Greetings to all of you on the forum. I'm a new member and I've actually known the forum for a few years.
Good. I state that I am a self-builder technician and I am writing to you because I am thinking of buying the pair of audioresearch classic 150 model amplifiers, one of which is not working. The seller says one works and the other is broken. Missing 2 transistors inside. Do you think they are worth buying? For both, 3,500 euros are being asked. As far as I know, audioresearch doesn't release codes for broken transistors, how can this be done? Can you help me understand what is right to do? Is it worth it? Thank you.
Good. I state that I am a self-builder technician and I am writing to you because I am thinking of buying the pair of audioresearch classic 150 model amplifiers, one of which is not working. The seller says one works and the other is broken. Missing 2 transistors inside. Do you think they are worth buying? For both, 3,500 euros are being asked. As far as I know, audioresearch doesn't release codes for broken transistors, how can this be done? Can you help me understand what is right to do? Is it worth it? Thank you.
Attachments
Last edited:
English please.
The safe decision is whether one Classic 150 is worth 3500 Euros, with some spare parts free.
Assuming that you cannot repair the amplifier, do you have an authorized ARC repair facility within driving distance?
Assuming that you cannot repair the amplifier, do you have an authorized ARC repair facility within driving distance?
Looks like a money pit to me. Even if both were working I'd say at nearly 40 years old 3500 Euros would be too much. With all of the silicon devices in there I'd say it's not really a "classic". Save your money and wait until something newer and better comes along.
Cheers, S.
Cheers, S.
Audio research will sell you the color coded transistors. You will pay more of course. Stacked Power supplies are not fun to troubleshoot but decent technician should not have troubles with them .
Sure , I'm waiting to see "something cheaper ,newer and better " in the range of true 150w per channel of tube triode power and built quality remotely comparable to those CL150 coming along ....
Sure , I'm waiting to see "something cheaper ,newer and better " in the range of true 150w per channel of tube triode power and built quality remotely comparable to those CL150 coming along ....
they usually have replacement for obsolete silicone . Switches , pots and mechanical parts , certain capacitors are problematic.
3500 euros seems a bit excessive for what is essentially a broken pair of Classic 150 amps. ARC may have replacement transistors available for these but they will be a challenge to repair. ARC hybrid amps of the era were quite finicky about the 6550s used in them, and tube rolling at some point may have contributed to the failure.
Last edited:
Why would they be finicky if ARC ran them almost at half of dissipation rate ? In Europe US made equipment is much more expensive than here and those are behemoths .
I have rebuilt a lot of Audio Research gear, but it's been limited to preamps and phono preamp projects. I have been able to get good schematics before I purchased, and it's worked out great. As said, not all parts are disclosed on the factory schematics.
If you can get a factory schematic, and maybe look for the transistor (or FET or whatever it ends up being) info online from other DIYers... then ultimately, like any DIY, if you commit you can finish it. You could finish it even without that, but it will be a much harder journey.
That price, to me in the US, seems pretty high. But obviously, I guess that equipment is much more available here, especially broken. So I don't know what to tell you. But...
At $3500 euros, you could build one heck of a set of amps from scratch based on any manufacturer you liked. That is something to consider too.
If you can get a factory schematic, and maybe look for the transistor (or FET or whatever it ends up being) info online from other DIYers... then ultimately, like any DIY, if you commit you can finish it. You could finish it even without that, but it will be a much harder journey.
That price, to me in the US, seems pretty high. But obviously, I guess that equipment is much more available here, especially broken. So I don't know what to tell you. But...
At $3500 euros, you could build one heck of a set of amps from scratch based on any manufacturer you liked. That is something to consider too.
What can he build for $3.5k Euro which would provide " real " 150 W in triode AND have any resale value ? You guys are dreaming
Fair question. My answer would be, maybe it would be scaled down a little, maybe not, but it would sound great, be brand new and reliable.
Current AR is a corporate conglomerate. It's not the old school, we will fix anything family business. There are lots of threads online saying AR is saying, 'you're on your own', or such crazy $, that's you're on your own is still the answer.
And you totally skipped the part where I said, if you want to commit to the time and effort, you can fix these.
And what does resale matter any way? Who does all this DIY work to lose money? Not me. I am in this for the fun and the audio outcome.
To each their own.
To be honest , I had ARC amp from that era D115 MkII which was misbehaving. Because I'm not a " decent technician " by any stretch I took a shoot gun approach- obviously. First I replaced all el caps . ( ARC tech suggested it too ) . Then I futzed with tubes ( bazillion of them ) than under the influence of some savvy techs I changed all the Zener diodes - boatload of them . Nope. So I came to realization its time to get the wallet out and pay. My EE friend spent considerable amount of time and found that o.90 cents resistor which was wrecking the havoc and accepted $500 bill to fix the amp. I found the ARC D115MKII smoking touted vintage French amp which sold south of $8k in US. BUT , like all US gear and generally everything here ARC amp is just butt ugly. Main reason for ARC gear not being collectible is its low sex appeal and large supply.
I never had fun with DIY. Only did it because for the reason the general population is populated by deaf morons wiling to spend tens of thousands on cars to impress people they hate but a few bucks on music making machines I had to spend big for something which by any reason should be sold in Walmart for close to nothing ...🙂
Because tube rollers generally don't buy tightly matched octets from ARC and there is no provision for individual bias adjustments in the design. I have not worked on the Classic 150, but grew tired of fixing M100s in particular with damaged power supply components and servo circuits. The Classic 150 is basically a solid state amplifier with a tube output stage, most of the driver circuitry is operating at high voltages (250V, 330V, etc).
https://www.arcdb.ws/Database/CL150/ARC_CL150_schematic_and_parts_list.pdf
This is a complex amplifier and will be difficult to repair if you are unfamiliar with the design. I am really good at fixing stuff and I would give this one a miss.
For $3800 you ought to be able to be build a pretty decent stereo amplifier if you have the skill and motivation. A pair of GM70 in PP will give you 150W or more, although the heat and power consumption will be something to contend with if you don't live in a cold climate.. (After a dozen years with SE GM70s I am considering phasing them out for something more efficient in the next couple of years.)
I've always seen people who focus on resale value as a bit of problem, when I was trying to make a go of it the lack of name recognition meant that flippers did not buy my gear. Many of those who did are still running it decades later, or upgraded when I had a new idea. Alas not enough to sustain a business. This is DIY and the Classic 150 I would argue is far from the most desirable amplifier ARC made. I would look at the stuff with a pure tube signal path if ARC floats your boat. (D75?)
Last edited:
They don't buy the octets from ARC because the price is ridiculous considering what ARC pays for the tubes wholesale.
I consider it a bargain to buy a 150W triode with build quality unachievable by 99% of Diy folks and 105% of DIY folks unqualified to build 150 W reliable tube amp . I don't consider Kevin a DIY since he is a pro ...And was he to build such amps the price would be north of 15k ...
I consider it a bargain to buy a 150W triode with build quality unachievable by 99% of Diy folks and 105% of DIY folks unqualified to build 150 W reliable tube amp . I don't consider Kevin a DIY since he is a pro ...And was he to build such amps the price would be north of 15k ...
Yes, the replacement tubes were ridiculously expensive, but they were burned in and tightly matched. I suspect the fallout in testing was significant based on my own very limited experience. The late 1980s early 1990s when these were probably made was not a good time for quality new production tubes.
First and foremost, I don't think we are serving the original poster. And that does bother me. Or maybe we did. Just don't do it.
Octets. Selling those with a warranty means you bought 1024 tubes, sold maybe 128. If you are lucky. Anyone with hands on tube experience knows how incredibly variable they really are. Thus that expense.
I guess you you'd consider me a pro too, I've been building tube amps since the 1980s and sold many. However, I very much disagree with the statement, "build quality unachievable by 99% of Diy folks and 105% of DIY folks unqualified to build 150 W reliable tube amp."
There isn't a pro engineer anywhere on the planet, in any field, that didn't start out DIY. And some of the "I have another day job" DIYers, have still gotten just as good or better than people actively working in a field.
I get you are bitter about your experience. And I hope you let that go and enjoy the audio experience more going forward.
I have seen multiple DIY projects for not crazy money blow people's minds.