Damping Factor value rationale in McLand.

[WhiteSE]

As I look for the next McMove upwards, I find that the amps have varying damping values...

MC2100 is 100 w/ch,,,damp fact is 14 or greater
MC2150 is 150 w/ch,,,DF is 30
MC2155 is 150w/ch...DF is 30 also
MC2200 is 200w/ch...DF drops to 16
MC2205 is 200w/ch, DF is also 16
MC250 is 50w/ch, DF...is 10
MC2300 is a whopping 300 w/ch, DF is now 14

MC7100, the DF jumps to 100 or greater (dc amp though)

so its obvious the autoformers limit that, but why is threre 100 % variation in some autoformer amps?

Does it really matter?

 

[Lefty]

not really sure, but have read that a high DF helps an amp keep a wayward speakers in tighter control. Back EMF can cause the speaker to try and fight the amp.

So I guess it all depends on one's speakers if a high DF is an advantage or not.

Lefty

 

[Bill Allan]

Damping Factor

Hi,
If you put those amps in chronological order you'll see that the specs gradually improve through the years. 250 is the first in '67, 7100 is the latest introduced in 81'. 2150/2155 and 2200/2205 are identical pairs with different cosmetics. They also show a progressive improvement in distortion as well, from .25% for the 250 to .005% for the 7100. The 7100 is infact an output transformerless amp which accounts for the much higher DF however the output stage is not protected by an Autoformer. Most of the McAmps of the 80's have similar specs to the 2150/2155. The MC 2255 is generally thought to be 'the 'classic' of that period. IMHO the next really desirable SS amp after those is the MC352.
DF seems to be a bit contentious. Bryston builds amps with DF in excess of 500 on some models and they have a reputation for bass response. Its generally accepted that anything over 10 is acceptable.
If you want to add to your collection why not pick up an MC240 if you want a real treat without spending a fortune.
Regrdz
Bill

 

[WhiteSE]

Re: Damping Factor

Originally posted by Bill Allan

If you want to add to your collection why not pick up an MC240 if you want a real treat without spending a fortune.
Regrdz
Bill

I am considering the 240, but I wish they had some blue meters..

 

[Bill Allan]

Hi
Are you still running McStuff in your car only?? If I were looking for my first McAmp for my home system and wanted meters I'd get something from the eighties like the 2155. Its got great specs, lots of power and will drive anything. Some people think the eighties was the most desirable gear to collect. The first amp with "blue eyes" was the 2505 which was introduced in 67 and is basically a 250 with meters. What are you using for a pre-amp?
Regrdz
Bill

 

[WhiteSE]

I had to sell my Mc car gear, now I have a pair of Adcom amps.

At home I have the MC250 mated to a Berning TF-10 tubed pre...12AT7's for line stage and 12AX7's for phono, feeding a pair of JBL L-96's.

There is a unit that is on audiogon, a 2205 that I could possibly manage to get,,,or an MC162 on ebay...

 

[Rich Andrews]

Here is an abbreviated matrix of some McIntosh amps. I have also uploaded an zipped excel spreadsheet of the same data.

As you can tell, I was considering all factors including price. I chose the MC2500 as my amp of choice. I won't get into all the details, but I am quite happy with it.

Model WPC Dist Noise D.F. Ret. Price Mfg Date
300 300 0.005 105dba 40 3750 95-98
352 350 0.005 116bda 40 4500 1998-
500 500 0.005 115dba 200 7000 1994-
602 600 0.005 134db 100
2250 250 0.02 95db 30 2495 82-87
2255 250 0.02 95db 30 2995 81-86
2300 300 0.25 90db 14 1799 71-80
2500 500 0.02 95db 30 3800 80-90
2600 600 0.005 105dba 40 6000 90-95
7200 200 0.005 105dba 200 2779 89-93
7270 270 0.02 100db 30 2499 85-91
7300 300 0.005 105dba 40 3400 91-95
2100 105 0.25 90db 11 600 69-77
2105 105 0.25 90db 10 800 67-77

 

[ron-c]

Dampening factor is not a very good indicator of the sound of an amp. If the amp is connected directly to the voice coil leads of the individual speaker it may mean something. The problem is the crossover and speaker wires quickly make DF irrelevant. Any DF over 10 is fine.
If you take say a 1960-200 watt MI 200 amp as an extreme example, it has a DF of 10. This amp should have poor bass performance and control if DF matters. Yet if you want an amp to equal the MI 200's bass performance you will need to look at 500 to 1000 watt SS amp.
DF is like slew rate. Does not tell us much. Now S/N ratio or multi tone and square wave response will define how well an amp performs. Distortion does matter and less is better.
In the list of amps above remember that transistor design has improved greatly over the last 50 years. We have much better transistors to work with today. Bandwidth and speed = frequency response is and is vastly improved in current amps. I compared the MC2255 mentioned above with the new MC252 this week and the MC252 is more transparent. Time marches on. Of course 20 years from now I am sure the MC252 will be a hot property on the used market!
Ron-C

 

[WhiteSE]

I will do a search,,,I am maxing out my budget at 1300 bucks. The 2205 has power and autof. and is relatively inexpensive...

 

[Rich Andrews]

The 2205 is a very good choice and should be about right for the money budgeted.

Of course the weight is another factor to consider. At 85 lbs, you will at least get your money's worth in iron. :thmbsp:

 

[WhiteSE]

I do dig the amp in yoru avatar...lol...

 

[Rich Andrews]

That amp would be only a few hundred more than your $1300 you budgeted. :thmbsp: