[medium jim]

The plan was to manufacture 500 pairs, but production was halted before that goal was reached, IIRC. Damn, I just talked to Kevin last week and I'm already foggy on the details.   I'll ask him about this next week, just for clarification.

Kevin:

Please do as they sold out and it would have been foolish not to make them to fullfil the commitment, economy or not. 

Jim

[JerryM]

...Power amplifier wattage capability and speaker sensitivity are the primary issues.

Somewhat after *sound*.

[avahifi]

I guess I could have explained it better.  The real problem is that the audiophile for the most part has no idea the power is an exponential function as a factor of voltage swing.  Exponential functions are definitely not intuitive.

In any event, if you have two speakers who's input sensitivity is 3 dB apart, the less sensitive one needs double the amplifier power for the same acoustic output.  If the speakers are 6 dB apart, the less sensitive one needs four times the power, 9 dB apart needs 8 times the power, and so on. A 3dB difference in sound levels is pretty much established as a difference anyone can easily hear, but not a large difference. It also requires twice the voltage swing to generate 3dB more output.

Power equals RMS voltage SQUARED divided by load resistance.  However apparent loudness is much better defined by RMS voltage rather than power. Peak V x .707 quantity squared divided by 8 in general.

For example our 200W/Ch Fet Valve 400R will swing 60+V peak, our 300W/Ch Fet Valve 600R will swing 70+V peak (both into an 8 ohm load both channels driven in phase).  That is a 10V voltage difference.  However that is about a 100 Watt power difference.  The apparent sonic loudness capability is much more in line with the voltage output difference (about 10 percent more) not power difference (50 percent more).

Note that measuring power into 4 ohms is a cheap way of doubling your power ratings (do the math) as long as the amplifier under question can supply the necessary twice the current needed for the low impedance load.

As an aside, in the real world, "gas milage" is also a non intuitive based exponential number.  Your car's gas economy is much better served by considering "gallons per one hundred miles" than gas mileage.  How important is it to improve your gas mileage by 10 miles per gallon?  Not much if you are going from 40 MPG to 50 MPG, you are only saving one-half gallon per one hundred miles.  But from 10 MPG to 20 MPG, that saves 5 gallons per hundred miles.  Do the math!  Makes me wonder why truckers drive so fast when they would save hundred of dollars with of gas on every long distance trip if they just stuck to 50 mph or so and the reduced drag with save them more than they would realize.  Again, do the math, its just simple algebra.

Frank Van Alstine

PS Yes I know that watts by themselves are not an end-all measurement, the quality of these watts (or preferred, volts) are probably even more important.  But at least the data above should help clear your head a bit.

[medium jim]

Frank:

You just added more fuel to the voltage vs current debate.

Jim

[Davey]

Somewhat after *sound*.

No, actually "sound" should be a secondary box to check on your amplifier checklist AFTER you've identified the amount of power you need for a particular speakers and preferred SPL's.  Once you have those parameters then by all means select the amplifier that has the best "sound" from the remaining candidates.

Cheers,

Dave.

[medium jim]

No, actually "sound" should be a secondary box to check on your amplifier checklist AFTER you've identified the amount of power you need for a particular speakers and preferred SPL's.  Once you have those parameters then by all means select the amplifier that has the best "sound" from the remaining candidates.

Cheers,

Dave.

Davey:

This we agree on.

Jim

[JerryM]

No, actually "sound" should be a secondary box to check on your amplifier checklist AFTER you've identified the amount of power you need for a particular speakers and preferred SPL's.  Once you have those parameters then by all means select the amplifier that has the best "sound" from the remaining candidates.

Cheers,

Dave.

Agreed, once one is making the proper *sound*, moreso than just SPLs.

[kevin360]

No, actually "sound" should be a secondary box to check on your amplifier checklist AFTER you've identified the amount of power you need for a particular speakers and preferred SPL's.  Once you have those parameters then by all means select the amplifier that has the best "sound" from the remaining candidates.

Cheers,

Dave.

This is absolutely true. With apologies to Rclarck, I question the extreme view on what is required, but as a primary requirement, sufficient power makes the most sense. It is impossible to state what the requirement is for everyone since there are so many variables involved. Changing one variable in my own system gave obvious testimony to the variability of this requirement. I was using a hefty solid state amp with my 3.7s (because I needed it). In my quest for better sub integration, I tried a Bryston 10B sub XO. That proved to be a great investment (though, I could use something far simpler and cheaper now), as it not only achieved the intended goal, but had the additional benefit of yielding an improvement in the sound of my 3.7s. The bias meter on my Pass X350 no longer deflected anywhere near as radically as it had before taking some of the load off the 3.7s. That opened the door to a 'less powerful' tube amp. The power requirements changed and so did the weight I could give to the sound check box.

[Freo-1]

Excellent point, Kevin.  It was widely held by most audiophiles that Magnapan and Audio Research were a excellent combination.  Maggies are a fairly constant resistive load, so tubes can and do work well with them.  Relieving them of deep bass can only add to their performance.  I have found integrating subs with dipoles to be somewhat challenging.

[medium jim]

Excellent point, Kevin.  It was widely held by most audiophiles that Magnapan and Audio Research were a excellent combination.  Maggies are a fairly constant resistive load, so tubes can and do work well with them.  Relieving them of deep bass can only add to their performance.  I have found integrating subs with dipoles to be somewhat challenging.

But rather rewarding if done right.  Tidbit of useless information, Saul Marantz used KLH 9 Electrostat's to show off his tube amps at trade shows and clinics.   I totally agree that AR's and Maggies are a wonderful combination. 

Jim

[SteveFord]

Lurching even further off course, here's a nice bunch bit of Marantz Model 9 info:
http://www.classic-audio.com/marantz/0009.html

I'd say that both the Marantz and VAC amps fall into the beautiful audio component category.

[kevin360]

Excellent point, Kevin.  It was widely held by most audiophiles that Magnapan and Audio Research were a excellent combination.  Maggies are a fairly constant resistive load, so tubes can and do work well with them.  Relieving them of deep bass can only add to their performance.  I have found integrating subs with dipoles to be somewhat challenging.

It was an Audio Research amp that I had in mind when I first entertained the idea of trying a valve amp. My timing, however, was incredibly good as there was a VAC Phi 300.1 at the top end of my budget allowance (in truth, a little beyond it, but we live once) on audiogon when I looked with intent to buy. Who am I to argue with fate? That amp was one of my dream components and here was a chance to own one (just don’t see them up for sale very often – when they appear (once a year, maybe twice - maybe not even once), they don’t last long). I sent the seller an email and told myself that I’d sleep on it, but I tossed and turned until I arose rather early with the decision made. I committed to buy it and went back to bed and slept very peacefully.

Getting the subs to behave with the room is a great challenge. Getting them integrated with the Maggies only exacerbates that issue. It is, indeed, a challenge. The crossover helped. Removing the bottom end from the Maggies allows them to do what they do best, and most of the character of the bass is defined in the midbass, which the 3.7s are still delivering. Without being called upon to deliver what is difficult for them, the 3.7s gain in smoothness and dynamics. The only downside is expense. I have more invested in the subs and the bass traps (not to mention the crossover) than in the 3.7s – and my 3.7s cost extra by virtue of what I lost on my short term 3.6 ownership. In both cases, it was worth every penny. Likewise, the valve amp was worth every penny – at least, to me.

Lurching even further off course, here's a nice bunch bit of Marantz Model 9 info:
http://www.classic-audio.com/marantz/0009.html

I'd say that both the Marantz and VAC amps fall into the beautiful audio component category.

Beautiful yes, but if the beauty were only skin deep, they would be poor choices. What’s wrong with an amp that was engineered over 50 years ago? That’s especially true when the design was uncompromising! Yes, those Marantz amps are eye candy, but they are prized because they are even more powerful ear candy. In my rather biased opinion, the same can be said for the VAC products (not just their reproduction of the Marantz masterpieces). Everywhere one looks, quality of parts and workmanship announces its presence. From bone to flesh, beauty abounds. Of course, the outer beauty is superfluous to the function of the device and it definitely factors into the cost (quite a bit). I don’t mind.

[SteveFord]

Here's how you can tell the "new" MMGs from the earlier ones:

Two capacitors as seen from the back side is the "new" MMG.

[Davey]

I thought the "new" MMG's used a quasi-ribbon woofer?
You should be able to see that through the grill-cloth eh?

Cheers,

Dave.

[SteveFord]

I don't know, I haven't seen a set for myself.

[josh358]

I thought the "new" MMG's used a quasi-ribbon woofer?
You should be able to see that through the grill-cloth eh?

Cheers,

Dave.

I don't think they do. Someone posted a picture with the socks off and while it wasn't particularly sharp it looked like they still use wire. I do know that the crossover uses .7 technology. Wonder what that second cap is for, though. Could they have a .5-way supertweeter segment like the 1.7?

[medium jim]

I don't think they do. Someone posted a picture with the socks off and while it wasn't particularly sharp it looked like they still use wire. I do know that the crossover uses .7 technology. Wonder what that second cap is for, though. Could they have a .5-way supertweeter segment like the 1.7?

Sounds like a good Question for Wendell...

Jim

[Davey]

An extra capacitor could be just a shunt to achieve a non-standard value.

Assuming there isn't .5 super-tweeter (marketing gimmick ) it seems the only difference is a switch to a series crossover.

Cheers,

Dave.

[Letitroll98]

Sort of back on topic here, I finally had a chance to play with the NAD 3020B driving MMGs.  I was a bit surprised by a couple of things, but I said back on topic so lets deal with dynamics and relative loudness first.  I used the Lab inputs and 4 ohm setting, later I tried the soft clipping circuit which proved unsatisfying.  Within the loudness envelop that the amp allowed, macrodynamics were not limited, with microdynamics being a strong suit.  The amp was limited to what I would call moderately loud before clipping.  Quite satisfactory for any normal listening levels, but well short of lease breaking levels.  PRaT was excellent, instruments sounded real and lifelike with foot tapping speed.  You could drive them louder without getting harsh clipping sounds by using the soft clipping circuit, but that took away the toe tapping speed and microdynamics that made the NAD sound like real music.  All of this was about what I expected, sans the speed of transients that I didn't remember about this amp.

So why would you use an amp that limits how loud you can crank up your Maggies?  The absolute glorious tonality and musicality you can get.  Every single instrument and voice sounded so natural and lifelike, I kept forgetting to analyse and just listened to the music.  In absolute terms imaging wasn't as deep and expansive as my normal rig, everything was pushed forward a bit, but still extremely accurate.  The Dick Hyman cut on Stereophile's Test Disc #3 is a tough one for many amps, the piano should always be placed far in front of the drums and many amps get this wrong, pushing either the cymbals or drums up front.  The NAD kept everything in it's proper relationship.  What surprised me was the speed and detail of the little guy.  From memory I would have said sweet, but a little soft and slow.  Not the case, there was excellent detail and sharp transients.  I've left the NAD in the system and it might be a while before it's displaced.     

[josh358]

An extra capacitor could be just a shunt to achieve a non-standard value.

Assuming there isn't .5 super-tweeter (marketing gimmick ) it seems the only difference is a switch to a series crossover.

Cheers,

Dave.

True, and they've paralleled caps in some of their designs. Of course, knowing Magnepan, I imagine they'd find a way to do things as cheaply as possible.