62dB vs 40dB Is More Better?

Thrill Kille

Active Member
I have a chance to get either a McIntosh C33 or a C42 Preamp. The 33 does 62dB of Phono Stage Gain. While the 40 does 40dB of gain. Is more Gain better?

My TT is a Technics SL1200MK5 w/ Nagoka 300 cart. And it puts out 3mV. The amp is a MC2205 2.5V
 
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PS: If I add a Emotiva XPS-1 Phono Preamp it says it will give me 40dB of gain with my MM Cart. With the 40dB of gain that the C40 already has. Would the phono pre add it's dB's to that for 80dB over all?
 
I do not think you have the complete information here.

The power amp sensitivity has nothing to do with a phono input stage.
The sensitivity of the MC2205 is either 2.5V or 0.75V, not millivolts.
 
From the C33 owner's manual:
Input sensitivity of the phono amplifier is 2.2 millivolts. The gain of the amplifier is 42 dB at 1000 Hz. The phono amplifier has a very wide dynamic range. At 1000 Hz the phono input circuit will accept 100 millivolts without overload, a voltage far greater than the output of any magnetic phono cartridge presently available.

The C33 has two MM phono inputs, the C42 has one, also MM. Either should have plenty of gain for a MM or HOMC cartridge.
 
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First of all, you cannot chain phono stages. Besides gain, the phono stage provides EQ, to restore fidelity to the signal, which is compressed to the RIAA specs. If you send a line level signal, i.e. output signal from the Emotiva, into the Mac phono stage, either one, you will overload the Mac, and may damage it. The Emotiva output will have to go into a line level input, like an AUX. Or, just use the Mac phono stage.

The 2.5V input spec is a max, not an operating level, especially since most records operate below that level. And, increased gain, at the phono stage level, will increase any vinyl playback noise. If you are maxing out this system, and you get a 'pop' in the vinyl, I fear for your speakers.
 
More is not always better.......depends on cartridge choice in this case.

External MC preamps or transformers could overload the input of a C33 so we needed to be careful when we speced them back in the day.

Either preamp can output in excess of 10 volts so obtaining 2.5 volts to drive a Mac amp to full volume is no issue.....you will also be able to knock down the amp gain controls further to improve the S/N......

C33s are a special vintage preamp, with them now 35 years old they benefit from a complete 6-7 hour restoration.

A C40 for 1k less sounds to good to be true.......
 
for MM carts 40 db (or so) gain is adequate.

for MC carts, there are normal/standard ones that will require about 60 db gain.

then there are HOMC (high output) that you can use the 40db gain for MM carts.

and if you go with the 40db/MM only, and if you get a standard or low output
MC cart, then you could upgrade the Mac or buy and outboard phono amp
and then plug it into an AUX port.
 
Both their phono sections are set up for Moving Magnet, 40 or 40db gain will work. Since both preamps have a lot of output potential beyond the voltage necessary to power any McIntosh to full volume the phono gain is not a big deal. MC carts would require another +20dB of gain to +60 total or more to bring a low output MC up to the level of say a CD player which is 2V peak out.

Ron-C
 
I personally would never choose a C33 over a C42 for any reason. You're reading too far into specs. Buy the C42, connect your tt and enjoy.

What puts the C42 over the C33, or C34v? just Curious. I've always heard good things for both. I'm buying my C42 from Q-Audio in Cambridge.
 
C-32, 33, 34 and 40 have the most flexibilities of any Mac pre-amps ever built. They do not however have a MC inputs. MC inputs have around 60 db gain. MM are around 40 db gain.
 
Lets see a C-42 doesn't have a 10 Khz control, strike one, Doesn't have a mode selector, strike two. It does have balance inputs, etc a definite hit. In my case it 17" wide ,Strike three, and its to deep, Strike four, but then neither has a MC input. If I had the room not having the 10 K control and Mode selector would still be the deal killer. I also like the HF and LF filters of the earlier preamps. OH I don't need a remote control. I wish the pre-amps with graphic controls had coaxial controls for separate left and right channel controls.
 
Lets see a C-42 doesn't have a 10 Khz control, strike one, Doesn't have a mode selector, strike two. It does have balance inputs, etc a definite hit. In my case it 17" wide ,Strike three, and its to deep, Strike four, but then neither has a MC input. If I had the room not having the 10 K control and Mode selector would still be the deal killer. I also like the HF and LF filters of the earlier preamps. OH I don't need a remote control. I wish the pre-amps with graphic controls had coaxial controls for separate left and right channel controls.

Touche!
 
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