6550 vs. KT88 tubes

I don’t know as much about non-vintage tubes. The winged c 6550’s sounded very good too (I liked the Svetlana Pre-Winged C 6550’s a little more), but the GE just stood out most with the most complex, rich tone. The ‘80’s JAN GE’s I didn’t like as much as the ‘60’s non-JAN GE’s, but they were a bit tighter sounding
Curious, did you test the “coke bottle” tubes? I believe they are tung soles. Rebranded by GE and anyone that bought more than a thousand?
Please lemme know.
 
Curious, did you test the “coke bottle” tubes? I believe they are tung soles. Rebranded by GE and anyone that bought more than a thousand?
Please lemme know.
Yes, I talked about it in my first post here. I have coke bottle Sylvania labelled 6550’s. They were tied with ‘60’s RCA (regular bottle) as my next favorites behind GE’s. The coke bottle Sylvania’s seemed to have a brighter, tighter, edgier sound vs my other 6550’s, but not as fat or full sounding. I really liked them. I had also some coke bottle Tung-Sol & JAN Tung-Sol 6550’s, but they weren’t working sadly. I still gotta try the Raytheon CK 6550’s. I also had Ei KT90’s in the mix. They had in some ways a more EL34-like character, but despite being an EL34 lover, I still liked my 6550’s more
 
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GE6550's for the WIN....

That being said the old 90's/2000's Svetlana/SED/WInged C 6550C are right up there with the GE6550 for reliability and tone, I've been running then since the 90's with no issues and they last as long as an NOS 6550. If you need a budget 6550 the Sovteks are a good tube. The Sovtek KT88's are also a good tube. I tried the Shuguang Valve Art 6550A(which was supposed to be the closest new production tube to a GE) and I had a couple go into runaway bias headed for a burn up...........
 
I think I slightly preferred 6550's over KT88's in my Deliverance 60 but really the difference is almost negligible (at least in that amp) in my opinion

At least at the time ValveArt 6550's were way cheaper than any quality KT88 so that was really the main reason I went with them lol
 
Yes, I talked about it in my first post here about it. I have coke bottle Sylvania labelled 6550’s. They were tied with ‘60’s RCA (regular bottle) as my next favorites behind GE’s. The coke bottle Sylvania’s seemed to have a brighter, tighter, edgier sound vs my other 6550’s, but not as fat or full sounding. I really liked them. I had also some coke bottle Tung-Sol & JAN Tung-Sol 6550’s, but they weren’t working sadly. I still gotta try the Raytheon CK 6550’s. I also had Ei KT90’s in the mix. They had in some ways a more EL34-like character, but despite being an EL34 lover, I still liked my 6550’s more
That’s right. Okay great, hey man I really appreciate the feedback!!
 
when i tried tubes on the Mesa S5000 the GE 6550 where too smooth sounding to me and Sovtek 6550we had a more aggressive caracter which i prefer
I’ve not tried those Sovtek 6550’s (might have to though), but the most aggressive ones I have to me are the coke bottle Sylvania 6550’s, but even the regular bottle Sylvania 6550 are more aggressive than others
 
Has anyone else here actually tried the other American 6550’s like the RCA’s, Sylvania’s, JAN Philips or Tung-Sol’s? GE’s were the clear winners for me as well, but seems like the others on here have only tried Winged C’s, GE’s or newer stuff. All I’m saying is if you have certain needs or specific amps some of the other American 6550’s may potentially work better in some amps and better not to be too conclusive sometimes
 
when i tried tubes on the Mesa S5000 the GE 6550 where too smooth sounding to me and Sovtek 6550we had a more aggressive caracter which i prefer
Well once I retube my jcm800 I’ll post my opinion, no shootout but I can leave the description. My other amps have el34s, 6L6s, and of course 6550s
The 6550s were rebranded but I assume they are either tung sol or GEs, and they are old. Which is fine. I’ll keep you guys posted.
 
when i tried tubes on the Mesa S5000 the GE 6550 where too smooth sounding to me and Sovtek 6550we had a more aggressive caracter which i prefer
My preference is mostly related to 2 amps, Marshall JMP/JCM/Jubes and VHT D60/120. I never tried any 6550s in my S400.
 
I don't like the way KT88's break up in power tube distortion. 6550's are much more pleasing when you get a head into power tube distortion. Some amps rely on preamp distortion and KT88's work well in these amps but KT88's sound like shit when they break up. Not many play loud enough to get them to break up so mileage varies.
 
I don't like the way KT88's break up in power tube distortion. 6550's are much more pleasing when you get a head into power tube distortion. Some amps rely on preamp distortion and KT88's work well in these amps but KT88's sound like shit when they break up. Not many play loud enough to get them to break up so mileage varies.
The other KT’s also IME (66,77 & 120’s) have that same thing. The only exception I found is my Gjika for whatever reason just likes 77’s. Even the very spendy ‘50’s GEC KT66’s & Mullard KT66’s didn’t do it for me. I spent the most I’ve ever spent on any set of tubes last week on a pair of Mullard KT88’s and they’re I guess good for 88’s, but still have that sound
 
I don't like the way KT88's break up in power tube distortion. 6550's are much more pleasing when you get a head into power tube distortion. Some amps rely on preamp distortion and KT88's work well in these amps but KT88's sound like shit when they break up. Not many play loud enough to get them to break up so mileage varies.
If you get a chance try KT90s. They sounded like a giant EL34 to me with the deep huge low end of a 6550/88
 
https://www.tubesandmore.com/products/vacuum-tube-6550a-str-tube-amp-doctor-premium-selected
I have not tried these. I've only ever had GE's but they are 300 bucks each now and nearly extinct.
Can you post a photo? Curious what to look for, Do they have a distinct look? I’ve got the coke bottle tubes, and they still sound okay, a little thin on top I think, moreso with a strat or single coils, my gibsons and other humbuckers not as much, but still seems a bit thin. Plenty of bottom end not a ton of gain even for an 800. Man I scored an ‘83 and I shit you not, it’s like brand new, must have been in a very very clean studio type environment.
But idk. I got it from a dude that had it less than a month. Said dude he got it from had it forever.
I’m stoked to get such a clean amp that’s 40 years old.
 
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