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had it for about a month forgot to post this... MC 2500 score.

jdwk

jdwk

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got this, had to trade in the 2205 to make the price lower.

Had to get this as I FINALLY got a set of Infinity RS Kappa 9's and while the 2205 did a respectable job with them, they need the MC 2500 to make them really open up. I need to get the proper power cord as this one is not "the" one. it is an old PC monitor power cord I am using., but here is is!

now maybe one day I can trade this up for an MC 2600! so the knobs will match of course! :banana:

now I wonder, the kappa's are rated for 4-6 ohms nominal impedance, I have them in the 4 ohm tap. since the resistance can dip down to below 1 ohm at times, what would happen if I put them on the 1 ohm tap? bad idea?

the picture is slanted because, the amp was so heavy the house tilted to the roght after I brought it in! (:
 

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jdwk said:
... Infinity RS Kappa 9's.. need the MC 2500 to make them really open up. The picture is slanted because, the amp was so heavy the house tilted to the right after I brought it in! (:
Click to expand...

Gosh.. if you had trouble moving the 2205 around, how are you going to manage the 2500? Lol


-Gregory
 
I know thats a heavy amp, I just got the MC402. Get help if you need to tuck it into something.

I don't know about the speaker app but you know the guys will be here soon.

All speakers work best when you max power to them. How do they sound? More base?
 
jdwk said:
got this, had to trade in the 2205 to make the price lower.

Had to get this as I FINALLY got a set of Infinity RS Kappa 9's and while the 2205 did a respectable job with them, they need the MC 2500 to make them really open up. I need to get the proper power cord as this one is not "the" one. it is an old PC monitor power cord I am using., but here is is!

now maybe one day I can trade this up for an MC 2600! so the knobs will match of course! :banana:

now I wonder, the kappa's are rated for 4-6 ohms nominal impedance, I have them in the 4 ohm tap. since the resistance can dip down to below 1 ohm at times, what would happen if I put them on the 1 ohm tap? bad idea?

the picture is slanted because, the amp was so heavy the house tilted to the roght after I brought it in! (:
Click to expand...

Nice one, thats a lot of amplifier.....

What is the nominal impedance of the speaker? Is it 4Ω or 6Ω....
I found running my JBL L7's which were 6Ω nominal actually worked better on the 8Ω tap...

I dont think its worth worrying what the speaker is doing beyond the nominal impedance, but theres nothing wrong with trying different taps if you want to experiment.

You wont hurt anything trying the 1Ω tap but remember when you are doing this, the power rating of the amp will change, and in this case, the lower Ω tap you go with a 6Ω speaker, the less power the amp will produce, conversely if you run a lower Ω speaker on a higher Ω tap then it will produce more power......
 
kevzep said:
Nice one, thats a lot of amplifier.....

What is the nominal impedance of the speaker? Is it 4Ω or 6Ω....
I found running my JBL L7's which were 6Ω nominal actually worked better on the 8Ω tap...

I dont think its worth worrying what the speaker is doing beyond the nominal impedance, but theres nothing wrong with trying different taps if you want to experiment.

You wont hurt anything trying the 1Ω tap but remember when you are doing this, the power rating of the amp will change, and in this case, the lower Ω tap you go with a 6Ω speaker, the less power the amp will produce, conversely if you run a lower Ω speaker on a higher Ω tap then it will produce more power......
Click to expand...

the impedance is listed as a range. if you google kappa 9 .pdf you will find a downloadable spec sheet for these speakers.

Was there an "if your in a hurry" sheet for this amp? I'd like to find a sales brochure as I have one for just about every other Mc piece I have.
 
jdwk said:
the impedance is listed as a range. if you google kappa 9 .pdf you will find a downloadable spec sheet for these speakers.
Click to expand...

Oh okay, I see, thats quite good really to have a nominal range....well, yeah I would just try it and see what sort of results you get, its not going to hurt the amp at all....
You never know, it might work out perfectly on the 1Ω.....
 
Congrats on acquiring a real beauty and a beast of an amp. My speakers (polk 1.2tl's) are 6 ohm and I've experimented with the different taps on my 2500. I've found that the 8ohm tap seems to be the best sounding match for them.
As far as the cord goes there really isn't too much to choose from because of the Edison type end and limited clearance. I used a good quality molded cord. I trimmed it down and used a hospital grade plug on the other end. Sadly that's about as good as it gets.
 
It has been rumored that McIntosh stocks the original power cord for $12 or so. Definitely worth a call to find out.
 
jdwk said:
very slowly. this amp is so big, it makes the 2205 look like an MQ101.
Click to expand...

Yes I bet it does. Never mind the floor tilting.. is enough air getting under that unit? I think there's a minimum clearance requirement underneath these amplifiers for airflow. Better look in the OM. Something doesn't look right in that photo.. not to mention the slanted room. :smoke:


-Gregory
 
The MC2500 is a thermostatically controlled fan cooled design. When called for, it draws air through slots in the sides, across the heat sinks, and then out the rear. No problem at all placing it on thick carpet. I had one for a while and honestly cannot remember the fans ever coming on on it. Mine also sat on carpet.
 
damacman said:
The MC2500 is a thermostatically controlled fan cooled design. When called for, it draws air through slots in the sides, across the heat sinks, and then out the rear. No problem at all placing it on thick carpet. I had one for a while and honestly cannot remember the fans ever coming on on it. Mine also sat on carpet.
Click to expand...

Was able to find a MC 2500 OM in less than a minute, and beg to differ.



On Pg.2 (page 4 of PDF) it reads...

Adequate ventilation extends the trouble-free life of electronic instruments. It is generally found that each 10° centigrade (18°F) rise in temperature reduces the life of electrical insulation by one half. Adequate ventilation is an inexpensive and effective means of preventing insulation breakdown that results from unnecessarily high operating temperatures.

The direct benefit of adequate ventilation is longer, trouble-free life. The heat generated in the operation of the MC 2500 is exhausted from the unit by two temperature controlled low noise, long life fans.

Cooling input air is drawn into the MC 2500 through the ventilation holes on the sides and bottom of the amplifier. The air passes over the transformers, output transistor heat sinks; and, is blown out the back of the instrument by the fans.

It is recommended that at least 2 inches of clear space be provided on each side and bottom. To permit the fans to operate best, provide at least 5 inches of space at the rear of the instrument. A source for input air and a means to exhaust the heated air is necessary so that the heated air does not recirculate through the MC 2500.


I'd think placing an Mc amp on a carpet for any length of time would promote rust to form on the bottom cover. Best to use feet or some kind of slats to `get air under it´ IMPO.


Cheers and keep the tunes playing. :thmbsp:


-Gregory
 
Gregory said:
Was able to find a MC 2500 OM in less than a minute, and beg to differ.



On Pg.2 (page 4 of PDF) it reads...

Adequate ventilation extends the trouble-free life of electronic instruments. It is generally found that each 10° centigrade (18°F) rise in temperature reduces the life of electrical insulation by one half. Adequate ventilation is an inexpensive and effective means of preventing insulation breakdown that results from unnecessarily high operating temperatures.

The direct benefit of adequate ventilation is longer, trouble-free life. The heat generated in the operation of the MC 2500 is exhausted from the unit by two temperature controlled low noise, long life fans.

Cooling input air is drawn into the MC 2500 through the ventilation holes on the sides and bottom of the amplifier. The air passes over the transformers, output transistor heat sinks; and, is blown out the back of the instrument by the fans.

It is recommended that at least 2 inches of clear space be provided on each side and bottom. To permit the fans to operate best, provide at least 5 inches of space at the rear of the instrument. A source for input air and a means to exhaust the heated air is necessary so that the heated air does not recirculate through the MC 2500.


I'd think placing an Mc amp on a carpet for any length of time would promote rust to form on the bottom cover. Best to use feet or some kind of slats to `get air under it´ IMPO.


Cheers and keep the tunes playing. :thmbsp:


-Gregory
Click to expand...

well these have different feet on the bottoms, I dont quite know how to describe them. I do not currently have an audio rack that would support this amp. I have the fan setting on "intermittent so they dont run all the time (although they are VERY quiet, unlike say a crown macro tech fan) this one still has the rack rails on the side and they come in handy having them when moving the amp. so far I have not heard the fans come on and I cant imagine im using enough of that amp for it to happen. you would really have to modify the feet on the amp to get this to sit on any surface 2 inches high, it's curious that it says that in the manual. If I had this on a shelf it still wouldn't have two inches under it.
 
I read the specs on the model 9 and there is no way the sensitivity is 102 db. If it were, a 100 watt amp would blow you ought the house. Personally I would start with the 2 ohm tap. Another thought: There were very few woofers built for home use in that period that could handle 150 continuous watts at or below its resonance frequency with out self destructing or compressing the signal acting like a load resistor warming the room and not playing any louder. So your 2500 will be valued for its short term performance approaching 700 watts per channel. Should be a nice combination, just don't push things. Cerwin Vega 18 inch woofers rated at 500 watts couldn't handle a 2500 in discos. Altecs and JBL's 18 " woofers crossed at 300 Hz would last 18 to 24 months with either a 2600 or 2500. I use to roll off the bass at 25 hz to protect the woofers from LP anomalies in big discos. The CD was a great boon for discos in the early 80's. .
 
twiiii said:
I read the specs on the model 9 and there is no way the sensitivity is 102 db. If it were, a 100 watt amp would blow you ought the house. Personally I would start with the 2 ohm tap. Another thought: There were very few woofers built for home use in that period that could handle 150 continuous watts at or below its resonance frequency with out self destructing or compressing the signal acting like a load resistor warming the room and not playing any louder. So your 2500 will be valued for its short term performance approaching 700 watts per channel. Should be a nice combination, just don't push things. Cerwin Vega 18 inch woofers rated at 500 watts couldn't handle a 2500 in discos. Altecs and JBL's 18 " woofers crossed at 300 Hz would last 18 to 24 months with either a 2600 or 2500. I use to roll off the bass at 25 hz to protect the woofers from LP anomalies in big discos. The CD was a great boon for discos in the early 80's. .
Click to expand...

I used to keep the loudness switch all the way up on the B&W's with the 2205 for more bass. With the MC 2500 and kappa's I have to keep it halfway down now because CERTAIN bass hits would stress the woofer so im learning....these speakers sound better on the 2500 than they did on the 2205 the meters rarely read much above 50w but its hard to see where the other levels would be because after 50 on the VU there isnt much space before the 500W mark. I kept the amp on "hold" for a month so I could see what the peaks were. I may have bought too much amp for the kappa's but I couldn't get close enough to what should have been "right on the money" for them. I do listen louder than some, but I know those discos were pumping out more volume than I am using......I cannot turn this up anywhere close to what this is capable of it gets WAY loud long before then.....
 
MC2500 has air vents on the sides and fans out the rear so they are made to stack unlike the home amps that use convection cooling.

Thanks,
Ron-C
 
If you ever start noticing hum from one of more of the channels, there is a fix for it. Basically it involves rerouting the fan power leads and moving a temp sensor.

There are other mods that can be done that were used in the later MC2600 amp. These mods lowers the noise floor to "digital" levels.
 
[/QUOTE] There are other mods that can be done that were used in the later MC2600 amp. These mods lowers the noise floor to "digital" levels.[/QUOTE]

if its not too much to type out, can you fill me in on the details of this?

so far no hum, the silence between tracks is dead quiet, though tape hiss from source material is MUCH more noticable on some cd's...as are drop outs in the master reels used....revealing means the good with the bad....
 
kevzep said:
Nice one, thats a lot of amplifier.....

You wont hurt anything trying the 1Ω tap but remember when you are doing this, the power rating of the amp will change, and in this case, the lower Ω tap you go with a 6Ω speaker, the less power the amp will produce, conversely if you run a lower Ω speaker on a higher Ω tap then it will produce more power......
Click to expand...

:no:
The power output doesn't change on the different taps. This amp has an autoformer so the power is the same on all the taps. :yes:
 
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