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McIntosh Mc240

PakProtector said:
hey-Hey!!!,
I used to want amps like that until I discovered it would be easier to learn to build better than it would be to acquire that much money at one time. I parted with a 275, a pair of HF50's, and a pair of 75's and now all that's left is a Citation II.

next time you're under the hood of the 240, re-wire the 12AU7 heater so it can run a 6CG7. You won't be disapointed.
cheers,
Douglas
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Really? I never heard of that mod before, what does it do sonically?
 
You got to be kidding right?

Now I am working on getting 2 new top plates for the chassies and working on layout. the top plates I have are of thick aluminum and will be hard to mount some of the gear. So I am having new ones made from steel and are way thinner.

I have all trannies
All tubes
sockets, wire, meters, Etc.

Got the wiring diagram and just about everything needed to complete the project.
This as you know is a very overwhelming first project! I want to do it right and make sure that I understand everything as I go along. I have point-to-point boards to be used and will be spending a lot of time on the wiring. I want it clean and noise free. I will be using nothing but the best parts under the chassie.

I catch myself staring at the project and dreaming :)

WO
 
WO, staring and dreaming are good omens!

I took so long, I have actually started, and and completely revamped a couple projects, three or four times. The result is doing it right.
 
IMO there is no way such a complex first build will come together right the first or even third time. Save yourself some trouble and make it easy to tear it all ( or most of it )out and start over with an improvment to the original circuit.
cheers,
Douglas
 
PakProtector said:
IMO there is no way such a complex first build will come together right the first or even third time. Save yourself some trouble and make it easy to tear it all ( or most of it )out and start over with an improvment to the original circuit.
cheers,
Douglas
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in my case.... or the fourth, fifth, sixth, seventh............................... (agreed, btw)
 
A little bit of math will go a long way toward setting "only 40 watts" into perspective for the OP.

We hear volume in a logarithmic way. Alexander Graham Bell and Flecher Munson did enough research to put the following information in the realm of accepted norms for human hearing. (Note that individual differences between people can fall outside these but not very far and not very often). One measure of sound volume is the dB. That measure is useful because it can also be translated to amplifier gain and 1 dB difference in amp gain is 1 dB change in volume. Now, those researchers found that it takes a 3 dB change in volume for most of us to perceive a change in volume and a 10 dB change in volume to see a doubling of volume level. That is 83 dB is a little louder then 80 dB and 90 dB is twice as loud as 80 dB. If you translate that to watts in an amp, a 3 dB change (small volume change) doubles the amount of power the amp needs to put out. To increase the volume by 10 dB needs 10 times the power from the amp. So the difference between say a 75 watt per channel amp and a 40 watt per channel amp is small, only about 2.7 dB, a barely perceptible increase in maximum volume at the clipping limit. Since the Mac is rated more consecutively then some of the other brands you may be considering the speaker output difference is even less.

Using speakers as efficient as the K Horns, you could be running as little as 5 to 10 watts and rarely push the amp hard. (The blessings of very efficient speakers.)

It would take either very inefficient speakers or VERY loud volume requirements to push the Mac up against the clipping limits.

Hope this helps.

Shelly_D
 
Just noticed tis is an old thread. Khorns need very solid corners to get the "correct" sound. MC30's can drive Khorns to ear splitting rock and roll volumes. My 2.5 wpc (or is it 1.5 wpc) SET amp drives Khorns just fine.

Did you actually ever set this system up? If you did how did you like it.
 
No Love :no:

I will get it right the first time. I guess I did not mention that I have a helping hand! And this extra hand has this down to a tee. There will be some fooling around with the circuit before final install but it will be done right the first time.

I am building these because I want to! No other reason needed in my book,

I know this seems a bit out of the norm but so am I and this is just another project in my life to keep me going.

WO
 
build em right... 14 or 12 ga steel, corners welded...have a metal shop cut your holes for you if you don't have access to punches.

you won't need an MC240 after you build your amps!
 
Can we get some more pictures of those chassis you had built? I really liked their style and I am trying to get some ideas for a build of my own.
 
wildone said:
HI,

I am picking up a McIntosh Mc240 tomorrow and was wondering if this was the best amp I can get? I have decided to slow down and want to focus on setting up a very high end system.

For $2000 I want to make sure I am getting all I will need and not be wanting more later. I have some K-horns to Abuse and this amp will be my dedicated "Rock & Roll" system.

It is only rated at 40 x 2 watts and I have a Jolida 2002a that is rated at 40w ch but puts out about 60 and there are other tube amps with more for less. But I looked on ebay and this amp (Mc240) is a good buy. And the gent selling it me is a very nice man and stand-up guy. I have bought other stuff from him.

If you seen this guy's shop you would DIE!:tears:

Full of everything you could ever want :yes:

Anyway I hope I will be happy with this and stop trying to do better. (will make the wife real happy if I just stopped)

WO
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MC 240 is a amazing amplifier once the power supply has been updated and new rectifier. it is hard to beat. My favorite of all Mac amplifers. Yes better than the MC 30's. IMO
 
I love the mc240's I own, from my experience the 12Au7 sets the tone, I prefer Fifties long plate Mullards in that spot.
 
702retrotodd said:
MC 240 is a amazing amplifier once the power supply has been updated and new rectifier. it is hard to beat. My favorite of all Mac amplifers. Yes better than the MC 30's. IMO
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That's your opinion and you are certainly entitled to it. But why the hell would you pull a thread that has been inactive for 2 1/4 years to state it ?
 
I just shipped my MC240 off to Terry yesterday. Its going to a long wait but oh so worth it. Cant wait to get that baby back
 
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