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

I think my comments on the 6550 tube replacement for the Ref 3 would be relevant to my failed experiment with this in my Ref 6.  I tried the Tung Sol NOS grey plate that was recommended by Andy at Vintage Tubes.  He assured me that it had a great mid-range.  He was dead wrong.  This tube was dynamic, tight, deep bass and extended highs--but the mid-range was utter crap--not musical at all.  I went back to the original Sovtek and this has a rich, sweet mid-range.  The expensive Tung Sol gives you listening fatigue in a very short time.  Stick with the original tubes used by ARC.

I have an ARC Ref 3 and also a Ref 6, which is the one I use in my main system. I recently bought a NOS Tung-sol grey plate and tried it my Ref 6. (I presume the comparison would be the same in the Ref 3, although I did not try it in this unit.) The original Sovtek had a nice coherent quality—a sweet, rich midrange with an all around natural quality. The NOS Tung-sol had a deeper, tighter bass, more extended highs and was more dynamic. However, the midrange was utter crap—bright and edgy. The original Sovtek was so much better, so I would agree with the people who advise to stay with the original 6550 used. One person mentioned that tubes are biased differently and that may be the reason why some tubes work better in some systems than others; I am not really tech savvy, so I can only wonder if this is the case here. I got this NOS Tung-sol from Andy of Vintage Tubes who assured me that the midrange was outstanding in this tube. Giving him the benefit of the doubt, I wonder if he was referring to how it works in equipment other than the ARC Ref 6. (He probably never heard it used in the Ref 6 and never mentined a caveat on how it might not be compatible with my preamp.) Another person mentioned that the Tung-sols need 200 hours break in time. That sounds excessive; I did a break in for 50 hours and there was some improvement, but not really that significant. Anyway, from someone who has done the comparison of the original Sovtek 6550 and the much more expensive Tung-sol, I would advise to leave well enough alone and stick with the original.

Most interesting Ptcl99 , my regards for your spirit in pursuing your experimentation, especially with your utilization of non NOS valves.

Forgot to come back with comments. But I'm back.

Ok, I swapped the ARC 6550 WE tube into my PH-8 and pulled the Tung Sol 6550. Maybe the 6550 isn't as critical in the PH-8 because I am not hearing a world of difference.

I have 3 ARC components that use the 6550 as a regulator tube in the power supply. Hopefully, Kevin will source a more reliable batch of SED Winged Cs when I am ready for a retube.

@Guido -- 500 hours seems kind of a long time for break-in. Can't say that I have had such an experience.

@Elberoth -- gotta say I am a believer about ARC sourced KT-120s. Maybe it's just bad luck, but for some reason, some of Kevin's KT-120s just don't bias as closely in my Ref 150 as those sourced from ARC. Can't say why.

In Ref 3, the SED Winged C 6550 from ARC takes almost 500 hours to break in fully... Sonic evolution is very significant during this period. What I herd from a brand new tube was not indicative of its capabilities post break-in. G.

My ARC Ref 3 approached 2000 hours. I obtained a 6550 tube from ARC. Upon replacement, it was alarming to find that the Sovtek 6550 WE could not produce the ambience of the original SED Winged C 6550. The soundstage shrank notably and the new tube sounded sterile. I reckoned that burn in was unlikely to change the character much and removed the Sovtek and put the SED back. I ordered a Winged C 6550 from Kevin Deal. He was credible and advised that his batch was suitable for Primaluna, not the more demanding ARC. I decided not to chance it even for a regulator. Not satisfied with the remaining options of the allegedly unreliable JJ 6550 and the pricy and sonically unproven Black Sable SED 6550, I turned to Vintage Tube Service to try an NOS Tungsol 6550 but found it unavailable.

I noted a buzz in various forums about the nice qualities of Shuguang's black Treasure KT88Z and in particular the improved Psvane gray KT88T Mk II. I spoke with Kalvin Dahl of ARC concerning rolling tubes. He was most supportive and believed that KT 88 could be a substitute but the warmer sound might differ from the original Winged C and the larger size would be a tight fit. I ordered the gray Psvane KT88T from an eBay seller ListeningChina recommended by Michael Samra on Tube Asylum. The tubes in a thorough package arrived in about a week. I have been listening to the new tube since last evening. Even brand new, the quiet Psvane KT88 clearly produced a tightly woven, wider stage and more layered depth plane along with exquisite high frequencies and bigger, rounder bass. I go through familiar disks successively to confirm the qualities and am continuously impressed with the rich tones. Instruments and voices have more bodies and string tones are lovely. This tube is about as extended at both ends as the Winged C and surpasses it in musicality. The trade off might be that the Winged C has more dryer low end impact. Unlike the Sovtek which I impatiently removed in 4 hours, the Psvane sounds both more powerful and delicate than the Winged C. I realize that the Winged C will not go back in any more. I have done some tweaks lately including a decent power conditioner, Stillpoint and Townshend footers, this single Psvane tube surprisingly produced the most pleasing improvement. The result is musical aside from hifi qualities. I have been tentatively in the market for a replacement of the Ref 3 with 5 SE. My previous audition of the 5SE did not impress me as much as this tube change. I am sharing the experience with those who are also dissatisfied with the current choices of the Ref 3/5 regulator. I was nervous as ARC was adamant before about not rolling with a KT88. I am happy to report the recent ARC change and my encouraging findings.

Now there are some shortcomings. This particular KT88 is wider and longer. The length requires slight bending of a small capacitor behind the display such that it does not touch the tube. Ref 5 owners with a horizontal board may not have the same issue. Further, one of the matched pair arrived with the getter flash largely vanishing and turning milky. ListeningChina communicated promptly and sent out a matched replacement today. So the Psvane QC may not be as solid as the Russian crowd yet. Given the remarkable sound quality, I will not hesitate to continue using Psvane tubes especially if I can monitor the conditions with a tester.

I'm affraid you are getting what you have paid for.

I've bought quite a few cryo'ed Sovtek 6H30pi tubes from Kevin. They work just fine. This is the first time I heard about issues with the SED "Winged C" 6550s and I've bought quite a few from Kevin over the years. So I wouldn't worry.

I seem to recall that Kevin told me some time ago that he sourced a bunch of the "original" issue SED "Winged C" 6550s in Europe or Transylvania or someplace like that. As you probably know, the old Svetlana (sp?) plant burned down. So no more "original" "Winged C" 6550s anymore.

Here's my issue. My ARC Ref 150 amp eats KT-120 tubes every 2000 hours. ARC charges $100 per tube. Ouch! Kevin and most other vendors charge half that amount. As you know, Kevin does a heck of a job burning in and testing his tubes. And so does ARC.

My dilemna is the matching process. ARC matched power tubes have always been an easy drop in. They bias easily and chnage bias evenly. By contrast, Kevin's match KT-120s are not as consistent. Some pairs match pretty closely and other pairs not so closely. I don't know why. So I may have to go back to ARC.

Cheers.

Let's hope Kevin's current batch isn't the one I've been sampling over the past 2 years. I've bought at least 10 pairs from Upscale! There aren't a lot of reasonably priced and trustworthy sources for these.

Also liked the stock ARC Sovteks better than the NOS Reflektor 6H30-DRs in the power supply.

Barry, I ordered a SED "Winged C" 6550 from Upscale Audio. Kevin Deal called me after the order was placed suggesting I pick another tube because he wasn't satisfied his current batch of "Winged C" 6550s were reliable. Ergo, the Tung Sol 6550.

I expect to receive the ARC 6550 WE in a day or so. I'll swap it in and report back. In the meantime, I'm using the TS 6550. It works ok.

I like the Sed 6550 Winged Cs better than the WEs in my Ref Anniversary.

This OP kinda spooked me about the Tung Sol 6550, so I ordered a 6550 WE from ARC. I should get it in a couple of days. In the meantime, I'm using the TS 6550. I'll swap the TS out for the WE when the WE comes in. I'll report back with reactions.

Ironic and timely that this thread has been resurrected. I am planning to replace the ARC supplied 6550 WE tube in my PH-8 phono pre. The 6550 WE has 2000 on it and its time. Not having read this thread, I went ahead and bought a "modern" Tung Sol 6550.

I realize this thread is about the Ref 3. As stated, I will be rolling the PH-8 PS tube. I'll report back with my reactions. Just thinking out loud -- I wonder if the 6550 PS tube in the PH-8 phono pre makes as much difference as tube rolling in the Ref 3.

Btw, I used to own the Ref 3 and have since swapped it for the Ref 5 and then the Ref 5 SE. I mention this because I think the Ref 3 was and is a **great** linestage. IMO, while somewhat different sounding than the Ref 5 (not SE), both are (were) great linestages. I think the SE upgrade does take the Ref 5 to another level, but I gotta tell ya -- the Ref 3 is a classic.

I thought that I would resurrect this topic perhaps with a little more pertinence to the later Ref 5SE and in particular with regard to comment made by Ethannn back in 08

" 07-13-08: Ethannnn
I would recommend the (blue label) GEC KT88 for this pre."

I would appreciate any further actual user expearience with regard to substituting 6550 with a KT88 in this circuit, given that they are very close in specification.

I did make inquiries with ARC only to received the standard

" We do not recommend , you will comply "

response .

I fully appreciate that there would be no economic incentive for this consideration by ARC , however that is not quite the same as ~

" Whilst we would not warranty support or be liable in instance of this substitution please find attached our considered opinion on a technical/circuit basis alone "

Hi Elberoth,

You were spot on. Problem was related with the combination of ARC socket and pins of 1957 6550. Issue is now solved.

Cheers Broederen.

I have been using the NOS 6550 TungSol Black Plate without any single issue for the past 6 months or so, and so do my two friends.

My guess is that the problem is not 6550 related.

ARC says you easily get 5000 + hours before retubing is necessary

Just to add that my ARC Ref3 time counter shows 3674 hours and today I tested the original 6550 tube : transconductance was 5200 micromhos - this means the tube is still perfect!

Dear all,

After one day (no power on) the unit is now functioning normal again with the original swetlana 6550C. Anyone any thoughts?

Cheers,

Broederen

Probably the 6L6GC aged prematurely. It is worth pointing out that any deviation from the ARC supplied SED Winged 6650C may potentially be an "interesting experiments" yielding unpredictable results. . . and any problems it yields may void the factory warranty. G.

I have to replace all 250 hours the 6L6GC in my powersupply. The sound becomes liveless. What's wrong?

Try replacing also the 6h30 in the power supply - perhaps a failure in the Tung-sol 6550 has damaged also the driver tube.

Dear all,

I encountered an issue. After replacing the Svetlana with a Tung-sol 6550 Black Plate I experienced sometimes a moment without sound. After some time the sound came back (black-out?). Now my REF3 is dead. I replaced the Tung-sol with the original Svetlana and still no music! I checked everything including connections etc. What can have happened?

hello forum members ,my local dealer supplied me a Tung-sol NOS 6L6WGB to try in my REF 3 , now the tube is 120 hrs in the amp .I like this upgrade . some month ago I also changed the other tubes to 6H30P-DR . This alltogether
made my REF 3 in my opinion a more musical machine .later on I will tell you the major upgrade my local dealer did in the REF 3 .This upgrade takes some more breakin time.
greetings from Holland Hans

Thanks Guidocorona

I have replaced the Svetlana 6550 with a 1957 Tung Sol. I'm surprised by the difference in sound. I'm not so good in describing but its seems tighter bass, increased resolution and more "punch". And the system is now playing only for a couple of hours.......................

I can imagine that for a company like ARC it is not possible to put these type of 6550's in simply because of costs and even more constraining: availability!

Cheers,

Broederen

Broederen, if the tubes are 6550 types, one of them can probably be inserted in the single 6550-compatible socket in the power supply of the Ref 3. As Tung Sols seem to be fatter than SEDs, make sure that the lower portion of the glass does not touch the 6H30 tube beneath it. G.

Hi Guidocorona,

The details of the Tungs are as follows:

Pair of 1957 Tung-Sol 6550 tubes. The tubes were " MADE IN U.S.A." by Tung-Sol and the matching production code is 3225711-3 . The construction is superb with smooth black plates, triple top mount rectangular getters, copper grid posts (killer) and tight metal bases with strong guide shafts. They were tested for gas, leakage and merit on my Eico 667 tester where the 60-80 range is somewhat acceptable. The tubes tested 136 and 136, very strong on the life test and matched.

Cheers,

Broederen

It all depends what Tung Sols Black Plate 1957tubes you purchased.

Dear all,

I became curious. I acquired 2 NOS Tung Sols Black Plate 1957. Can I exchange without any other "thing to take care off"?
Keep you posted.

Cheers,

Broederen

The short answer is. . . there isn't such a tube, nor there is such a linestage, nor there is such a system that will sound "just like a live symphony orchestra."
Your system can sound phenomenally fantastic. . . and yet it will sound always different from what your own ears heard at that particular live orchestra event. Welcome to the hyperreality of high end audio! G.

I've read every post in this thread with interest.

I have the Ref 3 in my audio system that replaced my SP-14. The system also includes a ARC CD-7 and a PH-7 phono stage. The addition of the Ref-3 brought my system to the best its ever sounded. I mean ... its great!

Now then, about a month ago, I, and a friend, went to a live symphony and sat in the third row center. My question is this: What tubes can I use in my Ref-3 that will make my system sound like THAT!? ~lol~

OP.

Marco
beautiful looking room

As anticipated here you can find my system to better understand my findings:
http://forum.audiogon.com/cgi-bin/fr.pl?vopin&1220291925&view

Thank you Marco, please keep us posted on Black Sable. . . I wish there were a 6550 variant that would outdo the SED 6550C with greater top to bottom extension, tighter bass control, and greater harmonic development. . . . as you may notice, I am not necessarily seeking 'warmth'.

Marco_esposito - your findings seem to confirm what Guido has written before - the current production TungSol 6550 (so called "reissue") does not bring a net benefit compared to SED 6550C.

When I was talking about the improvment I got by inserting a TungSol 6550, I meant the NOS (New Old Stock) TungSol 6550 Black Plate from the early 50s - which is a totally different tube to the one you have tried.

I cannot recomment it (NOS TungSol Black Plate) highly enough.

Being involved in this hobby for well over 35 years has always shown me that when something is changed I always ask "did I hear something different or did I hear something better"

Perhaps the chaanges in your system is what minimized fatigue as you were hearing something different, not neecessarily better. Nonetheless hearing from you about your conclusions will be informative

You are probably right Oneobgyn. Probably however we are talking about a different philosophy of "the zen of listening to music". From my experience infact, everytime I change something in my system (BTW Soon I will pubblish it to give more clarity about my listening experience), I'm prepared to maximize the benefit (If I sense there is a potential for improvement) by tweaking here and there. Sometimes even changing the Cartridge weight of 0,1 Gram forces me to change something in the system. So for me it is not strange that changing tubes I have to change something to get a new set-up. In this case I'm not saying I obtained miracles; I'm just sharing my experience and adding to the thread (And this is in accordance to Guido conclusions) that the 2 solutions give a different Sound...and that I like what I have with the new set-up because I can hear for many hours without feeling tired. On the other side I understand also that the better definition of Original 6550C is beneficial for easier interpretation of words of singers and or to catch the notes while listening to instruments. This is probably why Guido being a professional musician (I'm jealous!) is looking for the max detail and myself as a concert listener I'm looking for the closest "Concert like" experience....And I believe the current set-up is closer to the timbre I hear in Jazz concerts for a piano or classical orchestra being in the 15th row. Just to correct one sentence in your post, The bass with TS is more in quantity and extension. It is the tightness that I was mentioning as not as good as before. I look forward to getting more on the subject

Yes Guido it is a current Tungsol. I had to buy a matched pair. I'm very intrigued by trying the Black sable as possible next experiment. Probably the result would be half way from the 2 sounds.

Marco

From your post it seems to me that you are hearing something different rather than something better. The loss of bass with your tube IMO is one of the reasons ARC goes with their provided 6550C and then for you to have to adjust speaker position suggests to me that whatever difference you heard was not related to the 6550 Tungsram but rather speaker realignment. It makes no sense to me that by changing a tube you have to change speaker position and the feet on the Ref3 for better listening pleasure. I might suggest to you to put the original 6550C back in, keep the speakers where you now have them and keep the tweak on the preamp feet and I would bet your bass is again back to where you like it and overall the sound is better. By inference therefore the speaker repositioning and tweak is what changed, nothing more.

Marco, what Tungsol variant are you using? New production or NOS? Guido

Up date on 6550 Tungsram after almost 100 hrs. I believe a conclusion is not easy to be made. As I posted on the other thread VTL 6.5 vs Ref. 3, the only negative on the ref.3 is that sometimes it is tiring for eccessive details. I finally would not go back to the original 6550C Winged. There is more sense of pace listening to music now. I had to tweak the speaker position a bit since the speakers can now be more apart witout loosing focus. The only doubt still remaining is on the bass that is not as tight as before. I gained in extension but missing some control. This will require probably a tweak on the Preamp foot. By the way, for Ref. 3 owners, I strongly suggest to try something different from the original foot. I found excellent results with Soundcare. Simply Do not expect to replace without some adjustment to accomodate/leverage the differences. If you need more detail go for the Original Winged C, If you need more wormth the tungsol is an excellent help.I will keep you posted on the evolution, but either way the preamp sounds glorious.

Well I cannot say that I have heard the latest Shunyata Anaconda Helix Alpha p/c with my ARC Ref 3, I have heard many cords, including the older series Anaconda Matrix Alpha and Vx, as well as the Nordost Valhalla (amongst many others). I still feel that my favorite, in my system, to my ears is the Stealth Preamp Dream, FWIW.

Cheers,
John

Now returning in earnest to the main topic [grins!]. . . The 6550C Black Sable will make for an interesting experiment with my Ref 3 the coming Fall, when my music loft becomes once again 'tube friendly'. If it sounds even more linear and extended than the standard tube, I may very well like it. Conversely, if it sounded warmer to me, I probably won't.

i didn't ask re PC's

Jmcgrogan2 did.

i didn't ask re PC's but FWIW I use Valhalla throughout my system...nonetheless I think we are now talking apples and oranges (tubes with PC's)

Jmcgrogan2 ->

ARC uses Shunyata Anaconda Helix Alpha PCs at their factory.

Oneobgyn ->

99% of manufacturers stick to current production tubes. So even though, SED 6550 that is used in all ARC gear may well be the best current production tube available, there is also a broad selection of NOS tubes (various TungSol, GE), which very often, are far superior.

BTW - for those who wish to stick with current production tubes - there is a more expensive version of SED 6550, called Black Sable. It is made by the same manufacturer, but is twice as expensive. I was always wondering, what difference it may make.

Not that I would disagree with you Oneobgyn, as I haven't experimented with my Ref 3 tubes either, and according to this thread I don't intend to. However, out of curiousity, whilst speaking with the ARC folks, did they happen to mention that the best power cord was also being used? Because I might have some disagreement there....

Cheers,
John

Thanks Marco.

My bet is that even at 100 hours or more you will still prefer the original 6550C.

I spoke to the people at ARC severalweeks ago about retubing having read the comments that this should be done sooner rather than later and the person with whom I talked said there is absolutely noreason to retube before 4000-5000 hours. I also asked about tube rolling. he suggested that this is OK but that in their opinion the very best 6550 tube is already being used.
I have been in that camp throughout this entire thread as has Guido.

Marco_esposito - what TungSol 6550 tube did you try ?

NOS Black Plate/Gray Plate from the 50s-60s or the new production TungSol "reissue" ?

I'm asking this question since those are two very different tubes.