Amps for CLS IIAs

[raanan]

My Moscode 600 drove the CLS IIAs,with and without zero autoformers,but an Adcom 545,that is 1/3 the power at 100 watts does a better job-more highs,more lows,better dynamics,etc.
Of course,it is a must to use a tube preamp with the Adcom.
Is there any chance that for moderately loud listening levels in a small-medium room I can get by with a pair of tube monoblocks,using 4 6L6s apiece(SC AP-55)putting out 50 watts each.Using the Zeros at the x2 position may help,but that still leaves only 25 watts per speaker.
It is said that the IIAs are the most difficult to drive with the originals and the IIZs the easiest.Using the Zeros transforms the speakers in effect to a IIZ,with the amps seeing an impedance that is double the IIA's.
Can 25 tube watts do justice to IIZs?
Because of my experience in driving recently acquired SL3s with 12 tube watts on the panels,I have become alerted to the importance of quality amplification for the CLSs.
Thanks,Raanan

 

[Jeff Zaret]

raanan,
Although I own CLSiiZ's I am driving them with a power amp. I think Roberto may be the one to answer this one since he has had his a long time and experinced different amps with his.

Good Luck

Jeff

 

[Kaliar]

Hi raanan,

It is said that the IIAs are the most difficult to drive with the originals and the IIZs the easiest.

Yes, that is also my understanding !

The gentleman that sold me his set of CLS IIa was using a 60 wpc tube amp ! If I remember correctly, this amp (a hybrid unit) was the Classic Audio CA260. The demo was convincing since I bought the speakers !!

He could have used a Mark Levinson amp that was also in his listening room (approx. 12' x 21' x 8'), but he preferred the CA260 with the CLS IIa.

So, to answer your question, I guess 50 Watts of tube amplification could do the trick for moderately loud listening levels if your room is not too large. It will not be optimal but still enjoyable, mostly so if your listening position is not too far away.

Cheers !

 

[bublitchki]

I think tube 60 watts per side is probably marginal. i have the original II's (not the "a" model), and use c-j premier 12's, which are 140 wpc tube amps. I checked on this with c-j and ML, who both said the combination would be great. While I do feel this combination rolls off the highs a bit, it's very musical and sounds great. I'm primarily a classical music fan, so this works well for me.

Good luck with whatever you decide.

 

[roberto]

raanan,
Although I own CLSiiZ's I am driving them with a power amp. I think Roberto may be the one to answer this one since he has had his a long time and experinced different amps with his.

Good Luck

Jeff

Hola Raanan...my dear friend Jeff is right...when I had my first pair of CLSs back in ´87, the amplifier that I used was a CJ MV-50, and of course, the sound was a very moderated level, but it was enough for me. My room was small also, and this helped a lot for this small power amp. At that time, the recommended power amps for the CLS were the VTL 225s monoblocks. I think it depends of the level and your liking. At that time also, other brands of electrostatic speakers like Acoustat, Harold Beveredge and Quad were available, and the CLSs did hit my heart since the begining. The others sounded very good too, but the look, the see through was the click to me and of course the sound quality...I used at the amplifier the 8 ohms tab, it allowed at that time to have more bass...I was using a Golmund Studio turtable with the T-3 tonearm with CJ preamp PV-5. Still have the turntable...That sound is still in my head...so again, it is a matter of taste and liking. Moderated level was the key and I did that, having many hours of joy and pleasure with my system...happy listening,
Pura vida,
Roberto.

 

[raanan]

Thanks,All,for your responses.
Roberto,it is apparently easier to drive the originals than the IIAs.I have heard of many people who were able to drive the originals with a 50 watt tube amp.
Bublichki-thanks for answering my query on the AA amp forum.You now have the rare distinction of being the only person on this planet,who has posted relies to queries that I posted on 2 different forums.And within a few days of each other.Thanks.
The amps that I am referring to are Stromberg Carlson AP55s,that have earned such high praise on Salvatore's site.I will be happy if they manage to drive the CLS IIAs to moderate levels.The CLSs need quality amplification.I have heard them with too many amps that reflect the constraints of my limited budget.Beginning with a QUAD 405,a Moscode 600,and now an Adcom 545,that together with a 6BX7 linestage yields the best results.
Raanan

 

[jjqiv]

I think tube 60 watts per side is probably marginal. i have the original II's (not the "a" model), and use c-j premier 12's, which are 140 wpc tube amps. I checked on this with c-j and ML, who both said the combination would be great. While I do feel this combination rolls off the highs a bit, it's very musical and sounds great. I'm primarily a classical music fan, so this works well for me.

Good luck with whatever you decide.

My AES Sixpac's with 50 wpc have more than enough juice for my original CLS's. No rolling off of the high's either. I currently have the bass rolled off at 100hz to a sub and they will play much louder than I find necassary.