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Tube upgrades for Jolida 502B?

I realize this is something that has come up before, though in searching the archives I didn't come away with a clear path forward. My amp is completely stock and came equipped with Sovtek 6550s. Using it to drive Totem Forest speakers. I contacted Jolida. They recommend KT88s. Their reply is a bit unclear but they might be suggesting Electro Harmonix. They also indicate reliability issues with Chinese KT88s. Response Audio (Jolida dealer and modder) recommends Shuguang KT88s (Chinese). The Tube Store recommended JJ Tesla KT88s on the strength of their great imaging and deep bass (more bass being something I was looking for). I was initially leaning towards SED Winged "C" 6550s. Now I am a bit more confused. I'm curious about KT88 vs 6550 sonics and reliability differences. Thanks in advance to any one willing to take the time to share their experience and preferences.
128x128ghosthouse
bonger
47 posts
 
Replaced stock Shuguang KT88's with Tung-sol 6550 reissues on my Cayin amp used with Totem's also...right away there was a noticeable improvement.

Tung-sol's have all the bass of the Shuguang's but, slightly better imaging & resolution, tighter bass, but most of all, sweet, sweet midrange that makes voices, instruments more realistic sounding.

Without using so many audiophile terms, Tungsol's just "holds a note better".
mf2
24 posts
 
I once owned an upgraded JD-502B and played around with various NOS GE, RCA, and Sylvania input tubes and SED KT88, Sovtek 6550, and Shuguang KT88 power tubes. My favorite combination of those I tried:

GE long plate 12ax7
Sylvania Gold Brand 6201
Shuguang KT88
fishcat1's avatar
fishcat1
26 posts
 
I currently am running the EH KT-88's in my 502, to good result. I tend to think that the driver and pre tubes affect things a little more than the power tubes. Running a set of Mullard 4024's in the 12at7 positions, and tung-sol reissue 12ax7's in the pre positions have supplied really nice sound. The bass is not soft in any way-hits a little like solid state. I'm an electric bass player sensitive to that frequency region and I simply couldn't live with flabby bass. Hope this helps a little. -Fish
ghosthouse's avatar
ghosthouse OP
4,318 posts
 
Thanks to all. Interesting that no one advocated 6550s. I'll follow up once I make a decision and actually do something. Thanks again.
ghosthouse's avatar
ghosthouse OP
4,318 posts
 
By the way...
A follow up from Michael Allen at JoLida indicates the 502B now comes stock with EH6550s. EH was chosen for "excellent reliability". He said "If you wish to be perfect...look at the KT88s." He also suggested talking to the Tube Store for input on sound qualities.

The full 502B tube upgrade recommendation from the Tube Store was: JJ Tesla KT88, Ei Elite 12AX7E, NOS Mullard 12AT7WA. Any thoughts about this combination? The Tube Store review of the JJ KT88s using Quicksilver amp and Vandersteen speakers is very positive and appealing. Am just a bit antsy about reliability. The Sovteks ain't necessarily the "best sounding" but they are tough. Would prefer to compromise a bit on sonics to avoid blowing a tube or frying an amp circuit component. Thanks for your input. It sounds like KT88 is the way to go and I expect there are a number of options that will deliver very good results as your various systems show. May have to just close my eyes and "jump" as it were.
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