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MA2275 Info

MX117.MC7150

MX117.MC7150

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Had ask a while back if anyone knew if the MA2275 amplifier section was anything like the MC2301 and someone responded that it was "all tube in the signal circuits", or something to that effect. I've been unable to find that particular post to respond to, so thought I would post here that I've been in contact with someone 'in the know' at McIntosh and that the previous answer was incorrect. Indeed, the MA2275 was described as, "essentially a C220 preamp and MC275 amp with the exception of being like the MC2301 in having the initial stages of the amplifier section being solid-state." Thus, like the MC2301, the MA2275 is actually a hybrid rather than a true 'all-tube' integrated amp. The other primary difference between them is the fact that the MC2301 if fully balanced while the MA2275 is not. Just a point of interest for that thought I would share. Pretty good pedigree, either way.
 
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So what part of the MA2275 would be solid state? The phono and head phone sections are all driven by tubes. The only solid state part of the 2275 that I know about is in the AC power regulator. As far as the signal path is concerned, isn't it all tube?
 
You're not being very specific. When you say the "first 2 input stages in the power amp section are solid state," I'm not sure what you mean? Doesn't the power amp only have one stage?

McIntosh says that the MA2275 uses "all tubes" for amplification. If you going to post here with the intention of discrediting this integrated amp (we all know you didn't like it and you got rid of yours), then I suggest you come right out and draw us a picture.

What are you trying to say, MX117.MC7150?
 
Matt The Cat said:
What are you trying to say, MX117.MC7150?
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You are forcing me to repeat myself. The MA2275 amplifier section uses a similar design to that used in the MC2301, which, rather than being "all tube", as someone here stated here in the past couple of weeks, is actually a hybrid design. If you know enough about amplifers to be able to read a block diagram, go to page 23 here http://www.mcintoshlabs.com/downloads/product_manuals/mc2301om01.pdf in the MC2301 owner's manual and look. The MA2275 is very similar, using a couple of solid-state stages just like shown in the MC2301 block diagram. The primary difference will be the fact that the MC2301 is fully-balanced and the MA2275 is not. The fact that you like the MA2275 :thmbsp: and I don't care for its sound :thumbsdn: has nothing to do with the fact that is a hybrid amplifier. It is what it is regardless of who likes or dislikes it.

EDIT: Make that page 19 in the MC2301 OM.
 
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Thanks for the block diagram. I've never been able to find a block diagram or schematic for the MA2275. The owner's manual doesn't have either one, unfortunately. I respect your opinion regarding the sound of the 2275. I just feel you've become hell-bent on proving the MA2275 is crap lately and I wonder why?

Are you calling McIntosh out with this post? Should they call the MA2275 a hybrid amp, in your opinion?

Matt
 
Am not calling anybody out on anything. Am simply pointing out some interesting points in the design. Reread the last sentence in my original post.

And, remember...... just because you are not paranoid doesn't mean we aren't out to get you. :)
 
I too am curios. I also was under the impression the MA2275 was all signal amplification by tubes.

Maybe Ron C can weigh in?

Joe
 
According to the block diagram the balanced/phase input boards and the negative feedback differential pair use solid state circuits. While these circuits are supposed to be unity gain, they are solid state. Not really a hybrid like a MA-230 but I suppose if you want to be picky......
 
Perhaps McIntosh's definition of 'amplification' does not include unity-gain solid-state stages. That's fair enough. And, don't recall reading anything from McIntosh that states the MA2275 is 'all tube' in the signal circuits. But, don't pretend to read everything they put out, either.
 
Here is the first paragraph from the McIntosh website;

"The MA2275 is the first McIntosh integrated amplifier to rely exclusively on vacuum tubes in all audio circuits. The new design combines classic vacuum tube audio performance with state of the art control technology."

Joe
 
joe1515 said:
Here is the first paragraph from the McIntosh website;

"The MA2275 is the first McIntosh integrated amplifier to rely exclusively on vacuum tubes in all audio circuits. The new design combines classic vacuum tube audio performance with state of the art control technology."

Joe
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Exactly! And I don't think any proof has been introduced in this thread so far that counters that statement from McIntosh. Only that MX117.MC7150 has someone "in the know" at McIntosh who says that the 2275's amp section is similar to the MC2301 circuit.

Ron-C, please put this thing to rest.

-Matt
 
Matt The Cat said:
Exactly! And I don't think any proof has been introduced in this thread so far that counters that statement from McIntosh. Only that MX117.MC7150 has someone "in the know" at McIntosh who says that the 2275's amp section is similar to the MC2301 circuit.

Ron-C, please put this thing to rest.

-Matt
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Oh, Matt.......... you disbeliever. You need to read all the posts. c_dk, who has no skin in your game, stated accurately what is going on inside the MA2275.
c_dk said:
According to the block diagram the balanced/phase input boards and the negative feedback differential pair use solid state circuits. While these circuits are supposed to be unity gain, they are solid state. Not really a hybrid like a MA-230 but I suppose if you want to be picky......
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And, here is a link to the MA2275 service manual. You can check out the block diagram on page 5 or go further back and check out the components on the schematic. None of this makes the MA2275 any less of a piece of gear. If it had worked for me I might still have it instead of its solid-state brother. http://www.berners.ch/McIntosh/Downloads/MA2275_ser.pdf

Thanks to Berner's McIntosh for making this and so many other manuals and info on McIntosh available to the public.
 
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WOW! Putting up with you, MX117.MC7150, was worth it, just for that schematic. I bought my 2275 from Audio Classics and it didn't come with any of that service manual information. Thank you for for that.

I finally see what you're talking about ON THE PRODUCT being discussed AND NOT THE 2301!

I was just trying to get the real information and not hearsay, which I believe you were providing before.

Thanks for clearing this up.

-Matt
 
With this schematic, I also finally have proof that the non-phono 12ax7s are only for tone controls and nothing else. I had heard this before, but I had never seen it for myself. I was told by McIntosh that the 2nd pair of AX7s were for line-level inputs, but that's not true looking at this diagram. Very good to know.

Thanks again for this.

Matt
 
An interesting choice of tranistors they have chosen to use. It seems they have reactivated the 132-223/224 (2N4124/26) after subbing the 132-171/172 (MPS-A05/55)for them back in the 90s.

At least this hybrid won't work with the tubes pulled as David O'Brien used to love to tease a certain company about.
 
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