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6550 tube preferences

RS Steve

RS Steve

Tube Junkie
Subscriber
I am curious to know if anyone with a lot of experience using these tubes can post their brand preferences before I purchase a quad of them. I didn't want to spend a bunch on a designer brand if the lesser cost brands do just as well. They will be installed in a pair of Dynaco MK 3's, any experienced advice will be appreciated.
 
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I am running Electro Harmonix 6550's in my clone MK 3's shown in my avatar picture I have probability 200 hours on them now and so far so good. I haven't had to adjust the bias after the first 20 hours. My research made me believe that they were the toughest and most reliable of all the new production. There were good things said about the Gold Lions but are a bunch more bucks and seemed to have some failures.
 
New production or old stock? The Svetlana Winged C 6550C's are really excellent tubes, IMO. If you can afford them that's one option I would seriously consider. I've tried the new production Tung Sol 6550, and didn't like them as much as the Winged C's. Although they have reasonably good sound quality overall, I just found them to be a little more mushy and muddled in the mid range/upper bass as compared to the Winged C's. If you will consider the Tung Sol KT120, that is a great option too--totally compatible with the 6550, except for heater current, (about 1.9 A per tube), and an absolutely excellent sounding tube, IMO.
 
Any original Tung-Sol's with smooth plates , two-hole or three-hole plates. They're ALL good! Love them in my own design, SET amp.
 
All of the usual NOS suspects are a good choice for the MK3. GE,Tung-Sol,and Sylvania can all take the voltage and current these amps run at. Price and availability can be an issue though.

As for the Russian varieties,there are so many conflicting opinions regarding sonics and reliability that I really don't believe a true ''best'' has ever been clearly established. Do keep in mind that some of the Russian brands were specifically ''hyped'' as suitable for use in the Ampeg SVT bass amplifier,which runs at ridiculous voltage and power levels. These would probably be a good choice for the Dynaco's.

JJ: Not a hope in hell (unless you're into smoke and light shows)

Chinese: See above (I'll bite my tongue and leave it at that on this one rather than risk a profanity warning from the mods:rolleyes:)
 
crispycircuit said:
Go for the 120s!!
Click to expand...

Although the MK3's were intended to supply power to an outboard preamp,I'm not sure if they'll handle almost 2 amps of extra filament load.

Oh boy,did I ever blow the math on this one. Sorry guys.
I don't know the specs of the original transformer,but I just got back from the Dynakitparts website. Their replacement power transformer specs the 6.3v filament winding at 5 amps. The total current draw (2x KT-120 +1x 6AN8) is 4.25 amps,well below the replacements max current capability.
So,those KT-120's look like a possibility. I wanted to try them in my Audio Research amps,but was advised by AR that they wouldn't support the additional load.Darn!
 
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Thanks for all the great information everyone, I decided on these. Matched Quad 4x NOS Svetlana SED Winged C 6550/KT88 tubes. Price was not too bad .
 
You've already made your purchase, and what I'm about to write may be taken as blasphemy by some, but I've been told by 4 very experienced tube sellers / amp manufacturers than the current Genalex Gold Lion KT88 tube is their favorite 6550-type tube of all time. That they would take them, and do use them in their own amps, over any other 6550 / KT88 ever made. Even better than the original Gold Lion KT88s. I've also heard it from others too, people with less credentials & using them in their own amps.
 
Excellent choice,definitely one of the best available. I had an old high-hours set of these (still good,kept as spares) that I used for setting up and doing the trial-run when I restored my Audio Research D76A,which runs the outputs pretty hard.The bench tests were amazing. That was last August. They're still in there.....Lazy? Nope.
They just sound great!
 
Tom Bombadil said:
You've already made your purchase, and what I'm about to write may be taken as blasphemy by some, but I've been told by 4 very experienced tube sellers / amp manufacturers than the current Genalex Gold Lion KT88 tube is their favorite 6550-type tube of all time. That they would take them, and do use them in their own amps, over any other 6550 / KT88 ever made. Even better than the original Gold Lion KT88s. I've also heard it from others too, people with less credentials & using them in their own amps.
Click to expand...

I heard from a very well known seller of tubes that his favorite kt88 was the GL
His tech who does his amplifier repairs told me his favorite was the SED.
Kinda conflicting reviews seeing as they both have a common interest in the company.

I've compared both GL's and SED's and like the SED's [kt88/6550's] much better in my amplifiers

This was a few years ago, so maybe GL makes a better tube now
 
arts said:
Excellent choice,definitely one of the best available. I had an old high-hours set of these (still good,kept as spares) that I used for setting up and doing the trial-run when I restored my Audio Research D76A,which runs the outputs pretty hard.The bench tests were amazing. That was last August. They're still in there.....Lazy? Nope.
They just sound great!
Click to expand...


Between this thread, and all the research I have done, this seemed to be the best choice. I found no negative comments on the winged Svetlana tubes, and they were less expensive than the Gold Lion brand. Now I need to see what the best bias setting will be for them.
 
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