Martin Logan CLS IIZ

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I understand that this speaker demands an amplifier that will carry a 1 ohm load. Any recommendations solid state to use with these speakers. I am looking at PS Audio HCA-2 amplifier to run these because of price. What do you thinK? Thank you for your comments.
I have prevously read that the HCA-2 might have a difficult time with low impedance speakers.

The following is a direct quote from the PS Audio forum in response to a HCA-2 owner who happens to be the Jason, the President of our ML Club. I'll include a link below, although you might have to create a user name to get into the forum:

Quoted directely from Paul McGowan, owner of PS Audio:
"Thanks for the kind words. And, yes, the new cables just chew up anything in their path. Thanks for this note and we look forward to your extended review.

The HCA-2 just shuts off - and you think it is unrelated to the musical content? I mean, if you play something - it apparently doesn't matter what the level is or the particular point in the track?

I've not heard of this malady. The HCA-2 was never great on low impedance loudspeakers and the ML's can dip. But you suggest you've been playing them for a while. The two possib ilities are that the speaker's transformer has developed some trouble and the HCA-2 is simply responding properly, or the HCA-2 has a problem.

I suggest running the amplifier at another member's house with ML's. If you have the same problem, t's the amp and we better have a look at it for you."
End Quote

Now with that being said, I believe Jason's problem was minor and taken care of easily (please read all of the thread). I'm not trying to slam the HCA-2, because I've actaully been considering one myself. There's been a lot of used ones on Ebay and Audiogon for around $700.

But Paul's comment made me second guess my desire to get one. If you can you might want to get one try it out and worse comes to worse put it up for sale. The HCA-2's price has been pretty stable at $700 for some time and going fast at that price. So you decide you don't like it, sell it for $600 or $650, undercutting what's out there. I think your risk is limited to roughly $150-$200.

Research as much as you can. Paul McGowan personally responds to questions on PS Audio website forum.

Whatever you decide, let us know, and as always "Trust your ears".
I forgot the link:

By the way here's Jason's response:

Thanks Paul. The amazing thing is that I left the HCA-2 off for the rest of the day and when I plugged it in the next day, it worked effortlessly! This is the strangest experience I have ever had. Perhaps it could be the impedance with the speakers and the amp was particularly sensitive. The weather has been a bit unstable lately and I believe there was some fluctuations in current.

Either way, it works fine now- so I am still one happy camper, although I will possibly make the move soon to get the GCA power amp which should be a even greater step up in the performance scale.

I have nothing but praise for your exceptional products and that review on the transcendent cables will be coming out shortly. I have actually dared to compare it with some real pricey and prestigious cables and the results are certainly interesting! The Trancendent cable is certainly an amazing product.


Jason Liu

End Quote
Hola...the Van Alstine mod. on a very low price amplifier SS like Haffler will do just great. If you want tubes, you can get it from him also. It dependes of how loud you want to drive your CLS. Long time ago, when I bought my first CLS, I used a C-J MV-50 Tube amp. with only 50W/ch. They didn´t sound loud, but one of the best and cleanest sound I have ever heard!!!. Many people will tell you that for CLS you need a big power amp...and they are right if you are going to play it loud. If you just want to listen the performance of any musician, 50W/ch tube amp. is enough to my liking. I had them also in a very small room...and they look like if you were using them as headphones :p due to the small of the room, but I still remaind that incredible sound that I got there...Also, I used the 8 ohm tab at the gave me more bass and for jazz or small orchestra, solo instrument, voices, or combos, I really did enjoy my CLS. If you are going to buy SS amp. do your best to get at least 120W/ch. and make sure that the amp will drive low impedance. The CLS are very difficult to drive. Happy listening and trust your ears!! not the specs.
Roberto. :D

Welcome and enjoy the CLS

I think you need to decide a few things here. How much do you want to spend and do you want tubes or SS?

That being said there are quite a few choices in SS that will do fine and as Roberto said I would look at 100 watts or better. In the tube arena, there are many choices but expensive because you will need 50 watts or better and be able to handle the occasional dip in frequency. It is actually the high frequencies that cause the dip and this is not happening all the time but will cause the amp to get warm or shut down because of the prtective circuit.:eek:

On a personal side, and I stand alone :(, I have the biggest 2ch amp Rotel makes. It is 385 watts a channel and is basically 2 mono amps on one chasis. It has never given me any problems. For the price (retail) it is hard to beat. There are others that may be a little sweeter but are 2 or 3 times the price.

Just my 2 cents

Jeff :cool:
If you decide to use a low powered amp, lets say sub 100W you should consider buying a pair of impedance multiplying speaker cable substitutes like the ZERO AUTOFORMERS (very affordable, check which will enable any low powered amp to drive the CLS's. They are without doubt good enough to partner state of the art equipment. I use them with my CLS IIz's and believe me when I say they do a better job than Nordost Vallhalla speaker cable (slightly more detail retrieval).
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never go wrong with Krell, seen a few ksa50,s for sale , as roberto said trust your own ears good luck
I have an amplifier Plinius SA250
The marriage with the CLS is sublime.
If that is possible, to carry out a test.