ARC Ref 3: Tung-Sol 6550 in power supply?

I have sourced a new production Tungsol 6550 from The Tube Store in Hamilton (Ontario); I intend to use it in the power supply of my ARC Ref 3. Has anyone had any experience with the Tung-Sol TS6550 in the Ref 3? Have you compared it with the original Winged "C" SED 6550C shipped by ARC with this
line stage? Preferences? Reasons?

I have also 'toyed' with the idea of rolling that 6550, though I cannot say that I've done it yet. I've seen this topic come up a couple of times before, and there doesn't seem to be much interest, maybe that's why I haven't gotten around to it. I will be curious to read your impressions though, keep us posted.

I have used the Tungsol 6550 in the power supply of the Ref 3 for a couple of
weeks. I don't have a final word, but tentatively my thumb is down. The Tungsol gives
a very pleasing sound with a strong bass, luscious mids, and controlled treble. . . but
listening at length reveals that mids may be actually slightly bloated. Treble is probably
slightly depressed compared to the SED Winged. The end result is in my view a rather
romantic or euphonic presentation that is more nostalgic than real, lacking in complexity
and upper harmonic development. On the positive side, Tungsol might have slightly
more image specificity than the SED Winged. I have now reinstalled the SED Winged. I will conduct more tests with Tungsol on a recording that sounds somewhat etched using SED Winged: Dvorak complete strings quartets played by Panocha Quartet on Supraphon.

On a related note, I have also replaced all Sovtec 6H30s in the Ref 3. As I suspected, my
tubes were getting old at about 2200 hrs. Symptoms were reduced dynamics, reduced detail, colder sound, little etched. I am now getting
a sound that is significantly more involving and harmonically rich than what I have
experienced since early Summer 2007. 1800 hrs may be the extent that stock 6H30 tubes last in my Ref 3 before starting to decline. The new 6H30s are the EH 6H30PI "Gold" variant )(with gold plated contacts) that I have sourced from the TubeStore.
Hi Guido what I read in my manual was aprox. 4000 hours so at 1700 you were not even half way.

I am curious now so any other ARC REF3 owners if you could jump in.
Dev, yes I know. . . but I can only trust my ears, regardless of what the manual says. And in my Ref 3 the SED 6550C in the power supply declines even faster: 900 hrs may be the extent before the sound becomes dull and uninvolving with significant loss of dynamics and treble information. Please note that I am always specifying 'my' Ref 3, rather than to the Ref 3 model in general. . . it is entirely possible that the relatively rapid tube decline that I have observed is a phenomenon peculiar to my own unit.
Guido, thanks for the info. and I fully agree regarding manuals and respect any persons own findings. Allot of ARC owners recommend just as Oneobgyn above has mentioned to stick with the Audio Research tubes but obviously you have chosen to go another route what are your findings.

So regarding the tubes when do you start replacing them and which ones and at what intervals, it seems to me that you refer to your power supply going the quickest.
DEV, I agree with OneObgyn on the 6550 in power supply: the SED seems overall to be a more appropriate choice for me; I was able to compare new tubes directly. EH6h30PI Gold and the Sovtec 6H30PI apparently come from the same plant. According to the TUBESTORE they are not distinguishable electrically; I have compared a depleted Sovtec set with a new EH set, so I cannot say which I like better. Now on tube aging. . . in my opinion the SED6550C in PS is due for replacement after 800 to 900 hrs. The Sovtec 6H30PIs seem to start to decline at 1800 hrs of operation.
I hate to be repetitive but IMO there is absolutely no reason to use any other than the ARC recommended tubes
Thanks, time to get some new tubes and hear the difference. What's the difference between the tubes that are being sold by Gon members in the ARC section which are half the price and buying directly from ARC and paying at least 100% more.
To the best of my knowledge, ARC supplies a matched set of 5 Sovtek 6H30PI for approx $240. The same tubes can be sourced from the Tubestore for $21 each, with a $5 premium per tube for matching. EH golden variant is about $2 more than Sovtek. See:
I thought I had read somewhere that the 6H30 tubes were rated for 10,000 hours? I understand that this is probably a pipe dream but 1800 hours is a long way off 10,000.

I've got over 600 hours on my LS-26 so maybe I need to plan on an earlier swap out than first anticipated???

BTW, I have been to the Tube Store and they are great guys.
RGD, the answer is: not necessarily. the LS 26 is not the Ref 3. . . it is quite possible that the Ref 3 may drive those tubes harder. Keep listening to your system. . . your ears will let you know when the sound were starting to decline. It is also possible that tube lifespan may be a function of the system downstream. . . Until 3 months ago I have been driving a set of old Maggies IIIAs, which are notorious bears. Someone with more experience on tubes than I have may comment on effect of system downstream on tube lifespan.

Keep trying different 6550's (probably a voltage regulator). PS tubes have a huge influence on the sound (as you have discovered). You should go after some NOS Tungsols. I would be very surprised if they didn't outperform the SED's in a big way. The very best TS's are the solid blackplate (no holes in the plates) triple D getters. They are very pricey but you only need one. If evryone took oneobgyn's approach to this hobby, nobody would learn anything on this forum.

I second everything Bart just said. NOS Power supply tubes can provide a major sonic improvement to any equipment, and there are a number of excellent 6550 iterations out there to try. Obviously- You have the ears and system necessary to appreciate the differences. The narrow mind/narrow road approach will only rob you of the full music/venue information well recorded discs possess.
"If evryone took oneobgyn's approach to this hobby, nobody would learn anything on this forum"

That is a laughable comment. I have probably done more tube rolling in my 40 years in this hobby than you can imagine. I have a friend who also has a Ref 3 and has rolled just about every tube imagineable. When all was said and done his analysis was similar to mine. All you are doing is creating a different "flavor", most far from euphonic and many with tube bloom. I am not saying "don't experiment". I am saying that I have been there and done that. BTW, I am surprised that none of you have tried KT 88's of different manufacturers in place of the 6550.

I have always asked myself when I change a piece of equipment or roll a tube, "am I hearing something different, or am I hearing something better?" That is what experience has taught me. But heck, that is just me.
The best 6H30 tube is the hard to find 6H30 DR. My Modwright 36.5 also takes 6H30 signal tubes. If you can find the true DR tubes that make a pretty significant improvement.

BTW - oneobgyn is a huge help to people.
I have a pair of NOS TungSol 6550 Black Plates (solid) from the early 50s - I will try them and will report back. I'm aslo burning in a quartet of NOS 6H30DR tubes.
Gentlemen, rather than waxing poetic in terms of 'better' and best', it may be useful to describe what makes us prefer a particular 6550 or 6H30 iteration over an other one. As for Tungsol 6550 on Ref 3, I much prefer the SED 6550C supplied by Arc because of its perceivable (by me) linearity and minimal bloom across the spectrum. If there existed a tube that is even more nimble, linear, extended, tight in the bass, and less bloomy than the Winged C 6550C, I may consider it. Anything warmer, I will instead. . . cheerily ignore. I have also tried a set of 5 6H30DRs in the Ref 3, and I could not tell if they made an audible difference.

it seems to me that you, as I, have experimented and have found no appreciable gain with tube rolling on the Ref3. I still maintain my stance on that as you and I have found changes that involve tube bloom etc. Again, differences will be heard, BUT everyone must ask of themselves "did I hear something better or did I just hear something different"

Strange that no one is offering comments on swapping a KT88 for the 6550C
I did try the Tung-So in my Ref 3 and went back to the SED 6550C rather quickly. In power amps the Tungs were better but the Ref 3 seems voiced for the SED 6550C. I also found the Tung more noisy. I am using a Tube Store SED, but the best so far has been the ARC provided tube!!
So Posbwp555

It seems to me that so far most of the people that have been doing tube rolling on their Ref3's are coming back to the ARC tubes.

Once again there is a difference b/n hearing something different than hearing something better and I still maintain that tube rolling on this unit is unnecessary..but heck what do I know?
I will be swapping my $1200 Ming DA 2A3 preamp with a friend who owns a Ref 3. I had my pre up to his house for a comparison with his Ref 3 last weekend and it was a tossup. Some things done better by one and some better by the other. The tubeset in the Ming DA cost more than the preamp. It would not be competeive without these tubes. The Ming DA had all the stock caps and resistors when the comparison was conducted (inexpensive components that do not do justice to the preamp but unavoidable at the asking price). We then installed two blackgate power supply and two Mundorf SIO output caps in the Ming DA. This tightened the bass dramatically (even without proper burn in of about 300 hours) and eliminated the area in which the Ref 3 outperformed the Ming DA. To my ears it is superior to the Ref 3 in all parameters at this stage. We intend to address the resistors, tube sockets and rails next. I will use his Ref 3 for about a month while he uses the Ming DA. I have invested over $20,000 in an NOS tube collection over the past four years (I am trying to acquire a lifetime supply of the very best NOS before they are gone). If you are convinced that the SED 6550C is the ideal tube in the Ref 3, great. I would be very interested in hearing what Elberoth thinks of the Tung Sol when he tries it. Assumptions are often incorrect in this hobby. Experimentation is what helps us progress.

"Assumptions are often incorrect in this hobby. Experimentation is what helps us progress."

I completly agree. What I did say was "been there, done that and decided originals were best for my ears". Others seem to have the same feeling.

BTW by the time your NOS collection is gone today's stock tubes will be the NOS tubes of tomorrow. Just a thought but perhaps you should be stockpiling some current generation tubes for listening 30 years from now.
"Assumptions are often incorrect in this hobby. Experimentation is what helps us progress."

That's correct. . . and that's why I gave Tungsol 6550 a valiant try for several weeks. . . then went back to 6550C for good. G.
"That's correct. . . and that's why I gave Tungsol 6550 a valiant try for several weeks. . . then went back to 6550C for good. G."

so now let's recap. Other than Posbwp555 is there anyone here who agrees that there is a better choice on the Ref3 than the ARC installed 6550C. I have tried them all and when all is said and done IMO there is absolutely no reason to tube roll on the Ref3. BTW, I posed a question to all the tube rollers that is yet unanswered has anyone tried a KT88 in place of all of the different 6550's?

I am glad that you have stockpiled a collection of $20,000 NOS tubes. Given that most tubes can go easily 5000 and probably 20,000 hours you can leave the balance of your collection to your grandchildren. I also commented in all sincerity that you should be stockpiling today's tubes as in 20-30 years they will be the NOS tubes of tomorrow
Guidocorona - Which Tung Sol 6550 have you tried ? The original NOS Black Plate from the 50s that or the current "Tung Sol 6550 reissue" ?
Elberoth2, I tried the current reissue. I am not terribly inclined in delving in superannuated and proportionally priced NOS at this time.

You have tried them all? Really? Which have you tried?
What amazes me is that people spend 10,000 on a preamp and then are offended that the best sounding tubes cost a lot of money. There are some good current production tubes but I do not know of one example where they are not bested by NOS. In most cases the disparity is huge. Elberoth, when you try that NOS Tung Sol, let us know how you liked it.


If you are so correct how is it that all of us here who own this preamp ( I assume you don't)have done some tube rolling and come back to the stock ARC 6550C

And BTW, why haven't you answered my question about using a KT88 instead of a 6550? I believe you talk the talk but you don't walk the walk. I have asked this question several times in this thread and all you do is try to show how knowledgeable you are in NOS tubes. You obviously both don't know and presumably have not ventured out and tried a KT88....have you?
Posbwp555 - I think that the problem with Ref 3 - and all other components build around 6H30 tube for that matter - is the range of available alternatives is extremly limited. AFAIK there is only one NOS tube you can try - the mil spec 6H30 DR tube from the late 80s/early 90s.

There is a wider selection of NOS 6550s - you can get TungSol, GE - but that tube (single) is only used in Ref 3 power supply, so its impact may be somehow limited.

Yesterday, I have played with the quartet of DRs in my Ref 110 power amp. They improved HF extension, soundstage depth and allowed to hear more of the spatial clues. The improvement was not dramatic by any means - more like power cord upgrade, but it was worthwile nonetheless and I'm looking forward to try them in my Ref 3 as well (hopefully today).

The PS tubes have a dramatic imfluence on the sound. I agree with you about the 6H30, it is a shame it was used.
ARC has produced a well balanced sound with it though. I don't know if I am correct or not Oneobgyn. I do not own the ARC (as previously stated). I heard it at a friends house and compared it to my Ming DA (as previously stated).
We were going to swap pres for a month but he decided to sell his ARC and it sold as soon as he posted it. I guess
you haven't really rolled "them all" or you would have stated which ones you tried. If you think the sound you have with the stock tubes is as good as it can be, then don't try anything else. You should not discourage others from experimenting. It is the people that try things that advance the hobby. You should also bear in mind that because you in your system with yours ears think that rolling tubes in this pre is pointless, others with different systems and tastes may conclude otherwise.
By the way, what 20,000 hour tubes are you using? That is laughable.

Bart, if you have some experience with tube rolling for Ref 3 that we have not covered yet, please enlighten us. G. Ref 3
"Bart, if you have some experience with tube rolling for Ref 3 that we have not covered yet, please enlighten us"

The short answer is that he can't

He can't even answer me whether he has tried a KT88 instead of the 6550

I would like to make it clear once again that I would never discourage tube rolling. I merely said that when all was said and done it seems that those of us who own the Ref3 (he doesn't) come back to the stock 6550C. I have also stated that tube rolling will produce a "different" sound but not always a "better" sound and that is what we leave to our ears, judgment and most of all experience
OK guys, I have already installed NOS Tung Sol in the PS of my Ref 3. Now I'm wondering, how much time I should allow for burn-in (this is a brand new tube) ?
Elberoth2, I would give the Tungsol a couple hundred hours of playing time at various gain levels to stabilize. G.
I would recommend the (blue label) GEC KT88 for this pre. I experimented with Gold Lions and Gold Monarchs as well. These are 3 variations of the vintage Genalex KT88, not re-issues. While the I preferred the GEC best, it leaned towards the euphonic side. Despite its imperfections, it made going back an impossibility. I decided to either use this pre with the GEC or not at all. I still have the GEC if anyone wants to try it.
That's very interesting Ethannnn. Would you care characterizing in some detail the sonic results of the various tubes you tried on Ref 3? Thanks, G.
My recollection were all Genalexes had truer midranges. The Gold Lion was most detailed and dynamic, the Gold Monarch was most neutral, and the GEC was most full bodied. The GEC had the most impact while the other two were more subtle. In my system, the midrange magic of the GEC outweighed its shortcomings.
I know Ethannn and find him to be an honest audiophile. He has been to my house several years back and is an ardent tube roller. What he says about the mid range is exactly what I found and for those who love mid range any and all KT88's instead of the 6550 is the way to go BUT at the expense of deep bass. So pick your poison. How come Posbwp555 was unable to answer my question with all of his $20K in stockpiled NOS tubes.
First listening tests with NOS Tung Sol 6550 Black Plate on board are very encouraging. After 10h of break in, I'm confident to say that my system never sounded better in the following areas:

1. Purity of tone
2. Resolution
3. HF extension and air
4. HF clarity and purity
5. Soundstage depth and image bloom
6. Musiacal Flow

Supprisingly, changes are rather dramatic and similar in character to an interconnect or a speaker cable change - unlike substituting 6H30 tubes with their DR alternatives, which brought only minor improvements (so far, I have only tried DR tubes in my Ref 110 power amp, but my guess is that the effect will be similar in Ref 3).

This is the best $400 I have spent on my system in a long time. I cannot recommend this change highly enough. If you really haven't heard the Ref 3 with a NOS 6550 tube on board - then you haven't heard what Ref 3 can do.
Thanks to Elberoth and Ethannnn for validating what any experienced tube roller figuered out a long time ago. PS tubes have a huge influence on the sound and the best NOS beats the best current production in a big way. I guess Guido and obgyn are better talkers than listeners. I stated and restated on this thread my limited experience with this preamp. The friend that sold his did bring it by for one day and I did hear it in my system. It is not a good value in my estimation as my $1200 Ming DA beat it in most parameters. From its sonic signature I am fairly certain that the NOS Tung Sols would be a huge improvemnt.
I can't speak to the GEC (never heard it). Ethannnn you should take Elberoth up on his offer to audition the TS.
If you are falling short in the bass with the GEC, the TS should remedy this without any loss of midrange magic. I don't have time to argue with obgyn or guido any longer and it is obviouis to me I will not learn much from them (that is the reason I visit these forums). Don't take my lack of response to your inane attacks as evidence of anything other than I don't have time to waste on it.

"inane attacks"

Huh? did I? Guido not a listener? Truly? [now scratching head furiously] and how else would I evaluate equipment. . . by looking at it mayhaps? ]chuckles]
I am interested as well (rightly or wrongly) how so much magic happened to Elberoth's Ref3 after only 10 hours of tube burn in. Psychoacoustics or real??
I've been following this thread hoping to learn from the "experimental" owners of the Ref3 and their findings on various tubes here. Thank you Ethannnn and Elberoth2 for sharing the details of your findings. I hope to soon borrow a Ref3, perhaps first an LS26, to put it through a shootout with the Aria WV.

I am interested as well (rightly or wrongly) how so much magic happened to Elberoth's Ref3 after only 10 hours of tube burn in. Psychoacoustics or real??
I'm not surprised at all. The burn-in time for the "new" tube may have nothing to do with Elberoth's result at all. Rather it could easily have been the poor sonic performance of the tube it replaced.

I have experienced many times where a new tube easily outperformed what I had been using up to that time; the old tube never made it back. Whatever smoothness was achieved later on with the new tube was simply an added bonus. There's too much focus that burn-in is necessary to validate a product whose performance is stellar from the start.

Again, ARC is not putting in tubes that have the magical properties that many of us seek and discover through tube-rolling trials. ARC, CAT, Lamm, Aria, etc., are putting in tubes that are readily available and perform well on the electrical-measurements test bench. Such tubes are typically the starting point rather than the final choice. If one wants to get more out of their product, they need to put forth the effort like Ethannnn and Elberoth2 have done with their Ref3.

This recurring theme that the designers of a product are the only ones qualified to choose what tube works best for the product's owner is silly. The designer may have vast knowledge based on listening tests. But so do many owners of their products. And perhaps the designer has found a pair or two of coveted tubes that are used in their personal systems. But as a manufacture such an option is not viable in the shipped product for a number of reasons.

I commend Michael Elliot, the designer of Aria of Counterpoint products, for being candid to his customers that the tubes (mainly EH and Sovtek) that he ships with his products are fine as a starting point, but with very little effort, the customer can take his products to far greater levels of performance. He stays clear of recommending specific brands as his preferences are likely to be very different than those of a customer. But he does share the many different tube types for the customer to try. And he provides a forum for his customers to share what they have found. I would expect such knowledge and support from a dealer as well. But I think far too many are also under the impression that the only the manufacturer knows best on what tube(s) should be used.

Anyway, thanks again Ethannnn and Elberoth2 for going for it.
This tube-rolling looks exciting.

Guido, could you direct me to a tube to "improve" my Rowland Continuum 500? I'm looking for, you know, some magic. ;-)

Use all your senses this time and give me a really good recommendation.

Hello again Guido- It's gratifying to see you validated my original post in so very short a time. KUDOS and happy listening!!
Thank you Rodman. As you know, I can only report what my ears tell me. And I try to report my observations in as descriptive manner as possible, so that other Audiogoners can draw their conclusions, based on my observations, not so much on my 'judgement'. And their conclusions are happily often opposite from myine. Terms better/worse are unfortunately not terribly useful in this business, being purely value judgements based on personal and too often unstated parameters. The only thing I can say at this point is that, between the factory supplied Winged C 6550 and the new production Tungsol 6550, I do prefer the Winged version for the musical reasons described in some details a few months ago. As for any other 6550 or KT88 version, I do not usually comment on devices I have no experience with. If some NOS 6550s or compatible serendipitously found their way into my system, I will report my observations accordingly.