LP70S vs LP140m

[smodtactical]

I am running yamaha ns5000 and currently using LP70S with KT120 tubes. So far my LP70S has beat (with ease): Prima luna evo 300 + 400, Don sachs KT88, Willsenton r800i, Pass X350.8. It is truly a mind blowing amplifier.

I am going to get a chance to re-audition the lp140m (which previously i only heard with 6550 tubes)... but I am going to try to get another set of kt120 to put in because overall I Am really liking kt120 with the CJ sound. I think it makes it bigger, more clear, detailed but still has immense texture and magic.

Anyway my question is for my speakers do you think the LP140m will lead me to gain much in SQ over the lp70s? I guess I could use the money I save with lp70s and put it into a CJ pre.

[Big Dog RJ]

Ah, now I see you... on WBF you've posted under a different name. Ok, now I know more about your system with Yamaha NS series speakers.

Moving from a stereo power amp to monoblocks is a big step.There are far more tubes involved, which means more tube maintenance and of course the niggly issues with monoblocks, grounding factors, noise floor, etc.
Monoblocks require proper grounding and you must make sure that your AC mains are upto the task of providing the required steady current to the amps, without tripping off the CB. Monoblocks will draw twice the AC mains current from your house grid compared to just one stereo amp. So keep all these factors in mind.

How I would look at it, is three basic elements:

1. Is there something lacking with the power of the LP70S?
2. Are your Yamaha speakers not playing effortlessly when driven by the LP70S? Is the sound reproduced being forced in any way?
3. If not sure and you really must upgrade to monoblocks then refer to point 1 before your final decision.

Overall, within this particular LP series amplifiers, from the LP70S all the way upto the LP275M, the signature sound remains the same. What you will get though moving onto the higher powered amps is more of everything that the smaller amps offer. More: current, higher voltages, larger power supplies, which results in better drive, better control and full grip on difficult loads.

Therefore, the question is whether your Yamaha speakers will benefit from these bigger power supplies. Only you can answer that, since you own these speakers.

If you could leave the LP70S in there, and it's performing flawlessly to great effect then perhaps investing the extra dollars into a fantastic CJ preamp will get you over the line. After having obtained the higher powered monoblocks, you might notice only a marginal improvement compared to having upgraded towards a fine CJ preamp. If not, you'd be wondering... what if situations...and life goes on.

See how you go and let us know what you decided on.
Hope that helps.
Cheers, RJ

[smodtactical]

That makes a lot of sense RJ. I think the LP70S is driving my ns5000 with ease and probably monos will not improve much. I am tempted to try them 1 more time though with kt120 just to compare but maybe I should save my money and focus on my preamp now.

[admin]

Are you looking for more power for a specific reason? The NS-5000's are 88 db sensitive so you should not have any issues driving them with the LP70s unless you are cranking volumes up to very high levels. Or is this more just experimentation to see which one sounds better to your ears?

[Big Dog RJ]

Just to add: the LP70S, although rated around 70w/ch, is actually NOT a small power amplifier by any means, compared to the average tube amp with similar ratings. The LP70S is really a top performer!

It's got all the high current and highly stable voltages required to handle most loads, and 70w is plenty! The most significant improvement with higher powered monoblocks is the control and grip factor that larger power supplies possess when faced with difficult loads. So again, it all depends on your speakers and how loud you want it to be.

Also keep in mind, even though high powered amplifiers have all the watts you'd need, the human ear cannot tolerate 100s of watts at continuous levels, you'd go deaf! Even during the loudest passages of recorded music on high quality playback systems is only a handful of watts. Around 45 to 50w the most. It never reaches the 100 mark. This is recorded music we're talking about in domestic hi-fi settings.

Therefore, this is not a rock concert or a live gig in a huge stadium... that's where you need 100s or 1000s of watts to power up.

I've always said this, thought I'd mention it again since many get carried away with higher power ratings.

Cheers, RJ

[smodtactical]

I am more trying to see if LP140m with kt120 sounds better. When you put a separate amp on each channel with separate power / transformers etc then of course that can sometimes improve sonic qualities. But LP70S is so damn good already that maybe it won't.

I am not a person that listens at crazy levels so thats not really my focus.

[admin]

I think that this will come down to trial and error to see what sounds best to you. If you have the opportunity to audition the LP140m with kt120's, go for it. If you can't, I would not consider it the end of the world.

[smodtactical]

Hehe indeed.

[roberto]

Great advice Admin! I love the KT-120s in my system. I did try out recently an octet of KT88s, and ending again with the KT-120s. I found much better bass control and the stage too. The overall image with the right size of the musical instruments and voices, the KT-120s Tung-Sol are the clear winners here, in my system.

Happy listening!