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KT88 vs 6550 tubes

I recently got a quad of EAT kt88 tubes for my Mcintosh MC275. Those are supposedly revered as one of the best. However, less than 10 hours one of them had a spark of fireworks in it and shorted the fuse. I heard KT88s are in general not as reliable as 6550. Is this true? 

I thought also that KT88 and 6550 are interchangeable in the MC275 without any additional bias adjustment. The original 6550 tubes in it has been working for a long time without issue.
angelgz2

Showing 4 responses by angelgz2

angelgz2 OP
37 posts
 
Well, I don’t know man. The MC275 doesn’t even have a bias adjustment knob and manual says I can use both. No, no cherry red, just the golden glow like the color of a light bulb. 
angelgz2 OP
37 posts
 
@dentdog thats true. I didn’t like the EAT tubes at all as they sounded muddy and lacked bass, despite being priced at $450 each. Popped my RCA 6550s and unit came back to life lol. I’ll see if I can track down a quad of black plates 
angelgz2 OP
37 posts
 
@dentdog 

there are quite a few Tung Sol NOS black plates on eBay. Are they not the same? I mean there’s no way to fake those things based on what I’ve read. 
angelgz2 OP
37 posts
 
@dentdog actually there are also some original British Mullard KT88s. I’m not sure whether they are safe to buy because of my previous problem with the KT88s 
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