CAT has those great looking Knobs / display on the CAT JL2 sign , it was a nice easy system .
JL5 is autobias with only 4 tubes per channel .
JL5 is autobias with only 4 tubes per channel .
Whither Audio Research
- Thread starter davidavdavid
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It is always a compromise. You say you’re willing to compromise. I agree and do as well. We put up with some things because the alternative isn’t perfect either.
Does lousy have some hyper negative meaning for some folks? Here it just means “not good.”
I’ve got to admit that my value system and economy of time would be strained, and for no good purpose, if I explained why I find so much humor. It’s not schadenfreude, but I’ll bet there is a German philosopher who’s coined a word.
I’ll answer my own question. Wiktionary does give it more negative weight than I’d intended, but tempers the definition with
- Considered an offensive insult prior to World War II, implying filthiness. Now considered a mild or rather dated term.
And it is for this reason that I got an ARC 160S after 3 years of nervousness with the red light fuse and horrendously user-unfriendly Jadis PA100, which is manual biased but no instructions on how to do it. I had to watch out for those red lights at every playing session. Wore me down.
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Following up on my hilarious comment (because others have posted with similar ideas) … and I have some time having just finished setting up a TT.
Auto bias does not offer you protection against a meltdown. It is the plate fuse that offers the protection.
I am sympathetic with the preference for plate fuses instead of resistors which are more difficult to fix after they blow. The new ARC gear does include plate fuses for protection. Their auto bias strategy still pairs tubes, leading to the need for tube matching for best results.
Bias adjustments change the points where the amp goes into clipping. Clipping sounds bad and is hard on speakers. Auto bias is a big step forward from the methods ARC has expected their customers to suffer through over the years.
FWIW, my current main system is REF 6SE, REF Phono 3, REF 250SEs. I’m a fan. This gear replaced a similar CJ system I’d used as the main room for several years. I’m a fan of CJ too.
The CJ bias method (someone called it the equivalent of inaccurate above) is actually quite accurate. The LEDs are precise. The method is easy. Every tube has its own adjustment, so no tube matching is required. And there have always been plate fuses in CJ amps.
Maybe hilarious was the wrong word … but the ideas that auto bias would prevent a meltdown and that CJ’s big monoblocks have bogus LEDs just struck me negatively.
On the meltdown issue, the most important things you can do are
1. Buy good tubes, set bias, and check it every year.
2. Replace them on the recommended schedule
3. Make sure your plate fuses are the correct values.
4. If you hear motorboating, or see red plating, shut the amp down immediately before damage occurs. Damage is not generally instantaneous.
Historically ARC has not included plate fuses but has used resistors instead (for their sound qualities). The new amps have plate fuses, so that’s good. Wilson uses resistors instead of fuses to protect their speakers too, but at least the Wilson resistors are easy to replace (though absurdly expensive). Before anyone jumps me for saying that, I am running Wilson speakers and am a fan.
As a guy who’s had a lot of tube gear dating back to the original MC225/240/275 series, a lot of the drama doesn’t seem like drama to me. There’s very little new in the tube amp design world. Those old McIntosh amps were self biasing.
The picture I posted with a rackfull of ARC gear was from a while back when I was researching the Ref 3 phonostage for review -- iirc that was late 2016, it had just come out. With the Ref 2SE and Ref Phono 10 on hand I had good phonostage compares for the Ref 3. It was great fun. At that time I had Lamm M1.2 Ref monoblock amps (still do) and Wilson speakers, either the Alexia or Alexia Series 2.
For today's system, click the 'System' link in my signature. It is almost all different now.
"Buy good tubes."
From what I understand, ARC regards good tubes as only those coming from them. I have yet to meet or know someone who actually bought a fleet of tubes from them. And everyone knows the reason - $$$$$$. As I'm still at 500 out of the estimated 3000 hours for their KT150, I am not thinking about such scenario.
They are expensive but their tube quality control is legendary. It’s worth it.
I truly agree. Their factory supplied 6550s on my VS 110 and 115 have impeccable bias readings. I learned that when I substituted them with Gold Lions and Psvanne KT88s where the readings on some tubes were either too high or too low on the recommended range. I'm just conditioning myself when I need to knock on their door.
Upscale has sold ARC matched grade tubes in the past, but right now Kevin’s policy is to not sell KT150s unless you’ve bought a Prima Luna from him.
ARC’s current policy is to hold their KT150s back for new production.
Upscale gets a batch of tubes in and sorts them into multiple grades, each grade sold at a different price. Upscale’s rejects go to other wholesale buyers.
ARC gets a batch of tubes and sorts them into two grades. Suitable, and reject. The suitable are characterized and matched with others of like character. Rejects are sold to other wholesale buyers.
ARC’s in house matching will give you their best. CJ is the same, ie CJ believes that you will get the best sound by buying at two to three times prevailing market prices from them.
Does it matter? You have to decide for yourself. You are the one that’s going to listen.
I use tubes from ARC and from Upscale in my ARC gear. I’ve used tubes from CJ and Upscale in my CJ gear. Generally, a new tube from any source is better than one that’s about to red plate or motorboat because of eminent failure.
I like Upscale a lot. I had another nice chat with Kevin Deal at Axpona. My friends have good things to say about the quality of his tubes.
That will add to the already tough expenses for the tubes. Lol. I wonder if Upscale's KT150s are cheaper than ARC itself.
I understand what you’re saying, but it bothers me that people spend $80k and more on tube electronics and then worry about an extra $2k/yr in tube maintenance.
Phono cartridges are similar. 5 year life for a $10k cartridge is $2k/yr.
This is not a cheap hobby. Unless you stream with modest electronics and speakers.
ARC's quote for 8pcs KT150 with 4 small tubes is $3800, without shipping and taxes. That is twice the price of tube sellers on the net, not the likes of Upscale though. I do appreciate the strict selection process of ARC and others, and it's something that takes time to digest before laying out the money. It's called conditioning.
Well, I would be very pleased to present my point of view and debate it with you at the exact moment, but you preferred an unfriendly and hilarious "someone called it .." . But I will write for the benefit of our readers.
I am a cj fan - I have owned a lot of their amplifiers and still own the ARTs and a GAT2. I also own a Fluke voltmeter and large experience in electronic instrumentation, I know how to check and confirm bias currents and fortunately I could get the schematics of the cj amplifiers I owned and own.
cj bias system is based on a trigger system associated to LEDs - it just detects overbiasing and then by instinct we reduce bias just to switch off the LED. Many users have not hands firm enough to do it properly - they reduce it too much and are happy with the underbias condition. I know of it, most of my gear ends in the hands of good friends.
Next the system. The LED IC comparators are driven by 1.2 Mohm resistors wisely protected by diodes that have significant leakage current, unfortunately in my experience varying from diode to diode. Also, cj has a policy of not cleaning solder resin from boards, that can cause leaks in this system. My conclusion - in an 8 tube cj amplifier properly adjusted using the LEDs we can easily have variance of bias of around 8%. Considering the high quality and oversize of the cj output transformers it is surely good enough for the purpose, but IMO not exactly accurate.
BTW, the cj amplifiers have HV fuse protection and are extremely robust. To the point that I use them to burn-in all my 6550 and KT tubes - as anyone can guess seeing the large burn-in stations in photos of the Jadis, cj or ARC factories, the secret of proper tubes is significant time adequate burn-in and matching with proper gear.
If they’re selling again, I’m buying. I’m on the list for when they begin selling direct again.ARC's quote for 8pcs KT150 with 4 small tubes is $3800, without shipping and taxes. That is twice the price of tube sellers on the net, not the likes of Upscale though. I do appreciate the strict selection process of ARC and others, and it's something that takes time to digest before laying out the money. It's called conditioning.
As for $3800, the KT150s are predicted to be good for 3000 hours. The small tubes are predicted to go for 4000 iirc. So that would be less $1300/year for a 1000 hour/year user. About $1.30/hr.
I realize that it’s $3800 for maintenance, but many hobbies are like this.
I think the guys who it hurts most are the ones who buy gear that has been retired for a few generations. The electronics have depreciated from $80k to $20k, but the tubes have gone up from $1k to $4k.
ARC's quote for 8pcs KT150 with 4 small tubes is $3800, without shipping and taxes. That is twice the price of tube sellers on the net, not the likes of Upscale though. I do appreciate the strict selection process of ARC and others, and it's something that takes time to digest before laying out the money. It's called conditioning.
I usually bought 12 matched tubes - one octet and a quartet of the same specs from reliable sources in Germany. After burning-in I could easily get 4 or 5 closely matched pairs, most times a suspect tube (!) and used the remaining for amplifiers that do not need matching. The real issue with matching is that the tube should be measured in the exact conditions of operation and most sellers are not able to do it - I built my own matching jigs.
You mean the pins? I don't for new power tubes. But for NOS small tubes which are visually dirty, I do.
You’re basically saying that fumble fingered bias adjusters get it wrong. That’s true of any bias adjusting method, especially the three tube at a time kabuki dance you see on some ARC amps, like the REF 250.
I don’t know where you are or what your background is. And what’s more, I don’t care. You are entitled to your opinion … and I to mine. I am not interested in supplanting you as a resident expert. I do find many attitudes and assertions here to provoke a humorous reaction. And the folks who put them forward are anxious to “debate.” Like Pavlov will ring the bell and there will be treats.
Just sayin’. Nuff said.