Preamp Deal of the Century

For those Supratek fans, Mick's Burgandies have arrived and after some modifications (at his dierctions) they are staggering in their transparency, bandwidth, inner (micro) relosution, and power (in the sense of conveying the "authority" of the music). I'd been waiting for these mono-blocks for more than 4 months (we've all been there with Supratek). They are simply gorgeous! Mick's beautiful wood chasises with matt black finished top plates and transformer housings. I am driving them unbalanced from my latest version of the Cortese. By the way, if you don't have the version with the 12B4A's in the output stage, send your unit back to Mick and have it modified. Incredible improvement in low end performance,in extention, dynamics, and texture, without scarificing any of the other atrtributes we've come to love. I believe he is charging $500 for the upgrade.

Artar1 - "The Supratek is no less accomplished in presenting musical truth, but does so with greater sophistication and less austerity."

Probably a very astute conclusion. Especially considering you haven't had the benefit of an audition. Tube-rolling will allow you to tweak the sound more to your liking. There are 4 tube types to roll in the Supratek linestages. Only one in the First Sound, the 6922 I believe. The First Sounds 0A2 regulator cannot be rolled, or so I have been told.

Waltersalas has the Supratek Syrah and had the First Sound PD for a while also. I think he was able to do some side-by-side listening comparisons. You might contact him for more info.

Jazzdude and Tubegroover,

It's been several days since anyone has posted to this thread; the silence is a bit eerie for some unexplained reason. Perhaps the comradery and enthusiasm I have read thus far has given me an expectation that it will continue indefinitely.

I have now finished reading some 254 posts belonging to this thread. I must say I am learning a great deal, not only about Supratek preamps, but about audio in general. Moreover, I am learning about the manner in which very experienced listeners and audiophiles approach the subject of reproduced sound in the home. It's almost as if this thread is like a graduate-level course in audioharmonics -- the pursuit of absolute sonic beauty without resorting to paying tens of thousands to get it.

I am still attempting to get a "handle" on the sound of the Supratek preamp line. In addition to my previous remarks, and having the benefit of reading the comments in this thread and elsewhere, I would also like to add a few more descriptive terms, if I might, albeit from a purely theoretical level, for I have not heard the Supratek nor will I have an opportunity before I buy the Cortese.

I feel what may further differentiate the Supratek line of preamps from the First Sound Presence Deluxe, a fine preamp in its own right and worthy of the Reviewer's Choice Award bestowed upon it by Todd Warnke of SoundStage!, is soul and harmonic layering. The First Sound strikes me as being a little more stark in its portrayal of music with slightly less harmonic stratification and nuance than the Supratek. It seems as if the aim of the First Sound is to provide life-like purity, power, dynamism, and clarity while retaining much of its passive gain-stage heritage. The Supratek does not strive for passivity, the straight-wire-with-gain philosophy. Rather it conveys clarity and detail but never at the expense of subtle richness, musical rightness, and harmonic soul. Thus, the Supratek might be heard as being the more musical of the two without the burden of euphonic sweetening that is often attributed to Conrad-Johnson gear. The Supratek speaks of a sparkling purity with a trace of inherent beauty without the slight "clinicalness" produced by the First Sound. The Supratek communicates with a slightly more enveloping and suave nature while embodying the soul of its designer. In contrast the First Sound impresses the listener with solidity and an unvarnished view of reality, albeit slightly thermionic. The Supratek is no less accomplished in presenting musical truth, but does so with greater sophistication and less austerity.

I don't want to make too much of these perceived differences. Like I said I have not heard the Supratek, which may invalidate my point of view. Because I am left with no review sample to audition, I draw my conclusions based upon vicarious experiences. I hope that my careful reading and intuition have served me well in this regard.

In my next posting I will be asking about where one can buy replacement tubes for the Cortese and about what NOS tubes are preferred, and why.

Cheers

Artar1 - I would say that you have made a very accurate assessment of the cortese without having heard it. The one caveat being that with the neutrality of the cortese it will be possible to add some ying or yang with proper tube-rolling.

As a future owner of a Syrah (ordered two months ago), I am in awe from following this thread. I know that I have long ways to go (waiting) but my excitement and anxiety grows leaps and bounds for what it will bring on my system after lurking here for several months now and digesting all the info of present owners.

In fact, I began tube shopping a month ago and getting very close to have a set and a spare of what many (Bwhite, Tubegroover, Jazzdude, Ecclectique, Swampwalker, Fiddler, Slowhand, Jewel_Hasan, etc.)users recommend that gives positives to the performance of their unit.

Although I am not an initiated member yet, I find tis thread very informative and full of camaraderie from the group who are experiencing the Supratek marvels in terms of giving priceless and countless advice to those new to the Supratek world.

Keep 'em coming guys! Following this thread is more than educational to me. I am sure that future owners like me are benefiting from the info that others gladly share from their journey in squeezing the last drop of the Supratek brilliance.

Thanks, and looking forward to contribute here or in any forum in the near future regarding Mic's creations. All I know for sure is that when Stiltskin receive the preamp (I ordered two days after him), then theres a very good percentage that mine is also on its way.

Abe

Artar 1, by George, I think you've got it!

I could not believe it, this is such a long thread that I cannot even finish reading it.

Stevem1960,

Thanks for your insights about the Cortese. You have given me a better understanding about how the unit sounds.

Cheers

Jazzdude,

I hope that I did not give the impression that the Cortese is bright in anyway because I don't believe that to be the case from what you and others have said about the unit in this forum and elsewhere. So I apologize if there's any misunderstanding.

If my understanding about the Cortese is correct, it has the balance, neutrality, clarity, detail, impact, immediacy, and dynamics of a First Sound Presence preamp. The Cortese, however, offers a touch more lushness and sweetness than the First, which gives the Cortese a life-like sound that is not too ruthless and unforgiving. It puts instruments and voices in the room in an uncanny way, something few components are capable of.

If my view of the unit, of course without hearing it, is somehow way off base, please correct me. After all, those who have purchased the Cortese began where I am now -- poised to take the leap of faith that will lead to sonic bliss.

Artar: The Cortese sounds 'beautiful' for want of a better word. It *will* sound romantic if the nature of the recording demands it, and ruthlessly revealing if there is lots of information on the disc.

Midrange purity and correctness is a particular strength of the Cortese. You have to understand that Mick used a pair of stacked Quad ESL-57 electrostaic loudspeakers for a number of years before going to Edgar Horns and now Goodmans Axioms, so you have a person/designer who really appreciates nice midrange and strong dynamics from his speakers (there is no better midrange than that found in the Quad ESL).

The Cortese is 'alive' sounding with excellent 3 Dimensional and spacial presentation - on superb recordings the soundstage is brought right into your living room! I use upsampling 24 bit 96/192 kHz DACs and the full effect of these wonderful DA converters is realised with this preamp.

Regards

Steve M.

Artar1 - just for clarification purposes. I would not consider the Cortese "high-pitched, overly defined, etched, clinical, bright, or overly dynamic". It is certainly not etched or cinical. However it also certainly does not have that "golden" sound you are looking for.

Jazzdude,

Thank you, thank you, and thank you. I get it.

I like a more golden, relaxed sound, which others might find cloying, uninvolving, veiled, or syrupy.

I have very keen hearing and have a very difficult time tolerating high-pitched, overly defined, etched, clinical, bright, or overly dynamic sound of any kind. If you can believe it, Rock music has never appealed to me, especially Acid Rock, Heavy Metal, or dynamic electric guitar solos because of what I hear as excessive upper midrange energy.

Thanks again for creating an effective frame of reference for me to understand the sound of the Cortese.

Cheers

Artar1 - I have an older model Cortese linestage with only 12db gain. Current models have 27db gain. I can't comment on the phono stage but judging from the linestage I don't think there is the any romanticism in the Supratek Preamps. They tend to be about as transparent as you would expect with a passive linestage. FWIW, I also have what is perhaps the most transparent of all passive-preamps, EVS nude-attentuators. Maybe that qualifies as "ruthlessly revealing", I'll let you decide.

Painting with a broad brush in this comparison, I would say the Supratek preamps are the antithesis to the CJ and Hovland house-sound and more in-line with the First Sound products.

Hi,

With some reluctance I make this post to ask a question about the sound of a Supratek Cortese preamp. I know by asking this question I will be breaking the current flow of the conversation almost like a complete stranger coming late to a party in which he doesn't know anyone except the plant in the corner.

I have read about half of the postings here which span about 300 pages when printed out. I had planned to read it all before asking my question, but I guess I couldn't wait.

My questions is this: I am having a little trouble getting a handle on the sound of the Cortese, the preamp I am most interested in buying. Can anyone help? What does it sound like?

I am looking for a romantic sounding preamp, but not one that is overly lush or one that obscures too much detail and transparency.

The Conrad-Johnson Premier 17LS, EAR 864, and Sunfire Classic Vacuum Tube Preamp fall to this more romantic camp. Not too many preamps these days do.

Does the Cortese have any warmth, or would you say it's a very neutral, clear, present, dynamic, and natural sounding preamp? Would you describe it as having yin or yang energy, or do these terms even apply?

The C-J unit mentioned above has some warmth, sweetness, nice harmonic layering, ease, decent texturing, and a suaveness to it that makes that preamp easy to listen to. I would not call it overly dynamic and it does not have gobs of immediacy.

Would you say the Cortese is closer in sound to, let's say, the First Sound Presence Deluxe or to either the EAR 864 or Conrad-Johnson?

Todd Warnke at SoundStage! described the First Sound this way:

"Utmost clarity, jaw-cracking dynamics, intense and deep bass, and newfound layers of nuance," but a "complete lack of mechanical sound" too; "of all the sonic skills, detail retrieval was the most astounding"; "the preamp for those who want a passive but need the facilities of an active."

Does any of this apply to the Cortese? Is the Cortese ruthlessly revealing?

I know I am asking far too many questions, and I do apologize for that.

Waiting 6 months or more will not be a problem for me, even if I have to wait a year. What troubles me, though, is the possibility that after I receive the Cortese I either won't like the way it sounds or it will be too noisy for my tastes.

Thanks in advance for your help.

Artar1

Thank you Eccletique for sharing some more tecnhnical information with us. I do feel safer now and I will try a pair 6F6G in my Chardonnay.

For those who already tried the 6F6G I would like to know a bit more as for sound. How do they compare with (1) stock KT-66 and (2) Tung-Sol 5881 as for:

tight bass (less boomy)
sweet highs (less sibilant)
emotional presentation (instead of clinical)
air

Thanks once more.

Thank you for your kind words Rabelais. I can certainly appreciate Mick's take on using different tubes. For what it's worth,I did asked Mick that very same question the week I received my Syrah. I had a few pairs of the WE 350b,s in my stash and was curious about rolling out the stock 6L6's. His answer was the same. I also asked him the same question regarding swapping out the stock 6sn7s for euro eqivalents like the Mullards,his answer was no to swapping them as well. I have used the we 350b as my regulator choice[ an exact equivalent by the way] for well over a year now and they will "stay" in my Syrah until the day I sell it. My posts regarding tube choices in this thread are simply my observations with respect to how they sound in my system.They are not recommendations per say. Your mileage may vary of course.

I've learnt a lot from this thread, and certainly appreciate the sharing of info re the 6F6. For what it's worth, I did ask Mick about this about a week ago. He simply said "No;" he would not recommend it. He did not elaborate. Mick's take is of course valuable, but it is not necessarily a trump card, and Ecclectique your experiences with it are a great contribution to this thread. Thank you.

Re the Ken-Rad VT-231 black glass, they made an immediate and noticeable improvement in my system (tube CDP, Chardonnay, SS amp, Hales speakers: a greater tube "bloom" and deeper bass; no unreasonable microphonics). Clearly, system dependency cannot be ignored.

Hello Gang. RE: The use of 6F6g as regulators. Fiddler and Lisbon,I can certainly understand your apprehension and anxiety here.Consulting tube substitution guides and doing net searches will give you imformation that is simply not applicable here regarding our application in the supratek. Firstly...The 5881, and the 6L6 tubes employed in the supratek are are actually output tubes[beam tetrodes]. They were never really designed for use as a regulator tube.These tubes were originally designed for amplification duty only, re: output stages for amplifiers,radios and TV's. Just like many other common output tube types such as the KT-66,el-34,kt-88,6550,kt-90 etc to name a few . When one referrs to any tube subsitution guide or manual,the manual will give you direct substitions for that one particular tube type that would have similiar voltage curves[among other parameters] for the tube being substitued."IE" for voltage,amperage,bias and output power[wattage]etc. These paramaters are really not applicable here as they are not employed as an output stage tube in the supratek.The duty of these tubes in the supratek were specifically designed and employed as regulator tubes, whereby their application in the supratek are specifically used to smooth the ripple of the rectifier, "not" as an output tube per say. A tube substitution guide will tell you absolutely nothing when referred to in this context. Consulting any tube substitution manual will only tell you what tube can be substituted as an output tube . Example: A typical substition for a 6L6 found in any given manual, would be a 5881,7581,5932,Kt-66,6L6G,6L6ga,6L6gb,6L6gc etc.In actual fact, there are many relatively common power tubes[power tetrodes,power pentodes,beam power tubes] that can be substituted for the 5881/6L6 in the supratek. The 6F6 is a small power pentode and is perfectly safe and suitable for use as regulation duty in the supratek. I personally use the western electric 350b in my supratek only because I've had a pair in my stash for many years.I have also tried nos 5881's, all of the 6L6 itterations, as well as 7581's,5932's,kt-66's,6v6g's and of the 6f6g's. The legendary WE 350b beamer is the "King of the Castle" for regulation duty in my rig and in my humble opinion, the 6F6g [round plate] is the next best thing to it.If I didn't have a pair of 350b's, than the 6f6g would be "THE" tube of choice. I ran a pair of these in my syrah for more than a month. Try em, they are terrific.

Hat's off to you Slowhand. If it weren't for this thread I would't own this pre most likely. It has been a very pleasurable ride all the way.

Lisbon, I have an e-mail off to Mick to get the low down on this tube. I'll keep all posted.

Fiddler,

Thanks for the toast! I am wondering why the views of this thread is stuck at 48. I know we were over 10,000 views. We must have broke something at Audiogon, or they got tired of keeping track. Be careful guys, when we hit 1,000 posts smoke may start pouring out of our computers.

Fiddler has a point. Did some research on 6F6G and also found nothing saying that these could replace the 5881/KT-66/(...). Also the supratek "manual" does not mention the 6F6G as a possible substitute for the stock tubes (while other types are referred). As Fiddfler "I am foaming at the mouth to try the 6F6g. I just need a little reassurance that the tube will perform within acceptable operating points for the Supratek!" In the meantime, anyone asked Mich about this?

Tubegroover, I am excited about your discovery of the 6F6g and much of your experience with tube rolling seems to mirror mine with the exception of the Ken Rads. But I think your comment about taste and synergy is often grossly overlooked. I personally believe this whole journey is about taste and synergy, otherwise we would all be listening to the same thing. I applaud your comments.

Regarding the 6F6g, help me overcome my jitters about this tube. I would love to find another regulator as good as the WE 350B, especially at 1/10 the price!

However, when I looked up the 6F6g online I couldn't find anywhere that it is a drop-in replacement for the regulator tubes. I didn't take the time to research the operating specs, but I didn't see it mentioned anywhere as a replacement for any of the usual Supratek regulators. I have great respect for your help and experience here and I am foaming at the mouth to try the 6F6g. I just need a little reassurance that the tube will perform within acceptable operating points for the Supratek!

I apologize if this has been addressed in an earlier post as I have not read all of the posts lately.... realizing this thread continues to be the "Mother of All Audiogon Threads".

In fact, we should all agree to a virtual toast to Slowhand for making us aware of the Supratek to begin with and also for establishing an Audiogon record that will probably never be broken!

Here's to you and yours
And to mine and ours.
And if mine and ours
Ever come across you and yours,
I hope you and yours will do
As much for mine and ours
As mine and ours have done
For you and yours!

Clipsal you make some interesting observations and I would say that what people hear by swapping tubes must be more system dependent than anything. I wouldn't want to give the impression that different 6SN7 VT231's don't make a difference, they most certainly do but I found the differences subtle relative to each other. The Ken Rads did provide fuller bass but not better and I take issue with the fact I have tried 3 pair and haven't been satisfied, they were all too noisey. I also felt they were a tad too rich in the mids but I suppose I find this more a taste/synergy issue than anything else.

My point is I have heard much more significant differences with tubes in other designs I have owned over the years. This pre-amp is so intrinsically good that so far as the 6SN7 goes I haven't found the variety I've used to make a significant enough difference to rationalize spending the money on some of these tubes. Of all I have tried I prefer on balance the Sylvanias and National Unions with the Ken Rads my least favorite, good ones are hard to come by I suppose.

The regulator tubes I didn't find to alter the tonality so much as enhance dynamics, presence and bass. This may of course be system dependent as well. To me the 6f6g was most significant, a real eye opener. I agree that the stock tubes were not nearly as good as all the tubes I've tried but changing the regulators should provide an interesting result, you should definitely give it a try and tell us what you think.

Hi Slowhand,

I've had the line stage version of the Cortese (Sauvignon) for about 6 months now, and have just started experimenting with Tube Rolling, with vast array of information and feedback on this thread.

I've replaced the Rectifier with the Mullard GZ34 and the 6SN7's with a pair of Ken Rad Black Glass VT-231.

Initially upon replacing the Rectifier with the GZ34, the system sounded just a tad leaner with little or no loss in detail (Not much of a change after 1 week of usage).

But when I replaced the stock 6SN7 with the Ken Rad Black Glass VT-231, the improvement was immediate, extremely good bottom (Supurb Slam) with a glorious mid-range (Just put these babies in about 2 hours ago), after it's delivery by Australia Post this morning. The vocals which were once a little veiled, probably due in part to the Krell KSA-250 amplifier, is now completely brought to life. The detail is incredible, with a complete and utter transformation. I never thought changing these tubes could make such a difference. Hence the perplexation lately with some of the other comments on thread with regards to the Ken Rads (Microphonic, very little difference etc...)

Furthermore, the Sauvignon with the Ken Rads has no Microphonic qualities. I've tried tapping various parts of the Main unit and power supply, with no microphonics what so ever. Dead Quiet.

Just a question, If the bass is now very deep with an extraordinary level of detail, do you guys believe replacing the last remaining set of tubes (Regulator pair) with the 6F6G will make any more changes to it's character. Further to that, is the 6F6G a suitable replacement on the Sauvignon, I know some of the readers have replaced this component on the Syrah, but what about on the Sauvignon.

I just trying to think how the 6F6G can have any other improvements in light of the transformation that's already just taken place.

Thanks to everyone to date with their inputs. The information over the past year has been extremely informative, You guys know what you're talking about. Afterall it's not easy to purchase a piece of stereo equipment sight unseen and most importantly sound unheard.

Best Regards,
Clipsal

Lisbon,

My pair of JAN Sylvania VT-231's are not microphonic at all. The only tubes that I have microphonics issues with are the Ken-Rad Black Glass. I am finding that you can't label any brand of tube microphonic over another brand. You can have 2 sets of the same tube and one may be microphonic while the other is not. I have not found microphonic tubes to hurt the sound of my Syrah. Yes, when music is not playing you can hear the microphonic's, but when the music starts it sounds great.

Lisbon, The regulator tubes (6L6/6F6/KT66,etc.) will not increase the microphonics at all.

First, the Tung-Sols:

I am not an expert (far from that) on NOS tubes. Started with the stock tubes, then the Sylvanias VT-231 and now (since today!) the Tung-Sols Round Plates. The Sylvanias were airy (nice) but sounded lean and clinical in my Chardonnay. Actually, not too different from the stock tubes. But quite more expensive and microphonic. Sold them. With the Tung-Sols I had a very bad start while ago. Once I put them on the preamp they started to make some "huuummm...". When I got near them the "huuummm..." turned out to be a much louder "HUUUMMM...". Ouch! Well, I gave them a couple of minutes to settle down and the noise disapeared almost completely (!) As for the sound, it is quite the opposite of the Syls. A bit less airy (can I "fix" that with the 6F6G?...) but everything else was much better. Natural highs and lows and a palpable midrange. This is a very musical, very emotional tube. I guess I am done with 6SN7 type.

Now the 6F6G:

First of all, THANK YOU Eccletique and Bwhite! I guess I can get a pair of Sylvania Green base print 6F6G tubes. But I must confess that after my experience with the Syls VT-231 - regading sonics AND specially microphonics - I do not feel very confortable to go again with the Syls... So I ask: are these really good? How do they behave as for tight bass / sweet highs / air AND microphonics (comparing to the stock KT-66)?

Thanks guys!
Lisbon

Photos of the 350b and 6F6G courtesy of Ecclectique!

Photo One showing 350b and 6F6G

.

Thanks Bwhite,

It is the round plate that I have. I have paired these with the Sylvania 6F6G tubes that Ecclectique recommended and this seems to be the magic combo in my system. The strongest, most tuneful bass I have heard in my system, but not at the expense of mids or highs. Cymbals have a beautiful shimmer, drums have a nice crisp snap, brass has that nice burnished sound and the mids are clear as a bell. I have had 1944 Sylvania VT-231's, Ken-Red Black Glass, Neotron's in the line stage, but the Tung-Sol round plates make the best combo with the 6F6G's (for me).

Hey Bryan.Tell me how you post pictures on this thread?

hello Lisbon. The original 6f6 valves[power pentodes] date back to the early 1920's and were actually first produced in all metal form and looked similar to the early 6v6 metal valves that are so common in early guitar amps.Do "not" use these metal types as they do not sound the same. To the best of my knowledge,the 6F6G [Shoulder shaped glass vavles] were produced from the late 20's through to the early 40's. The tube was produced by either Sylvania or National Union and rebranded for many radio companies of the day. Mine say Rogers,however I have also seen them labelled philco,electrohome,RCA,westinghouse etc.There are also quite a few different versions of the 6F6g's with different looking plates and internals.The ones that I am referring to had rounded black plates like the Western Electric 350b.I have seen many with flat black plates as well. I am not sure if I can post a picture on this thread,if you want to see a picture of the internals of this valve,I can e-mail you one off-line. Cheers David.

Hi Slowhand, Here are some pictures of the Tung Sol Round Plate tubes grouped with some other tubes:

Photo One

Photo Two

The images are not terribly high resolution but might give you some idea of what to look for. Look closesly at the tops of the tubes to see the U shaped plates which are visible in Photo Two - at the very top of the tube - above the Mica spacers.

Do Tung Sol Round plate tubes come in both clear and black glass? Do they say round plate on them or just tung Sol SN7GT?

Hi guys

I am getting VERY curious with this 6F6g thing. I am willing to try a pair in my Chardonnay. But what about the brands? Any suggestion? Tung-Sol, Ken-Rad, Sylvania...

Best,
Lisbon

Hello Gang.I have been out of town, just catching up on the thread. Swampwalker, hope your progressing on your troubleshooting.... These things can be frustrating, but persevere there brother as you will indeed be rewarded. Jewel.... regarding microphonic 6sn7's??? As bwhite correctly pointed out, many 6sn7's tend to be microphonic in the supratek,noteably the Kenrads, however...your dealer states that: "all nos 6sn7's tend to be microphonic" That is a rather profound statement to be sure, and nothing but total pile of BS.Perhaps it is just because of the sad supply of kenrads in his inventory.Yes, the Kenrads can be microphonic in the supratek but certainly not all of them.They need to be cherry picked. I had to go through a dozen of mine to find a pair that were quiet. The least microphonic and quietest of any 6sn7 types are the rca 5692 [red base].Personally.... I preferr the sonics of the Kenrad vt-231gt's[navy version] or the tung-sol rounds in my rig. That said: any strong testing RCA redbase 5692 will simply stomp the modern chineese or russian 6sn7.These have more air and extension up top and are a little leaner in the bass, but the bass is nice and tight,very fast and has very good resolution.Does not have quite the atmasphere or bloom in the midrange like of the kens or the tung sol rounds but good examples of this tube are very smooth and non-fatiguing.Very system dependent here with regards to tone and synergy. A good example or a case in point: I have a MFA luminescence B that employs a 6sn7 for gain in its line stage... The Lumi tends to be a shade on the dark side of nuetral. Both the Kenrads and tungsol rounds would be my "least" favorite 6sn7 when employed in the Lumi, while the rca 5692 is "far and away" the best 6sn7 type tube in the lumi.The sylvania 6sn7wgt vt231 metals are very similar tonally to the rca 5692 however,these tubes also tend be microphonic in the Supratek and also need to be cherry picked per sey. The tung sol round is an all around great performer in the supratek, as well as the much more common 1930's rca grey glass 6sn7gt's. The RCA's can be sourced just about anywhere as there were more of these manufactured than any other tube ever made. The RCA gt's are tungsol roundish sounding[read sweet] in the supratek, traditionally much easier to source and easier on the pocket book as well. Again... system "synergy" is the key word here. Personally... I find the Tungsol round just a little too "tubey" or sweet sounding in my rig. Your mileage may very of course. Suggestion here: It may be a good idea to acquire a batch of say a dozen of the same 6sn7 type and then cherry pick the best pair and sell off the rest.I know... can get a little costly,but they are pretty easy to sell on ebay or right here on the gon. Slowhand and tubegrover... Sure happy to hear you guys liked the 6f6g's for regulator duty[amazing huh].A great alternative from the insanely priced we 350b.To be candid: I am always a little aprehensive about recommending anything in a public forum as we all have different rooms,amplifiers,rigs and ears. PS: For those sourcing early bottle type 6f6g's for regulation duty in the supratek....these can also be substituted with a 1611 or 1621 tube. These tubes are physically about the size of the we 350's with similiar internals. Cheers David.

Jewel - *I* liked the KenRad Black Glass tubes and I like the Tung-Sol Round Plates. They are both very good choices. Honestly, the stock 6Sn7's sound a bit like a cross between both tubes - somewhat closer to the Tung-Sol but less harmonically complex.

The Tung-Sol Round Plates are sweeter, more open, and have less midrange bloom than the Ken Rads.

Ultimately, the tubes you choose as "best" will depend 100% on your listening preference and the rest of your system. No-one can tell you what is best for YOU.

It is good to attempt to determine what character your system needs before seeking out tubes. I don't know what the rest of your system is so its difficult for me to determine (guess) its sonic signature. Even if I did know what your system consisted of, odds are your listening preference is different than mine to some respects and my choice in tubes would not be correct for you.

So.. that said, with the stock tubes in your Supratek, what elements do you think would be beneficial to your system?

Be cautious when buying "names/model numbers" of tubes vs. construction of tubes. Often times a tube will carry a specific number yet the internal construction may be different. The Tung-Sol Round Plate referrs to a specific construction or type of Tung-Sol 6SN7GT which is to my knowledge MUCH different sounding than the more common "black glass" Tung-Sol 6SN7GT.

Vingage is also important. Tubes can sound different from one another, even on a month-to-month basis in some cases - ie; January manufacture sounds different than February. To me, a matched manufacture date is VERY important otherwise the tubes, however identical in appearance, can sound somewhat different. Also... matching the electrical ouput is important because the L/R channels on the Supratek cannot be biased. A severely mis-matched pair of tubes could result in a soundstage that leans to one side or the other because the gain on one channel is greater than the other.

Likewise - just because a tube is a "6F6G" doesn't mean its THE 6F6G that everyone is talking about. THE 6F6G you want, I believe is the Sylvania 6F6G - clear glass - green print or the somewhat different - National Union black glass 6F6G. Ebay is a GREAT place to research tubes and to get more familiar with the internal construction. For an example, go do a search on Ebay for "6F6G" and see how many different versions there are.

Bwhite: I know you mentioned in one of your earlier posts that the Kenrad Blk-Glass(6sn7) worked best for you but have you tried the TungSol (6sn7) black-glass in your setup? I wonder how they perform (sound & microphonics) against the kenrads. I called my tube vendor yesterday and asked about the microphonics and whether it was worth sending these back to try a different pair. He told me, most if not all old 6sn7 tubes would have microphonics, that's a given. However, I'm thinking of calling him back today to see what it would cost to replace the kenrads with a pair of TungSol blk-glass since I'm still within my 10-day return/exchange period. And perhaps pick up a pair of 6F6g in the process.

Jewel, Glad you're having fun! Finding good 6SN7's is actually quite difficult because most are microphonic in the Syrah. I estimate that 1 out of 10 6SN7's you'll find will be troublesome.

Hi Tubegroover: You know what, initially I too was looking for some NOS 6F6g based on Ecclectique's recommendation but the fella (Mike) at www.vacuumtubes.com was telling me that he didn't think 6F6g's could be direct replacements for 6L6 application. I decided not to take the chance - oh well! In fact at the vacuumtubes.com's website they list 6F6gs at $20 new and $10 used without mentioning any brand names etc. But it's cool, I really didn't mind the process as I've been wanting to try this for a while. And really, it's all been quite fun so far. Just the process of tube hunting and then waiting in anticipation was fun & and educational in itself. Now I'm going to set my focus on getting damping material and possibly some DH cones; oh yes and some 6F6g tubes.

Jewel I tend to agree that there is less difference between the 6SN7's and 5881 tubes. I've tried 5 different types of these tubes including National Union, Ken Rad, Sylvania, RCA and the stock tubes. There are differences but they tend to be rather subtle. I find the rectifier the same having tried several of the recommended ones. I am currently using a BEL which is a manufactured in India and was a supplier to among others Mullard.

I agree with Fiddler. Where I have noted the most significant changes and improvements in the Syrah's performance is in the regulator position. The 6L6 type seems to open up the dynamics on the pre to a greater degree than the 5881's, greater plate voltage maybe? And for the most significant improvement to date per Ecclectique (thank you David for this great recommendation) you must try the 6F6g. Relatively cheap NOS, less than 50.00 bought me a pair of Brimars and I was stunned at the enhanced dynamics and the bass, oh the bass. Everyone must try this tube. They are readily available and can be purchased used at considerably less than 50.00 for the pair.

Tube Rolling Update: The replacement set of NOS tubes arrived last friday. After about 20 minutes of listening with the stock tubes (at a set volume level) I decided to go ahead and replace all the tubes all at once just to be sure all the tubes are working and that they light up properly - and they did.

The replacement tubes I receive:

1. 5Z4 Type - 5AR4/GZ34 Mullard standard-base.
2. 6L6 Type - Tung Sol KT66/7581 (matched pair).
3. 6SN7 Type - KenRad VT231 black-glass (matched pair, rectangular plate - not round plates).

First impressions: not much of a difference I'm afraid. I was expecting a more immediate and easily discernable change to the sonic characteristics of my system; but that was not the case at all, not like the time when I replaced a set of unknown Chinese KT88s tubes with Valve Art KT88s on my Air-Tight ATM-2 power amp. The KT88 experience was immediate; it felt as if the power had doubled on my amp. So in comparison, my first real tube rolling experience was a bit of a let down. Also, this was my first experience with “microphonics”. With the Kenrads plugged in, even a mild tap on the preamp knobs will generate loud humms through the speakers.

But now that I’ve had these tubes for a few days in my system, I feel the sound has warmed up appreciably, the music has more “air” and the bass is definitely more defined. I think some of the characteristics discussed throughout this thread are slowly beginning to appear in the system.

Late last night my wife and I returned home from a birthday party and instead of going right off to bed, I decided to play with the system a bit more. So I took out the Kenrads VT231s and put the stock 6SN7s back to see what changes are, if any. I could be wrong as I was quite tired and slightly intoxicated - I thought the stock 6SN7s sounded better with the rest of the NOS tubes in place than the kenrads vt231s. As I said, I’m not a 100% sure however I will check this out tonight as soon as I get home and report back soon.

Tubegroover, It turns out that I may be in Florida this weekend with my wife for some R&R. Is there any chance that I could come for a listen to the zh-270 and the Syrah? I guess it depends where in Florida you are!! I would love to hear the combo before ordering them!! Talk about a great long weekend!!

Hi Swampwalker, Actually I may have an umbilical that might work for you. Its from a Chardonnay and its 10 feet long. Its worked on a friends Syrah and it may work on yours.

Some of the umbilicals are slightly different than others depending on how the motorized remote control & board gets its power. This cord should work in your preamp but you may not be able to use the remote (if you have one).

I would be happy to send you the cord but it might be faster to just have yours fixed locally by a technician.

Let me know.

Correction- Now he's got me taking the darn umbilical apart and re-soldering it. Stay tuned boys and girls, reading voltages is one thing, soldering may be a whole different story.

In case anyone is interested, Mick walked me thru trouble-shooting it w/a multimeter. Found out that there was no voltage to the pre, but voltage out at the PS (360 vdc, careful there, boys and girls. Traced it to a broken center (hot) wire on the umbilical (I hope). If anyone has an extra, I'd love to borrow it until a new one arrives from down under. If you can help me out, shoot me an email. Of course, I'll pay shipping both ways.

Sorry, I had to ask about the inputs - I realize its a trivial thing.

If the DC power cord is connected properly and not mis-aligned, then perhaps there is a real problem.

I wonder if this could have been caused by tubes which are shorted.

Did you by chance remove the 6L6 tubes and play the Supratek to see if that solved the problem?

I rotated the input thru every choice, Bwhite. The only sound I get sounds like "cross talk". Faint but clear presentation of CD, no matter what input I select.

Swampwalker - Guess I was trying to say that maybe your input selector switch (front right knob) was on the wrong input. I know this is silly but it happens. Sometimes when we switch cables around we mistakenly put them back on the wrong input.

Thank you everyone. My Syrah does not have a gain attenuator or an RCA/XLR switch. I am in contact with Mick, but so far no cigar. He had me check a dc voltage near the 6L6s which is supposed to be 300v, mine shows 0.16!!! I will double check the dc umbilical.

Bwhite- Do not understand "Check that you do not have the RCA cables from your EMC1 plugged into the wrong RCA inputs on the Syrah - that ones you used to have them plugged into. Double-check. And thanks for the info on the tubes.