Hi everybody, I am interested in get an Audio Research 100.2 amplifier. As I know, the production of these amps was from 1998 to 2003. I wonder if transistors, capacitors and other electronic parts have some deterioration with age. Thanks.
Transistors can be replaced. If matching transistors are unavailable, often times sets of different transistors can be retrofitted. Though this would probably be a relatively expensive procedure, one would have to consider what the costs would be compared to the much more likely need for frequent tube replacements over a similar time span. Furthermore, the quality of new tube replacements are somewhat suspect, which is evidenced by the ever escalating costs and decreasing availability of of NOS tubes. The likelihood that such a problem will occur with transistors in the realistic need/use of a ss amp is extremely low.
To sum up: Tubes die the quickest followed by hot running class A stuff. So there. I shall stick with my beloved 13 year old Class A/B amp until it leaks, blows up, or I feel like trading it in for something else...like a really expensive tube amp. Heh heh.
Jorge- You flatter me, but to be mentioned in the same sentence w Steve Mc is an honor I do not deserve. I am a consumer of high end audio; Steve is a creator! There is no comparison. But many thanks for the kind words. As far as the OP's question, yes of course everything deteriorates w age ('cept for vintage winos like me and Steve) but unless your particular amp was v early in that model run, or was pushed hard w/o adequate ventilation (heat is a major killer of electronics) its likely to be good for quite some time.
I forgot to place the web site of the Yaqin amp's seller. Here it is: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310248614281&ssPageName=STRK:MEWAX:IT
The great thing about this forum is that we can learn a lot from people who have deeply knowledge of High End Audio.
Everyone agree that electrolytics have deterioration with age. But the first post of Kiyanki shows that caps of a temperate amplifier like mine or a 100.2 can last probably more than 20 years.
Elizabeth, Kiyanki and Unsound agree that transistors can last many, many years. I think now that they are right.
Raquel goes deeply and her last post shows that low impedance, heat and overload might be a problem for output transistors. I dont really think that would be an issue for amps from Audio Research, especially because my own good experience with this brand.
Also, the web site she placed is absolutely great.
The posts of Raquel make me think in something that was floating in my mind: tube amplifiers.
For less of $700.00 including shipping to my Country a YAQIN MC-100B KT88 Tube Amplifier could be a good option. The unit has 65 watts ultralinear, 35 watts triode, two separated power supplies with their own transformers and can be used as integral or power amp.
I think 65 watts are not enough for my electrostats.
So the question is, if this amp can be bridged to double its power without any issue and if its output impedance can go at half or so and make a better match to my CLS,s.
If possible, a pair of NEW monoblocks is quite less costly than a not so old ARC 100.2 or a Sanders ESL amp and even I will get an authentic tube sound.
While they tend to be reliable, output transistors can and do fail. The following is a useful summary of the issues (note: the British term for "tube" is "valve"):
"Transistors also have their fair share of problems, and there are some things that they are just not very good at. Some of the major failings include:
* Low Impedance - Bipolar transistors are inherently low impedance, and additional circuitry is needed to make them work satisfactorily in high impedance circuitry. Noise is also a problem when high impedance sources are used. * Heat - Transistors dislike heat, and if it is not removed, they will destroy themselves. Most transistors can operate with junction temperatures up to about 125 degrees C, but at that temperature, can do no work at all. The life of a transistor is severely shortened by operating at high temperatures. * Thermal Stability - Transistors are subject to some major changes in operation, depending on their temperature. This can make the design of high quality amplifiers difficult, because the transistor has a tendency towards "thermal runaway". This means that as the device gets hotter, it will draw more current, which makes it get hotter still. This continues until the maximum operating temperature is exceeded, and the transistor(s) fail. * Second Breakdown - This is a version of thermal runaway, but at a molecular level. Parts of the internal structure become hotter than others, causing the hottest part to do the most work. This makes it hotter still until the transistor fails. Second breakdown is the most common cause of output transistor failure in power amps. It also happens very fast, and without warning - transistors can fail from second breakdown even when at ambient temperature. * Short-term Overload - Largely due to second breakdown effects, transistors do not tolerate short term overloads, and in many cases even a momentary short circuit will cause instantaneous failure. Compared to valves, transistor circuits are much less capable with difficult loads, and usually must be over-engineered to sometimes extreme levels to prevent failures. * Hard Overload - when a transistor amp goes into overload, it does so with startling clarity. The harmonics produced are such that tweeters can be destroyed very easily, and the sound is altogether unpleasant
Again, there are many advantages as well. Transistor amplifiers are very reliable, and can be counted on to give many years of life without requiring even a basic service (most of the time anyway)."
Once again Kijanki makes a good post. While most anything can ultimately fail, all but the very first transistors introduced many decades ago, have proven themsleves to be extremely sturdy devices.
Nelson Pass re: the Pass Aleph O's:"...The amplifier does not need any maintenance. While the design in conservative, this is a hard running amplifier, as single ended Class A is the lease efficient operating mode. In fifteen years the electrolytic power supply capacitors will get old. Depending on usage, you will begin to have semi-conductor and other failures between 10 and 50 years after date of manufacture. Later, the sun will cool to a white dwarf, and after that the universe will experience heat death..."
I think it's fair to say that the Audio Research amp your considering will not be as "hard running" as Nelson's single ended Class A design.
Im new in Audiogon and I was answering one by one to all the replies in the order that were wrote; I was in the third answer when I saw that one response can be for everyone.
Bdgregory (the fourth): If that manufacturer is right, I need to replace electrolytic caps of a total of 130,000 mfd. probably the cost will increase too much.
Schipo: Your answer is very logical. We have a saying in Spanish: Todo por servir se acaba. I think is something like this: Everything for serving ends.
Unsound: You are right. But I think there is no longer an audio Research dealer in Mexico.
Elizabeth: As I wrote, my concerns are more about transistors than caps. As I know, these devices are very different between them, even if they come from the same production line. So, High End manufacturers of solid state amps, place the output transistors to work at their extreme for 6 months or more; then match all of them to each amplifier. So, if one transistor breaks, the replacement if it is found is not going to match with the rest. If deterioration of transistors occurs with age, a mismatch is logical. And I think there is no dealer in my country.
Inna: Maybe you are right about ARC, but the same problem without a dealer.
Raquel: You are right about tubes, but as I wrote, maybe are not the best to match the stats as George Sanders said.
Wolf: I appreciate your advice. After all, maybe is not a bad idea the 100.2 especially for the cost.
Tmsorosk: As I wrote, maybe we dont notice the lost of quality after many years of probably very slow deterioration.
Kijanki: I have heard exactly what you said about long time storage electrolytic caps and how to restore them. My amps are in use since I purchased them and run warm not hot.
Weseixas: Thanks, my ML stats have new panels.
Kijanki: Is so complex all this. Someone posted in Audioasylum that with age, transistors have small leaks between their elements. Im confused.
Thanks to every one. I have a pair of ML CLS IIz stats driven as I wrote, by an ARC D200 amplifier. I like the tube-sound of my solid state amp, but I heard so many positive comments of the 100.2 that I think it will have the same sound character of mine, but quite better in every aspect. Then I heard something about deterioration of capacitors and transistors with age. For my budget, a used 100.2 or a Sanders ESL amp (specially designed for stats), are the two options in my mind. The Sanders (not the Inner Sound), is more recent but as I know this amp doesnt have tube-like sound. So my thoughts were more on the 100.2 The problem is that I live in Mexico and would be a blind purchase in Audiogon. So seeing your answers, maybe a more recent ESL Amp will be a better choice. I dont know. Also George Sanders said that tubes are not very good for electrostats, because they have bigger impedance than the speakers. Buy the way, I cannot afford the exception: the Wolcott amp. Thanks again and best regards
Thanks, I apreciate your reply. I already have an ARC D200, predecessor of the 100.2 (same output MET transistors, dimensions, wattage, etc) purchased with an ARC SP9 MkIII preamp in 1994. I thought that both are now as when were new. Not a trace of hum or unbalanced channels, distortion, etc. It is possible that I have not noticed a decrease in quality of my amps over the years. I can replace capacitors, but if transistors are with some deterioration, thats other thing and maybe is better not to buy a relatively old solid state amp. Best regards
Thanks Jaybo, I apreciate your reply. Most answers I received said that age deteriorates capacitors, even transistors and other parts. Now I am thinking that maybe is not a very good idea to get a 100.2 amp at this time. Best regards
Iv'e had decent Solid State amps for 38 years and the only issue I had was a blown fuse , do to my own duefesness . I leave them turned on all the l time .
If you only get 10 years or so from a SS used component that cost a fraction of a new one, I say you win. If you can't get it fixed somewhere that is kinda sad, but I've owned some stuff that seems to go on forever. I still have an Adcom 535II that I use for a utility amp (secondary summer deck speakers) that sounds great and refuses to die.
Electrolytic caps can last 50 years but every 10degC in temperature increase cuts life by half (it is simply drying out). It is gradual process that increases ESR (Effective Series Resistance) of capacitor up to a point where ESR is so high that capacitor is getting hot from the power losses. Thermal runaway is even possible since hot capacitor has even higher ESR that heats up capacitor further creating condition for explosion (capacitors have vent/fuse).
I would replace 10 year old cap only if it was exposed to temperature (next to tube, etc). Be careful with amplifier that was in storage for a long time (many years) since electrolyte eats up aluminium oxide that serves as isolation (lowering breakdown voltage). Voltage on capacitor builds up aluminum oxide layer again - increasing breakdown voltage but it has to be done slowly - over few days using variable transformer slowly increasing voltage in steps.
I remember I read an interview with Jeff Rowland somewhere. He promised that he would fix every amplifier he'd ever made, for as long as he was alive. Maybe ARC will too. It is their problem to find proper transistors and other stuff not ours. True, well-made and maintained tube amps can probably last for longer than hundred years, no one knows yet.
The above comments are generally correct, as is the comment that an amp made in 1998 is not old.
I would add, however, that age with solid-state amps is more of an issue than it is with tube amps. The output transistors in solid-state amps can go out of production, and if such an amp loses an output device, it can't be fixed and the amp is toast. This won't happen to a tube amp that uses output tubes common in the tens of thousands of tubed guitar amps that are sold each year, e.g., EL-34's, 6L6, 6V6, 6550, etc., or that use a classic triode like the 300B, i.e., this won't happen with most tube amps.
In addition, when a solid-state amp breaks, it usually has to be sent to a tech or to the manufacturer to be repaired. When a tube amp malfunctions, it's more often than not a tube that is the source of the problem, and they are user-replaceable.
Finally, with a tube amp, the tubes are the circuit, and when the amp is retubed, it's basically a brand-new new amp.
Well, my Nakamichi deck is 30 years old, I bought it 10 years ago and heard no difference until I had it cleaned and aligned. Electronics seems to be just fine. Also, I bought Audiolab integrated new 12 years ago and again - no difference. So it depends, I guess.
Yes, but probably not a worry for the age of the amps your considering, and they usually can be refurbished, especially with an established brand like ARC.
at least one manufacturer recommends replacing capacitors every 10 years or so. Many mfg's though say don't bother til they break. Most other parts are good for nearly ever I believe, except maybe panel lamps, or electro-mechanical components such as switches.
Any local tech should be able to recap the amp for you, if you are at all adventurous you could do it yourself as well. As Jaybo said it is possible it will be in fine shape, it could possible go many more years.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.
