[atmasphere]

From my experience its highly unlikely that the amp itself is still having a problem.

OTOH, right after shipment is when we experience 90% of the problems we have with the power tubes. I was pretty sure Gopher was having power tubes initially, but in further conversations with him, it sounded like there was another explanation.

All of our amplifiers have current limiting resistors in the output section. These resistors have been proven effective at getting the power tubes to work more closely with each other, and work very much like the emitter resistors do in a transistor amp. In the early days when we first started using this part, we installed 3-watt devices that on paper *should* have held up, even if the tube arced, but in practice some of them did fail.

So about 10 years ago we started using 5-watt devices, which hold up quite well. We rebuilt the output section of  Gopher's amp with these parts. So If the amp is having an issue now, it really will be the fact that the power tubes are unhappy due to shipment.

Due to its age we felt that while the amplifier was here it would have been a good idea to update it to the latest level (which reactivates the warranty), but Gopher didn't want to do it. I almost feel like we should send him a demo unit just so he can hear how much the circuit has improved since his amp was built 12 years ago.  But despite that, we have found that with sort of work the amplifier needs to break-in, which usually takes a couple of weeks.

[sunnydaze]

So offer to refund the man's money as it was a known problem to you (and us) that obviously didn't get fixed correctly. It's the right thing to do,,,, imho anyways.
 
Cheers,
Robin

Why are you even sticking your nose into things?!   
I notice you do that quite a bit around here, and have the annoying tendency of telling folks what to do.  Have you been appointed some sort of enforcement officer on here?

I know Fred personally.  He is completely 100% stand up.  He was completely honest with the amp and its history and condition.  There was no deception whatsoever.  The buyer knew exactly what he was getting, and the risk he was undertaking.  And it just came back from AS with what one would assume is a 100% clean bill of health.  Fred is no more responsible for what happened, than the buyer is!

While I don't think Fred should wash his hands of the matter, I don't agree that he necessarily owes him a refund.  I agree with Berto.  You are off-base and you should butt out and let them work it out however they see fit.  It's none of your business.

[Gopher]

From my experience its highly unlikely that the amp itself is still having a problem.

OTOH, right after shipment is when we experience 90% of the problems we have with the power tubes. I was pretty sure Gopher was having power tubes initially, but in further conversations with him, it sounded like there was another explanation.

All of our amplifiers have current limiting resistors in the output section. These resistors have been proven effective at getting the power tubes to work more closely with each other, and work very much like the emitter resistors do in a transistor amp. In the early days when we first started using this part, we installed 3-watt devices that on paper *should* have held up, even if the tube arced, but in practice some of them did fail.

So about 10 years ago we started using 5-watt devices, which hold up quite well. We rebuilt the output section of  Gopher's amp with these parts. So If the amp is having an issue now, it really will be the fact that the power tubes are unhappy due to shipment.

Due to its age we felt that while the amplifier was here it would have been a good idea to update it to the latest level (which reactivates the warranty), but Gopher didn't want to do it. I almost feel like we should send him a demo unit just so he can hear how much the circuit has improved since his amp was built 12 years ago.  But despite that, we have found that with sort of work the amplifier needs to break-in, which usually takes a couple of weeks.

Ralph,

Thanks for chiming in!  I've appreciated your help getting this matter sorted from the beginning.  Few designers are as gracious and proactive in supporting their products and it is appreciated.

With respect to tubes,  I did want to chime in that every single tube in the amp was changed and different combinations tried and the problem still presented.  Whether with 1 (brand new) power tube per side and Russian 6sn7s or NOS Raethons it was consistent.

Also, I did want to add the point of information that I did not ship any tubes to you for the repair--just the amp itself.  I avoided shipping the tubes as you said they don't ship well.  I also did not ship to Roscoe he came over to pick it up personally and we rocked out for a couple hours with the amp followed by a full week of healthy operation in his rig.

As much as I'd love for it to be the tubes--especially discovering diyhifisupply has them DIRT cheap, I'm not quite sure it is.  I used the tube 8 brand new 2 as new for about 2 weeks after receiving the S-30 back and Roscoe got about another week, so I really tend to think its something else.  Probably something silly and small and not even anyones fault, but SOME other cause.

I'd have loved to do the updates, Ralph.  Your enthusiasm made them hard to decline, but budget just didn't allow.  As it was I had 2 expensive (for me) amplifiers and could only afford to keep one...  One day when I hit the lotto, I'll probably own another A-S.  As is I would have loved to keep your amp for analog listening and my 845 SET for digital.

Sunny,

Thanks for the confidence, my friend!  I don't think Robin meant it maliciously, though I too was taken aback by the phrasing.  I've exchanged a few PMs with him and I believe he means well.  No harm, no foul.   

[sunnydaze]

I have had my share of PM's with Robin as well.  He is a Mr. Buddinsky!

[roscoeiii]

Talked to Ralph and looks like the culprit may be a power tube. I will try to ferret out the culprit later today.

[Larkston Zinaspic]

I've met both Roscoe and Fred...they are both great guys, and the S-30 is too much of a gem of an amp to go to waste...I hope the situation is resolved to everyone's satisfaction because it's clear everyone had good intentions from the get-go.

I had a power tube crap out on me today, out of pure coincidence. Some fireworks implicated the faulty tube at least, and upon close inspection both fuse links were gone. Bought these from tube depot right at the end of June...so far 4 out of 10 are now garbage.

[sunnydaze]

In the late 90's I owned a pair of AS M-60's Mk2.  I remember going thru tons of fuses.  They would often blow for reasons unknown to me -- no associated blown tubes, or any other amp problem.  When replaced the amps would work 100% fine....till one blew again.

Logically, I figured there must be some sortof of underlying problem, but the occurrences were fairly spaced out, so I never really investigated.

I simply kept a generous fuse supply on hand, replaced them when needed, and got back to the music.  No biggie, no sweat.  I figured just a part of owning such a tempermental thoroughbred specifically, and tube ownership in general.

[jtwrace]

In the late 90's I owned a pair of AS M-60's Mk2.  I remember going thru tons of fuses.  They would often blow for reasons unknown to me -- no associated blown tubes, or any other amp problem.  When replaced the amps would work 100% fine....till one blew again.

Logically, I figured there must be some sortof of underlying problem, but the occurrences were fairly spaced out, so I never really investigated.

I simply kept a generous fuse supply on hand, replaced them when needed, and got back to the music.  No biggie, no sweat.  I figured just a part of owning such a tempermental thoroughbred specifically, and tube ownership in general.

Did you have a power conditioner?  That sounds like an power surge problem.   

[sunnydaze]

Right...that's what I thought, and why I wasn't overly concerned.  Was living in NYC apt with crappy and erratic power supply.  I know this cause during the day my system was often literally unlistenable, while in wee hrs of the morning it could be absolutely glorious.

I had no PC at the time.

[atmasphere]

I had a power tube crap out on me today, out of pure coincidence. Some fireworks implicated the faulty tube at least, and upon close inspection both fuse links were gone. Bought these from tube depot right at the end of June...so far 4 out of 10 are now garbage.

There is a simple way to make power tubes last longer. If you have purchased new (untested- and most 6AS7Gs from Russia are untested) power tubes for any amplifier from a 3rd party tube dealer, the thing to do when you get the tubes is to put them in the amp and put the amp on Standby for 72 hours continuous. I know it sounds like a pain in the rear, but this can double the life of the tubes and cut the number of arc-over events to 1/3rd.

[atmasphere]

In the late 90's I owned a pair of AS M-60's Mk2.  I remember going thru tons of fuses.  They would often blow for reasons unknown to me -- no associated blown tubes, or any other amp problem.  When replaced the amps would work 100% fine....till one blew again.

Logically, I figured there must be some sortof of underlying problem, but the occurrences were fairly spaced out, so I never really investigated.

I simply kept a generous fuse supply on hand, replaced them when needed, and got back to the music.  No biggie, no sweat.  I figured just a part of owning such a tempermental thoroughbred specifically, and tube ownership in general.

The M-60 Mk2 was a manual-bias amplifier. On the early versions (pre-2000), if the bias was even slightly over the mark, it would blow the fuse. The later amps had an increased fuse rating.

[zybar]

There is a simple way to make power tubes last longer. If you have purchased new (untested- and most 6AS7Gs from Russia are untested) power tubes for any amplifier from a 3rd party tube dealer, the thing to do when you get the tubes is to put them in the amp and put the amp on Standby for 72 hours continuous. I know it sounds like a pain in the rear, but this can double the life of the tubes and cut the number of arc-over events to 1/3rd.

This was done with the current set of output tubes I am using and I am a happy camper.

The person who did the conditioning also did tube matching, so I am really set.   

I even have some measured spares to insert into the mix as needed.

George

[roscoeiii]

There is a simple way to make power tubes last longer. If you have purchased new (untested- and most 6AS7Gs from Russia are untested) power tubes for any amplifier from a 3rd party tube dealer, the thing to do when you get the tubes is to put them in the amp and put the amp on Standby for 72 hours continuous. I know it sounds like a pain in the rear, but this can double the life of the tubes and cut the number of arc-over events to 1/3rd.

Thanks for the tip Ralph. And thanks for taking the time over the phone today helping me diagnose the problem. Now off to search for the offending power tube.

[zybar]

The M-60 Mk2 was a manual-bias amplifier. On the early versions (pre-2000), if the bias was even slightly over the mark, it would blow the fuse. The later amps had an increased fuse rating.

I remember those days...glad you changed things for the better.

Besides sounding killer, I have had one tube go bad in almost three years of fairly heavy use.  When the one tube went bad, it kept taking out the fuse until it was found and replaced.

George