Best KT88s (specifically for VAC Auricle Musiblocs)


I'm using a KT88 based amp for the first time - the VAC Auricle Musicblocs. I just had them serviced but one of the cheap Svetlanas blew, probably from my biasing it too high, and its been replaced by a used Genalex Gold Lion for the moment. The amps sound very good as it is, but I'd like to get the best out of them with a good matched Quad of something decent.

Ideally I would like a little more mid-range luxury and presence without sacrificing too much bass control. However lower bass is not so much of an issue because my speakers have powered subs with an active crossover (Vaughan Cabernet One).

I'm in the UK, and valve selection here is a bit limited. Nobody seems to have Svetlana Winged Cs anymore, and I've read reports of dubious quality in the later batches. Genelex Gold Lion are easy to get from good dealers who can match and measure, so that is the obvious choice. But would I be better of with some Chinese valves such as the Shuguang KT88-98? Are they going to be a bit warmer in sound to the Genelex?

I've read great reports about the Psvane KT88 T2 but they are very expensive. Also the Shuguang Treasures. The riskiest option is to buy these from Mable Audio in China, who have them up for a good price:

http://www.mableaudio.com/en/

From what I have read Kevin Hayes supplied the Auricles with the Shuguang KT88-98. These are very affordable, but I suspect that Kevin only supplies selected ones. 

I could also buy from the US, and I'd appreciate any recommendations for the best source.


andreweast
I don't have your amp, but IMHO you are better off with the Gold Lions than the base Shuguang tubes, and the Black Treasures are far better than the base Shuguang. To my ears teh Black Treasures are worth the money., and in my experience found them to have more body than the Gold Lions, but that just may be my ears and my amp (Ayon Spirit 2). 
You are in UK and saying that there are any good KT88 tubes? How about UK made NOS GEC KT88? If you like to buy best out there, dont look further. I have tried those Chinese made, so called great, tubes and nothing come close. I dont have your amp either and sold my KT88 a while back, but I would save some cash and forget the rest, but thats me.
I should have said 'for reasonable money'. The prices for NOS GEC KT88 are absolutely crazy now, if you can find them! So they're out of the question.

Black Treasures are appealing, but some things I've read suggest that the Psvane KT88 T2 will be more tight and controlled than the BT as well as having more body than the Gold Lions. However I can only think of one internet post that has compared them in detail so there's not much to go on.

Yes, these are not cheap, agree, but if you look, you may find them for a good price, check vintage radio shops in UK and you may be surprised, or, here is the link for the seller I bought some tubes in the past, ask for the price, if you like

cant post the link, but you can make it from vacuumtubes com
I have a VAC 160iSE integrated amp, and I'm using the Psvane KT88's. 
They are the best I've heard, but that only includes stock and the reissue Genelex Gold Lions.

The differences were not huge, in fact you may even hear a bigger difference by changing out the 12AU7 driver tubes.
Thanks, so did you find the Psvane only marginally better than the Gold Lions? There seem to be several varieties of Psvane now, including the cheaper KT88 UK, which are meant to have a slightly warmer 'classic British' sound. They are also less expensive. The KT88 T2 are the priciest, more expensive than Shuguang Treasures. 

maxmad, thanks for that link. They don't seem to have much in at the moment, but I'll keep a look out.
I suggest jumping over the 88s to KT120s or better yet KT150s. Based on the research done by the GTITCSS (Garcia Transformer Issues from Tube Change Scientific Study) this tube swap would be unlikely to kill your amp, but if it does please let me know so I can add the incident to my study. It would be the first such incident reported anywhere I’ve seen, but then I don’t get out much.
I think a more concise acronym would be GITS (Garcia Issues from Tubes Study). I'd be happy to take part in the experiment, but only if I get a confirmation from Kevin Hayes that it is safe to use the new uber-tubes in the Auricles. I've fired off an email.

I don't need anything like the enormous power of KT150s with my 93dB speakers and small room, but KT90s might be a good choice. A friend of mine uses the EH KT90s in his VTL 150 and that sounds great. 
I tried 50 yrs Ann BT 300B ones in my Cary CAD 300B SEI and nothing good I can say about these tubes, not by their look, how they feel, their build and especially their sound. Sure, tubes do sound differ in differ amps and maybe it was simply mismatch, but same was with Sophia, so called Mesh and Royals, which were much better, but for the money they selling them, no way. To make a good KT88 is not that simple plus material they use, lowest quality you can find. Like Dr. R. Kron said onse, we make 500 tubes a month and in China they make that in 1 hour, so, go figure.
ure.
I'm pretty sure that Kevin will nix the idea of KT-120's and KT-150's.
His amps are pretty selective with only KT-88's as far as I know. VAC doesn't even recommend trying any 6550's.

Yes, I am using the Psvane KT-88 TII's, and I only slightly prefer them over the Gold Lions. Just a tad more relaxed sounding.
I found bigger differences changing preamp and driver tubes.
Kevin has just told me that the Gold Lions might be the best idea to get what I'm looking for, and that is certainly the easiest option for me.

I take your point that the input valves are likely to make more difference, but I can't get much warmer than my Mullard CV4003. Pre-amp valves I can work on.

I suspect the change I'm looking for may not come with small things like valve changes, I've just switched speakers from my Vaughn Cabernet 1 to my Harbeth SHL5Plus. There's certainly no lack of warmth with the Harbeths, as you'd expect. It might be that I will need a differnet power amp to get a warmer and more intimate sound with the Vaughns, but then I'd risk losing the amazing dynamics. Always a tricky balancing act. 


If you're looking for more warmth try an amp that uses EL34's and get a set of Gold Lion KT-77's. It's a great sounding tube that was far better than PSvane, not the regular EL34 I tried a pricey vintage PSvane Philips reproduction tube, great packaging but they sounded bright compared to the GL KT-77s. I don't have a specific amp to recommend, mine is a custom Deja Vu Audio amp, but there are tons of good EL-34 amps on the market. Happy listening!
This doesn't really answer your question regarding best KT 88, but I thought you may find some interest in it. I too am considering replacement of power tubes in both my Ars Sonus Filarmonia, and Primaluna P5.
I have been researching Psvane EL34, and KT 120 (including Black treasures)
I have a spare set of JJ E34L quad for my Filarmonia that I substituted for the Gold Lion KT88 in My Primaluna 5.
A truly unbelievable improvement. It is the most difference / improvement I have ever experienced in a power tube and I have tried a number Including the GL KT 77 and NOS GE 6550. I am pretty surprised how well this $14.00 US dollar sounds. You may give it a try. There available at The Tube Depot in quads and for a couple bucks a piece you can get them burned-in. Just want to clarify that these are the E34L's and not the EL34's. Also came across a couple of vendors selling NOS Siemens EL34 https://www.tubedepot.com/products/rft-made-siemens-el34
http://www.tubeaudiostore.com/elpremgrad.html.
http://www.nosvacuumtubes.net/product-category/power-tubes/power-tubes-6550/
The above 3 links/stores have several type of NOS power tubes, including NOS Mullard EL34 (expensive) and Amperex EL34, and others
You may find the new production Telefunkene Black Diamond EL34 tubes of interest. In addition to EL34's they are also producing 6550's and KT88's.
With the exception of the JJ E34L tube, I can't help you regarding the sound of the above referenced NOS tubes, that's something I am trying to gather info on.
Any one reading this, who has tried any of the above NOS tubes or the new production Telefunkene Black Diamond tubes your input would be helpful. 
If you’re considering KT90’s look for the Ei KT90 Type II. They don’t come up often but when they do they are a bargain IMO. Tough as nails with mids similar to El34’s but with more sparkly highs and tighter lows. I found the sound stage improved by getting wider.

As far as KT88’s I have the winged ’C’ SED KT88’s and they have a lot more bass than either the Ei KT 90 or Gold Lion (Russian reissue) KT88’s (which I also have). The original Gec KT88’s are very linear sounding. Extremely good and almost as good as the EAT KT88’s. But those come with a hefty window sticker.

That said I had an Octave V70se and later a V110. A lot will depend on the topology of your amp. More important IMO is the speakers. If you’re looking for a warmer sound the SED or GL KT88 is the ticket. If you’re looking for more detail and linear the Gec or EAT KT88 is the direction you want to go. Never tried any of the Svetlana or Shuguang tubes. Personally I hated the KT120's. To me they never sounded coherent like any of the tubes I have.
Ah, so you are not looking for different KT88's, you are looking for a different amplifier.
In this hobby, there are many different tastes. Obviously you have a sweet tooth. Nothing wrong with that. You are right, you won't get much sweeter sound from a VAC than using the Mullard CV4003 driver tubes. VAC is not really a tube amp designed to sound sweet. They have a bit more air and refinement than the ARC house sound, but overall VAC is still on the high resolution side of the fence in the tube world.

If you are looking for old fashioned sweetness in a tube amp, you would probably be happier using one designed with EL34 tubes as jond suggests, or an amp from conrad johnson or Cary.
KT150s won't increase the power of your amp substantially unless it's designed for more power. My modest (I keep saying that to remind people how thrifty I am) 6550/KT88 specified Jolida 502p simply "sounds" better with 120s (which sounded splendid during 3 years or so of heavy use) and even better than that with 150s, and neither of these tubes has caused transformer overload or anything other than tighter, more concise full range tone (I have 6550s and KT88s in my reserve tube stash so I've compared these things).  Don't fear the 150…it's shaped like a pickle...
I take the point that I might be better off with an EL34 based amplifier. I could go much lower power than that. I've got a 2A3 based integrated which powers the Vaughans well. If there is a tube I have a natural liking for its the EL84, but I don't think 4 would be enough, so I'd have to go for an amp that used 4 per side and that is getting more pricey with tubes. 

I actually realised that what I'm missing is not mid-range warmth, it's mid-bass. I switched in my Croft amp for the VACs and whilst it doesn't  have the same level of vivid clarity in the mid-range and exceptional resolution as the VACs, it has an all round warmth and ease.

 It was clear that what I'm missing with the KT88 based amp is the mid-bass. The question is whether this is the amp, the KT88s I have, or whether it's the nature of KT88's to lack some warmth in that area in comparison to EL34s.

A friend of mine is in Japan at the moment and could pick me up some Shuguang KT88s for the same price as importing from China. I just don't know if it will quite bring the change I'm looking for. 
In my opinion, KT88 is much better tube than EL34 and I simply dont understand why people buy USD 5000-10000 amps and put shity tubes in it, all beyond me. From many things I learn in this hobby there is one simple, bigger bottle>bigger sound, I compared KT88 to EL34 and 6550 and they eat both tubes for breakfast and I had most wanted Philips EL34, NOS Tesla EL34 and Tung Sols 6550 smoth plates and GEC KT88 won just like that. For me, stepping from KT88 to EL34 is stepping down, only to 300B would be my choice and thats what I did, but thats another story.
maxmad, did you compare in the same amp? And what kind of speaker efficiency? 

Surely it will all be relative; with 86dB speakers you are going to want a KT88 based amp if you are using valves; with 106dB horns you are going to want 300B. And with my 93dB speakers ... well, I'm in between all these possibilities. 

A friend brought round his Unison Research S2K a couple of weeks ago. A budget SET amp but a very nice design. He had a pair of 6550s in and the sound was extremely immersive, a great sense of space filed with micro-detail. It had a wonderful way of getting the inner detail of a saxophone (the close focus on Coltrane's vibrato was new to me). But central voices tended to be lost a little behind the whole soundscape. Then we switched in a couple of my KT88s. Suddenly the voices were central and clear, but all that lovely spatial immersion and the inner detail was lost. I don't know if that is a comment on my particular KT88s, or how that amp works. It was supposedly designed for KT88s, but we were clearly missing something when we took out the 6550s.
I tried the Gold Lion KT-88s in my 300.1a and did not like them at all--very detailed but too mechanical and hard. The Shugang KT-88SC are much better to my ears, with more bloom and texture along with plenty of detail. But VAC can no longer source them, so they've shifted to the GL. 

Fortunately, after a long search, I found KT-88SC at The Tube Store, labeled as their "Preferred Series."  After six months of steady use, thet have proven far more reliable than the ones VAC was selling toward the end of their supply (I had 4 tubes out of 8 new ones from VAC blow within 6months of light use). Much less expensive than the VAC SC, too.

I like these tubes so much I bought six matched quads. Meanwhile, the GLs (2 matched quads from Jim McShane) sit in a drawer with all of 50 hours on them, unlikely ever to be used. Of course, YMMV.
wrm57; thanks for that very useful information. I'll see if my friend can pick up some of the Preferrred Series. He just told me that this shop in Kyoto has Shuguang. It's apparently a very messy little shop full of tubes, with a couple of shabbily dressed guys. Sounds dodgy, but charming! I suspect they will be the cheaper KT88-98 though. Have you tried those?

My amp was Prima Luna Prologue Two, which is KT88, but can use EL34, 6550 and I believe some more of KT series, but I havent tried any than above. Dont get me wrong, I liked EL34 and if you deside to switch, try NOS Tesla.

Also, I tried Unison Research S2 ones and it was clear not my thing, however, they guy who sold me Tannoys advised to check S8 model, but I havent try it yet.  

I drive my Tannoy’s D700 by Cary 300B ( classic chrome body with 11 w p.ch. or something ) and the match is very good, they are 93dB, think that mono’s will be better, but it is good for now. I also tried Zanden 7000 300B ones, which is 8 w p.ch. only, and the sound was superb, as it is all about transformers.

I wish I had the money to get Tom Evans pre and power amps, maybe one day.

I'd love to try 300B with the Vaughans. I'm sure you're right that its the big trannies that matter, but it seems that is what you pay for. 

The Unison Research S2 had no bass control, so that was out of the question. But I tend to like the UR sound (I used the Unico Pre/DM for years) so I would like to hear one of their higher models.


Shuguang kt-88 
I have tried regular and Cryo ed. For $180 for a quad Cryo ed  are clearly more detailed and refined then thd standard tubes Which are very good these have 36 hours tested in the factory plus several hours after 48 hr Cryo treatment.
From a 5 man blind test after a 30 minute warm up treated and untreated 
The Cryo ed tubes are clearly better,and on average last longer.
Great qc vs the Russian tubes since 1858 Shuguang has been making tubes.
Tubeman.com is very good and if close match they do quad or whatever .
You are most welcome, andreweast. No, I have never tried the 88-98.
I have some breaking news, which is that the Auricles should be ok with KT120s. Very tempted to give them a go.

As I predicted, and I bet KT150s would be OK also, although maybe you shouldn't ask about those as they might say, "leave us alone dammnit." This data will be added to my extremely important and thorough scientific study of weak and silly transformer issues with valvage (valvi?).
I have a pair of the same VAC Auricle Musicblocs that have been in my system since 2007. I have enjoyed the Shuguang Kt88-98 and Kt88sc the most. I recently put in a set of Psvane 12au7-TII driver tubes and was amazed at the improvement. I tried a set of the Shuguang Kt88 Treasures a few years ago and didn't care for the sound that well. The standard Shuguangs sound more natural to my ears. I might try a couple matched pairs of Psvane Kt88-T series once my regular Shuguangs run out of steam, but I just put in a new quad and have a new spare quad for back-up so that might be a few years off. I have also experimented with different power cords for my VAC amps and found the Fusion Enchanters to be the best matched. I previously had the Fusion Predators on them and they are a very good choice if you're on a tighter budget.
  If I ever decide to sell my amps and upgrade, it would probably be for a used pair of Vac Phi 160 Musicblocs or one of the newer Phi amps. I really like the Vac sound when it comes to amplification.
That's interesting Sherod, thanks. Do you have a VAC pre-amp also. The only reservation I have about the Auricles is that they are extremly insensitive at 1.5V and need lots of gain. I suspect they are made for pre-amps with gain of 20dB or more. Even with my ARC LS26 I don't feel I've got that much headroom. However I don't need high volumes so it's not really an issue. 

So, I bought some KT120. It's almost like I've got a completely different amp to when I was using the Svetlana KT88s (although admittedly they were not a matched quad, one of them had blown, and I'd replaced it with an aged Genelex).

The KT120 have a much warmer sound. So much so that I've switched back from Mullard to Philips driver tubes. Previously I thought these amps might be too lean and clinical for me, but now it's almost gone the other way. Very good, but I still wonder if there might be an option somewhere in the middle.

I do have an option on some discounted Shuguangs, which are apparently selected examples that a dealer has had since the 90s. Tempting to compare them, but I've just spent money on the KT120s, so I'll see if the sound opens up any more first.
Andrew,

   I have never listened to a VAC preamp, however, my Audio Horizons preamp has plenty of gain to drive my 90 db speakers. I was buying from www.dougstubes.com my Penta SC tubes( specially selected tubes from Shuguang) which have the solid plates, but Penta apparently has raised their prices so Doug recently brought in the Ruby KT88V-STR, http://www.dougstubes.com/power-tubes/6550-kt88/ruby-kt88-v-str.html which are identical solid plates with top and side getters made by Shuguang. I haven't tried these yet but bought a quad for future use. The solid plate Shuguangs are very neutral and natural in tonal balance and timbre, neither too warm nor too cold, but tweaking the right combination of interconnects, speaker cables and power cords, helps to bring that all into focus. 


   Sherod


Tweaking is what I'm doing now. And I have to take back what I said about KT-120s since I switched to the 8 Ohm tap. Now they are neutral and dynamic rather than warm. I think the previous tubes I was using sounded too harsh and forward on the 8Ohm so I was forced to use the 4 Ohm tap. My speakers hardly drop below 8 Ohm so I guess this was overworking the amps. 

I actually want a bit of warmth back now! Oh for a 6 Ohm tap. I'll try chanigng back to Mullard driver tubes. 
I used a lot of different kt88 in my VAC integrated and found gold lion reissues to be best.