new power amplifiers ART108A Class A

[AnotherJohnson]

FWIW, I owned a pair of 150 wpc into 8 ohms class A Krell amps and vertically biamped them. They were incredible, but the LP275Ms sounded better in direct comparison. So all watts, including even class A watts, aren’t necessarily created equal.

[roberto]

I found the presentation of the new power amps in Facebook. Here is the link:

https://www.facebook.com/search/top?q=c ... n%20design

[admin]

Interesting. I am surprised at the price point. The average buyer is going to wonder why the 108A's are more expensive than the ART300's. I'm not exactly sure of the answer myself.

[Big Dog RJ]

Yes, good question Admin.

The only answer to that could possibly be the Class A rating of these new monoblocks. I had a feeling that CJ would eventually produce a monoblock version of the ART27A. Although not entirely power related in terms of push-pull Class AB config but similar to the ART27A, these are supposed to be all out Class A power amplifiers... am I correct?

However, the question I have at this stage is, exactly how much power is in Class A bias?

Can certainly understand the pricing, for merely two reasons:
1. Operation in Class A bias, especially with tubes is no easy task. They heat up an awful lot and deliver vast amounts of unwanted energy, yet at the same time, they sound awe-inspiring! It takes very skilled hands to do this design and I'm thinking that JF and his team have done a marvellous job here. Very similar to what I've had modded on my monoblocks but obviously not with these newer transformers, that's where the magic is I believe. I can certainly follow how these would perform, and it would be an eye opener to experience these on some very high grade speakers.

2. The price point stands for prestige and top notch quality, no compromises here. It is definitely targeted to those who can afford the big bucks, and those who demand nothing less. It's not saying that these are superior to the ART300's, just different in design and tube topology. ART300's are power houses, rated at a whopping 300w/ch of raw tube power. These new ART108A's are equally capable but supposed to have serious Class A power, thus will surpass the ART300's in terms of Class A bias operation.

Whether you like one over the other or which one's better, can only be answered by the individual owners. It's definitely a personal preference.
A few years ago, when I visited my good mate in Spore and I experienced the ART300's driving his CLX's, that was my reference point. It was superb! However, the preamp wasn't the GAT, it was a Momentum preamp.
After a few months upon my return, I personally tried the ART27A on my CLX's. Although it was a remarkable experience in the midrange, it didn't quite have that control & grip factor on full range stats, especially in terms of explosive dynamics, transient speed and acceleration, compared to my present Class A 125w monoblocks. So, there we were thinking, if only they made a monoblock version of the ART27A's... and there you have it!

Now, spending nearly 50grand just for amplifiers is an insane amount of dollars. However, like I said, plenty of other eager consumers out there who demand the utmost top tier stuff and won't settle for any less. I believe these monoblocks will be a massive turning point in the highend arena. These will very easily surpass ARC's new M series monoblocks and will very easily compete with VTL and VAC's Statement amplifiers. The Statements are about another 150grand more price wise but this is where these CJ amps are offered in terms of better value, I would say.

If I'm lucky this year round or perhaps sometime early next year, I'll definitely get a chance to audition these. I sincerely believe these are truly unique.

Nice one and well done to JF and his team.
Cheers to Class A!
RJ

[roberto]

I don't argue that the type Class A has some benefits and much better specs too. But having an amplifier as a car motor with only one gear, as should say the first gear, and the motor spinning at the top of the revolutions, let say a 6500 RPM, there is a lot of waste of energy. Type Class AB is the way to go. Yes, I do know that I am missing something, but this something it not as good to cut my veins for it.
Perhaps if I were wealthy enough, and spending that amount of money in a couple of mono blocks I might buy them, because they are better than what I have...

Happy listening!

[AnotherJohnson]

Interesting. I am surprised at the price point. The average buyer is going to wonder why the 108A's are more expensive than the ART300's. I'm not exactly sure of the answer myself.

I don’t think there’s any doubt that the price goes with the class A performance.

That’s a heck of a lot of class A watts for a tube based amp.

As RJ points out, it was probably a fairly difficult project to be able to develop a product that would be warranteeable.

They’re trying to recoup R&D costs, and they’re making a SPLASH!

[Big Dog RJ]

I don't argue that the type Class A has some benefits and much better specs too. But having an amplifier as a car motor with only one gear, as should say the first gear, and the motor spinning at the top of the revolutions, let say a 6500 RPM, there is a lot of waste of energy. Type Class AB is the way to go. Yes, I do know that I am missing something, but this something it not as good to cut my veins for it.
Perhaps if I were wealthy enough, and spending that amount of money in a couple of mono blocks I might buy them, because they are better than what I have...

Happy listening!

Very good point Robbo mate!

There is something truly unique though in the tonal quality of Class A, and it's quite a difficult balance to get it right in terms of SS design... Pass Labs comes to mind, as well as Momentums or the Relentless amplifiers. Yet, this is an all tube design, Class A rated top to bottom, with the legendary KT88 tubes. No easy task to design this, and very time consuming with plenty of hours in trial and error. I'm sure JF and his team were designing things out since the introduction of the ART27A... I wouldn't be surprised!

I'll say one thing though, this would be a real holy moly experience to drive with CLX's! Very nice indeed. Having modded to Class A myself on just 60w possible is mighty fine! Most probably, all the power that I would ever require. Yet, the possibilities and challenges of a high powered tube based Class A bias is something that takes years to develop, and get it perfect! I think the choice of KT88's is solely for that reason.

Would be very interesting to learn if these would sound very similar to the ART27A but with far greater grip and control, plus a far more effortless drive factor, compared to a single stereo version... just my thoughts.

Cheers matey,
RJ

[roberto]

We do know Class A has better sound. On the other hand, the Class A at moderated level switching to Class A-B when energy demanding is, the linear power design is the solution. The Classic 120 is a linear power design.

[AnotherJohnson]

I will guarantee that if you put the 108A side by side with the Classic 120 … or even against the ART300, if your ears work, you’ll hear a difference.

It will depend on how sensitive you are to the switching distortion.

In guitar amps, we don’t care and are generally happy with A-B amps. Edit: although now that I think about it, I do have one class A guitar amp.

If I won a contest and could have any CJ amp at no cost, I would probably choose the 108A. Why? Because every time JF has told me that something was better or worth the cost, HE’S BEEN RIGHT! JF probably believes that new amp sounds like $48k. Otherwise he wouldn’t have priced there.

I am not going to be among the first to buy. But I would be more likely to get the 108As than the 27s.

[roberto]

Linearity refers to the ability of the amplifier to produce signals that are accurate copies of the input. A linear amplifier responds to different frequency components independently, and tends not to generate harmonic distortion or intermodulation distortion.

[roberto]

I will guarantee that if you put the 108A side by side with the Classic 120 … or even against the ART300, if your ears work, you’ll hear a difference.

It will depend on how sensitive you are the the switching distortion.

In guitar amps, we don’t care and are generally happy with A-B amps.

If I won a contest and could have any CJ amp at no cost, I would probably choose the 108A. Why? Because every time JF has told me that something was better or worth the cost, HE’S BEEN RIGHT! JF probably believes that new amp sounds like $40k. Otherwise he wouldn’t have priced there.

I am not going to be among the first to buy. But I would be more likely to get the 108As than the 27s.

Of course they are better than my 120s. Class A has more magic. And the new amps are my dream. As I said before, if money is not an issue which it is for me at this moment, I will love to have them with me.

[roberto]

Official announcement for CJ distributors

Happy listening.

IMG_6095.PNG (1.5 MiB) Viewed 773 times

[Big Dog RJ]

Correct there Robbo mate,

In fact, this is what the LP series stands for- Linear Pentode amplifier. It's a marvellous design, and definitely linear to the input signal, no distortion and outstanding performance, without a doubt.

These new ART108A's though, will be a very interesting presentation of sound, Class A bias with the KT88 config, I would think basically a monoblock version of the ART27A...?

What are your thoughts?
Best, RJ

[AnotherJohnson]

The goal of EVERY high fidelity amplifier is to follow the input linearly. Some do it better than others, but every defender of every design believes that his amp is linear.

[roberto]

Hola,
I just would like to show what ultra linear circuit is. It is what Jeff is using on the amps not class A. They are different amps than Class A-B.

Here is more explained:
https://en.wikipedia.org/wiki/Ultra-lin ... d_circuits

[roberto]

On the other hand, Class A has a magical sound that when you hear it, you are hoked immediately.

[AnotherJohnson]

An amp can be class A and ultra linear at the same time. One does not preclude the other.

CJ uses a relatively small amount of negative feedback (usually 12 dB) to achieve the ultra linear label.

In the link below, you will find more detailed information, but from a listeners perspective, it’s not important. If you’re sensitive to the class A-B hand off from one tube to the other, you’ll like class A better, regardless of ultra linear status.

http://www.oestex.com/tubes/ul.html