C-40 Preamp

[62caddy]

I for one am really tempted to go for a C 37 should one come up. Talk about rare - you hardly ever see them. I really like the rotary volume w/motorized pot. I really dislike the 1/2 glass and metal fascia panel. It does not match anything else I own, stylewise.

I've been using the C 30 w/ CR 7 remote preamp but there's a little bit of hum I have to live with - unless I bypass it.

I wouldn't care about remote so much but I listen to TV through the system and commercials are like 10dB louder. Plus I can switch to FM or something until the "words of from the sponsors" are over.

C 40 is really a beautiful unit though.

 

[kevzep]

No its not stepped, but as expected, it appears to be very high quality. Am I correct in saying your C40 IS stepped? Have you had a look inside the case, and if so, is the pot a fairly large module?

BTW, I don't think Mac has ever made any of their multi-band EQ's digitized. I believe they are still all analogue right up to the latest models.

Yes the C40 is a sealed 4 gang Alps Pot, and it is stepped.....

No, none of the McIntosh multiband EQ's are digital, BUT they are digitally controlled, just as the volume, balance and other control features are.....
The knobs on the front of the unit are just digital encoders, they have no actual audio passing through them just as the balance and volume controls....
Of course then on some the encoders are multi functional too.....

So to be clear, its the control encoders which are digitally controlling the ANALOGUE functions, the actual functions are not digital.....

 

[62caddy]

Kev - are you saying the EQ controls are electronically controlled on the C 40?

 

[MORTIS]

Yes the C40 is a sealed 4 gang Alps Pot, and it is stepped.....

No, none of the McIntosh multiband EQ's are digital, BUT they are digitally controlled, just as the volume, balance and other control features are.....
The knobs on the front of the unit are just digital encoders, they have no actual audio passing through them just as the balance and volume controls....
Of course then on some the encoders are multi functional too.....

So to be clear, its the control encoders which are digitally controlling the ANALOGUE functions, the actual functions are not digital.....

Ok that's interesting, and good to know, and def better than having the signal passing through it. Thanks for clarifying.

It is odd however that the EQ's are digitally controlled and yet the knobs are marked to reference their position. I don't recall any of Mac's digital controllers having a reference mark on the knob, but if such controls (including Balance) need a center 12 O'clock position, then I suppose they still need that reference mark if there is no display showing the position.

 

[kevzep]

Kev - are you saying the EQ controls are electronically controlled on the C 40?

No, not on the C40, the only encoders on the C40 are the Listen and record selectors, and they use a SSL (solid state logic) control to switch the reed relays at the back of the unit to make the input and output selections....

 

[MORTIS]

Kev - are you saying the EQ controls are electronically controlled on the C 40?

Even though I accept what Kev says about all the EQ controls on the modern pres, I doubt the C40 EQ is digitally controlled... but i could be wrong.

EDIT: Ok Kev, you beat me to the post.

 

[kevzep]

Ok that's interesting, and good to know, and def better than having the signal passing through it. Thanks for clarifying.

It is odd however that the EQ's are digitally controlled and yet the knobs are marked to reference their position. I don't recall any of Mac's digital controllers having a reference mark on the knob, but if such controls (including Balance) need a center 12 O'clock position, then I suppose they still need that reference mark if there is no display showing the position.

It's pretty much how the digital mix consoles are which we use mostly these days....digital surface, absolutely no audio whatsoever passing through it, and it's all in what we refer to as a local rack, and a stage rack, and that is where all the digital to analogue magic happens....some are connected via advanced network protocols, and others are optically connected....

I have noticed when an encoder is used for more than one function, say volume/ balance/ bass/ treble.....(not referring to any Mc product necessarily) then they will have no reference markings, they normally refer to some sort of digitally displayed reference (or GUI graphic user interface).
Because the wheel can be in any position after adjusting 4 different parameters, the actual physical position is meaningless, because when you switch back to another parameter the encoder assumes the new position as the last position it was in.....
Its all a bit weird when you think about it, I use digital mixing consoles all the time, and I am intimate with about 4 or 5 different brands....its second nature to me all this digital control stuff.....
But if the encoder does only one thing, then it may have physical markings next to it.....

The EQ encoders on the Mc pre's will be like that, and I dont know because I don't have one yet, but they may even have stops on them like a real analogue control.....
Maybe a C48 owner can confirm.....

 

[62caddy]

Makes sense. That's how my C 30 is too. Electronic input selector, mode selector and maybe a couple of the front panel buttons. Balance & loudness are definitely conventional pots though - I've had to clean them every so often.

I'm not sure about the volume control but it is stepped. It is a an extremely precise volume control whatever it is- I must say.

 

[kevzep]

Makes sense. That's how my C 30 is too. Electronic input selector, mode selector and maybe a couple of the front panel buttons. Balance & loudness are definitely conventional pots though - I've had to clean them every so often.

I'm not sure about the volume control but it is stepped. It is a an extremely precise volume control whatever it is- I must say.

Yes thats right, although the switch on the C30 is a regular switch rather than an optical encoder like it is on the C40, the C40 also drives the switching with a logic circuit which has to have backup memory power so it can remember where the encoders last position was.....The C40 encoders can turn endlessly, they have no stops.....
So when you turn the C40 off at the wall or unplug it, the encoders reset to whatever their default setting is, they don't default to the last position they were in as the logic circuit needs to be powered up all the time...
The C30 does use the same theory, although an older idea......but still it was an important stepping stone in the development of where they are now.

The volume controls are purely analogue on the C30 and C40....they do use very high quality Alps pots.....

 

[tuffstuff1]

WOW! You guys are very techological when it comes to audio controls and features. I guess my questions have been answered over and above. I read you posts thourghly and sometimes 4 times over. I am learning a lot. I actually never realized that the volume control is motorized. The pictures are great and the learning is great. You know I actually come from electrical rebuilding background of rotating electrical for vehicles and just in my office manipulating big long spread sheets. I have been remanufacturing all my life so some of it I can grasp. Some of abreviation is foreign. Aside from the preamp qusetions and more on a personal side if you don't mind me asking. Have you all learned what know from being audio enthusiasts and just learning over many years of dealing with and being associated with forumers like AK? Are some of you audio technicians and repair and sell for hobby or business. Good to meet all you guys here so far and over the last cople years I have really enjoyed myself.

So if I had a choice between the C-40 or 41 at the same price which would you choose? I think it would be the C-40. Who care about the remote.

 

[kevzep]

Aside from the preamp qusetions and more on a personal side if you don't mind me asking. Have you all learned what know from being audio enthusiasts and just learning over many years of dealing with and being associated with forumers like AK? Are some of you audio technicians and repair and sell for hobby or business. Good to meet all you guys here so far and over the last cople years I have really enjoyed myself.

So if I had a choice between the C-40 or 41 at the same price which would you choose? I think it would be the C-40. Who care about the remote.

The C40 doesn't have a motorized volume (no remote as you know)......

I am a Audio tech and Sound Engineer, I repair analogue audio, mostly power-amps....

I would take the C40, to hell with the remote.....but I am a bit biased as I already have a C40, and love it....Its a "mans" pre-amp and fully featured, and it has an onboard 40W per channel amplifier with power-guard too....
AND it has variable loudness feature too....

 

[MORTIS]

It's pretty much how the digital mix consoles are which we use mostly these days....digital surface, absolutely no audio whatsoever passing through it, and it's all in what we refer to as a local rack, and a stage rack, and that is where all the digital to analogue magic happens....some are connected via advanced network protocols, and others are optically connected....

I have noticed when an encoder is used for more than one function, say volume/ balance/ bass/ treble.....(not referring to any Mc product necessarily) then they will have no reference markings, they normally refer to some sort of digitally displayed reference (or GUI graphic user interface).
Because the wheel can be in any position after adjusting 4 different parameters, the actual physical position is meaningless, because when you switch back to another parameter the encoder assumes the new position as the last position it was in.....
Its all a bit weird when you think about it, I use digital mixing consoles all the time, and I am intimate with about 4 or 5 different brands....its second nature to me all this digital control stuff.....
But if the encoder does only one thing, then it may have physical markings next to it.....

The EQ encoders on the Mc pre's will be like that, and I dont know because I don't have one yet, but they may even have stops on them like a real analogue control.....
Maybe a C48 owner can confirm.....

Thanks for the extra info Kev. Even though the later Mac EQ's are digitally controlled, I'm pretty sure they would need to have stops; mainly because they have that reference mark on the knob to show position + or - of center detent. It would be just too weird to turn it past full + and then suddenly its at full -.

Makes sense. That's how my C 30 is too. Electronic input selector, mode selector and maybe a couple of the front panel buttons. .

Wow, I didn't realize Mac was doing that as far back as the C30

WOW! You guys are very techological when it comes to audio controls and features. I guess my questions have been answered over and above. I read you posts thourghly and sometimes 4 times over. I am learning a lot. I actually never realized that the volume control is motorized. The pictures are great and the learning is great. You know I actually come from electrical rebuilding background of rotating electrical for vehicles and just in my office manipulating big long spread sheets. I have been remanufacturing all my life so some of it I can grasp. Some of abreviation is foreign. Aside from the preamp qusetions and more on a personal side if you don't mind me asking. Have you all learned what know from being audio enthusiasts and just learning over many years of dealing with and being associated with forumers like AK? Are some of you audio technicians and repair and sell for hobby or business. Good to meet all you guys here so far and over the last cople years I have really enjoyed myself.

So if I had a choice between the C-40 or 41 at the same price which would you choose? I think it would be the C-40. Who care about the remote.

At the same price I'd definitely go for the C40 if you don't care about remote. I must have remote, so I wouldn't choose either because I also need a variable loudness or 5 band EQ. I tell ya, if the C40 had remote, it would be the ultimate preamp... for me at least.

I don't have as much tech knowledge as a lot of guys around here, but the knowledge I do have comes from 40 years as an enthusiast in this hobby.

 

[rolltide]

I'm impressed with all the people who don't need remotes, I guess I'm lazier then I thought. I don't tend to use tone controls, so the C41 was perfect for me.

 

[kevzep]

I'm impressed with all the people who don't need remotes, I guess I'm lazier then I thought. I don't tend to use tone controls, so the C41 was perfect for me.

The way I have my system set up, I am quite close to the pre-amp, I just have to lean over a bit and extend my arm and I'm there......
I play records and you know, its that old thing, you have to get up and change sides, and so this is when volume control things happen too, although sonce Ive had the Benchmark DAC I am playing less records, so now I need to make the C48 purchase happen....
I use the tone controls maybe a couple of times a year, I like to have them there, I would feel a bit weird if I didn't have them....

 

[rolltide]

The way I have my system set up, I am quite close to the pre-amp, I just have to lean over a bit and extend my arm and I'm there......
I play records and you know, its that old thing, you have to get up and change sides, and so this is when volume control things happen too, although sonce Ive had the Benchmark DAC I am playing less records, so now I need to make the C48 purchase happen....
I use the tone controls maybe a couple of times a year, I like to have them there, I would feel a bit weird if I didn't have them....

In the system with my C41 vinyl is my main source and its probably 3-4 feet away, I'm just sort of fidgity with volume sometimes, especially later at night when my sixth sense warns me the wife is about to complain. :nono:

 

[kevzep]

In the system with my C41 vinyl is my main source and its probably 3-4 feet away, I'm just sort of fidgity with volume sometimes, especially later at night when my sixth sense warns me the wife is about to complain. :nono:

Hahaha, yeah, I see what you mean, you need to be quick with the volume in those situations....
I took care of that about 7 years ago.....I got rid of the wife.....:thmbsp:
But of course that's not the solution for everyone though....

 

[62caddy]

So if I had a choice between the C-40 or 41 at the same price which would you choose? I think it would be the C-40. Who care about the remote.

Another vote for the C 40. Better tone controls allow for more precise tweaking when necessary.

Wow, I didn't realize Mac was doing that as far back as the C30

Actually even further back than that. C 32 and MAC 4100 receiver had electronically controlled switching as well.

I'm impressed with all the people who don't need remotes, I guess I'm lazier then I thought. I don't tend to use tone controls, so the C41 was perfect for me.

Key to not missing remote is never getting one in the first place.

 

[chef free]

The problem with remotes is that they give reason for manufactures to delete manual controls. I hate having to use a remote just because it's the only way to adjust things! Plus, they are always getting lost...