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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 I just had them serviced but one of the cheap Svetlanas blew, probably from my biasing it too high, and its been replaced by a used Genalex Gold Lion for the moment.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
xti16
1,525 posts
 
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.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
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.
wolf_garcia
6,695 posts
 
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...
andreweast OP
30 posts
 
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. 
maxmad
182 posts
 
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.
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