Solid State Amps for Quad ESL 57?


My system is feeling pretty tube-y and I was looking for suggestions of a solid state amps that people are liking with their original Quad ESLs. Looking for more speed and more of the bass I know the Quads can put out if set up right.
dhcod
We've had a number of customers running stacked Quad 57s. They used our M-60 amplifiers, and the Quads were wired in series. David Magnan of Magnan Cable fame ran this combo for years prior to his retirement.
Just to clarify if I was misunderstood with my post from above!
The way I want to run my stacked 57's is with two stereo amps and each amp to run one side of the stack! Each amp needs to be bridged and use both amp outputs, for each speaker from the stack!
That is the reason for the Pass Labs would be a better choice!
Also my point was that I trust Mark from RENO HiFi more than the reviewer from that link above!
Mark knows his stuff and would never sale you what is not right product for you!
Only if you insist! :)
Another controversy is on this link:
https://www.cnet.com/news/first-watt-f7-very-special-amplifier-dazzled-the-audiophiliac/

In the end of the review it says that the FirstWatt F-7 sounded better than the ASR Emitter II amplifier!!

Like saburo said, ASR Emitter II amplifier is the amp of choice for 57’s and the best match of Chesky, Wyatt!
And when I wanted to replace my tube amps with two FirstWatt F7 amps (one amp for each side) and speaking with Marc from Reno HiFi, he said that the F7 can’t drive a pair of 57’s.
He recommend PASS XA-30.5, or 30,8 at list!
Thanks noromance......just a bit different way! :)

If no kids or pets, I really don't see a reason to have any kind of screen!
Before the rebuild, in original state, I tried the difference with and without screens and immediately I knew that the screens are out!
Geoff is SO right about the stock perforated metal screens on the 57---horrid things. Jerry Crosby (known for his QUAD 63 mod) at one time made a replacement for it, with much larger holes and much less resonance.
Post removed 
I don’t have the screens since I build different, much sturdier and heavier frames.
Also removed the felt form the bass panels.

https://postimg.org/image/6vpz9zqm7/



If you haven't done so already I highly recommend removing the metal screens. It's shocking how much of a (negative) impact the screens make.

If a pair of low-watt Pass amps are too rich for your blood, the old Bedini 25/25 is considered one of the all-time best ss amps for the Quad. They show up from time to time, the last one I saw selling for $795 here on Audiogon.

Hello to all Quad lovers! :)
I'm running stacked 57' with JAS super tweeters and with Audio Aero Prestige mono's, in parallel.
Also 2 MJ Acoustics Ref.1 subs with modded cabinet.
Quads were 100% rebuild by Kent and each speaker has Valhalla shotgun speaker cable.
I built the frame from the scratch (not using the original frames) and as much as I wanted to make life easier for myself and have them in the strait line, I always liked when each pair can be tilted separately, facing my ear level. Frame is from maple-ebony real wood and it weights over 200lbs and with adjustable tilt.
Bottom pair is in the similar tilt and position like would be on the original legs and the top pair are tilted downward a bit.
Probably most will not agree with this setup, by this way I got the best detail and transparency and suits my taste.

I'm very, very happy with the sound, but I'm tired of searching for tubes!
I'm looking to  replace my amps with SS. I'm thinking two stereo SS's on each side, one speaker per channel.
The only problem is finding those SS amp's and at reasonable cost! :)

Best,
Adam

Chris (ct0517), a man sharing my point of view, both figuratively and literally! I too prefer to look up at the stage, and find many, many loudspeakers to produce too low an image---as you said, a balcony perspective.
That is an interesting set up for the ESL-57s. The Dynaudio subs sound interesting as well. I may look into them a bit more.

The spider legs I have do use a three leg approach like the original. The back leg is affixed in the exact position as the original. The difference is the bottom of the panel is now raised about 14" off the floor and the and panel is no longer tilted back. I am going to try and push them out into the room a bit more. I probably have another foot to play with.

I can say these speakers were a game changer for me in a lot of ways. Even in stock form. I'm regret it took me so long to get there.
Clio09
The subs are Dynaudio Acoustics BM12s . In the search to replace the previous sub they were a kind of dark horse for me. Not really known in the consumer area in North America, but well known and used in the recordings studios. For serious listening it’s just me really, so my setup with two works really well with me sitting in the area of the couch position. If I was to extend the seating "around" the room, and needed good sound all around the room, one could just add one or two more in master slave fashion. Each sub has its own 250 Watt Class a/b amplifier. I was given the ability to trial them first.
The subwoofer category in the audiophile world has to be at the top when it comes to # of choices these days ? So many choices. I find the companies like to call the way they control their woofer by a special code name. Dynaudio’s special woofer control is called CEC (Cone Excursion Control) :^)

******************************

Your comments re; RM3 settings on the OTL versus Push Pull amp were very interesting - thanks for that.

There is no significant difference in the RM-3 settings with either the amps. Sometimes I trim the high end a couple dB when running the RM-10 depending on the music. I run the M-60s with 4 tubes each channel so probably about 20 watts. I do use Speltz autoformers with them at 3x setting so that bumps up their power at some frequencies.

My Quad room has an adjacent music room which is really my main room - defined by (where do I go if I need a quick fix) Fwiw the Quad room can not be called my main room because the right sub is placed in very close proximity to where my wife sits upstairs ......anyway.

So I was running 200 wpc OTL’s on the matrix 800 in that room. It was sweet and very nice. Then one day when they were being serviced, I subbed in my modded RM9. It outperformed the OTL’s in the bass department with half the power. That was sort of the beginning of the end for them.

******************************
sorry to digress back to the Quad 57.

The three wood legs allow the speaker to be planted well. This is important. When raised it is important to affix them in a way to allow for the same thing to happen. Stock presentation is like viewing an orchestra from a balcony. I have spent time in the balconies, but it is more the norm to be in a room with multiple tables, and the band/group of musicians on an elevated stage. So the first mod was a 2x4 piece of wood under the rear leg - lowering - the projection angle of the speaker - but - raising - the soundstage. This is one example for me of "Audio Magic" happening in this Audio Hobby. When you experience this the first time, it goes against the way we think. IMO, we don’t generally think about the back wave on an ESL.

From there the speakers were raised onto Arcici stands and moved 7 feet out into the room. This provided the best bass in the space, but I needed better sound dispersion. Raising another foot did it. If you click on the runner and see pic 41 - the last one shows current setup from the last year. The subs are positioned with the woofer cone slightly forward of the speakers with 0 Phase.


Chris,

Sounds like a nice set-up. What subs are you using? My room is 12' w x 18' d and there is a lot of stuff taking up space. So I am pretty limited in placement. I have them about 4' out from the front wall and they are on wood spider legs so they are lifted off the floor. This does make a difference versus the original feet in my opinion, although I'm sure Peter Walker had a good reason for having the speakers so close to the floor.
Hi Clio09 - the bass impedance hump at 100 hz can be managed by modified placement in the room, especially when it is a fairly large room. See pic 41 on my virtual system. It is roughly 20 x 24 with stairs going up at the back end.
I could never go back to running the speakers in stock mode on the 3 wooden legs. This setup with mid panel at approximately 44 inches, fills the room with sound. and also pretty much eliminates the head vice characteristic of the stock mode.
The preamp has two direct outputs. I am running the Quads full out on the RM10. 
My subs receive a separate direct signal from the preamp and are crossed over at 60 hz. The subs each have Class A/B amps with Linkwitz-Riley crossovers. So with the RM10, three amps are being used in the setup.

George,

Interesting you should point out that Pass design. About 20 or so years ago N.E.W. loosely based their DCA-33 amp off the A-40. It was about 25 watts Class A and used a separate battery (lead acid) power supply. I owned this amp along with their P-3 preamp which was built for them by Cary and essentially an SLP-50. I still scour the ads for a DCA-33. Nice little amp.

Chris,

The crossover is 100 Hz. The ESL-57s have a 90 Hz bump so you want to crossover above that. The 8" woofers Roger selected can be built in a small sealed enclosure which allows them to have a resonance frequency above 100 Hz that compliments the crossover setting.

There is no significant difference in the RM-3 settings with either the amps. Sometimes I trim the high end a couple dB when running the RM-10 depending on the music. I run the M-60s with 4 tubes each channel so probably about 20 watts. I do use Speltz autoformers with them at 3x setting so that bumps up their power at some frequencies.
One of the most memorable times I’ve heard a pair of single stack Quad 57’s, was with this little beauty from Nelson Pass, it gave them extension in the highs and a great taught extended bass with a midrange to die for.

It impressed me so much I built a massive 100watt class-a water cooled version of it to drive double stack 57’s Kelly Decca ribbon 12khz up, and 2 x 24" Hartley woofers for bass from 70hz down.

https://www.passdiy.com/project/amplifiers/the-pass-a-40-power-amplifier

Cheers George


Clio09
In my setup I use a Luxman M-02 on the bottom and either the M-60s or RM-10 on the top. Instead of modding the Luxman to house the crossover I bought a used Beveridge RM-3 (designed by Roger) and made my own low pass and high pass cards (Roger still had some blank circuit boards for the RM-3 lying around).


Hi Clio09 - interesting as I also own a Beveridge RM3. I am not using it right now.
Would be interested to know what frequency you are crossing over at, and, if there is a difference in the Rm3's crossover box dial -  high pass "level" setting,  when used with the OTL M-60 versus the Push Pull RM-10. 
   
Cheers Chris 

Chris (ct0517), I believe the RM-9 is no longer available, even as a special order. I could be mistaken however. Roger has relocated to the Bay Area, and appears to be more involved in his Audio Engineering school than in running Music Reference. He has a right-hand man still operating out of his old Santa Barbara location.

Sorry I am late to this thread and for the long post. I don’t hang out much here anymore, but I’d like to point out a few experiences of my own as a Quad ESL-57 user. First though I’d like to address the quote above. Music Reference is alive and well and in the Bay Area, the right hand man in Santa Barbara is no more and I have been helping Roger for the last year and a half. We also have a couple more folks working with us now.

While the RM-9 is no more, we have a few RM-9SE’s left. Otherwise we are still producing RM-10 and RM-200 amps, and Roger has some new designs he is tinkering with. We also just introduced a prototype for an ESL Headphone Amp (that also plays dynamic and planar headphones and doubles as a preamp) and it was received really well. It will be in production shortly.

Now to the ESL-57. When I purchased my set it was more out of curiosity, but once I heard them with my Atma-Sphere M-60 amps I was hooked. I also own an RM-10 and this little amp as previously mentioned is a great match for the speakers. I ran the ESL-57’s this way for about a year. Then Roger Modjeski introduced me to something new.

Roger, while owning ESL-57’s, also built his own ESL speakers which we exhibited at THE Show Newport 2016. In this biamped configuration Roger uses what he calls the AirSpring Woofer system. It’s a woofer array of 2 or more woofers operating below 100 Hz. The low pass is a 4th order L/W crossover specially tweaked with a passive EQ circuit taking the panels down to 32 Hz (can go lower with the change of a resistor). A modified Class AB solid state amp with the crossover circuit built into it handles the woofers. The high pass is also L/W Riley and covers 100 Hz and above. We used an RM-200 and RM-10 on the top.

In my setup I use a Luxman M-02 on the bottom and either the M-60s or RM-10 on the top. Instead of modding the Luxman to house the crossover I bought a used Beveridge RM-3 (designed by Roger) and made my own low pass and high pass cards (Roger still had some blank circuit boards for the RM-3 lying around). I use 4 woofers spread asymmetrically around the room (similar in theory to Duke LeJeurne’s Swarm concept) to eliminate bass nodes tune the set up. The RM-3 has bass and treble trim controls so those come in handy as well.

Overall I can say this is very pleasing set up. I occasionally still use the ESL-57s stand alone to much enjoyment as well. An amazing speaker to say the least

Disclaimer: Atma-Sphere dealer and I work with Music Reference RAM Tubes.
^^^^^
Electrocompaniet 250R.

Rated output power

8 ohms 2 x 250 W
4 ohms 2 x 380 W
2 ohms 2 x 625 W
1 ohms 2 x 1100 W

Power consumption (no load or signal) 230 W

**************************
in comparison
**************************

Music Reference RM10

2 x 35 watts
Power consumption (no load or signal) 70 W

The real story - imo - is how much the wattage difference grows between two when actually listening to music.

And

For those that do not have a dedicated space and can’t position speakers for the best High Frequency dispersion; Roger provides the "Quad Mod" feature on the RM10.

This is a Switch which is designed to lift (boost the response) from 2khz - 20khz. It’s a 3 position switch ( +1, 0, +2 )

The +2 position adds a boost at 2khz of 2db - This, and I quote from the RM10 owners manual.

"Brings the speakers to the brightness level of modern speakers."

*********
So you see; you really can have your cake and eat it too. Especially if your wife will not allow you to place the speakers in the room as designed for the most detail. Gets the job done, but I have to admit....

Not as funky looking as some of those external tweeters I have seen hanging off the speakers. Hey......I used to hang the things off the speakers myself .....in the earlier days. My external tweeter versions had no dial or toggle switch, but used actual resistors that I could add and remove for the desired brightness.

One benefit of those resistors hanging there; it made the speaker look more dangerous, so the wife would steer clear. Now if I can just train my kitty to stay away from them :^(

...I have used this combination before... the 250R will put yours quads to sing beautifully.
I should add, the Quad 2905's come properly compensated for solid state right out of the box. The 2805's less so. Re-working compensation for the 2905's is only necessary if you mess with the electronics.

It's a bit tricky alright. Of course, you could put an air core inductor between the amp and the speaker to compensate, but that's tricky because it risks electronic resonances. Actually, it's quite unwise to attempt this unless you've made your own equipment to be bullet-proof.

The alternative is to compensate upstream, at the preamp or the cartridge step-up transformer. The obvious thing is to increase the capacitance of the 75uS RIAA compensation, starting by say doubling capacitance. Let your taste be your guide.
I ran Decca ribbons with my Quads and a small sub back in the early-mid '80s- could never get the thing to cohere completely, but as my late audio friend, Chuck Lamonica said, "You could kiss every note." 
I still have the Deccas--also in need of a restoration, but lower on my list. (I used Sequerra ribbons at one point too, and was able to talk to Dick S. to get replacement ribbons from him. He was very kind).
The history behind this stuff is fascinating, as is the ability of equipment now 60+ years old to deliver a level of quality that in some ways, has not been duplicated. 

ct0517                    1-11-17

" When discussing the Speakers with the Amp manufacturer, and he/she can’t answer directly with facts, and says.

"Oh, don’t worry your speakers won’t hurt our AMP"

Then it’s not the right amplification for these Quads "

Soon after I purchased my first pair of quads I asked a Technician who was building amps on his dining table whether his amp would damage my Quads and he replied. " No, my amps are kind to loudspeakers." I was so impressed with his reply that we became good friends but I never tried his amp on my Quads.
 
bdp24                                   01/10/2017
 
" One great way to add bass to the 57 is with a pair of Magneplanar
Tympani bass panels. "

Agreed. It might even be the best way, provided the quads are allowed to run full range.
kalali
So, is this the right "type" of amplification for these Quads?

hmmmm.....

Sometimes...it is easier to turn the question around a little to get the right answer ? like.....

How do you know if it is "not" the right type of amplification for these Quads?

********************************

1) Are the Canon shots on 1812 Overture so real, that you believe you are actually seeing sparks in your room; which you believe are related to gun powder.

Then it’s not the right amplification for these Quads.

2) When discussing the Speakers with the Amp manufacturer, and he/she can’t answer directly with facts, and says.

"Oh, don’t worry your speakers won’t hurt our AMP"

Then it’s not the right amplification for these Quads.

3) When you read about reviewers talking with Peter Walker and they ask.

"For people who would like to use your speakers as mid-range and high-end
reproducers - do you make suggestions about what they might add for moving-coil supplement below 100Hz, say?

Then it’s not the right amplification for these Quads ?

Quads play down to 45hz. You will have difficulty crossing over at 100hz. (just take my word on this one)

4) When you see someone’s setup and it looks like this.

http://2.bp.blogspot.com/-urEs8lxKAII/Upb0foVkinI/AAAAAAAAA-w/oNYggMVMkgQ/s1600/Quad+ESL-57+advertis....

Don’t even bother asking the question.....go to the next question.

But first from the Quad Owners Manual

"As a general rule radiation of sound waves from the front and rear of the speaker should be restricted as little as possible. While corners and positions closer to the wall should be avoided. A corner position is often necessary for other types of loudspeakers because it accentuates the low frequencies, but such a position for the Quad will both reduce the bass seriously and cause deterioration of middle frequencies due to standing waves."

5) If someone needs to use external tweeters with the speakers.

Then it’s not the right amplification for these Quads.

***************************************

Having a lot of fun here w u guys.........so cold outside but a lot nicer today.....still, .......boating season seems so far away.

Cheers
^^Thanks!

If you were planning to use an SET on the 57, you would likely use the 16 ohm tap. You would get a similar proportionate spread in total output power.

However, the total output power does not represent what you would actually hear in practice. This is because there is less energy in music at higher frequencies. So the amp does not need to make as much power at those frequencies. In practice it seems to work well- we have a lot of Quad customers.

Since the M-60 can make far more power than the 57 can handle, many of our customers run the  amp with less than the full complement of power tubes (which is easy to do with our amps). This would further limit the 4 ohm power but this does not seem to be a problem. Alternatively the 57s can be outfitted with a modern protection circuit which shuts down the amplifier power if it senses too much output voltage.

FWIW, Quads and OTLs have a long history together going back to the 1950s.

Atma-Sphere M-60 Mk. 3.3:

80 wpc @  16 ohms

60 wpc @ 8 ohms

45 wpc @ 4 ohms

So, is this the right "type" of amplification for these Quads? 

By the way, magnificent piece of audio jewel.


It has been quite a while since I heard the HQD system.  That was a very expensive system in its day. 


I have heard, much more recently, re-built and heavily modified 57s done by a company called MyEmia.  One of these pair of  speakers came with an active crossover and was bi-amplified using dedicated EL34 tube amplifiers.   The other pair, I cannot remember the specific details, but, I think it was a similar setup.  Both pairs were able to deliver music at quite high volume levels and with fairly deep and impactful bass; this is NOT your father's Quads.  It was hard to say if they could do all the other things that the 57s are known for because I heard them at two different DC -area Capital Audifests (2015 and 2016) and they were mainly demonstrated at exceedingly high volume levels. 

Yeah Bill, Pearson had really high ambitions and aspirations for TAS, sometimes unachievable. Moncrieff had his own unique reviewing and writing style (which was to beat a subject to death, saying the same thing three different ways)---whatever happened to him? I think I heard he was in a very bad car wreck, and hasn’t been the same since. The same thing happened to the Bay Area’s leading Hi-Fi dealer in the 1970’s and 80’s, John Garland, who had the Wilson Audio WAMM speaker in his sound room! Another interesting mag was Art Dudley’s Listener, his publication before joining Stereophile.
bdp- Pearson also waxed over the maggie bass panels with the Crosby Quad 63. For one issue or so. And then he moved on. What always killed me about The Absolute Sound in the glory days was the promise of a follow up after a sneak preview, which never happened. I used to read those things religiously back in the day, along with an assortment of other stuff, Montcrieff, etc. 

One great way to add bass to the 57 is with a pair of Magneplanar Tympani bass panels. They take a fair amount of floor space, however---each is 32"w x 6'h! That's what Harry Pearson mated with the m/t panels of the Infinity IRS to create his hybrid super-speaker.

Another way is with the GR Research OB/Dipole Subwoofer, the world's only Open Baffle/Dipole Servo-Feedback Subwoofer. Very special, and very good with planar loudspeakers. But it's available only as a DIY kit. Worth the effort!

nyame
But this is the first time I have heard of stacking 3 pairs of Quads.


Why stop there ?

https://s-media-cache-ak0.pinimg.com/564x/72/13/36/7213361b9e13336a168f4c0d98008eb3.jpg

The funny thing is that when I had my Quads I was never aware, while listening to music, of any deficiency in the bass or treble. It was only when my brain kept telling me the bass did not go low enough and that the high frequencies were rolled off.

My rooms are adjacent to one another. I can have the same music material running at the same time for fun. There are matrix 800’s in the adjacent room. I can tell you and so can others that there is no roll off in the HF’s with the RM10 and 100% functional Quads. The room treatments between the two rooms is also very different.

Now the bass.

******************************************

Interview with Peter Walker

Interviewer : For people who would like to use your speakers as mid-range and high-end reproducers - do you make suggestions about what they might add for moving- coil supplement below 100Hz, say?

PW: We try to keep out of it. Two or three people have made good attempts at this, adding woofers. It’s not that easy to do. Initially it’s quite impressive, but to try to give this a homogenous sound is difficult. Another thing people do is to use two of our panels, one above the other. This is quite reasonable because it is really a strip source, you can extend the strip source without deteriorating anything. All you do is add 6dB at the bottom end and 3dB everywhere else. It gives you a louder sound, a more impressive sound. That’s all right. Adding woofers has never been very good.

*****************************************

So it gives you 6 db more in the low end, and 3 db everywhere else. So it is not linear, and they still don’t play any lower than 45 hz .
Peter Walker never heard today’s subwoofers.

I had one occasion to hear stacked quads. Whether the setup or one of the panels was off a little, the magic I hear with two was lost. Seemed like a lot of effort and risk (multiple panels) _ to me at the time and the reason I pursued the sub route for db levels in the larger room. The secret for me in my space - to have the single pair panels elevated so they are 44 inches off the ground at the mid panel point. .

******************************************

@Kalali
there is no such thing as a good deal with Quads. I would never buy any without seeing. and hearing them, along with the paperwork for when they were restored. Also removing the back panel to determine if they were a smoker. Would you buy a car that was owned by a smoker ?

Cheers

glennewdick                     1-09-2017

I have heard stacked Quads. AWESOME  It was at " Sound Components "  a high quality dealership in Miami. They had in the their showroom a system referred to as the " HQD" system. Stacked Quads, one Decca Ribbon tweeter and a 24" Harley sub-woofer housed in what looked like a coffin.
But this is the first time I have heard of stacking 3 pairs of Quads.

The funny thing is that when I had my Quads I was never aware, while listening to music, of any deficiency in the bass or treble. It was only when my brain kept telling me the bass did not go low enough and that the high frequencies were rolled off.

A friend of mine runs his 3 stack ( 6 panels) with 6 Quad 2 mono amps these were made for the 57's and i have to say they sound wonderful, deep base fast and articulate and highs mids to die for. i recomend you get another set of 57's and some Quad 2 amps and enjoy.  ok maybe extream but the Quad amps are made to run these speakers and do so very well.

When you stack more then one set the base filles out alot and the panels just fill the whole room.

kalali- i don't know what is on offer, but keep in mind that most of the original Quads do need some work, whether it is sympathetic restoration, repairing or replacing panels or both- you have to factor that in, unless the pair you are looking at have already been redone by a reputable restorer and not abused since. Kent McCollum of Electrostat Solutions is the person I'm having restore my old Quad loudspeaker. There was a double pair restored by him that a friend recently pointed me to for sale here, but that takes it to a whole other level....
This must be how people get hooked on drugs; following this discussion - with no interest in or prior knowledge of Quad speakers, then all of a sudden a pair of 57s come up for sale on the A'gone, completely restored in an incredible shape and affordably priced (for me), which can be paired with a Quad amp for sale on the opposite coast from a very reputable dealer, all a click away on my PayPal account. You guys are exactly what my parents warned me about....
ct0517                     01-09-2017

  " btw - do your amps have a brand name ?"

" No. The amp I refer to as "my amp" was a joint project with four other friends. Five amps were built, each one slightly different. Four stereo versions, each with separate power supplies, while mine was built as mono-blocks. " 
Four of the amps were used to drive Quads, and one was used to drive a pair of Apogees. Three were built to produce 40 watts per channel, which was thought to be safer for the Quads. My friend with the Apogees actually used 16 output transistors per channel. This lead to heated arguments between us.

I am no longer in possession of the amp.

.


Chris (ct0517), I believe the RM-9 is no longer available, even as a special order. I could be mistaken however. Roger has relocated to the Bay Area, and appears to be more involved in his Audio Engineering school than in running Music Reference. He has a right-hand man still operating out of his old Santa Barbara location.
Hi nyame
yeah,
I get the fact that the Quad 57 presents a capacitive load. Atmasphere also made this clear earlier. Also I do remember now, similar discussions with the OTL manufacturer who made the 200 wpc OTL amps I was using with my Acoustats.
    
btw - do your amps have a brand name ?

So I have a recommendation to unravel this Quad 57 mystery.

Nyame - you may send me your ML_2's.

Kalali - you may purchase those Quad II's you linked earlier, and send to me also.

or alternatively Whart;  can send me his Quad II's while his Quad's are being restored.

I promise to complete the shoot out with my RM10, post results here, and all equipment returned by April 1, or when boating season opens; whichever comes first. :^)

How's that sound ? My LP assimilation project can wait .  8^0 

**********

Bdp24 (Eric) Is it my correct understanding that Roger will only build RM9's now upon request, due to the cost ........or is this a myth too ?

Cheers 
ct0517                            1-09-2017

I am not sure that ohms law is the correct tool to unravel the mystery of the Quad 57 which present a capacitive load. My own experience is that very little power is required to reach acceptable music levels in a small/medium sized room. A friend of mine drove his quads with a 12 watt per channel solid state amp at bass levels which surprised me. 

Roger Modjeski  had the same experience: "The RM-10 came into being in early 1990, when I noticed I rarely played music above a few watts on my Vandersteen 2C speakers. Later, I acquired a pair of the old QUAD electrostatics and achieved the same listening levels at even lower power."


 
I am curious this morning and questioning this ML_2 that has been mentioned.

There are two outputs coming out of my preamp. One goes to the RM10 which is run full out to the Quads. The second preamp line out goes to the Subs which are set to cutoff at 60 hz.

I am trying to understand how the ML_2 mono pair, not having heard them, and just based on specs.....can get the job done. if I was using them I think I would need to use a higher cutoff on the subs?  

************************************

From nyame’s post

ML_2 Mono - Pair 25, 50,100 watts into 8, 4, and 2 ohms

this implies to me and please tell me if I am wrong.

2..............4.............8............16..............32 OHMS

100..........50...........25..........12.5...........6.25 ML_2.....Output Watts.

***So only 6.25 watts available at 32 ohms***.

The Quad 57 use approx 32 ohms to make 100 hz. See the graph that was posted earlier and here it is again.

http://www.quadesl.com/graphics/quadGraphics/quad_impedance_graph.jpg

Somebody explain this one to me please.

***********************************************

Whart - would have loved to have met Peter Walker in person. Also John Bowers.

Cheers Chris

I wonder, just out of curiosity, what it would take to resuscitate a pair of those old Mark Levinson ML 2 amps. After all these years, they gotta have needs- are the parts unobtanium? I know Charlie King found a stash of some old ML parts at one point that he used to Frankenstein some tape preamps.
If I didn’t already have the Quad II amps, I’d probably be interested in exploring other options. I did get to meet Peter Walker back in the day--he was pleasant to talk to- I was pretty young, but he was polite and tolerated my questions.
In some ways, reviving this old gear is more interesting than buying current high end stuff off the shelf--I think my expectations are different, and there is something satisfying about getting a commanding musical performance out of an antique. I haven’t settled on a preamp yet for this "funk" system, but the McI MX 110z seems to ring a lot of bells- a bit of a sleeper since it isn’t a purist preamp only; has an FM tuner that could be a kick to use for a household system and looks like the build quality is stupendous. (Sympathetic restoration would be required as would a little tube rolling).
As to multiple systems being a cheap substitute for an uber system, I have yet to hear any system --at any price- that didn’t have some area where the illusion collapsed. Again, I think it goes back to expectations- you can get a hell of a lot of musical enjoyment out of older gear if you don’t expect it to do everything well. And, I might just be surprised- one pretty well known guru of old Quads told me I might find myself spending more time listening to this system than my "main" system--
I’m certainly open to that possibility. I’m a gear head for sure, but I’d really rather spend the money on records at this point in my life than constantly search for the latest and greatest. These last few years have been very gratifying for precisely that reason- my main system was pretty well dialed in, I knew what it could and couldn’t do, and focused on buying records. Now everything is packed and crated. The movers arrive in a few hours. Yay! :)
I bought a Bedini 25/25 in the 90’s, specifically for my Quads. Pretty good for ss, the poor mans ML 2! I still want to get a little Music Reference RM-10 for them, which is THE amp for the speaker. But I’m presently focused on my Tympani T-IV’s, which require very different amplification. I’ll be bi-amping them, with the wonderful RM-200 Mk.2 on the midrange/tweeter panels.
Kalali         1/8/2017

+1

Nice thread !

 The loudspeaker/Amplifier partnership should be viewed as a matched pair.

When building a system one should first choose a loudspeaker, then find an amplifier (within budget) that is up the task. 

I made the mistake of purchasing a Quad 57, and was unable to find an amplifier that could do justice to it. I had to build a suitable amplifier. At that time ( A very long time ago ) the only serious amplifiers I was aware of were the Mark Levinson ML_2 and the Bedini. The ML_2 was the inspiration for my amp.

ML_2            Mono - Pair            25, 50,100 watts into 8, 4, and 2 ohms
My Amp        Mono - Pair           50,100, 200 watts in 8, 4, and 2 ohms
We never tested the amp at one ohm, but it was designed to be stable into one ohm. Eight 150 Watt Motorola bipolar output transistors per channel.