an un-natural way (may have been the recording) also more sibilant than I’ve noticed before. Not really fatigued though.
4) Mids punch on vocals. Mids are good but can be a little challenging on really busy parts. A little blurry in upper mid/treble regions in busy passages but higher frequencies ring through. Excels in midrange overall but can sound a little harsh.
5) Bass is definitely not as big or impactful as with the 6j5 or 6L6 but obviously seems better with more highly compressed recordings (brick wall). Bass most impactful in upper to low midrange. Lacks the usual punch and doesn’t dig as deep.
I will definitely have to let these sit in the dac and cook a little longer before expecting much more from these. The last pair of new adapters/tubes I worked into did take a good 4-5 days before they performed their best. My only issue is that I’m so impressed with the 6J5‘s I don’t really want to have to wait. I may do off listening burn in while doing other things just to get the time on them.
That’s all for now!
Your dedication is impressive. Time for me to back read this entire thread, carefully.
I got an RCA Radiotron 280, which from what I read is supposed to be the same as the 80, 180 and I think 380 (is that true?). Mine was used but still tested reasonably good. What I hear from this one after a good 150 hours of re-burnin in a GG3 and with Marko’s 5Z3 adapter is a very good sounding tube with a bit of warmth (good), good pitch, articulation, speed and rendering of voices. It’s main limitations so far are heavy handedness, i.e., not much instrumental delicacy, and not quite the level of transparency and three dimensionslity of the very best (and most expensive) rectis, such as the RGN2004 meshes, and I presume the Valvo 2504.
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this is awesome. i'm a little surprised at the triodes being plug and play, but definitely not chagrined! The 6J5 and it's cogeners are a big and sonically tasty bucket to draw from - does that include dual triodes like the 6sn7?
Another tube usage question - @ronfint actually asked previously - has anyone tried the RS1003 in an A3 TRP?
The 50s vintage metal canned 6J5s and the glass tube 6J5GTs work and simply sound excellent. A surprisingly big sound comes from these tiny triodes, especially with the nearly 100-year-old RCA Globe 80/280 I blew the dust off of. Great call/good ears on this pairing, Designfx. Thanks for unearthing it. Super bargain vintage tubes here!
My thoughts after a few days of listening: These tubes offer the big, ambient, engaging sound, with an equally impressive amount of soundstage depth with solidarity to the image. This 3D space created with density heard deep into the stage magic reminds me of when I have a great 6sn7 tube preamp in the mix (but better, as I've found most active tube preamps make everything sound great, to perhaps a beautifully veiled fault...which I'm not hearing here with the 6J5s that let more nuance and variation pass through).
Both 6J5s take the ambiance retrieval of the Sophia KT88 up another notch while adding a little more image density/focus. Most striking is the GTs ease at unraveling complex passages and following subtle vibratos in vocals to a deeply enveloping degree beyond what I've heard in other tubes. The metal cans offer a little more density, while the glass tubes have better imaging and inner detail, making them slightly favored overall.
Otherwise, bass and mid-bass are ample, more so with the metal tube--which overloads my room a bit when played much over 90dB--although neither 6J5 has the Tesla el51s dynamic jump/snap/control/energy (...nothing does), nor, on the flip side, the 2Fa's standout shimmering top end. However, neither top nor bottom seems lacking without difficult back-to-back listening and all of the flaws therein with such listening experiments (I prefer longer-term listening, yet these particular tubes are cut from the same sonic tapestry, making comparisons a challenge).
Most importantly for me, the midrange is sublime with the 6J5s, with acoustic guitar, vocals, and other midrange elements presenting as dulcet yet detailed and otherwise divine...and deeply distracting...I have 2 big grant applications due, and the music is devouring my attention!!!
My thoughts after a few days of listening: These tubes offer the big, ambient, engaging sound, with an equally impressive amount of soundstage depth with solidarity to the image. This 3D space created with density heard deep into the stage magic reminds me of when I have a great 6sn7 tube preamp in the mix (but better, as I've found most active tube preamps make everything sound great, to perhaps a beautifully veiled fault...which I'm not hearing here with the 6J5s that let more nuance and variation pass through).
Both 6J5s take the ambiance retrieval of the Sophia KT88 up another notch while adding a little more image density/focus. Most striking is the GTs ease at unraveling complex passages and following subtle vibratos in vocals to a deeply enveloping degree beyond what I've heard in other tubes. The metal cans offer a little more density, while the glass tubes have better imaging and inner detail, making them slightly favored overall.
Otherwise, bass and mid-bass are ample, more so with the metal tube--which overloads my room a bit when played much over 90dB--although neither 6J5 has the Tesla el51s dynamic jump/snap/control/energy (...nothing does), nor, on the flip side, the 2Fa's standout shimmering top end. However, neither top nor bottom seems lacking without difficult back-to-back listening and all of the flaws therein with such listening experiments (I prefer longer-term listening, yet these particular tubes are cut from the same sonic tapestry, making comparisons a challenge).
Most importantly for me, the midrange is sublime with the 6J5s, with acoustic guitar, vocals, and other midrange elements presenting as dulcet yet detailed and otherwise divine...and deeply distracting...I have 2 big grant applications due, and the music is devouring my attention!!!
@budburma
Hey Bud! Did you ever try the Bendix 5839 rectifier? I’m not familiar with any of the Bendix stuff (have my other experiments going) but thought you may have moved through a few of them.
@Socrates428
You obviously more poetic than I when it comes to describing your listening experience- thank you for the great feedback!
The comment you made on the F2A’s “standout shimmery top end” makes me think I may have made the right decision in NOT jumping to chase down a quad. I’ve not heard the speakers you’re using nor have any idea of how your room plays into things but I felt that the 6J5’s were actually more complimentary in use with my Dynaudio’s as even the 6L6WXT+ tubes are WAY up there when it comes to that end of the spectrum. Although they are not in any way fatiguing the 6J5 (for me) put things on a more level field- as if everything, whether it went up or down was more balanced and in a better place.
I’m definitely keying into your comments regarding the differences of metal vs glass though as I’ve already heard many opinions on the matter. I do believe that the metal versions are definitely the way to start the experience as the investment is low and the reward is high. I’m currently investigating other glass versions of this (and other) triodes to try next. Not moving to quick though as I want to know everything about the differences of each before accumulating more. For now in my setup the antique Globe 80 paired with a quad of 6J5’s rules!
@Designsfx I didn't. It's a good idea though! Once I zeroed in on the 6384's, I ran through all my on hand recti - including a Majestic globe 80 - and landed on the Bendix 6106. Some of my 6384's are TungSols (they bought the tool and dye machinings from Bendix and I can't hear any difference). ALL of that was done with an LTA Ultralinear Plus integrated and I now have a VAC Phi Alpha - an integrated of a different color!
There're plenty of pairings that seem have some synergy, so the reinvestigation won't be as wide ranging...and I sold a few things off, but still plenty to play with. Just like the 80 with the 6J5, for me KT88's seem to like the 5xxx type or rectifier and 6L6's seem to like 247b/AZ1's.
I'm excited by the 6J5's. i LOVE the octals in general. And the VAC has 6sn7 and 12au7 onboard. I did a bunch of research around the 6J5's while looking hard at a Supratek Grange preamp. And some are damn pricey like the GEV L63's. Anyway, there's a pair of metal 1948 GE's and glass '50's Sylvania military gt's on the way to my home - and they're so cheap! Suwweeeet! I have the Majestic and a Marconi u50/80 to get started with and am looking forward to furthering/deepening the discussion.
I might have to give that some consideration. I found even more tubes today (apparently also with 2.5v heaters, an American standard back then??):
82
46
I must've gotten pulls from old radios at some point. If I get a TRP and manage to use 1930's tubes successfully, yes, I do believe I would brag about it to my colleagues (despite them not having a clue or caring about what I'm talking about in the least). It would make me smile, though. And, that's what counts.
- Good catch! Memory failure on my part there. It’s the 5852 that works here-You should get one- they have a lot to offer when it comes tuning the characteristics of your sound!If I get a TRP and manage to use 1930's tubes successfully, yes, I do believe I would brag about it to my colleagues
Guys just one sincere and honest advice - run the type which you would like to buy/try in TRP with Lampi guys as TRP was made for pentodes with 6.3V heater voltage.
So better to ask then to be sorry later...for the old NOS precious tubes and DAC as well.
Stay well and enjoy the rolling experience.
G
So better to ask then to be sorry later...for the old NOS precious tubes and DAC as well.
Stay well and enjoy the rolling experience.
G
I've never seen so much eagerness to try new tubes, adapt tubes that don't fit the socket, and discover obscure tubes that I've never heard of. Apparently there has been much success here. I'm currently using a pair of 01As--a tube I had never owned before. Apparently the DAC is much more tolerant of wide parameter ranges than most amps are.
I see many recommendations from people I trust and people I don't know (not to imply they are untrustworthy, I just don't know). But for every tube I do my own research before buying it and using it. It isn't just voltage. there are other parameters. Make sure the pin out is the same. If the current draw is less, then you are generally ok. I'm pretty sure the Lampi power supplies can supply as much current as necessary but make sure you aren't looking at a tube with an extremely high current. Take your time, understand your tube, and enjoy the music.
Jerry
I see many recommendations from people I trust and people I don't know (not to imply they are untrustworthy, I just don't know). But for every tube I do my own research before buying it and using it. It isn't just voltage. there are other parameters. Make sure the pin out is the same. If the current draw is less, then you are generally ok. I'm pretty sure the Lampi power supplies can supply as much current as necessary but make sure you aren't looking at a tube with an extremely high current. Take your time, understand your tube, and enjoy the music.
Jerry
I find that extremely cool about the Lampi DACs
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