2. amps-preamps
  3. 149865-131497

Will a pair of Manley tube amps be a good match for Martin Logan ESL 11A's?

I have been looking into the Manley power amps to drive a pair of Martin Logan ESL 11 A's. From Manleys specs they report a speaker load of 5 ohms is recommended. The Logans are rated at 4 ohms.
pvmike
bdp24's avatar
bdp24
9,892 posts
 

@mijostyn, I’m not sure of the year Strickland and Beveridge each introduced their direct-drive ESL (the first Beveridge ESL, the Model 1, was invented in 1965), but I do know Strickland discontinued his amp and went with a transformer because of reliability problems in the amp. Modjeski says he has repaired a few of them, and found it’s design weaknesses, designing a mod to correct them. One of his services is to rebuild the Acoustat amp, for which owners send him their broken ones. Roger was hired by Beveridge to solve the reliability problem in his direct-drive amp.

Roger worked in an electronic repair shop in high school, and learned how NOT to build an amp. If a circuit calls for a 2w resistor, he uses a 20w. Trouble-free operation is a very high priority for him, in contrast to some more widely-owned high end brands who put other priorities first. When I bought my first ARC electronics, turning on the SP-3 pre-amp for the first time blew a resistor. I couldn't believe it. My dealer (Walter Davies, who co-developed his patented Last Record Care Preservative---which is NOT Freon ;-) put it on his workbench and had it up and running in a coupla minutes). That was a long time ago, and Bill Johnson did eventually learn the lesson he should have known long before (he too started his career as a repair technician). At a seminar I attended in the 1990's, Johnson talked about how a batch of bad parts almost put ARC out of business in the 1980’s.

celtic66
1,674 posts
 
pvmike,

One assumes having posted the specs for the Manley 500 monos, these are the amps under consideration.  I've not heard them, but am a long time owner of the Mahi Mahi and can attest to them being scary fast and able to handle many different speakers with ease within their power limits, about 40wpc, 25wpc triode depending on the speakers.  

Manley tends to over build and invests heavily in power regulation.  I would tend to believe these monos would handily power anything thrown at them.  I took a pair of VTL Tiny Triodes to a shop once and powered their smaller ML speakers and they were shocked at how easily they drove them, how smooth they sounded and how quick it made the MLs.

I would not back away from the Manley amps.
mijostyn's avatar
mijostyn
8,570 posts
 
The Acoustat Model X was released with the direct drive amp in 1976. He came out with the Transformers somewhere around 1979 because the dealers were telling him that people wanted to use their own amps plus without subwoofers the direct drive amp would at best push things to 85 dB on Monitor 4s. I though the amps sounded beautiful but also wanted more dB which is why I jumped into subs way back then. The RH Labs sub was perfect for the Monitor Fours. You just took them off those silly plastic stands and plopped them right down on top of the woofers. Perfect fit. A set of Kenwood LO7-M mono amps and 95 dB was your playground. I never had any trouble with the direct drive amps. They were discontinued because nobody wanted them. I sold my system when I moved from Florida to Ohio. Jim Strickland had already set me up with a dealer in Akron who would deliver my first set of 2+2s at dealer cost + 5%. John Ashe of Golden Gramophone and I would become good friends. I got my Krell KMA 100s at the same time. Now 30-40 years later I am sure whatever direct drive amps remain are in need of help. Those oil filled Caps are probably leaking all over the place. 
Roger is an interesting character. One thing I can say for sure is he knows how to find quiet 6922s. Last? Who said anything about Last? 
jafox
1,466 posts
 
My assessment is that your review samples were hooked up incorrectly. 
No.  The JC1's were not review samples. This was at a dealer for Atmasphere and Parasound products.  The rest of his system was top notch.  The only way to incorrectly connect an amp to speakers would be to reverse the speaker cable polarity; the result is immediately obvious with all instruments conveyed at the outer edges of the speakers rather than within the speakers.  

It would be the only way you would hear something as bad as you relate.
Compared to the Atmasphere and CAT amps at that moment, the JC1's were severely dimensionally flat.  That was just how it was.  The dealer downplayed the result but to me, it was not subtle at all.  Going back and forth between the two tube amps was an incredible experience.  Nobody had any desire to return to the JC1's whose performance was in the mid-fi zone.

I recently purchased a Symphonic Line RG1, a model near the bottom of the SL product line, and this amp is phenomenal with the A1's.  This mid-sized, mid-powered amp portrays space and harmonic structure in a most impressive manner.  Directly comparing the baby SL with the mighty CATs shows me how well engineered the SL amp is.

As for Sound Lab dealers or show demos using JC1's as part of their setup is not surprising.  I heard SL's at a So Cal audio show some years back and the system result was mediocre at best.  I could not believe the midfi gear in that setup.  One of those head-shaking moments.  I wanted to go home and bring my tube preamp for his demo as it would have transformed the result.



More to discover