LUXMAN L509X VS M700/C700U

Hi @builder3

Eric, please cite your source on the all of you claims you made two posts up about the Luxman class A’s, legality of power ratings, etc, etc.

I have no issue at all with having my sources questioned, though I am not a paid contributor, so please keep your questions polite. I know it’s hard in an online forum, but I would appreciate it if you gave me the benefit of the doubt and treated me as some one trying to be helpful. I did cover a lot of ground in very few statements and I can see how it can seem to be incoherent.


Please understand that I really am a Luxman fanboy, so I was trying to be quick about my typing. I myself own a 507ux, which is A/B.

I will give you two hard fact sets, and then my inference.

First, the FTC rule I was talking about:

https://www.iqaudiocorp.com/pages/FTC-amplifier-power-spec.html


This is how Stereophile measures when they determine an amplifier’s legal power rating. It isn’t the only thing they measure. For more on that seek out Stereophile’s pages on their measurement process. If you’ve followed Stereophile’s amp reviews you’ve read a few times when amps did NOT make it past the warmup period. They shut down and had to cool off before they could be meausred fully.


Next, let’s talk about the Luxman 590. According to their website it is a 30W / channel amplifier:
http://www.luxman.com/product/detail.php?id=1#spec


I honestly believe that this amp will produce at least 30 W / channel per the FTC regulations. I was really more curious how it could be SOOOO very low in power, given it’s power consumption at idle and full power. Wow, that’s one inefficient amp, even by class A standards. :)  Fortunately my question was answered in this A’gon thread:


https://forum.audiogon.com/discussions/luxman-l-509x


Specifically with this British review:

http://www.navratilaudio.cz/novinky/Luxman_L590AXII_HFW.pdf


They measured it at 90W/Channel or 156W/channel into 4 Ohms. Substantially better than the rating of 30.
So, based on this, I make an inference that Luxman may have chosen to underrate the amp to keep the heat sinks in the same form factor as the other integrateds in the line, which was not a limitation on the stand-alone amplifiers.

That is, to meet the 90W/Ch rating of the FTC they could have kept all the circuits the same, but been forced to use much larger heat sinks.

You seem to have some strong opinions on amps you’re never seen or heard, but only read about.

Please explain what part you feel I was making unfounded claims on.

Best,

Erik

Interestingly, the 590 and 700u share output transistor topology and have very similar damping factors.

The m900 however uses 2x the number of transistors per channel, and cuts the output impedance by half.

As I wrote before, the issue I was most worried of is VERY easy to hear. The OP should have no issue at all judging for himself.

erik what I understand that the first few watts is what it counts and 590 has enough watts

Hi OP,

I guess my point was lost. :) Based on the reviews, I think the 590 is a much bigger amp than it's rating, as I wrote above. 


Being in LA in an apartment, with 90+ degrees outside I can't afford a Class A amp and am very happy with my compromised 507. :)


I think it will be interesting, given the similarity of output stage, and damping factor of the 700 and 590 if you find any difference at all.  I had forgotten how similar these two amps are.


Shame we aren't made of money so we can just order the m900. :)

Best,

E

Erik, I appreciate the effort, but am still unconvinced of your conclusions. The first Luxman link you cite was provided by me, during one of the ever-recurring threads where people continue to talk about the lack of power in the L-590AX. And as I've stated before, I own that amp.
My issue with what I called your "unfounded claims" is based on your conclusion that the amp wouldn't meet the FTC requirements to claim a higher power rating. Perhaps you're correct, but you don't know that, you merely surmised as much. In fact, you jump to a bunch of conclusions about the amp, it's engineering, even going so far as to state what it can and can't do, all without having ever even seen one, let alone heard one, as far as I can tell.
What I've surmised (but also don't know for a fact) is that Luxman chose to advertise the amp as pure Class A, and stated the output as such. This seems more likely to me, considering that they never even so much as hint at it switching to A/B beyond that 30wpc. This will be my last post on the subject, the last word is all yours, take care

 “What do guys think about cl 38uc and combine it with m700u with triangle speakers ? Vs c700u” 


I think CL-38 should sound better with 700u and triangle. 
What makes the SS preamp c700u 50% more expensive than CL-38? Has anyone compared the aforementioned preamps?