McIntosh C52 Preamplifier Review

[crwilli]

What taps are you using on the MC452? That might gain you some but still wouldn’t explain the need to have the volume so high.

Also, what do the meters on your MC452 read when you are cranking it to 50+ on your C52?. If it is hitting above 100Watts, you should have plenty of sound unless you are also in a very large room.

I don’t know what else would cause that beyond you (I am kidding) having hearing issues.

In the end, it isn’t really a problem.

[Bob Bubeck]

The C52 is on the front cover front and center of the latest issue of The Abso!ute Sound. Will wonders ever cease?

Bob

[newbie78]

Bob. That is a shocker. Willi , I'm using the 4 ohm taps. As far as the meters, when listening loud, they go all way right, sometimes even the red clipping light comes on. I mean it's loud, but not ear bleeding loud. I was showing my new set up to my Mom, Even my Mom was baffled the metes were going all the way to the end for loudness in the room. I don't know man. It's a medium sized room.

[crwilli]

If your are hitting the protection limits of a MC452, you are pumping Up to 600 WPC through your system. That has to be above concert levels and not good for your ears.

I wouldn’t want to be in that room for long.

[Pampero]

The position of the preamp's gain is somewhat irrelevant as long as the preamp isn't going into clipping. The meters of the preamp and power amp should read the same (i.e. -20 on the preamp yields -20 on the power amp). This "equality" is called unity gain and is an important calibration for best signal to noise ratio and to assure that the preamp doesn't clip before the power amp does. The easiest way to obtain this is to use a steady state signal such as a 1K sine wave or the like. Any of the numerous test CDs available from various sources will include signals that can be used for this calibration.

If there is a discontinuity in the results, use the preamp's trim controls to achieve unity gain, or adjust gain on the source device (if available and it's found to be needed).

Until you do that, discussing level as a function of the preamp's output gain setting is pretty academic. If your system is calibrated for unity gain and you still don't have enough level to satisfy your needs, you'll either need more sensitive speakers of a much more powerful amplifier to get where you want to go. A clean signal often doesn't sound as loud as a distorted signal since it will have fewer distortion artifacts and will usually be less harsh/bright sounding before it goes into hard clipping. That might trick you into thinking the system is playing louder than it actually is when the signal is clean.

Moral: Do your basic set-up and check that your throughput from source to preamp to power amp is calibrated for unity gain. If it still isn't loud enough for you (it really should be) then you might consider more power. My Salon 2s play loud enough for me (86dB sensitivity) to not feel any need for more, and I do like a full presentation with lots of impact. With your 88-89dB sensitivity speakers, you should be able to routinely reach pretty close to 100dSPL in any small room that isn't over damped, and even more on peaks. At such levels, you are doing permanent damage to your hearing in very short order.

[newbie78]

Thank you Pampero, I learned a lot there. I appreciate it.

[crwilli]

No matter if you have unity gain or not, if your MC452 is hitting its power guard lights, you are cranking it and it should be, not very, but incredibly loud.

[Cohibaman]

Originally Posted by crwilli

No matter if you have unity gain or not, if your MC452 is hitting its power guard lights, you are cranking it and it should be, not very, but incredibly loud.

+1

[Pampero]

Originally Posted by newbie78

Thank you Pampero, I learned a lot there. I appreciate it.

You're welcome.

Here's a thought that might (maybe!) describe your perception of "loud" and what you expect versus what you're hearing. If it explains what's happening in your room (and between your ears), it may guide where you need to focus.
We hear bass and treble more uniformly at louder levels. That's because our ears are most sensitive to sound in the midrange of our hearing. Everybody wants solid, impactful bass but that won't reveal itself with most speakers until they're really cooking and by that point you might be approaching the edge of what your system can achieve as currently configured. If this describes your sense, (that you don't get the slam and impact you're looking for unless you have the level raised to a certain point) you might consider looking into how you can improve the low frequency performance of your rig for a more satisfying balance at lower levels.

Doing that is a journey but here's a good place to start understanding why and how you may be perceiving your system as needing more power.

Fletcher Munson Equal Loudness Curves.

The first thing you might realize regarding this info is that it takes considerable level before the ear perceives bass in balance with the midrange.

The solution might be as simple as moving your speakers to a place where they interact with the room for more satisfying low frequency performance. Or you might be a candidate for subwoofers, a solution many turn to. Your amp is not lacking in power. That's why a solution probably lies outside seeking a replacement for your otherwise excellent electronics.

[JBT]

Well it's safe to say TAS loves the c52. Very impressive review!