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Tube Suggestions Onix SP3

As a rookie to tubes, one of the Melody 5881s tubes on the Onix SP3 I recently purchased on Agon has gone pzzzsst and I'm clueless and suffering without good sound. I have to keep within a reasonable budget but at the same time have a solid replacement for resale value. Can the original Melody 5881's be had anywhere? Otherwise the tube shop I called said I need to replace all four, rather than only 1 and recommended the NOS Sylvannia 5881 at nearly $90 per. I'm tempted to just buy another used Onix if that's the case. (Just kidding) Help
get2it1
tooter
85 posts
 
Are you sure that the reading isn't 1.055? Is your voltmeter set to the right "range"? Try swapping positions of the 5881 tubes and see if the same position gives the abnormal reading. You may want to just get in touch with av123. They've been very good aboout responding to emails/questions. I bought my amp second hand here on audiogon and when I had questions they were great to deal with. Best case scenario is that you just have a bad tube. Good luck, hope you get to the bottom of this!
get2it1 OP
24 posts
 
I ran the test again before and after switching tubes and the reading actually went up to 11.23.

The rest are holding fine. Any idea what part is the contibuting factor? I will try av123 on Monday. I haven't had success getting an answer via email from them yet on finding the original tubes from Melody.

Thank you
newbee
4,767 posts
 
The tube which went out, if it shorted out, could well have damaged some of the electronics in the bias circuit. This is not a rare event. I've had it happen 4 times on three different amps in the past 10 years. Probably time to take it into a repair shop (get some references 1st - not all repair shops know how to repair tube amps.)
get2it1 OP
24 posts
 
Will do Newbee . . . it's an odd comfort to know this is somewhat common. I will do the shop . shopping. Any suggestions for a repair facility would be greatly appreciated, as I have not had work done prior to this?
tubeears
136 posts
 
* Copied and pasted from another post under "Amps/Pre-amps" forum: Best 5881 Tubes.

In a short answer to my own question, I dropped in a pair of NOS GE 6dj8 (6922)'s in the SP-3 and found a slight but very distinct difference. The GE's (similar in sound to the Philips imho) brought out a more "single ended" immediacy with a tad more "forward" presentation. The images are a bit more localized and a bit more transparent. Not whole bunch better, but a little. Combined w/ the 12ax7wb change, it is a lot. I'm sure that cost was a factor in selecting the stock tubes for the SP-3, but in all fairness, they did choose some musical ones. The stock tubes are very open and non-fatiguing, but they are in need of a bit of speed and texture (again imho).

Tubby
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