KT88 vs 6550 in Dynaco MKIII

Adam N.

Trying to keep it simple.
A local fellow had some cheapo KT88s that he took out of a low hours new amp he had.Shuguang KT-88's which are about $40 a piece new and half that used.

These replaced my Winged C 6550s in the MKIII. I think I like them better. We listen mostly for folk and acoustic music and subs handle everything below about 80hz so I cannot really comment on the bass. This is mostly about the mids and highs.

It seems to do great with women's vocals and has a clarity I didn't know I was missing. Everything seems super detailed but still has a nice warm natural feel. I wish I could hear them really back to back, but I gotta say I am liking my cheap 88s.
 
I have seen several people voice the opinion that the Chinese KT88s (such as the Shuguang KT88-98s, KT88SCs and such) had a bit more "open" and "airy" high-end sound, compared to Russian KT88s (which tend to have more bottom end). This can manifest in the Chinese tubes seeming to have more resolution of detail, as opposed to the Russian tubes having more "sock".

With you having a sub in the mix, this is one of those cases where the Chinese tubes should be able to do very well...

Regards,
Gordon.
 
Shuggies really are no slouches at all IMO. I’ve got several different ones and none of them have been disappointing at all.
 
yep, would agree with dosmalo, the newer Shuguang and PSVANE KT88s are quite good. The both offer several grades or models of tubes. Their higher priced spread is quite nice. The days of finger crossing and hoping you'll wont get any chinese tubes that go super nova on power up seem to be greatly reduced. The Chinese tube guys have been hard at work improving their product.

I recently bought a quad set of the shuguang Nature sound KT88s, and was quite impressed with their sonics. have not had any issues with reliability either. Have not tried em in a Dyna MK3 but have plugged them in quite a few other amps, all with good results. Prior to the arrival of the Nature sound my favorite KT88s were the Mullard Re-issues. The GL 88s are nice, but the Mullards have a tad warmer sound. The gray glass PSVANE 88s are very good as well.

Also run a set of PSVANE gray glass 88s in my Inspire single ended amp, which has better sonics than the KT150s that came with the amp.

best
 
yep, would agree with dosmalo, the newer Shuguang and PSVANE KT88s are quite good.

I went over to the PSVANE site and was looking at their KT88 tubes. As an example they list the Treasure GF Select 88 at $235 and the z Cobalt at $495 and I thought "Geeze that's expensive!". I didn't realize those were the prices for quads! LOL.
 
A local fellow had some cheapo KT88s that he took out of a low hours new amp he had.Shuguang KT-88's which are about $40 a piece new and half that used.

These replaced my Winged C 6550s in the MKIII. I think I like them better. We listen mostly for folk and acoustic music and subs handle everything below about 80hz so I cannot really comment on the bass. This is mostly about the mids and highs.

It seems to do great with women's vocals and has a clarity I didn't know I was missing. Everything seems super detailed but still has a nice warm natural feel. I wish I could hear them really back to back, but I gotta say I am liking my cheap 88s.
Any good KT88 or 6550 will sound good in MkIII, providing that they are matched and has correct bias.
 
A local fellow had some cheapo KT88s that he took out of a low hours new amp he had.Shuguang KT-88's which are about $40 a piece new and half that used.

These replaced my Winged C 6550s in the MKIII. I think I like them better. We listen mostly for folk and acoustic music and subs handle everything below about 80hz so I cannot really comment on the bass. This is mostly about the mids and highs.

It seems to do great with women's vocals and has a clarity I didn't know I was missing. Everything seems super detailed but still has a nice warm natural feel. I wish I could hear them really back to back, but I gotta say I am liking my cheap 88s.
I replaced my 6550/kt88 with kt120. They seem to be loafing around at over 500vdc.
 
Any good KT88 or 6550 will sound good in MkIII, providing that they are matched and has correct bias.

I guess my point is they sound diffrent and to my ears in this application, better. I kind of make this kind of post so someday someone else with a MKIII will be able to find it and see what was said.
 
the reason the Shuguang and PSVANEs are more expensive is the Chinese reverse engineered the materials used in the orginal Genelex and Telefunken tubes. They then tried to re-create that same tonal quality.
If you compare them to NOS KT88s, they are quite reasonable. That is the market they were going after not the Russian re-issue market.
 
I'm not sure you're referring to using them in a mkIII, if so I'd be a little concerned about the additional filament current.
Actually, the difference is between .2 and .4A over the regular kt88. The JJ kt88 is 1.6A while the kt 120 is 1.7 to 1.9A. It should be ok as long as you are not running high wall voltages. I sold my MK3 a long time ago so i can not do an "in situ" test to verify difference. IME, that difference is within the built in design spread of voltages.
 
the reason the Shuguang and PSVANEs are more expensive is the Chinese reverse engineered the materials used in the orginal Genelex and Telefunken tubes. They then tried to re-create that same tonal quality.
If you compare them to NOS KT88s, they are quite reasonable. That is the market they were going after not the Russian re-issue market.


The point of my post is that I thought that those prices were for single tubes, not quads! I thought it would cost $2000 to put a set of cobalts in my MKIIIs
 
I tried a set of the cobalt blue tubes. don't waste your money. the Gray glass versions are nice.
If that is still too much to spend, try the PSVANE Hifi grade KT88s, they are good sounding tubes and are priced similarly to Russian KT88s.
 
I gotta say though, in my application, the cheapo shuggies are great. With the bass taken care of by subs the clarity of the high end it magnificent.

I guess tubes sort of go with the system. You can use them to tune the whole package.
 
My next purchase will be a set of 6550's for my M125s (due to cost). I've only run various KT88's - I'm not expecting much difference - ex sovtek - to gold lion wasn't an upgrade - they both sounded great.

Biggest difference I've found - has been in the driver tubes.
 
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