CT6 vs original Premier 17LS? Same circuit?

[JoshT289]

Back in the day I had a Premier 17LS version 1 and absolutely loved how it sounded with my MF2250. I actually owned it for several years, but it had operational issues that neither my dealer nor CJ could duplicate, so I ended up trading it in for a CA200 and setting the MF2250 aside for awhile. The story evolves per my recent introduction and posts, but my question is whether the CT6 was identical inside to the first 17LS. In fact, my dealer, who's name I'll not mention even though he probably wouldn't care and is now retired, told me exactly that, and he truly was someone who would have known.

It came up because one of my thoughts at the time was to swap my used 17LS for a new CT6 (with some extra payment, naturally), and my dealer told me outright that it was the same preamp in a new case and so he didn't want me to swap them. And yet no one online or in any of the reviews of the CT6 ever pointed this out. They sure look the same in pictures, though I prefer the faceplate of the 17LS. He might not have meant literally, but that's how I understood it. Back then, the CT6 was the same price as the old 17LS ($4,500), the 17LS2 was $6,000 and being phased out, and the CT5 was $7,500.

As posted, I now have a Premier 11A, which, by the way, I just had upgraded with the new C1 Teflon caps (more on that to come)! I love it with my Rogue Audio RP-5. They are truly a lovely match and there is no logical reason for me to upgrade. I even love the Rogue's built in phonostage. But I do find myself lurking on the used equipment sales sites for a 16LS or an Art, or something else of the same era as the 11A, just perhaps to think about in the future, lol, and have seen a CT6.

[Joe Appierto]

Hi Josh,

Glad you're continuing to enjoy the upgraded 11A

I just looked at the two on the CJ web site and they certainly look the same in terms of specifications. About the only difference I noticed was the 17LS being 2 pounds heavier which could easily be explained by casework differences. The CT6 is a 5 year newer model (2005 vs. 2000) so maybe some of the innards changed?

Regards,
Joe

[AnotherJohnson]

1. I don’t KNOW.

2. It has been commonplace for CJ to migrate the good ideas and topologies from high level models to newer lower level models.

3. A big distinguishing feature between upper and lower levels or between lines has been, and is parts quality.

4. Nothing CJ makes contains bad parts (except possibly the lowly RC10). But not everything CJ makes contains the very best parts.

5. So … it is possible that the topological differences have vanished, but there may still be differences.

6. In my own case, between these two, I would choose the CT6. It is the newer unit, and the time difference in development, and the overall transition in the product line, are in the CT6’s favor.

[JoshT289]

Hi Josh,

Glad you're continuing to enjoy the upgraded 11A

I just looked at the two on the CJ web site and they certainly look the same in terms of specifications. About the only difference I noticed was the 17LS being 2 pounds heavier which could easily be explained by casework differences. The CT6 is a 5 year newer model (2005 vs. 2000) so maybe some of the innards changed?

Regards,
Joe

Thanks Joe! It really is an amazing piece, and the Winged C SED 6550s are sounding amazing! I'll report more after I figure I've hit 200 hours, but I sure have been enjoying it already.

On the CT6, I think my dealer was not being literal after all - I'll respond a bit more to Another Johnson's replay below.

[JoshT289]

1. I don’t KNOW.

2. It has been commonplace for CJ to migrate the good ideas and topologies from high level models to newer lower level models.

3. A big distinguishing feature between upper and lower levels or between lines has been, and is parts quality.

4. Nothing CJ makes contains bad parts (except possibly the lowly RC10). But not everything CJ makes contains the very best parts.

5. So … it is possible that the topological differences have vanished, but there may still be differences.

6. In my own case, between these two, I would choose the CT6. It is the newer unit, and the time difference in development, and the overall transition in the product line, are in the CT6’s favor.

Thanks AJ! After some Google Images searches, I think my dealer was NOT being literal after all in what he said. The CT6 appears to have a slightly different layout internally than the Premier 17LS, and I think the 17LS pictures I found were version one. The CT6 actually seems to have fewer (and maybe smaller) capacitors than the 17LS. In any event, the PCB arrangements do no look identical. So, my dealer likely meant they were effectively the same circuit and hence made no sense to swap (even though he said it in what seemed a literal meaning).

[AnotherJohnson]

FWIW

http://www.enjoythemusic.com/superiorau ... on_ct6.htm

[JoshT289]

FWIW

http://www.enjoythemusic.com/superiorau ... on_ct6.htm

Thanks. I did read that and other reviews and, as I noted, none suggest that it's anything but an entirely new preamplifier.

Anyway, I think the answer is that it was not identical and so the dealer who told me that must not have meant it literally, so it makes sense that what he said wouldn't appear in a review. FWIW, my dealer also told me that the MF 2275 was identical to the MF2250 and that the MF2550 was the same as the MF2500. He said they were just put in newer boxes to match the look of the other new products. Not the SE versions, of course, but the base versions. No one else has said that either, so maybe he was wrong about both or not being literal about either. Dunno.

[AnotherJohnson]

FWIW, my dealer also told me that the MF 2275 was identical to the MF2250 and that the MF2550 was the same as the MF2500. He said they were just put in newer boxes to match the look of the other new products. Not the SE versions, of course, but the base versions. No one else has said that either, so maybe he was wrong about both or not being literal about either. Dunno.

Man, he must’ve had tin ears, or was overstocked with NOS needing to move.

The difference between the 2500 and 2550 is obvious even to casual listeners.

[Big Dog RJ]

Without a doubt!

Had the MF2550SE for a while driving the CLX's, whiles my monoblocks were being modded. Visited another chaps place where his main amplifier was the MF2500. After a few home trials he wanted to try out my MF2550SE just to experience how much further it would enhance his Maggie's. Oh! Boy, it not only enhanced his 3.7i's but took the performance into another dimension.

Another home demo worth the effort and worth the spend. He ended up purchasing the MF2550SE!

The two are quite different, such that the MF2550/SE uses both Mosfet inputs and Bi-polar devices for the output stage. Making it a very powerful amplifier capable of handling reactive loudspeaker loads. It's DNA was derived from the mighty Premier 350, which was CJ's top of the line in SS. Nothing ever came close to the Prem350A, other than the MF2550SE.

The SE version takes this brilliant performance to another level, whereby it utilises Teflon caps, Vishay resistors and upgraded internal wiring in it's power supplies. Whereas the MF2500 was quite similar to CJ's original MF series power amplifiers, primarily replacing the MF2300. It is not as notorious as the Prem350A and doesn't have the raw brute force and finesse of the MF2550SE, although the MF2500 is still quite a good amplifier in its own way. Partner it with the right gear and matching speakers, it will drive pretty smoothly.

Partner the MF2550SE with anything, and it will bring the live performance to you!

Cheers and all the best,
RJ

[JoshT289]

Guys,

First of all, this fellow certainly does NOT have tin ears nor was he trying to push product on me. When he said this, the MF2275 had just come out and he had no inventory of the older amps as they'd been discontinued several year before. I've known him since the late 1990s, and he sold me my Premier 17LS and MF2250, and later a CA200. We are friends.

Big Dog, comparing the SE version of the newer amp to the older amp (which did not have an SE version) is apples to oranges. As would be comparing the newer SE versions to the newer base versions of the equivalent amp. My understanding is that they are completely different animals. And yet not everyone bought the SE versions when the newer amps came out (though you'd certainly think so based on reviews, just as you'd assume everyone gets the SE versions of the Classic 62 and 120 based on the reviews out there).

Also, Big Dog, the older MF2250 and MF2500 also used FET inputs and Bi-polar devices for the output stage. That's a fact you can confirm on the CJ sight. Those two amps were a departure from the earlier MF stuff.

To be clear, the dealer I am referring to was not comparing the MF2250 or MF2500 to the SE versions of the newer amps. What he told me, when the MF2275 was first introduced, was that the basic MF2275 was the same circuit as the MF2250 but in a nicer box. I am very familiar with the MF2250 as I've owned one since 2000, but I never bothered to audition either version of the MF2275 because I was happy with the 2250. So I'm just reporting what I was told.

This was a private conversation that came up when we were chatting about this and that, and maybe he was just telling me not to bother upgrading to the base MF2275. He might have been wrong, or maybe meant they were so similar as to be functionally equivalent. In any event, this fellow is a bit of a legendary CJ guy FWIW. He had a huge role in the distribution and sale of CJ products. Eventually he was selling mostly online and was seemingly the only guy out there. He has since retired and closed his shop, but still sells NOS CJ products online.

Josh

[Big Dog RJ]

Ah! Yes that's correct Josh.

I did miss that... good point you raised.

In fact, seems like I was referring to the earlier MF2000 series amplifiers (MF2100, 2200 & 2300/A) all of which I've owned and were ordered for several of our valued customers, who all upgraded towards the newer MF series over the years. Those previous MF series used Jfet inputs and Mosfet outputs. Then when the newer MF models came out, these amplifiers were able to handle difficult loads, delivering more current capacity, especially those reactive loudspeakers, where their impedence curves are notorious.

The combination of Mosfet & Bi-polar devices was a breakthrough for CJ in SS design, and these newer amplifiers were definitely something to consider in terms of overall performance. Yes, your dealer mate is correct, in that these latest MF series models pretty much have the same base circuit. Infact, even CJ's tube gear share the same base circuit, it's all fairly simple and clean. The SE versions are designed the exact same way, only differences are the higher quality parts along the chain and power supplies, which yield better results. That's about it really!

Many thanks for pointing that out, afterall being in the dealership network myself I should have known better .
This is what happens when you pass a certain age, work too hard for 6 days in a row and do late night/early morning listening sessions... it's now 2:40am and the tubes are glowing!

Cheers Josh, keep safe and be well.
Oh! And enjoy those fine tunes!
RJ

[JoshT289]

Thanks Big Dog, and I hope you're sleeping well as I type this. As the days get warmer down there, they're getting colder up here in Boston. I told my wife I was turning on both space heaters this morning: Our gas fireplace and the Premier 11A, lol!

[admin]

Yes, it is certainly getting colder. I live an hour outside of Boston. We had temps in the 30's last night. My CJ ART monoblocks make good space heaters as well!