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Audio Research 6550 vs KT88 and tube brands

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All ARC owners should really try replacing their 6550s with KT88's. Once you do, you'll never go back. The 6550 has a midrange grain that is unmistakable and frankly, annoying. ARC says they use them for best overall sound but the real strength of the 6550 is the bass slam. Surprisingly, there is little sacrifice in going to KT88's here and the trade off in the rest of the range is well worth it. KT88s' are just so far superior to 6550's that ARC really should offer it as standard equipment.

For what its worth- here's my take on several KT88s I've used in my ARC Ref 300 MkII over the past few years. Bottom line, The Shuguang 88-98's are the best overall tube in many important ways, namely, overall sound and even more importantly, reliability. Sourced from The Tube Store in Canada at $25/pair. I use matched octets if I can get them. I went through living hell using the Valve Art KT100 version of these tubes sourced from Antique Electric in Arizona. 3 failures out of 16 in 6 months. Blew a few tube power resistors. Not fun. Not fun at all. The sound was excellent but I cannot deal with the quality control problems. I've also sourced the KT 88s from VAC, and these too were superb but very expensive ($50/pair). I do not know the OEM but I think it is Shuguang also. Also sourced from Quicksilver. Gorgeous top end, less impressive in the bass and dynamics than the Shuguangs. I won't try the Electro Harmonix as they are quite bright. I'd be interested in hearing some Russian KT88's but the Shuguangs are so good, I am not motivated to do so. By the way, I'm driving Pipedreams and I play loud. The Shuagungs can take it and they deliver the goods.

My sense is that the issue of quality and failures have as much to do with the manufacturer as the importer/distributor. Kevin at VAC really QCs his tubes well as do the quicksilver folks and they are both impeccable. The Tube Store in Canada, and the Tube Depot are also quality operations with good QC and bias matching. Needless to day, I would not use Antique Electric again due to a very bad experience but its hard to know if they are at fault or whether the Valve Art is inherently unreliable. Since I believe the Valve Arts are made by Shuguang,, the distributor seems to be the likely cause of my high failure rate in this case


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Topic - Audio Research 6550 vs KT88 and tube brands - mbw817 10:41:04 03/10/07 (5)


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