Why, yes they were. I talked to the President of Jadis (the son of the original designer I do believe) and he told me he thought highly of the GL KT-88 tubes.
Enough Tubes For You?
- Thread starter MylesBAstor
- Start date
Why, yes they were. I talked to the President of Jadis (the son of the original designer I do believe) and he told me he thought highly of the GL KT-88 tubes.
Keeping along the lines of the original post, my Atma MA1 MKII.2 amps have been pretty reliable and are certainly easy enough to live with. I check bias/DC offset every few months, and have only lost three output tubes in four years (two went right after initial setup). You could probably lose a few tubes per channel and not even be aware of it, unless you checked the DC or had one go off with a flash.
The newer MA3 is interesting....the output banks are selectable in thirds, 1/3 power, 2/3 power, or full (42 tubes, or 84 triodes to be exact). The amp runs auto-bias and offset, and features a built-in tube tester, which tests tubes within individual banks.....sounds like a neat feature. Although the Circlotron requires a fixed-bias arrangement, my guess is that the tube tester is a voltmeter of some order across the cathode resistors (older Atmas have 1-ohm cathode loads, for tube stability in parallel arrangement).
Also of interest, the MA3 power supply...the other two big boxes in the photo, allow the output stage to stay in regulation even if the line voltage drops off to around 100 volts. Now that is cool.....
Tom
The newer MA3 is interesting....the output banks are selectable in thirds, 1/3 power, 2/3 power, or full (42 tubes, or 84 triodes to be exact). The amp runs auto-bias and offset, and features a built-in tube tester, which tests tubes within individual banks.....sounds like a neat feature. Although the Circlotron requires a fixed-bias arrangement, my guess is that the tube tester is a voltmeter of some order across the cathode resistors (older Atmas have 1-ohm cathode loads, for tube stability in parallel arrangement).
Also of interest, the MA3 power supply...the other two big boxes in the photo, allow the output stage to stay in regulation even if the line voltage drops off to around 100 volts. Now that is cool.....
Tom
Actually the biggest issue is when an output tube goes--and you're not watching--is figuring out which is the bad tube since there's only one fuse. You don't fully appreciate it until you use a VTL amp where it tells you which is the bad tube
Myles
When an output tube goes on a cj amp, the bias light goes red showing you what tube has failed.
Is this not the case with the ART?
This situation only happens it the very improbable case that the tube shorts - when tubes age they go open, not in short. It happens also with poor quality or defective tubes - its is why one should always use reliable tubes, having gone through a short burn-in period. If you own ARC tube amps you should forget about buying cheap rejects at eBay.
In decades of owning ARC equipment I only had this problem at a period when 6550 tubes when scarce and we had to use the first generation of chinese manufactured new tubes. Modern tubes are much more reliable, and since using approved russian manufactured tubes I never have experienced any failure.
I have asked ARC about why they did not use fuses in the B+ rail, and the answer was that they degraded a lot the performance of the amplifiers.
BTW, changing the resistor is a two minute affair - take the cover, cut the body of the old resistor, make two rings in the new resistor with a small pliers and solder the new one on the wires of the old one. I did it in the REF110 of a friend who bough cheap tubes from an alternative supplier. A good way to get a dinner from a good friend!
OTOH, I wonder how they might feel with some of the newer "audiophile" fuses like I use in the B+ of the cj amps?
Hi
People .. We, audiophiles are so prone to overstatements and the thread fits the mold. A person with basic or advanced electrical knowledge may be able to repair Tube equipment more easily than SS. I have no doubt. For most audiophile however their electrical knowledge stops at reading voltage from a multimeter. So regardless of the amp they use Tube or SS, a malfunction that goes beyond changing a fuse or a tube equate with shipping, often after lengthy phone calls with the manufacturer.
Today SS seem to be more reliable than tubes. I have no number to back that assertion, perhaps some facts would have me review my position. I moved to SS relatively late in my audiophile life and I can tell you that I have had fewer problems with SS than tubes which I found finnicky and temperamental, although I never had any major blow-up with tubes equipment (VTL, CJ, Quicksilver, Jadis, Dynaco, Audible Illusions, Counterpoint, etc). Anyone with numbers to back their point is welcome.
To go back on topic , I have a fondness for OTL, if I were to move toward tubes ever again it would be OTL, they seem to me the more "universal" type of tubes amplifer and in my experience they more than any other tubes amps can drive drive strange loads. I remember a friend drove his Sound LAb to excellent results with Atmasphere while many SS the other side of Krell Class A monsters were struggling with it ... I also heard an OTL driving a Magnepan and it was the best I heard from that maggie, of course Maggie are polite loads but to extract serious bass and coherence from Maggie require serious, read high power from tubes, 300 wats and up .. the OTL was a 100 watts or 80 watts... The MA-3 measurements by the way are very good and the technology , rather unique: Built-in tube tester, the Atmasphere OTL implementation, the Power supply, etc, one can only be admirative. And if this amp sounds like a more powerful and refined MA-2, it is destined to walk over several well regarded tubes amplifers sporting similar tag prices. It remains however that the logistics of this MA-3 amps, even for those who can afford it are daunting, from the Heat generated by 84 tubes to the very large footprint and likely the AC current draw. So it can be a difficult amp to deal with even for many who could sign the check and not even have a zero come out of their balance account
P.S. I would welcome in passing a move toward a more balanced discussion atmosphere. Pushing point of views that are only based on beliefs will not help fellow audiophiles. Points that can be substantiated with repeatable experiences or maybe numbers do. They allow all of us to better our system henceforth our enjoyment of music... Lately It has become too much my faith againt yours, often at the cost of Logic and Science. It seems that once a person makes apoint it is difficult to back from it or to amend it, logic and common sense be damned! We do need those two to unersand each other and to progress.. We certainly don't want the forum to become an echo chamber, which is what faith-based behavior leads to.
People .. We, audiophiles are so prone to overstatements and the thread fits the mold. A person with basic or advanced electrical knowledge may be able to repair Tube equipment more easily than SS. I have no doubt. For most audiophile however their electrical knowledge stops at reading voltage from a multimeter. So regardless of the amp they use Tube or SS, a malfunction that goes beyond changing a fuse or a tube equate with shipping, often after lengthy phone calls with the manufacturer.
Today SS seem to be more reliable than tubes. I have no number to back that assertion, perhaps some facts would have me review my position. I moved to SS relatively late in my audiophile life and I can tell you that I have had fewer problems with SS than tubes which I found finnicky and temperamental, although I never had any major blow-up with tubes equipment (VTL, CJ, Quicksilver, Jadis, Dynaco, Audible Illusions, Counterpoint, etc). Anyone with numbers to back their point is welcome.
To go back on topic , I have a fondness for OTL, if I were to move toward tubes ever again it would be OTL, they seem to me the more "universal" type of tubes amplifer and in my experience they more than any other tubes amps can drive drive strange loads. I remember a friend drove his Sound LAb to excellent results with Atmasphere while many SS the other side of Krell Class A monsters were struggling with it ... I also heard an OTL driving a Magnepan and it was the best I heard from that maggie, of course Maggie are polite loads but to extract serious bass and coherence from Maggie require serious, read high power from tubes, 300 wats and up .. the OTL was a 100 watts or 80 watts... The MA-3 measurements by the way are very good and the technology , rather unique: Built-in tube tester, the Atmasphere OTL implementation, the Power supply, etc, one can only be admirative. And if this amp sounds like a more powerful and refined MA-2, it is destined to walk over several well regarded tubes amplifers sporting similar tag prices. It remains however that the logistics of this MA-3 amps, even for those who can afford it are daunting, from the Heat generated by 84 tubes to the very large footprint and likely the AC current draw. So it can be a difficult amp to deal with even for many who could sign the check and not even have a zero come out of their balance account
P.S. I would welcome in passing a move toward a more balanced discussion atmosphere. Pushing point of views that are only based on beliefs will not help fellow audiophiles. Points that can be substantiated with repeatable experiences or maybe numbers do. They allow all of us to better our system henceforth our enjoyment of music... Lately It has become too much my faith againt yours, often at the cost of Logic and Science. It seems that once a person makes apoint it is difficult to back from it or to amend it, logic and common sense be damned! We do need those two to unersand each other and to progress.. We certainly don't want the forum to become an echo chamber, which is what faith-based behavior leads to.
Never met an OTL owner that would say they are reliable. Doesn't matter the manufacturer.
To me, 5 to7-yrs represents the cut-off in age I’d consider buying used high-end gear with smt devices knowing they need servicing well before older through-hole type gear.
a service mgr at a major Japanese elec co. said the mean time between failure for most goods mfrd w/ SMT devices is about twice as high as older through hole construction. They stopped offering repairs on gear from as recent as the ‘90s when smt became more prevalent. Whats good for miniaturizing cell phones, tablets, PCs isn’t as reliable in the long run – and for those types of devices it needn’t be. I’d question its inclusion into high-end audio. Dan d’agostino considers his gear to be like an heirloom, in his video he states he only uses through-hole mfrg in his momentum amps – a backhanded remark aimed at his competitors perhaps.
I never had any real problem with any elctronics.(Amp or preamp) Other than a blown fuse my problems were limtied to blown transistors. The manufacturer explained they had no real way to to test them. They bought a batch and they would either fail early on or last forever. That was my experience.
Frantz I feel you. But this is a discussion group not a think tank. We come to give our testimonials as well as whatever scientific knowledge we may posess. I think you'll just him to skim over the faith based assertions.
Count yourself lucky and I assume you just mean you have never had an output tube blow up or a small signal tube go noisy/microphonic. So why did you have to replace a fuse or two??
Depends on what you mean by modern. Is the ARC VT-100 series of amps considered modern? If so, biasing is a major pain. Is the Jadis Defy 7 MKII considered modern? If so that is a pain to bias. But guess what? Biasing a tube amp never had to be a pain or difficult. Marantz got it right over 50 years ago. They built the bias meter into the top plate of the amp with the adjustment pots next to it. Couldn’t have been simpler. Since the 1950s when Marantz had made biasing an amp as simple as it could be, ARC and some other companies managed to turn it into brain surgery and I think it was intentional on the amps where the biasing scheme is ludicrous. I think it was done in order to force people to take their amps to the dealer. But that’s just my theory because nothing else makes sense.
From experience with my own OTL's and discussions with other owners, I'd have to disagree with that. At least in the case of Atma-Sphere products. If you're running one of the older Futterman designs or something that's 6C33C-based, then you'd best flip the power switch with trembling hands.
Tom B.
Frantz,
Your comment about polite loads and high powers is quite important. Many audiophiles have reliability problems with tube amplifiers because the speakers they are using are not adequate to the amplifier. Tube amplifiers clip more gently than solid state ones, and owners liking loud levels sometimes push them a lot. But tube life is most reduced under these conditions, and excessive currents can damage the tubes, increasing the probability of the terrible tube shorts.
Most modern speakers have low or very low impedance to increase sensitivity when used with SS amplifiers. Most of the time they are not the best electrical choice to a tube amplifier, even those with output transformers.
True but not limited to the Futtermans. Remember Robert Reina's joke about Jadis amps in Stereophile? It was pretty tasteless
True but not limited to the Futtermans. Remember Robert Reina's joke about Jadis amps in Stereophile? It was pretty tasteless
No, I must have missed that one. What did he say?
Tom
I observed a Forsell...very groovy, hehe
I'm enjoying the valve universe.
Recently took delivery of a TEK 576 Curve Tracer...having adapters made to characterize tubes
Sam,
The Forsell air bearing CD transport had a long time permanence in my system - about fifteen years - although with several factory upgrades, from MK1 to Mk3. Only the appearance of the Audio Research CD7 tubed unit persuaded me to let it go, but I had to replace it with a Forsell Air Force One turntable.
. Retrospectively, I should have kept the Forsell Air CD Transport - if I ever move to a music server I will still need a top CD transport.
The TEK 576 is a fantastic tester - much better than the usual transconductance meters. I use a DIY tube tracer controlled by LabView that emulates some of its functiions.
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