Which Mono block amps for ML Summit Speakers?

I would like to stay under $5000+/- used, any suggestions?
Well, I would definitely recommend tubes. Audio Research because of their output transformers which have taps down to 2 ohms; but there may be other makes of tube monoblocks which have that same capability. You'll have to check the ML website for power requirements, but I'll bet they'd do nicely with 150W per side, since the bass is self powered.

Go balanced interconnects if your preamp has balanced main outs. If you do select tube amps, then I'd also recommend a SS preamp, or a tube preamp if you decide to go with SS monblocks. If you do go with SS amps, consider some of the older Levinsons like the 23.5 or 27.5, which are well within your price (used) and they are amongst the most musical of all SS amps ever made; as opposed to Krell, Rowland, Bryston, etc. which I feel are a bit bright/edgy for this application.

I'd be hesitant with the ARC CL150 mono amps. I had these for over a year and their 150w rating was quite wimpy to drive Magnepan Series 3.x speakers. The 110wpc VT130 stereo amp that I had before controlled the Maggies quite well without shutting down like the CL150s did regularly. I ultimately changed to Wolcotts for the Magnepans which worked beautifully in driveability and the openness of a tube amp.

Perhaps the ARC VT150 mono amps would be super here. The incredible dimensionality of the VT130 stereo amp leads me to believe the VT150 monos would be even more in this direction and a great match with the MLs which have a lesser 3-dimensional, bloomy, volume-of-space presentation than the Magnepans.

When I got the CAT JL-3 mono amps a couple years later, also rated at 150w, I realized 150w does not equal 150 watts. The CAT 150w rating was able to drive the Maggies like the CL150's never could come even close to doing. There's a lot more to a manufacturer's power rating when it comes to driving many speakers.

Perhaps the ML's are not difficult loads, but if you want more headroom, I suggest you look into the VTL 225 & 450 or Wolcott mono amps....or even a pair of the BAT VK60's. All of these are in the $4-5k range with the VT150s closer to the $6k price when you can find them.

I still have the Wolcotts. If you are near Minneapolis, I'd let you borrow them and try them out in your home.

I've owned both Maggie IIIa's using their passive xover and Martin Logan Monolith IIIx's. The latter used the Krell designed electronic xover, allowing one to drive the panels with a separate amplifier, not unlike the Summit's.

The ML panels are more efficient than the Maggies. An amp's current drive is generally not the big need for ML panels (which it is for the Maggies) but the ability to drive the load presented by the panel. For tube amps, this gets down to the capabilities of the transformer. If it can't handle the load and phase, you'll generally suffer from some roll-off of the higher treble range. Per ML, the impedance is .7 ohm @ 20khz but I've not seen the impedance curve over its operating range but my guess is that it's a lot friendlier than the Monolith's.

I'd also run this set up in balanced mode although this will eliminate some of the amps such as the older Deluxe VTL 225 and 300 which are single ended or after market modded. Regardless, the VTL's come with nice transformers which should be able to deal with the load. Same for the Manley's although new, they're more than you want to spend.

Personally, I would look at the following on the used market.

The ARC VT-200 will do a decent job and offer good reliability and a company which has been around for a long time, thereby ensuring good service. You can also go mono bloc with the VT130 or VT130SE. One thing to note is that ARC generally rates their power output at 16ohms where their amplifiers are most efficient. Unlike some SS amp designs, power does not double or increase as impedance goes down. Generally, you lose power depending on the design and transformer.

VTL MB250 or MB450 would be excellent choices as well and should be investigated. Their products are reliable and again, they're around to service their amp's should something go wrong.

VAC makes some very nice products but they're above your range. There are a pair of Standard 220's on Audiogon but I've not heard that model. I have a pair of VAC PA-160 II's and they drove the Monolith 'stat panels to high levels with ease. VAC makes excellent transformers.

My top choice would be Manley's Neo-Classic 250 but it's quite expensive and rarely shows up used.

Depending on the music you listen to and the size of your room, you only need about 120 watts/side of clean tube power to make those speakers sing. Good luck.

Not necessarily the mono-blocks (very expensive) but something like a Passion 700.
I would look at Blue Circle amps.
Gilbert the designer uses ML CLSiiz and Statement E2's as his reference speakers.
I think gilbert has owned about 15 pairs of Martin Logan's over the years.

Blue Circle amps are voiced to sound very good with ML speakers and have NO problems driving them. Do some reading about Blue Circle amps. I think they are just what you are looking for.

In you price range I would look at the BC202. It is a hybrid amp with 1 tube on each side on the input stage. Or if you want to go all solid state you could look at the BC26, but IMHO the 202 is much better.



BTW: You can get the amps in pretty much any color combo you want. Don't let some of the pics scare you off. That is just Gilbert's sense of humor. :)
I am very happy with Meridian monoblocs on ML Aerius speakers.
Yo 'lectrostaticman! My last pair of Logans (Prodigys) sounded extremely good driven by a pair of JC-1's... if you really need monos for some reason.

Also, I heard a pair of Odyssey's at a friend's driven by a Pass 250.5 that was every bit as good as I've ever heard.

Please be sure and let us know all about the Summits if you ever spring for a pair.
I just checked the ML Summit specs. The built-in woofer amp is 200W. Recommended external amp (for the panel only remember!) is 100-300W. None of the prior ML speakers had on-board amps, and thus would have employed a completely different electronic interface between the power amp and crossover -- so I feel that amp/speaker experiences w/ previous ML models must be considered anecdotal when speculating what would work best with the Summit, which is decidedly not an evolution of their previous hybrid models.

While not having an on-board amp for the woofers, the interface, ie electronic xover, is the same as the Summit as it relates to driving the panels.

I also missed the Antique Sound Labs Hurricane and the Cary v-12 mono's. Again used.

I have no view on SS amps having not listened to any model seriously in almost 10 years. A lot has happened then, as I found out when I replaced my tube pre with a Pass Labs X-1.
There has been a change in my thinking. My wife has decided she will accept the speakers in her living room but no other equipment in the vacinity. So I will need recommendations on equipment which will now need to be located 50ft away in a equipment cabinet. I will need to run the these speaker cables in the wall to the attic above the room, then over to a equipment closet with a 10 or 12ft.drop.

Please continue to suggest equipment & cable (cost effective).
Two points, if you really need to be cost effective, then you should rethink your decision to buy such an expensive speaker. Also, 50 feet of cable will degrade the performance of all but the stoutest high current amps into the load the Summit's present. You can do it, but you'll never be able to optimize the speaker's performance. Why get such a nice speaker if you not going to optimize?
I sold my JC-1s (downsizing, I'm still crying over it) to a guy who's now running them with ML Prodigies. He absolutely loves it. My experience with the JC-1s was solid as well, so that'd be my recommendation.
Is there any chance to get a pair of mono blocks to put behind the MLs that could not be seen? If this is the case, I think you'd be ok to run 50' interconnect like the MIT 350 series. I gotta think something like the Wolcott monos would fit perfectly behind the speakers.
I know very little about tube equipment. My last system was all SS. This time I would like to experience a combination Tube & SS. Either I will use a Tube preamp with SS monoblocks or SS preamp and Tube Monoblocks. What do you think?
Electrostaticman: When it comes to purchasing an amplifier, it has everything to do with the speaker being driven. The amp/speaker link requires careful match much like the tonearm/cartridge.

Do a search for threads that cover the topic of amplifiers that work well with ML speakers. There seems to be a lot of owners that have had great success with tube and ss amps. Maybe they can give you some ideas on pros/cons, why they changed from one to the other, etc.

As for tube preamps, I have yet to hear a music system with a ss preamp match the 3-dimensionality, decay of notes, and harmonic richness like many of the great tube preamps. Of course, just because a preamp or line stage has tubes does not mean anything either. But I find this link in the chain to be crucial to convey the above qualities. I can be content with changing amps, speakers, cables, etc., but take such a preamp out of the system, and so much is immediately lost. It just makes no sense but time and time again, for me at least, the line stage is THE critical link. And the most critical cable link has been from the line stage to the amp so don't short change yourself here either.

John, what preamp do you recommend?
Electrostaticman: Send me an email as to your current system, what sonic qualities you want that you currently don't have, and a preamp budget. I will respond with some models for you to keep your eyes out to audition. John
I must second the Blue Circle suggestion. They match beautifully with the Summits. I have the 206 paired with them and its amazing. I have also heard the 204 with the summits and its fantastic as well. I have no doubt that the 202 would be outstanding within the desired budget.

Electrostaticman: how are things going? I myself have had Summits for few months. I've tried various SS and tube amps, but I've found that speaker placement seems to have quite an effect, especially on the bass. My advice would be to hold off on amp purchases until you've had the speakers for a while and you find a good placement. I have had particular challenge with getting uniform bass throughout the room. If you don't get the bass right, it totally throws off the tonal balance. I've never had speakers that sound so different in different places in the room. Until you get the placement right you may not be be really hearing the electronics.

I have found that power makes a difference in the bass, even though it is powered internally; puzzling, but that's what I have heard. I have not been happy with 100wpc. 500wpc SS amps was enough. Right now I'm using two tube amps in mono mode, 200wpc, seems to be working OK. I like the tube sound better, but boy do these suckers get hot! Might not be suitable for putting in an enclosure.
I like the McIntosh MC-252 amplifier. With the included autoformer, it is less susceptible to impedance anomalies associated with longer speaker wires. It looks and sounds outstanding.


It would be prudent to consider one of their preamps too.