LP125 monoblocks/ KT120 output tubes

Greetings to all from Melbourne.
It's getting bit chilly now, winter is slowly settling in, time for some nice relaxing music with your favourite cuppa!

I have come across the LP125 monoblocks not having that much of a "great sound" compared to the bigger LP275's (no longer in production) or the new ART monoblocks. However, I was wondering what if these amps are fitted with KT120 tubes, I am pretty sure they would sound awesome.

So far, the c-j amps that I have heard with KT120's refitted, are the LP66S, LP70S, the new classic 60, and of course my very own MV60SE. The sound was in a different league compared to the 6550's. Not that the 6550's are bad, it's just that the KT120 overall is a far better tube. ARC is using them on every new design of theirs, and I am pretty sure McIntosh, VTL along with Manley are thinking about it as well; test results are still being carried out is what I heard.

I was just wondering whether anyone here has actually bought a pair of LP125 mono's and replaced them with KT120's? If so how does it sound? and what has improved?

As much as I like the solid state McIntosh MC301 amp, I am after all a tube lover, so my intentions have always been leaning towards that classic tube sound. I did finally get to test the MC301 with my Quads, and they sound fantastic! However, that little MV60SE still keeps me smiling with a classic evil grin... specially on the midrange, vocals and extended highs.
So as far as it goes for now, I am once again thinking of pursuing the world of music realism with monoblocks.

As I did mention somewhere before that I really didn't care for massive power amps such as 300 watters since to me they didn't really do anything in terms of big improvements in "musicality". Also there are far too many tubes to replace in large monoblocks. When you're considering 300 watts plus, you're looking at around 16 to 18 tubes the least. Plus the Quads don't really require that much of power. The 2905's prefer current, and anywhere between 50 to 150 watts push pull, or class A would be fine. Therefore, I think the LP125 would be a very nice fit for the Quads.

Any suggestions are welcome. LP125 owners out there let me know your comments.
Have a good one, RJ

Grooves said:

Did you have to do anything when putting KT120's in the MV60SE? Any changes to the amp to allow KT120's? A Stereophile article last year had suggestion that nothing needed to be done, but I could never get CJ to answer this via email. I am thinking of doing KT120's into my
MV60SE.

Click to expand...

G'day Mate,

Great to see that the curiosity between 6550's and KT120's are still flaring!

No, I did not have to do any modifications when replacing the 6550's with KT120's, other than turning the bias all the way down on all four tubes before installing the KT120. Once the KT120's have been installed, and the amplifier is switched on, bring up the bias slowly until the (red) LEDs light up; and then as usual turn down the bias just as the LEDs go off. (do this with zero volume, and with no signal from the pre-amp).

Also, PLEASE remember this replacement can only be done with the MV60SE, and not the standard mv60! The standard mv60 does not use 6550 tubes, rather they use EL34's (triodes) which is a very different design. Hence, please make sure that your amplifier is actually a MV60"SE" version.

You will notice the difference straight away, and when played after about an hour, the sound will be awesome... and after several hours, you won't be able to turn off your system. Rather you would want to listen all night long till the cows came home...

I am somewhat surprised that c-j didn't reply to your email. They are usually prompt, maybe they're just out fishing...
Anyway, we have many c-j owners here, so you simply cannot go wrong.
I also didn't know that Ed retired, wow that guy must have been with c-j for nearly 50 years... and the funny thing is Ed never owned c-j gear. He had B&W nautilus series with Classe' ss amplification, ha! But he sure loved his music!

Do let me know how your KT120's sound, and how you are enjoying them. I know you won't be disappointed.
After your experience, you will be wondering why the hec didn't c-j think of this before...!

The MV60SE with KT120's is a very "rare" sound; an absolute top sound quality that is hard to match. Unless willing to spend some mega bucks in excess of 20 grand.

Have a good one,
Cheers, RJ