Which Amp to buy? The most frequently asked question on this site. READ THIS!!

[MUTZ57]

Yes, miniature tubes in the 300, I think Musical Fidelity bought up the tri-vista tubes wholesale and have a considerable stock of them using them in a number of limited edition units to date, ( I also had their Tri-Vista 3D CD player which was very impressive, big as with most of their kit but sound was top notch!), so likely replacements for their kit not really an issue for the time being……..hopefully!

Interestingly I had read about the NAD M33 and the use of the Purifi modules and wondered how these would differ from the Hypex modules, there appears to be many different implementations of class D and it’s a job to keep up!

Devailet get really strong recommendations, not a cheap alternative (relatively speaking) but one to try and similar casework to the Linn amps I had, these could be put anywhere as their size is quite diminutive.

Don’t get me wrong the NC500's don’t do a bad job on the ML’s and if it wasn’t for the fact that I had the Musical Fidelity to benchmark them then I may well have stuck with them, for their cost they are incredible (less than £1/watt). For me they just lack the grip and get up and go of the Musical Fidelity something that maybe the new Purifi design resolves?

I would be interested to see how you get on with the M33 into your Montis, and also how this compares with the Benchmark as I can get options on both of these readily easily.

Worth noting I also tried a Quad 909 power amp which had a similar sound signature to the Musical Fidelity, however I never really got to evaluate it properly as there appeared to be either an earthing or screening issue which prevented the electro stat panel discharging properly resulting in an earth-shaking crack from the panels when the plug was pulled from the speakers. May have another look at this to see if I can see what the issue is as this combination did sound good for the short time I had it running and I have one collecting dust so would be interesting to see how it fares and fits in the current hierarchy of amps tried to date!

 

[jofi]

The choice of amp for your MartinLogan speakers will depend on the specific model and your personal preferences. MartinLogan speakers are known for their electrostatic technology, which can present unique challenges for amplifiers due to their low impedance and high current demands.

Some amplifier brands that are commonly recommended for use with MartinLogan speakers include Parasound, McIntosh, and Bryston. These brands offer high current and stable power output, which can help to drive the speakers to their full potential.

It's also important to consider the power rating of the amplifier and match it to the power handling of your specific MartinLogan model. Generally, a high-quality amplifier with a power rating that matches or exceeds the speaker's recommended power handling should be sufficient.

Ultimately, the best amp choice will depend on your personal preferences, listening habits, and budget. It's always a good idea to audition different amps with your MartinLogan speakers to find the one that sounds the best to you.

 

[Rascal]

Jofi,

Do you have specific examples of ML ESLs and amplifiers that you have found work well together? What speaker(s) and amplifier(s) are you currently enjoying?

 

[MUTZ57]

The choice of amp for your MartinLogan speakers will depend on the specific model and your personal preferences. MartinLogan speakers are known for their electrostatic technology, which can present unique challenges for amplifiers due to their low impedance and high current demands.

Some amplifier brands that are commonly recommended for use with MartinLogan speakers include Parasound, McIntosh, and Bryston. These brands offer high current and stable power output, which can help to drive the speakers to their full potential.

It's also important to consider the power rating of the amplifier and match it to the power handling of your specific MartinLogan model. Generally, a high-quality amplifier with a power rating that matches or exceeds the speaker's recommended power handling should be sufficient.

Ultimately, the best amp choice will depend on your personal preferences, listening habits, and budget. It's always a good idea to audition different amps with your MartinLogan speakers to find the one that sounds the best to you.

In the main I agree with this and it’s a good starting point to ensure the specifications of an amplifier meets the demands of the individual speakers, but thereafter it’s a bit of trial and error as to which of the “compatible” amplifiers provides the best performance given the individual system requirements and as you say, the individuals personal preference. I think most will agree that no two amplifiers sound the same, albeit as we know it doesn’t necessarily follow that what I like, you like.

There are many, many different amplifier combinations that will (on paper) drive the ML’s but as you quite rightly say, what may be good for 1 model may not be so good for other models given the many iterations of ML’s over the years and bass, panel configurations, sensitivity etc. (my own experience with amps suitable to drive my own ML’s and varying results bears this out for the ESL 11’s alone)

That’s why this type of thread is invaluable to ascertain which options others have tried and had success with (some may not even fit the “compatible” model per se but have been found to perform well despite this) so as to give pointers that may help narrow down the field or offer suggestions of what works well. (given the caveats stated above, preference, system etc)

It’s very difficult for many to get access to equipment for audition purposes so look to others experiences to try and narrow the field (bit like reading the many different on line reviews but with the benefit of being in more real world systems and home environments)

I myself have found this invaluable so hence my own contribution to this thread to set out my own experiences in the hope this may be useful others.

 

[Dobbler]

Moving to a separate thread.

 

[Big Dog RJ]

There was a chap on one of our amplifier forums who highly sought after specs and nothing but specs. So just as a gig, we posted him a spec sheet and asked him to compare it to the other amps we were using at the time (Parasound, Bryston, Krell, Sunfire, Mark Levinson etc.) After a few posts, he replied with much enthusiasm saying that this particular amp's specs were the best he's ever come across and very highly recommends the amp. We all laughed our socks off... one of us fell off the chair so to speak. Then he was very eager to find out the amp type and brand, so we replied to him with much enthusiasm. It was a Kenwood car power amp!!!

That's all she wrote!

Goes to show, at the end of the day, specs can only be taken as guidelines, not the ultimate test. The ultimate test is to actually try out the damn thing. For unless you really tried it out, you'd never know.

I've used various so called high powered amps with ribbon panels and full range stats, although they were highly rated at 100s and 100s of watts, they ran out of puff! Just couldn't drive stats. I'm not mentioning brands for ethical reasons but specs doesn't give the full picture. Therefore, I take specs only as guidelines, nothing else.

Don't get carried away by spec sheets.
Cheers, RJ

 

[Big Dog RJ]

OTOH with reference to speakers, it's good to consider the specs, just to be familiar with what you're up against. Obviously the amplifier/s driving the speakers will deliver an outstanding performance or a very mediocre one. Whichever performance it delivers will determine its overall standard, by which only then will you be able to justify its price vs performance ratio.

Cheers, RJ

 

[rulerofrecords]

I'm still very much in the honeymoon phase with my ML-Ethos and these are already planting strange ideas in my head. I have studied this thread very much from start to finish and as a complete panel noob I just would like to confirm - with the active bass (class d, is it not?) this whole be very afraid of the "below 1Ohm impedance at 20hz" does not really concern me with the Ethos?!
So at above 90db sensitivity I finally feel tempted to break my old rule of "tubes in the preamp, solid state for a power amp" Even if I'm not going to - I'm happy to be able to give preference to "quality" vs "quantity". Happy days indeed shortly after witnessing a McIntosh 8900 fall in its sword trying to propperly drive a Magnepan 1.7

 

[ttocs]

. . . with the active bass (class d, is it not?) this whole be very afraid of the "below 1Ohm impedance at 20hz" does not really concern me with the Ethos?!

Be afraid, be very afraid!!! just kidding.

But, I can provide a graphic showing how my 13A with active woofers is seen by the amp as having very low impedance at upper frequencies.

The graphic in the linked post below, the Red Trace shows the speaker connected directly to the external Krell amp, and, the Blue Trace is using a AntiCables Autoformer connected between speaker and amp which doubles the impedance. I did this to create an impedance curve and see exactly at what point does impedance go below 3Ω and 2Ω. This is reflected in what I heard when I used my tube amps, which don't like impedance below 3Ω at all, so I noticed a lack of upper frequency rolloff when listening to music.

The graphic in the linked post also shows, via a spreadsheet, why amps which double in power as impedance is halved work so well. You'll see that the amount of power used goes waaaay up when impedance goes super low.

Impedance Anyone?

 

[rulerofrecords]

"Just when I thought I was out, they pull me back in!"
So thanx for that ;-)
Interesting read and observation nonetheless!!
Cheers and I'll keep that in mind

 

[ttocs]

The premise here is that, even at lower volume levels the upper frequencies can be attenuated if the amp can't quite get enough power through to the speaker.

I've been meaning to do more testing on this, but this year has just been super busy. Things are just about to get slower for me which should allow me to have more testing fun!

In the Impedance Anyone? thread I used a very capable amp. So I'd like to test using a tube amp, which I love but it loses the upper frequencies starting at 7kHz, to see if at very low volume it can push enough power through at the top end. This would be an eye opener to actually see a difference in the graphing of the power output at various output levels.

My theory is that at very low volume levels the frequency response curve in REW would look normal. But as volume level is increased, the top frequencies would begin to sag relative to the lower frequencies due to the amp running out of steam.

However, it might be that those upper frequencies ALWAYS sag no matter what volume level is used. Dunno. Either way, it'll be fun to find out.

Sometimes I test things just to see for myself how things work. Other times, like this example, I test because I can't find any info that specifically answers a question I have.

 

[Nuri58]

Try running the room correction SW and look at the response curve. In my case it is where it should be and close to the Dirac suggested target. One thing to keep in mind is it's the bass taking the power not the high frequencies meaning power reserve should be more than enough for most AVRs/amplifiers. I'm actually running my amo in bridge mode meaning my amplifyer is rated at 8Ohm only. And I do not hesitate to play (too) loud often. The only issue I have been facing for the four years with this configuration is that issues with recording seems to be doubled

 

[Doug033]

I’m the original owner of a pair of CLSs, and I’ve used Audio Research with great results. I started out with a D-125 (115 watts) and upgraded to a REF-150SE (140 watts). The 8-ohm tap sounded best in both cases, neither amp had any problems with the impedance, and I’m a real believer in the synergy between tubes and ESLs. The acoustic space extends well beyond the speakers, which disappear on all but the most poorly-mastered recordings, and sometimes even through the front wall. REW traces show a gradual roll off beginning at 14k, but that exceeds the rolloff of my ears.

 

[Leporello]

The premise here is that, even at lower volume levels the upper frequencies can be attenuated if the amp can't quite get enough power through to the speaker.

I've been meaning to do more testing on this, but this year has just been super busy. Things are just about to get slower for me which should allow me to have more testing fun!

In the Impedance Anyone? thread I used a very capable amp. So I'd like to test using a tube amp, which I love but it loses the upper frequencies starting at 7kHz, to see if at very low volume it can push enough power through at the top end. This would be an eye opener to actually see a difference in the graphing of the power output at various output levels.

My theory is that at very low volume levels the frequency response curve in REW would look normal. But as volume level is increased, the top frequencies would begin to sag relative to the lower frequencies due to the amp running out of steam.

However, it might be that those upper frequencies ALWAYS sag no matter what volume level is used. Dunno. Either way, it'll be fun to find out.

Sometimes I test things just to see for myself how things work. Other times, like this example, I test because I can't find any info that specifically answers a question I have.

It's not a matter of running out of steam. An amp, below clipping level, is essentially a linear device. It's output impedance is complex, in the sense of having a reactive component (e.g. the from leakage inductance of the output transformer) but linear. The amp and speaker comprise a voltage divider. The lower the impedance of the speaker, the more of the internal voltage appears across the amp's impedance, which goes into heating up the amp.

BTW, as I'm sure you know, the lower the sound level you do a sweep in REW, the more interference you get from ambient noise in the room. If the power spectrum of the ambient noise were flat, though it rarely is, it would tend to flatten out peaks in the measured response. On the other hand, the subjective frequency response will be rolled off, due to the Fletcher-Munson effect.

I do hope you find the time to pursue this further, and let us know the results. I'm sure the autotransformer dohicky you used with your M125's had everything to do with getting reasonable results with ESL's.

 

[Littleman]

Chiming in here....recently acquired a very nice condition used Bel Canto 300 i class D for the recently added ML Ethos. Have tried and compared 3 three chains...
1. Sony STR da5700ES Pre / Amp only as before...
2. Sony Pre into Bel Canto AMP (Theater Bypass)...
3. Bel Canto Pre / Amp on it;s own.

Not knowing anything different...1 was very enjoyable.

2 improved the top and mids....much cleaner / clearer, better soundstage, depth, lower mids into bass more "fuzzy / whooly" by comparison to 1.

3 initially sounded very bright on top....fatiguing...almost unlistenable on some tracks.

Left Bel Canto on with CD repeat for 100+ hours...

3 now is far better up and down the frequency range including the bass with bass cabinets set at "0". Rocket 33 speaker cables gave a nice boost to mids and tampered down the top just enough.

 

[Brandon Hartwick]

Chiming in here....recently acquired a very nice condition used Bel Canto 300 i class D for the recently added ML Ethos. Have tried and compared 3 three chains...
1. Sony STR da5700ES Pre / Amp only as before...
2. Sony Pre into Bel Canto AMP (Theater Bypass)...
3. Bel Canto Pre / Amp on it;s own.

Not knowing anything different...1 was very enjoyable.

2 improved the top and mids....much cleaner / clearer, better soundstage, depth, lower mids into bass more "fuzzy / whooly" by comparison to 1.

3 initially sounded very bright on top....fatiguing...almost unlistenable on some tracks.

Left Bel Canto on with CD repeat for 100+ hours...

3 now is far better up and down the frequency range including the bass with bass cabinets set at "0". Rocket 33 speaker cables gave a nice boost to mids and tampered down the top just enough.

Are you saying you attempted to "break in" an already used amp?

 

[Littleman]

I purchased it from a former Bel Canto employee...and current repair person...my understanding is that it was very lightly used. Not being certain of the usage....I went with the "break in" process...and am continuing to do so....multiple listeners are commenting on the improvement as well.

 

[FastEddy]

I’m the original owner of a pair of CLSs, and I’ve used Audio Research with great results. I started out with a D-125 (115 watts) and upgraded to a REF-150SE (140 watts). The 8-ohm tap sounded best in both cases, neither amp had any problems with the impedance, and I’m a real believer in the synergy between tubes and ESLs. The acoustic space extends well beyond the speakers, which disappear on all but the most poorly-mastered recordings, and sometimes even through the front wall. REW traces show a gradual roll off beginning at 14k, but that exceeds the rolloff of my ears.

I recently tried a vintage Audio Innovations Series 1000 power amp to drive my Montis. It’s a 7.5 watt SET tube amp and I really didn’t expect it to drive them well. To my surprise it’s great and more dynamic than the 100 watt hybrid Counterpoint amp it replaced. Mid range and vocals in particular are very strong.
Just goes to show, you never can tell - just have to listen.

 

[Robert D]

I recently tried a vintage Audio Innovations Series 1000 power amp to drive my Montis. It’s a 7.5 watt SET tube amp and I really didn’t expect it to drive them well. To my surprise it’s great and more dynamic than the 100 watt hybrid Counterpoint amp it replaced. Mid range and vocals in particular are very strong.
Just goes to show, you never can tell - just have to listen.

Wow. Is it able to reach a good level of volume without distortion? Listening to music/ media at 70 dB or more?

 

[Nuri58]

Then you need to define distorsion - I guess there will always be a bit not least from the loudspeakers. My take would be when you hear it. A bit like dynamic range.