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
The 5881 is a suitable replacement for the 6l6WGC tube. The Tube Depot has new production Tung Sol's for $50 each, used Tung Sols for $40 each and NOS Tung Sols for $70 each..they are all excellant tubes. Also at the Tube Depot, are Sovteks for $23 each. Also, Andy Bowman at Vintage Tube Services can also help you. Don't get ripped off. Happy Listening.
I think the original 5881 tubes in the SP3 are Shuguang (Chinese). Check with I have the same amp and replaced the 5881 with a set of JJ/Tesla 6l6gc and have been really happy with the results - much fuller bass response and an overall smoother presentation. They cost about $60 for a quad if I remember correctly. I bought mine from TubeDepot. I'm sure Mcfarland's recommendations are also excellent.
If your amp can take 6L6GC's the SED model is excellent sonically and its rugged as well. If you must have 5881's on a budget the Sovtek's are OK.
This forum is unbelievable - it really does shorten the learning curve and help avoid the trial and error track. Tooter is the Tesla you mentioned a JJ-6L6GC. The lower case L shows as 1? Just want to be certain. McFarland at my age I've learned that there's always 2 miles of ditch for every mile of road, so I'm just grateful to keep it on the road most of the time on those audio learning curves. Much gratitude to McFar, Newbee and Tooter.

I'm also dealing with an Eastsound CD-e5 that won't read a disk. Snowy at Cattylink has been helpful so far. I'll keep those up to date who are interested in the resolution.

get2it1 - yeah, 6L6GC. There are several people on the av123 forum who second Newbee's recommendation of the SED 6L6. I haven't tried them yet myself but when my Tesla's die on me I plan on giving them a listen. My own experience has been that changing the preamp tubes, 12ax7, make the most impact on the SP3's presentation.

Good luck with your CD player.

Save yourself some money and call Sean Parque at and order replacement Melody-branded 5881 power tubes. They only cost $10 per tube and they're decent tubes for providing good-to-great music out of your Onix SP3. I have this wonderfully affordable amplifier and I have found that the stock 5881s are fine. As Tooter recommends: where you can really make a vast improvement in the audio quality is replacing the two stock 12AX7 preamp stage tubes with two Groove Tubes 12AX7-Ms. These 12AX7 "Mullard reissues" will really open up the soundstage, improve the imaging and extend the frequency response. For about $40 per pair of the Groove Tubes 12AX7-Ms, you can't go wrong. Later on, if you want to upgrade the power tubes, you can get a matched quad set of the SED 6L6GC power tubes.
I received the SED 6L6GC tubes and installed. On immediate listening they seem much more harsh on female vocals than the original Melody tubes. Almost to the point of sounding like clipping. Could this result from no burn in time yet? It was as if I hooked up an inexpensive receiver, nothing close to the original sound. Do I need to change some settings on the Onix? I've heard others talk about bias but not sure if this is possible on this Amp. (No Manual came with it) Any suggestions would be helpful.
Power tubes usually do require break-in. I've frequently found that the top smooths out and the bass developes after 24 to 100 hours of operation, BUT.....

Proper biasing is manditory and the bias setting for the 6L6's would be quite different than the 5881's. I'm not up to speed on the bias arrangement for the Onix but if its not auto bias (as I suspect) you should contact the distributor, referred to earlier, and find out how to bias in your new tubes.
Hey get2it1 - the SP3 is not an autobiasing amp, you need to re-set the bias whenever you replace the 5881s. Technically the 6l6gc is not a direct replacement for the 5881 and needs to be biased higher than the 5881. The 5881 bias should be set a 1.15V. Some fellow sp3 owners on the av123 forum calculated the 6l6gc tube bias as 1.60V for the sp3. When I put in my 6l6gc I just biased it at 1.15V with the plan of increasing up to 1.60 but I never got around to it because it sounds good at 1.15 and I figure I'm stressing the tube less.

As for actually biasing the unit you need to get a voltmeter if you don't own one already. You can pick up a digital voltmeter at Radioshack for under $20. Turn your system on and let the amp warm up for 5 minutes or so. Don't play any music while you are biasing the amp, this is important. On each side of the amp you will see 5 holes. Turn your meter on and insert the black lead into the center hole. Insert the red lead into the hole on the far right and check the meter for a reading. Insert a small screw driver in the hole between the leads and turn the screw until the bias reads 1.15V. Once this is done remove the red lead and insert into the far left hole and then adjust the screw between the leads until it also reads 1.15V. You've just biased the two tubes on the side of the amp. Repeat the procedure on the other side and you're done!

One thing to remember is that these tubes take about 24hours of play time to break in and during that time the bias will often drift so you may need to reset occasionaly during this break in period. After this breakin period you should only need to check the bias every 6 months or so.

Good luck!

Go to the following forum thread and you'll find some great information on biasing the Onix SP3 amplifier:
Outstanding Tooter, Rhing and Newbee. Left a message with av123 checking on the replacement Melody as a plan B. I will work on the Bias per your instructions Tooter. Much Appreciation All.
Now there's more than one explanation for the distortion! On the right rear test the reading is 10.55 and won't go any lower. That's also the one that blew. I don't know much about this but something tells me I bought an amp from an Agoner with a bad 'wheel'. Can this be repaired or replaced in anyway? I'm O for 2 on Agon buys now - but with the great help from you guys I still have faith.

Any suggestions or should I post this as a new thread?
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!
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
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.)
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?
* 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).

Thanks for the post Tubeears. Here's an update with outstanding news. I contacted John at av123 and they are replacing my amp . . . that's how to stand behind your product! Can't say the same for my CD. I was so thrilled by the Customer Service at AV123 I went on-line and bought a sub-woofer. Now if only all the dealer/distributors would back up their product to secondary buyers like me.
What a winner! And you bought it used. Many dealers/manufacturers would not even have talked to you except to say send it in, we'll fix it, and you'll pay for it! Hope the new one works for you.
I will second that one... literally. My first amp had a bit of a problem and AV123 gave me an RA (return authorization) and sent another amp immediately (before the old one left to go back). My first one had been a "B" stock, but was screwed up in transit. No questions, no problems. They contacted the shipper and had them pick the old one up at my door. The delivery guy was listening to my new one as he left. It just does not get any better than that. AV123 is one of the best companies out there. No bull and a fantastic product at a good price. This little SP-3 will be historical little amp (Dyna 70, Aleph 3, Mac 275, and quite a few more on that list). It has already shaken more than a few heads and caused lost sales for both new and used gear... many times it's price.
I really like the amp (quite obviously) and if I do ever part with it, I'm sure it will be on of those "highly regretted" losses (my old Martin Login CLS's and Rowland 112 come quickly to mind).
I'm glad that everyone is having a good experience with the amp and the company. Nice ink for a change.


Hey S3 lovers.....mine just died.  I think a tube is bad, but not sure which one?   First can someone recommend how I can tell?

next, where should i get my new tubes now that AV123 is toast?

Finally, which tube do folks recommend these days (seeing as OP is 14 years old...).

Thanks in advance!