Premier Eleven XS vs. MV-55 (both in triode configuration)

[tubesound]

Hi friends,

I hope some members here could tell us a bit about the differences between the Premier Eleven-XS (a Premier Eleven-A with the output stage configured to use a pair of EL34s operated as triodes) and the MV-55 in triode configuration.

I would appreciate any thoughts or comments!

The Premier Eleven XS uses 5751 and 6FQ7/6CG7 tubes, while the MV-55 uses 12AX7 and 6SN7.

[roberto]

Hola tubesound,

What do your ears tell you? Trust in them, those are the final judges. My liking might be different than yours...and also, what I do like not necessary must be your liking.

Just choose the one that you do liked most and keep that one. This does not means that the older one could be the one that has more finesse and the other might be more dynamic...play the type of music that you are more happy and more intimate presentation... and you can't go wrong with your decision...both are great power amps, and I do love the EL34/6CA7 power tubes.

Happy listening!

[Big Dog RJ]

Nice amps, both are classics in every sense of the term.
I had these amplifiers as well, a Prem11A XS (triode version) driving Quad ESL 63's on top of Gradient subs, it was a marvellous presentation in soundstage depth, probably one of the best at the time.

The Prem11A just came out as a slightly modded version of the original Prem11. Rated at 70w /ch rms, it drove most speakers quite well. At the time, we had Maggie's MG3 3, MG3.5 and Infinity's Ren90's, the Prem11A was excellent!
We ordered a second unit in XS version and that was the one we tried in our reference system at the time, comprising of Quads, it was a beautiful sound.

Although the XS version is an excellent amp, the Prem11A in standard Ultra-linear version using 6550C output tubes had better drive and control on difficult loads, compared to the XS version. We also had the Prem11A driving a pair of Apogee's Duetta's, which was fantastic!

In another serup, when we sold off the XS version to two customers, one had Tannoy Westminster's and another chap had Sonus Faber monitors. On both these types of systems, the Prem11A XS version proved to be superior. So it all depends on what type of system config you have.

The MV series amplifiers, although great in sound with that classic tube circuit, are not comparable to CJ's Premier line. The Premier series amplifiers are in a different class altogether.

Hope that helps.
Cheers, RJ

*Note* forgot to mention: that the Prem11A is rated at 70w /ch in UL config using 6550 Output tubes.
The XS version is rated at 35w / ch in Triode config using EL34's. When the XS version is done, due to triode config, it halves the rated output. This is why the UL version sounds more powerful and can handle more difficult loads.

[Big Dog RJ]

Just to add on comparison:
The Premier series amplifiers use higher quality parts, higher grade power supplies, and wide bandwidth transformers. It's the trannies that make a significant difference, especially in the high current capability.

From Input stage to driver to output stages, there are higher quality parts used in each stage, resulting in an overall improvement in performance. Hence, it's not just one particular area that has been upgraded, it's the entire layout of that classic tube circuit that has been further refined.

If you can get hold of the Prem11A XS version that's a fine amplifier. Better still, would be the non-XS version, you'll have more power on tap with a factor of more drive, resulting in greater control over your speakers.

Cheers, RJ

[AnotherJohnson]

Two key takeaways from RJ.

The MV series amplifiers, although great in sound with that classic tube circuit, are not comparable to CJ's Premier line. The Premier series amplifiers are in a different class altogether.

If you can get hold of the Prem11A XS version that's a fine amplifier. Better still, would be the non-XS version, you'll have more power on tap with a factor of more drive, resulting in greater control over your speakers.

My own take on it is that until you define the rest of the installation, you really can’t talk about the sound of amplifiers.

And

Amplifiers from this era are not going to sound like anything as they further age out. They are already well past their useful life. If you’ve already got one, or if you are collecting one of each piece CJ ever built, then these may be “must have” items. If you’re buying one to use as a main amp in a system that will see a lot of use, don’t. Waste of money and/or time. I would say the same about old McIntosh, old ARC, old Linn, etc.

[Big Dog RJ]

Yes, good point!

I'm not sure what the rest of the OP's system config is, hence my earlier statement regarding system dependent...
I was initially thinking that since he's looking at two kinds of amps, Premier and MV series, being moderate powered... then perhaps his speakers are of higher efficiency with easy loads. Between the two, considering both are in triode version using EL34's, they're about within the same power ratings.

Nonetheless, even though the Prem11A is in XS version rated 35w, it will have more current though compared to the MV series amp, plus higher grade power supplies.

Correctly stated on the useful age... both these units are really vintage. They would require quite a lot of work in parts upgrades. A collectors item I would think.

Best, RJ

[AnotherJohnson]

I agree 100%.

I do think that the vintage CJ unit service will eventually fall to a handful of old guys who pursue it as a labor of love.

They will eventually age out themselves.

Who supports Julius Futterman’s old amps? Or the amps of Saul Marantz? Who will support Mccormick’s stuff? Or Carver’s? Or Levinson’s? Ad Nauseam.

One thing JF did for me was to clearly help me recognize that advancements are real. If you’re serious about the quest for the best, most realistic music reproduction, you need to be looking at the most recent decade, and preferably current or one gen out, models.

[tubesound]

Thanks to those who commented! Some nice thoughts here but I wonder soundwise, what one gains AND what one loses with the move from MV-55 in triode to the Premier 11XS. I imagine you gain better extension at the frequency extremes, but is there a bit less liquidity, golden glow, and "romantic tube character"?

AJ, you mention that until you define the rest of the system, you really can’t talk about the sound of amplifiers. Nonetheless, some general differences in sound between these two amps could still be described assuming the speakers are efficient enough for both amps and have sufficiently benign impedance characteristics.

So let the discussion continue and thank you again to everyone here

[AnotherJohnson]

Thanks to those who commented! Some nice thoughts here but I wonder soundwise, what one gains AND what one loses with the move from MV-55 in triode to the Premier 11XS. I imagine you gain better extension at the frequency extremes, but is there a bit less liquidity, golden glow, and "romantic tube character"?

AJ, you mention that until you define the rest of the system, you really can’t talk about the sound of amplifiers. Nonetheless, some general differences in sound between these two amps could still be described assuming the speakers are efficient enough for both amps and have sufficiently benign impedance characteristics.

So let the discussion continue and thank you again to everyone here

Ok. Suppose I’m listening to stat panels that present a largely capacitive load that may approach a dead short as the music reaches into high registers. And the other guy is listening to Rogers LS3/5as with a nominal 15 ohm impedance exhibiting inductive dips to 12 ohms in the low bass.

Neither of these are particularly efficient. But … they are very different as amp evaluation tools.

In my recent experiences, I would say that what we often attribute to amps may actually be related as much to speaker cables and interconnects. Sometimes even the power cords on the amps may be a significant factor. I was an unbeliever, but have converted based on personal experiences this past year or so.

Aside from asserting that the Premier will be better than an MV on the same load, virtually without regard to the era, there’s little else to assert with reliable certainty.

My experience with the MV amps when they were not yet antiquated, was that they did not have solid bass control, and they were often barely capable of meeting CJ’s lax distortion specs … but in a good way. McIntosh used to absolutely rail against these amps that had significant “pleasing distortion.” McIntosh’s view was, and is, that distortion is not the goal in audio amplification.

Nevertheless it is good to have choices. Why not buy one of each and do your own comparo? Your ears, your conclusions.

[tubesound]

Does anyone know the damping factor of the MV-55 and the Premier 11 when they are operating in triode configuration?

[Big Dog RJ]

Damping factor...? Looks like you're heavily into specs or focused on specs rather than sound/ performance. I would only take specs as guidelines.

OTOH if you're considering damping factor as a critical aspect of your system them I'm thinking about horns or at least some sort of "horn- loaded" type speakers. In which case damping factor can be a serious problem. In this regard, both these amplifiers are not high powered, they're around 50w mark with the MV55 and around 35w for the Premier 11 XS. If they're driving horns or very high efficiency ratings, that should be more than adequate. I'm referring to efficiency ratings of greater than 100dB with easy loads around 8 to 16 Ohms.

If you use much higher powered tube amps then there's a problem with very high efficiency speakers. It will hum & buzz or even hiss, there's no way around that.

I'm still wondering what speakers you're using... as what we've all said is only speculation, not concrete advise simply because we don't know what you're using as your primary speakers. It's very hard to say in such situations.

For example, I had the opportunity of finalising on the CAV45 driving the Avant Garde Duo XD's. The CAV45 was more than adequate in this set-up but definitely not now in driving CLX's full range, hell no! Although the CLX's are rated at fairly high efficiency, around 92dB, it's their impedence swing that craps out many power amps. The impedence swings from 22 Ohns and suddenly drops to less than 1 Ohm 0.7 to be exact, and this happens in a blink of an eye. So only a handful of amplifiers are really capable of driving and controlling the CLX's to their full potential.

Hope this helps to understand the importance of amplifier to speaker matching, it's not just the watts.
Best, RJ

[AnotherJohnson]

I read a critique of damping factor recently. I’d include a link, but I don’t remember where I saw it.

The premise of the article was that damping factor’s affect on the sound presentation was inextricably tied to the driver suspension of the speakers in use. Some speakers have more articulate bass response with lower damping factors, while some sound better with higher damping factor.

I used to look at damping factor when considering amps, but I don’t anymore. The ARC amps have anemic damping factors, and yet they sound beautifully realistic with the speakers I’ve heard them drive. So … a good demo trumps a good spec sheet in my experience.

As for the OP’s question, maybe JF knows, but I’ll bet he won’t tell.