Pr350 to LP140M ?

[lotus340r]

What would happen ?

Been offered a good deal and thinking about doing this as a stop gap till i get some Arts.


Cheers, Rich.

[Puma Cat]

I would say go for it. The LP140Ms are beautiful amps with excellent performance. You should have enough power (current, actually) for your Avalons for almost all listening situations and content. Probably won't be able to match exactly the dymanics of the Pr350, but my guess is it would be damn close, as my little LP70S is. Bass and damping factor will be a touch better on the Pr350, but I think the tube amps are more musical and have a fuller, more organic quality. Personally, I would LOVE to have a pair of LP140Ms...

[lotus340r]

Thanks puma, for me its all about fullness, richness, texture, dimensionality and air so i think i would trade a wee bit of slam.

Are there any reviews of them anywhere ? Cant seem to locate any.

[Puma Cat]

There was one in HIFI+ I believe, by Martin Colloms, IIRC. I know that none of the LP-series were really reviewed other than that 1 review. Unfortunate, as they are absolutely killer amps!

[Myles B. Astor]

There was one in HIFI+ I believe, by Martin Colloms, IIRC. I know that none of the LP-series were really reviewed other than that 1 review. Unfortunate, as they are absolutely killer amps!

Actually I think it was Roy Gregory and he compared the LP70S, 140M and 275M in one piece. His conclusion was that as good as the 70 and 140 were, the 275 was in a different league. But having had the 140M, it's not chopped liver either.

[lotus340r]

Small bit here:

awards (http://www.positive-feedback.com/Issue34/awards.htm)


Do they have a long burn in time with the Teflon caps ?

[Myles B. Astor]

Small bit here:

awards (http://www.positive-feedback.com/Issue34/awards.htm)


Do they have a long burn in time with the Teflon caps ?

Oh yeah, forgot about that :)

Yes, but less than the preamp/phono due to the high voltages involved in the amplifiers. But they do need a hundred or two hours.

[lotus340r]

Ok thanks. I am actually going to california this week and Katli audio have a set of used LP275 for sale but i reckon it'll be a struggle getting them into a suitcase !

[Myles B. Astor]

Basically the only difference between the ART and LP275M amplifiers is the driver stage.

[lotus340r]

Testimony of a former owner of LP140M about the LP275M, speakers are Wilson

''I have a confession to make. After upgrading my amplification to a CJ ART S3 and CJ LP140Ms, I have totally fallen in love with them and they just go so well with the 555 (shame Naim doesn't do tubes).

My speakers a pretty sensitive and having gone from a 30W SET to the 140W mono blocks it gives me more power than I thought I would ever need. My dealer offered me to give a listen to the LP275M mono blocks to draw a comparison to the LP140Ms.

I didn't expect any significant difference but took him up on his offer. Big mistake, after having spent the last 72hrs with them I don't really see them going back. The presentation is just so much more confident and life like, it's hard to believe they share the same basic design.''

[turntable]

Testimony of a former owner of LP140M about the LP275M, speakers are Wilson

''I have a confession to make. After upgrading my amplification to a CJ ART S3 and CJ LP140Ms, I have totally fallen in love with them and they just go so well with the 555 (shame Naim doesn't do tubes).

My speakers a pretty sensitive and having gone from a 30W SET to the 140W mono blocks it gives me more power than I thought I would ever need. My dealer offered me to give a listen to the LP275M mono blocks to draw a comparison to the LP140Ms.

I didn't expect any significant difference but took him up on his offer. Big mistake, after having spent the last 72hrs with them I don't really see them going back. The presentation is just so much more confident and life like, it's hard to believe they share the same basic design.''

Ah ha, big mistake:D

Quite a few years back when I was looking at buying a pair of prem12 mono blocks. I made the mistake of also listening to the prem8a's. The difference as not subtle, in every musical parameter. I signed up to the prem8a's. :yes:

Enjoy your new lp275's, they are superb:thumbsup:

[lotus340r]

For reference:


Review Roy Gregory - HiFi+ issue 52
"..so far so good and the 70 is certainly no slouch, wich makes the gulf in performance between it and LP140M once you put them face to face so much more surprising. The monoblocks bring a dramatic increase in weight, musical and harmonic complexity, instrumental body and presence, musical poise and authority. This is a big change : it's not a little bit more at the top, a little bit more at the bottom, it's a wholesale reassessment of the musical performance-both of te recording himself and the system playing it.
....
Listen to the 275s and you get more of what the 140s deliver. You get better separation and greater air....You get a more defined acoustic with clearer boundaries....you get even more dynamic range...but beyond all that, you get more musical message, greater musical impact. With the 275, drumbeats are not just more solid, they're more emphatic. Musical accents and pauses have greater effects, the line of a melody, the intent in a phrase is more definite...
The draw in the music is almost like emotional undertow, pulling you in. You might start by listening to this track or that, but you finish up just listening. And you listen longer tan you should, even whiilst deadlines beckon. Yes you can define what's happening in terms of extended bandwidth and quicker transient response, the temporal authority that they bring. You can talk about air and control, but the result of these qualities in combination is wonderfully, almost addictively compelling on a purely musical level. The 140's are extremely fine amps, sharing many of the qualities that make the 275s so special. But their big brother take things that much further, go that much deeper into the music and the performance they produce is at once wonderfully unforced and immediate.....this is a contained delivery that projects the intent in a performance with such direct power that it connects straight to the listener, placing you in the same place as the performers.....you feel the guiding hand of Dorati as he directs and balances the performance, binding soloist and orchestra into a single whole. It's that makes a great performance, it's that the 275s deliver.
There's a real magic lurking in the elegantly burky, ruinously expensive 275s and those who can ignore question of value are lucky indeed..."

[pstrisik]

How can you get better separation with one set of monoblocs over another set of monoblocs?

[Briz Vegaas]

1. Measure distance from mono block A to mono block B
2. Take mono block A, move away from mono block B in an outward direction
3. Do same for monoblock B
4. Measure distance from monoblock A to monoblock b
5. If overall distance is now greater there will e better separation between monoblock s.

Note you may require shorter speaker cables and longer interconnects.

6. Obtain beverage and relax in the knowledge that separation is artificial anyway. Plus you have not eliminated the inherent problem of stereo- I.e. that you have 2 ears each perceiving a slight timing difference from each speaker. Ie. right speaker Is heard slightly earlier in your right ear than your left, and the opposite for the left speaker. A true central image would arrive at both ears simultaneously- something the binaural recordings try and tackle, but I think it only works properly in headphones. Good reason to have a centre channel even for 2 channel music, making it no longer two channel of course. So why worry about a smidgen of crosstalk, which may begin in you pre amp or source anyway. I guess if you have to be obsessive, get that smidgen more separation.

[Joe Appierto]

How can you get better separation with one set of monoblocs over another set of monoblocs?

One reason that comes immediately to mind is that doubling the power results in better defined spatial cues.

[pstrisik]

1. Measure distance from mono block A to mono block B
2. Take mono block A, move away from mono block B in an outward direction
3. Do same for monoblock B
4. Measure distance from monoblock A to monoblock b
5. If overall distance is now greater there will e better separation between monoblock s.

Note you may require shorter speaker cables and longer interconnects.

6. Obtain beverage and relax in the knowledge that separation is artificial anyway. Plus you have not eliminated the inherent problem of stereo- I.e. that you have 2 ears each perceiving a slight timing difference from each speaker. Ie. right speaker Is heard slightly earlier in your right ear than your left, and the opposite for the left speaker. A true central image would arrive at both ears simultaneously- something the binaural recordings try and tackle, but I think it only works properly in headphones. Good reason to have a centre channel even for 2 channel music, making it no longer two channel of course. So why worry about a smidgen of crosstalk, which may begin in you pre amp or source anyway. I guess if you have to be obsessive, get that smidgen more separation.

:icon_beer:

Funny!

I don't even have a center channel for movies. I have 4.2 theatre system. I like the imaging that well executed stereo creates.

Speaking of crosstalk in the source.... I just acquired a Cambridge Audio Stream Magic 6 which is streamer and DAC combined (basically a NP30 plus a DACMagic Plus in one box). I was not prepared to have such an improvement from the DAC. They use "dual differential" chips. I think basically a DAC chip for each channel. I had one of those "wow" experiences with the increased imaging quality that I attribute to that difference, i.e., minimizing crosstalk from earlier in the chain. The DACMagic Plus may be one of the best "bang for the buck" DACs out there. MSRP of something like $650.

One reason that comes immediately to mind is that doubling the power results in better defined spatial cues.

That seems reasonable. That would suggest it is likely perceptual but not measurable.

[jimtranr]

How can you get better separation with one set of monoblocs over another set of monoblocs?

If, as the Gregory review indicates, you get more "air," you're getting more top-end extension, and with it not only more perceptible highs but better delineation of upper harmonics that flesh out tonal, timbral, textural, and spatial cues much further down the frequency spectrum. The result: more perceptible separation of instruments and/or voices within the soundstage and a sense of greater overall separation. One of the benefits of larger power supplies.

[Coppy]

After all those lucid and semi-lucid explanations I can pass along a significant additional reason for the various increases in fidelity from the larger mono amps.

The big, specially designed for c-j, transformers coupling the output tubes to the speakers in the 275s (and ARTs) have wider frequency bandwidth capability per Lew Johnson. I was over at c-j at the mfg. bench one day a couple of years ago admiring those huge output transformers and got a quick lesson on the subject. I asked him if could install a couple of those babies in my LP140s and he was not amused. Had to ask.

Guess you get what you pay for...

Bob

[Puma Cat]

After all those lucid and semi-lucid explanations I can pass along a significant additional reason for the various increases in fidelity from the larger mono amps.

The big, specially designed for c-j, transformers coupling the output tubes to the speakers in the 275s (and ARTs) have wider frequency bandwidth capability per Lew Johnson. I was over at c-j at the mfg. bench one day a couple of years ago admiring those huge output transformers and got a quick lesson on the subject. I asked him if could install a couple of those babies in my LP140s and he was not amused. Had to ask.

Guess you get what you pay for...

Bob

Interesting. So, the output transformers on the LP275s are larger than the 140s? I thought they were the same size as the chassis for both amps are the same size.

[Tonepub]

I got the same thing going from the Pass XA160.5s to the 200.5s, now to the Xs300s.... More power done properly means more control. I think that's what Roy Gregory was trying to say there....

:)

[Coppy]

Interesting. So, the output transformers on the LP275s are larger than the 140s? I thought they were the same size as the chassis for both amps are the same size.

Stephen,

The chassis of the 275/ART monos are a couple of inches deeper. The output transformers are larger and the windings are different, wound somehow to pass greater bandwidth. They are, of course, more expensive with the sophisticated windings. All eight of the output tubes per side can't be sent to a single trannie input side winding, so the they have to have multiple input windings to handle all the output tubes.

Bob

[ronenash]

Without going into to much electronics detail, more output tubes per channel means less wire turns on the output transformer. Less wire the signal goes throes equals more transparency and generally better Sonics. This is why larger tube amps usually sound better.

[Joe Appierto]

Without going into to much electronics detail, more output tubes per channel means less wire turns on the output transformer. Less wire the signal goes throes equals more transparency and generally better Sonics. This is why larger tube amps usually sound better.

I think that's the same reason, other things being equal, less wire turns on a phono cartridge is desirable.

[Coppy]

Well said Ron. And that would argue for the transfomerless output tube amps. But then there's the pesky high output impedance issue for tubes that transistor outputs don't have, making it impossible to drive low impedance speakers well. Of course, they sound like transistors. Have you had any experience with the transformerless output amps? Seems to me that some c-j amps have tubes except for the output devices that are solid state and thus eliminate the need for a transformer. I believe my GAT has a solid state output device to keep the impedance down so it drives cables better. And, it sounds terrific.

Bob

[ronenash]

I think that's the same reason, other things being equal, less wire turns on a phono cartridge is desirable.

With a phono cartridge its the lower mass that makes a bigger difference but shorter wires help too.

[Myles B. Astor]

With a phono cartridge its the lower mass that makes a bigger difference but shorter wires help too.

Lower mass = Less intertia :)

[ronenash]

Well said Ron. And that would argue for the transfomerless output tube amps. But then there's the pesky high output impedance issue for tubes that transistor outputs don't have, making it impossible to drive low impedance speakers well. Of course, they sound like transistors. Have you had any experience with the transformerless output amps? Seems to me that some c-j amps have tubes except for the output devices that are solid state and thus eliminate the need for a transformer. I believe my GAT has a solid state output device to keep the impedance down so it drives cables better. And, it sounds terrific.

Bob

I never had an OTL (output transformer less) amp. They are not very popular and never were because of their limitations which are more than just the high output impedance.
Hybrid designs are very different and in most cases use tube for the voltage gain and ss for the current output stage although ARC and a few other manufacturers did it the other way around, ss input and tube output, in some of their designs.
The GAT is again a different story using a mosfet buffer at the output to keep the output impedance low. This allows cj to use only one gain stage with no feedback and still enjoy the benefits of low output impedance.

Many different designs can achieve great sound in the hands of capable engineers.

[Puma Cat]

Stephen,

The chassis of the 275/ART monos are a couple of inches deeper. The output transformers are larger and the windings are different, wound somehow to pass greater bandwidth. They are, of course, more expensive with the sophisticated windings. All eight of the output tubes per side can't be sent to a single trannie input side winding, so the they have to have multiple input windings to handle all the output tubes.

Bob
and
Without going into to much electronics detail, more output tubes per channel means less wire turns on the output transformer. Less wire the signal goes throes equals more transparency and generally better Sonics. This is why larger tube amps usually sound better.

Thanks, guys for the write-up, informative and helpful.

[Briz Vegaas]

Deleted, commented on post on previous page, did not see we had moved on.

[lotus340r]

and


Thanks, guys for the write-up, informative and helpful.


+1 lots of good info, thanks for sharing.

[lotus340r]

Its a 275 Day !

Might be able offer some more insights on this thread after a bit of listening:


http://farm8.staticflickr.com/7296/8722821779_05dcf9845c_c.jpg

[microstrip]

Its a 275 Day !

Might be able offer some more insights on this thread after a bit of listening:


http://farm8.staticflickr.com/7296/8722821779_05dcf9845c_c.jpg

Congratulations Rich!

[ronenash]

gorgeous setup. congrats!

[Coppy]

Its a 275 Day !

Might be able offer some more insights on this thread after a bit of listening:


http://farm8.staticflickr.com/7296/8722821779_05dcf9845c_c.jpg

Congratulations... Really would like to hear your comparison of the two amp systems.

Bob

[Rayooo]

Goodness all mighty that's a sweet set of CJ gear. :yes::D

Its a 275 Day !

Might be able offer some more insights on this thread after a bit of listening:


http://farm8.staticflickr.com/7296/8722821779_05dcf9845c_c.jpg

[Joe Appierto]

Beautiful system -- best of luck with it and enjoy!

[lotus340r]

Ok, had a few hours listening. Its complicated by the fact that my Allnic H3000V is out on a string of home demos and I am making do with the baby H1201 which is a fabulous stage for the money but nowhere near the mighty H3000 which i have always found quite revelatory in a good vinyl setup. So when I am playing records they don't sound how I expect them to on either amp ! I have also spun quite a few CD's as well which is a constant, but not yet gone back to the Pr350 so comparison is limited to gut reactions from memory. Excuse some of my language. I am not a jargon expert but will try my best.

When I first switched on the monos from cold and played the CD tracks i'd played on the warmed up Pr350 I actually found them to be very similar. So I went outside for a bit and changed some brake pads on one of my cars and let the things warm up for an hour.


1. Most obvious difference is the slight 'steely' glare of my system has been largely eradicated. I had suspected this was in part something to do with the 350. The 275 are less bright, somehow drier sounding with no sort of metallic sheen on the upper frequencies. In other systems I am sure it wouldn't be an issue but after a while, with my bass light Avalons, I did start to become aware of this. (Is there a solid state amp that doesn't have this ?)

2. In the same vein, the lower end seems fuller and a little richer. Bass is a bit more filled out and palpable. Mids as well. At one point I was playing some Andy Shepard and I have never heard his sax playing so full and blossoming in my room before. Beautiful.

2. Lower noise floor. The sound is also slightly cleaner with greater clarity ... like a hoover has gone in and just sort of sucked up some unwanted stuff that you didn't really notice before but you now know isn't there anymore. The sound is a bit more stable or solid spatially if that makes sense ? This I wans't expecting but the 275's do sound more poised and measured.

3. The sound is a little more dense with more dimension. You feel more like you could crawl inside and around the music a bite more although I accept that the Pr350 was very good in this respect also.


I can't say that I heard much more detail or any more microdynamics. Maybe they are about equal in this respect. The timbral accuracy of instruments seems to have improved a tiny little bit but much of this might be down to point 1., esp. with piano not having that sheen across it. I didn't play too many energetic/dynamic tracks either so can't make a comment yet on out and out slam and dynamics.

Although I've said quite a lot up there I will state that with my junior model Avalons, the overall change isn't massive. Definitely worth it but not huge. The change funnily enough in some ways mirrors the ACT2.2 - GAT change but perhpas not as large in overall subjective effect. It will interesting if I get a chance to go back to the Pr350 but suffice to say that for the money on the used market the 350 is one amazing performer.

More listening tomorrow when I will report some more and when I have the 275's supported properly and also both plugged into the Running Springs Elgar. I may have an ART coming here as well so will be able to bring that into the mix as well.

[Joe Appierto]

For someone who's not "a jargon expert" you did a darn good job of giving us your initial impressions. :yes:

Thanks, Rich, for the initial write-up and we await your further experiences.

:thumbsup: