Zaikes,

I appreciate the info on tube ratings you discovered at Vacuum Tube Valley. I had that data at one time but could not find where I stored it on my computer.

Like you, I am curious as to what amplifier (and at what rated power) as well as associated equipment was used to make the determination. As you pointed out in a earlier thread, you and I seem to differ on some tube choices even though we chose almost identical amps.

Regarding:

It's kind of noteworthy that they didn't prefer the newer Svet 6550C to the previous version, which isn't the received wisdom I've seen elsewhere.

Actually, VTL tells me the "true" Svetlana (St Petersburg plant) tubes are preferable to the newer Reflector tubes by Sovtek which are now branded with the "Svetlana" logo.

You are probably aware that the original Svetlana-St. Petersburg plant was forced to re brand the original Svetlana 6550 with the name Wing C. My VTL has the original Svetlana, so exact replacement would now be called Winged C, NOT Svetlana.

A bit confusing, but Bea claims the original is still the best 6550 and the KT88 Wing C is the best "overall" tonal balance with some loss of bass compared to 6550.

This name change game has been a mess, it's too bad I can't afford NOS Gold Lion Genelex, I agree with VT Valley ratings that it's still the best KT 88 ever made.

albertporter September 19, 2005 04:38

zaikesman:

I found your detailed post on tubes very interesting. I also concur with some of your observations. My amp collection includes Jadis JA-500 (6550), VTL 750 Reference (6550) and Audio Valve Challenger (EL34s). I have not tried KT88s. But I observed a major improvement in my Jadis when I switched from Svetlana 6550 to new Tung Sel 6550. I also like the sweet sound of my Audio Valves that use EL34s.

GD

gallant_diva September 19, 2005 04:26

What does that have to do with Audiofest, Eldartford?

albertporter September 19, 2005 04:03

For the record, I have cleaned many many LPs.

With regard to surface noise, people should listen and decide for themselves. It would make sense to do this before investing many kilobucks.

eldartford September 18, 2005 23:46

Pat,

I spoke to Koetsu on Friday to be sure my check arrived.

Immediately after AudioFest, Ronnie must travel to Japan for a meeting with Koetsu. So instead of faxing my order and rush shipping with hopes of getting it in my hands before Denver, I will wait and have my Jade carried back by hand.

Ronnie promised to pick out the best sample and return with it. Probably best sample refers to the beauty of the Jade. I think it's difficult to tell two Koetsu's apart (assuming exact same model) as their quality control is so tight.

So with that delay, I will probably not have it until the week of the 10th or 17th and may have the second pair of VTL 750's and possibly, the new cables from Purist Audio before the cartridge even gets here.

Thank you for the compliments on my system. I hardly know how to respond to your extremely kind words. I will NEVER forget the week that you, Nate, Cello, Vetterone and I spent listening to great music together. Louis, John, Dennis and others are still commenting about how courteous and interested all of you were.

albertporter September 17, 2005 19:34

From what I've read, it seems among people who switched, somewhat of a majority prefered KT-88's, but I can think of a few reasons why that may be a skewed sampling, so I don't read too much into it. The topic is addressed in some AA threads, and if you search the Net you'll find more.

I suspect your 750's will have the qualities you list in your fourth paragraph no matter which output tubes you use. IMO these are mainly a function of high power and large power reserves, and with two pairs of 750's, I'd imagine there could not even be a question there. But having said that, I will stipulate that in absolute terms and with everything else being equal, in my system the 6550C's do sound a little more 'powerful' than the KT88EH's (partly because they actually are about 1.5dB louder, partly because of their tonal balance).

For pristine treble, there seems to be consensus that the KT88EH, at least, is superior to the 6550C, as I have found. I don't see that consensus with the SED version. There seems to be some feeling that KT88's generally image better than the 6550C, which I have also found, though someone who prefers the musicians to sound as if they're in the room rather than in the original performance space might disagree.

To your last paragraph, I'd say the bass will definitely be different, but whether it will be compromised will be a matter of opinion. Again, in my system, it's not the bass per se that gives me any pause about the KT88EH, because I think it's actually more natural-sounding than with the 6550C, but the overall balance, and neither tube is perfect to me in that regard. On the other hand, I've not heard an EL34-based amp with highs as clean, detailed, and extended as I get with the MB-185's fitted with the KT88EH's, but I probably don't have enough experience for that to prove much (for one thing, I think I've only heard EL34's wired for ultralinear operation). I usually think of EL34's as sounding pleasingly consonant, but not as wideband, clean, and transparent in the highs as KT88's apparently can be. In any case I have little doubt that you'd find the KT88EH's better in the highs than the 6550C's, which may be the more pertinent question.

I do find it interesting that the word on the Web overall in no way seems to place the KT88EH in some kind of lower echelon despite its roughly 1/3-cheaper price compared with the SED and JJ versions, either in sound or reliability. I also saw a couple of positive reports about the Chinese Shuguang KT88-98 - though maybe with a sonic preference different than mine - and from my most recent experience in the area (comparing Russian and Chinese 6SN7's), I wouln't rule out hearing any of the late-model Chinese non-miniature tubes either.

FWIW, here's the ranking arrived at by Vacuum Tube Valley in their home audio listening test for 6550/KT88 types:

1. Genalex KT88 Gold Lion 1969 - 4.87
2. Tung-Sol 6550 1963 Solid Grey Plate - 4.77
3. JJ KT88 2002 - 4.63
4. Ei KT90 1999 - 4.52
5. EH KT88 Reflektor 2002 - 4.16
6. Sveltana 6550 2001 - 4.13
7. Svetlana SVKT88 2002 - 4.09
8. Svetlana SV6550C Reflektor 2002 - 3.98
9. Philips Sylvania 1970s - 3.98
10. Chinese 6550 Valve Art 2002 - 3.89
11. GE 6550A 1970s - 3.78

I pulled this off a thread somewhere from a guy who presumably copied it from VTV (I don't think they make this stuff available online) but not the whole article, so I have no idea about the conditions or ancillaries involved in the test, or how the numerical scores were derived. In any case, though the KT88EH fared well, they obviously really liked the JJ in their application (note that the KT90 is not a drop-in replacement for VTL amps that use 6550C's), and the test seems to have been done before the Svet/SED split, or the introduction of the new Tung-Sol 6550 (not an exact copy) or Shuguang KT88-98. It's kind of noteworthy that they didn't prefer the newer Svet 6550C to the previous version, which isn't the received wisdom I've seen elsewhere.

Upshot Which Lets Me Maintain Deniability: If you're thrilled with the sound using 6550C's, why gamble on such an expensive change before your current tubes wear out? Rolling output tubes could accomplish nothing more than to show you how they're all flawed... :-)

zaikesman September 17, 2005 19:21

Albert, I know it's unfair to ask you to do so but when you mount your new cartridge would you be kind enough to post initial thoughts on it out of the box? I'm very curious. Cartridge break in takes a fairly long time but I'm familiar with what to expect later on if you just give me a hint as to its performance when new. I think I can wrap my mind around it having heard your system myself previously although my audio memory doesn't enjoy the benefit of hearing your new tube crossovers.

I'd like to share a thought here but don't expect any type of response from you. While you and I have invested differently in our systems we strive for similar goals. Both of us seem to just like music and view our systems with pride but see them as the tools they truly are, a means to an end. We both have been avid record collectors from the sixties with you doing it a little longer due to the seven year age difference. Between the two of us we have nearly 80 years of fairly intense analog experience and have shared our findings generously. Myself with new initiates and somewhat unseasoned enthusiasts. You, with your vast knowledge have given help to everyone. I'm going to ramble a bit in this un-paragraph, so I ask the reader to just bare with me. I've heard Alberts system and it is sometimes impossible to tell if the stylus is in the groove. Honestly, that is the bulk of the time. With or without the benefit of audiophile pressings. The dynamic range *seems* to surpass digital and certainly simply destroys digital in detail, realism and soundstage. My much more humble front end with its pivot arm enjoys most of the advantages of yours but on a smaller scale. Records are so silent in the groove that seasoned digifiles are amazed and a few have stepped up to owning turntables themselves as result. Both of us are hands on guys. I'm more mechanical I think while you are more electronic but we both think a lot alike. I'm pretty sure if we compared notes of how many record cleaning products we have tried in our lifetimes and the different methods we have employed along the way we would have shared most of the same experiences. Okay, I'm getting to the point here and I think this is the perfect place to post it. There's no question in my mind at all that there are distractors to analog constantly lurking in these forums that enjoy a sick attempt at popping the bubbles of budding/seasoned vinyl lovers in regard to surface noise. It's scary but they seem to actually believe what it is they write although the most grievous of offenders admits to never having cleaned a record. Funny but when I read his posts he invested a ton of money in electronics to remove noise but never invested in a cleaning machine. Admits to not hearing anything that approaches SOTA analog. His list of turntables/tonearms and cartridges he's owned are of the kind that always seemed to enhance the negatives. All of this is a shame. My take on the audiophile community represented here is that most are professional people, buy their gear and follow the directions. Cleaning vinyl is one of the best places to make your own directions for greatest benefit and the beauty is the hard work has been done for you. Let me state up front that to become a professional takes so much time that also becoming a mechanical/electrical wizard seems impossible. I have great respect for doctors, lawyers and other highly educated folks. The only point I'm trying to make here is that those struggling with surface noise need to listen to seasoned pros like yourself and ignore the naysayers. Your thread is so popular approaching 400 posts it seems appropriate to assume you have around 10,000 hits. I'm trying to insert some hard earned help to the 9,600 folks that read this thread rather than get into the tired old fights with the naysayers. Forgive me if this post is over the top and maybe similar comments have been made elsewhere before. My intentions are good in that I'd just like to see folks enjoy analog if they are moved to try it. It need not break the bank.

See you at RMAF.

lugnut September 17, 2005 14:42

I have it on good authority that the Denver AudioFest will sponsor an Analog Forum on at least two occasions during this great audiophile meeting.

Among the panel members sitting in are:

Chad Kassem of Acoustic Sounds, Garth Leerer of Musical Surroundings and Roy Gregory of HiFi+.

Odd that i mentioned liking Roy Gregory's style a few days ago on this very thread. I hope to have the pleasure of meeting him.

This show is shaping up to be as important as CES in many ways. Any Audiogon members that can make it should do so.

albertporter September 17, 2005 05:49

Alex, now you have my curiosity aroused, how much did you find on this subject?

Or short answer, what is the general consensus of strength versus weakness between the Svetlana 6550 and (whatever) is supposed to be the cool KT88?

I ask because I have owned my 750's for more than a year now, first powering the Sound-Lab Ultimate ones and now the Dali's.

Frankly I find them near flawless. Huge dynamics, contrasty as can be and bass from hell. This all coming from a VERY black background, where the music flows with intense power.

I will grant you the extreme high frequencies are not quite as pristine as a perfectly designed, hand wired EL34 amp fitted with NOS Mullard EL34 XF1 or XF2, but now were talking about having it all, and so far I know of nothing in audio that gives you 100%.

What I’m afraid of is moving to the KT88 and wind up with compromised bass compared to the 6550, and compromised highs compared to the EL34.

albertporter September 16, 2005 02:41

No doubt. It took me the better part of a year to become even vaguely disatisfied with any part of the KT-88EH's performance. I've looked around about this on the Internet today for the first time in a while, and read many comments basically echoing my take on the tube, with the overall impression still being very positive with little exception. The Svet seems to get more of mixed response in terms of preference, but the consensus seems to be that it's a warmer-sounding tube. The JJ I haven't found as much on. There's also some positive buzz on the new Tung-Sol 6550. But as you and I know from our divergent takes on my RCA 6201 black-plate input tubes, there's so much else going on to affect such judgements, and the only real point of slight similarity in our systems is the amps, which are still not the same by any stretch...

zaikesman September 15, 2005 22:21

Alex, if you do that test I would be eager to hear your conclusions.

It's a big deal for me to accumulate that many tubes, even with your generous offer. It will be a long time before I get to that part of my testing. The new tube crossover is still improving every week and I don't want to confuse results.

When the second VTL arrives I will be able to tell better what (if any) I'm giving up in the highs to go from Mullard EL 34 to Svetlana (Wing C) 6550. Could be I will prefer the 6550 and change my mind after a week or two when the "new" wears off.

That's exactly why I am so slow to make comments about my tests. I am a true believer in slow and steady progress and long term listening.

albertporter September 15, 2005 20:02

Although Bea and I are talking about different KT-88's (mine EH, hers Svet), our characterizations seem like they could still be fairly consistent. I do think the Svet 6550C has subjectively 'more' bass than the KT-88EH in the sense that its balance is richer, with more emphasis on harmonic overtones that add warmth, but with less deep extension, grip, and transparancy to detail, as well as less specific and holographic imaging. The quantity of the 6550C's bass is enjoyable but not strictly necessary, the quality of its bass also enjoyable but not strictly defensible. In a nutshell, I find the KT-88EH's portrayal of bass instuments more informative and convincingly believable, but a touch more reticent within the big picture (though not dynamically, and with the possible exception of true bottom-octave weight, which my speakers can only hint at).

However, my reservations about the overall tonal balance of the KT-88EH have less to do with its bass balance per se than with its handling of the octaves immediately above, where the meat of the lower-to-mid midrange gets a bit thinned in comparison, which can be important, at least in my system. In the context of its overall balance, this comes across as a subtractive deviation deriving only from frequency response, but one that has an impact on soundstaging in terms of what is brought out most in the program. Combined with its greater top-end extension and clarity, this can make the KT-88EH's overall presentation less full and more analytical, despite its uniform advantages in transient speed and cleanliness, spatial openess, lower added harmonic distortion, and transparency to fine dynamic shading. So things like male voices can sound more naturally real, but less robust and present - an occasional dilemma, depending on the source material (and with potential implications for one's selection of input amplifier 12AT7 tube).

I think it's high time I ordered a pair each of the Svetlana and JJ KT-88's, and make some 1/3-power, monophonic comparisons to the Electro-Harmonix using only two tubes per single chassis in the MB-185, just to get a more complete idea about this choice without making a big financial commitment...

zaikesman September 15, 2005 16:51

Alex, I sincerely appreciate your offer. You, Nate and Bea all seem to think I should at least consider switching over to KT88's.

No doubt I will eventually give it a try.

Bea (VTL) does state that the bass is superior with the 6550 and last night may have been the best bass I've ever heard. My system was kicking the sh*t out of us !

The good news about the test ? With the loan of your dozen KT88's, I only need another 36 to start up the system :-O.

Wonder if I can offset the power usage by killing all the room lighting and work via tube glow?

The second pair of VTL's will not have the adjustable feedback control. There are only three or four pair of those, but Luke did offer to match resistor load with my favorite setting from the adjustable pair.

Yes, the custom crossover I had built works at exactly the same frequencies as the original Dali piece. The exact numbers are in my review at Positive Feedback but I think about 1100 HZ is correct.

albertporter September 15, 2005 02:33

Come on Nate, I'm ready !

Maybe we can get Pat Malone, Steve Dobbins and Larry Howkins to come again like last time. I promise to take all you guys back to that great "home style" restaurant (the one with great food and all you can eat).

All of us pigged out but I was amazed that Pat could still go for Peach Cobbler and Blue Bell ice cream after all that salad, steak, veggies and potato's :^).

albertporter September 15, 2005 01:57

My offer to send down a dozen of the KT-88EH's on loan still stands anytime if you want it, even though that'll only outfit one monoblock. I'm not sure it's as simple as it might appear at first blush to prejudge whether or not the 6550C's will sound 'better' than KT-88's on the Megaline's 'bass' drivers, since as I recall they actually handle a significant portion of the midrange as well (crossover at about 1KHz? - don't know the slope). Plus the KT-88's, or at least the EH's, still retain certain advantages all the way down, and your crossover may be well-positioned able to ameliorate any minor balance issues . BTW, is your second pair of these amps also to be fitted with the custom variable feedback control? If not, I imagine you'd use the pair that is on the ribbons and the pair with the fixed 6dB of feedback on the dynamic drivers...

zaikesman September 14, 2005 23:15

Albert I like your tube idea. I've been happy with the KT 88's but I think you would be looking at something better than mine. Sounds like another trip to Dallas might be in order. Lock up the women and children...

nrchy September 14, 2005 21:55

Alex, I hadn’t thought about output tubes as the second VTL has not yet arrived.

The KT88 interests me, particularly in light of comments by you and Bea at VTL. The KT88 promises to be a superior full range choice, giving up a bit to the 6550 in bass performance.

Might be really cool would to run 6550 Wing C (original Svetlana) in the bass amp where this tube really shines, and the best KT88 for the ribbons.

Since my new custom tube crossover has both gain and EQ controls, I could easily balance the two amps and maybe create the best of both worlds.

Thank you for the idea.

albertporter September 14, 2005 19:59

Albert: Are you planning to try some KT-88's, and if so which brand, and for which set of amps (top, bottom, or both)? As you know, I've tried the EH's, which show superior extension and purity up top, combined with a tighter and deeper but leaner-balanced lower range, including a less-rich but cleaner and more holographic midrange (compared to the stock Svetlana 6550C's). Ideally I would like to have these tubes' advantages of better speed, transparency, extension, speaker control, and lower distortion/coloration, while retaining a bit plusher, less austere tonal balance overall. VTL says they like the Svetlana KT-88's compared with the 6550C's except in the bass, while Trelja has extolled the JJ/Teslas, but I still haven't heard either of these.

Regardless, IMO you're making the smart play trying a uniform amplifier type all the way around. It can only help overall coherence. As for why the VTLs might extract more from the ribbons than the Air-Tights do, my suspicion is that you were running up against the inherent limitations of EL-34 output tubes as much as the difference in power, though I never underestimate the benefits of more power (and a bigger power supply) as well. After all, there's got to be a reason why VTL makes the 1250's (not that I blame you for not getting four of those!). BTW, if you can balance the levels with your crossover, it seems worthwhile to experiment with running the bass amps in tetrode (bigger space and slam) combined with the tweeter amps staying in triode (better harmonic, tonal, and textural neutrality).

zaikesman September 14, 2005 14:46

Oh yes, I have been a fan of HiFi+ for several issues now. Roy Gregory is a breath of fresh air in the review world now. Right on with your cartridge upgrade. I enjoy my RWS very much here.

jafox September 14, 2005 06:14

Thanks Jafox, we had wonderful sound tonight.

I don't know if any of you read the review at HiFi+ on the Koetsu Jade. A very fine magazine with concise layout and great images. Anyway, after living with my Koetsu Rosewood Platinum Signature for so long, it's time to take it up another notch. I ordered the Koetsu Jade Platinum Signature and expect it within two weeks.

I expect an unpleasant break in process, as was the case with the Rosewood, but think this will be the icing on the cake for the system once it settles in.

albertporter September 14, 2005 03:29

All smiles here. It is wonderful to read about the continued progress and refinement of your system.

jafox September 13, 2005 15:21

I have negotiated a deal for another pair of VTL 750 amps. Should be ready in less than two weeks.

I borrowed a pair of Air Tight ATM-3 from a friend (Louis) in my audio group who had them upgraded by Tom Tutay and subsequently shipped to me as he (Louis) was on vacation in Spain.

I selected a matched set of Mullard Xf2 EL34's for the outputs, substituted 12 BH7 in place of original 12U7, and matched Telefunken 12 AT7 in place of the original 12 AX7.

These changes mirrored the glass in my Air Tight ATM-3 after an incredible amount of tube rolling.

The plan was to sell the VTL 750 powering the bass, gain floor space and free up some cash as another pair of Air Tights would be less money. Unfortunately the test proved the horsepower of the VTL to be undeniable.

Dali recommended matched amps, but the VTL 750 on the woofers and Air Tight ATM-3 on ribbons was clearly superior to "matched" all Air Tight's.

Just for the sake of saying I had done it, I swapped the two amps positions, driving the bass with the Air Tight and ribbon with VTL 750.

Not too surprising, by comparison the bass was gone. What I did not expect, the ribbons now had balls like the bass and contrast I didn't think possible.

To say I was shocked would hardly describe my reaction

How could a ribbon, 90 DB efficient and running only 1000 HZ and above possibly benefit from swapping between two world class amps, one with 130 watts a channel, the other 750 watts per channel ?

As mentioned at the start of this post, more VTL's on the way. Not exactly how I thought this turn out, 3000 watts on Dali Megalines.

Just lock me up now.

albertporter September 13, 2005 06:53

Thank you Sirspeedy for your compliment.

I have been lucky enough to get advice over many years from many sources, helping me get my system where I wanted it.

Tonight was music night and we played Elvis Costello's "The Delivery Man" followed by the new Classic Records repress of "Candy" by Lee Morgan and then the original LP pressing of Louis Prima and Keely Smith's "Old Black Magic."

Next was the "Ray Charles and Betty Carter" LP, then "Ballad Of The Fallen" with Carla Bley, Don Cherry and Charlie Haden. To really confuse the troops I dug out an original Everly Brothers mono from the late 50's and never even stopped to clean it.

We had so much fun and the system was so totally engaging that my wife had to tell us to turn it off, we were still blasting away until nearly 11:00 O'clock.

That is what this hobby is all about. Sitting with friends when the sound is right and being totally immersed in pleasure of great tunes.

albertporter September 07, 2005 06:09

Albert,regardless of my sometimes,seemingly,silly posts on this site(I occassionally try to be a bit edgy),I am truly happy for you,in that your crossover has been such a success.The Megalines are one of the few speakers I have not heard,that really interest me.You are a true gentleman,and I love ,no LOVE your enthusiasm in this "so much fun" hobby.I hope you get many years of real listening pleasure from a system that you have clearly put so much careful attention into.I'm sure you will do just that!!

Warmest regards,

Sirspeedy.

[email protected] September 06, 2005 21:33

Guess I should read my own thread instead of shuffling though the paper on my desk :^). Thanks Ray.

albertporter September 04, 2005 20:22