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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 I just had them serviced but one of the cheap Svetlanas blew, probably from my biasing it too high, and its been replaced by a used Genalex Gold Lion for the moment.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
sherod
1,690 posts
 
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.
andreweast OP
30 posts
 
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.
sherod
1,690 posts
 
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


andreweast OP
30 posts
 
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. 
truemaineiac's avatar
truemaineiac
249 posts
 
I used a lot of different kt88 in my VAC integrated and found gold lion reissues to be best. 
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