Can I vertical biamp with NAD C372 and C272?

john1970 · « **on:** 19 Mar 2006, 01:43 am »

Dear AC,

I am considering vertically biamping my speakers with the NAD C372 (which I currently own) and a NAD C272. One requirement of vertical biamping (where each amp drives 1 channel) is that the amplifiers are identical.

Comparing the C372 and C272 reveals that the amplifier sections are identical EXCEPT for the input sensitivities (1.3 V on the C272 and 770 mV on the C372).

THE QUESTION:

Would the differences in the amps input sensitivities prohibit vertical biamping? FYI both amps have identical input impedence and voltage gain. Please respond.

Thank you,

John

rbrb · « **Reply #1 on:** 21 Mar 2006, 05:55 pm »

The C272 and C372 were designed to work together all though maybe not like you are suggesting. It would be easier to use the 272 for the woofers and the 372 for the mid/tweeters.

pacifico · « **Reply #2 on:** 21 Mar 2006, 06:02 pm »

I thought of adding another amp to my C372 as well. I am glad to actually know of someone that owns one. They don't seem to have gotten much good press. I am actually thinking more along the lines of getting a tube preamp for it. I will eventually switch from 150 W/ch to about 5 and use a sub for deep base.-ap

andyr · « **Reply #3 on:** 23 Mar 2006, 07:46 pm »

Quote from: john1970

Dear AC,

I am considering vertically biamping my speakers with the NAD C372 (which I currently own) and a NAD C272. One requirement of vertical biamping (where each amp drives 1 channel) is that the amplifiers are identical.

Comparing the C372 and C272 reveals that the amplifier sections are identical EXCEPT for the input sensitivities (1.3 V on the C272 and 770 mV on the C372).

THE QUESTION:

Would the differences in the amps input sensitivities prohibit vertical biamping? FYI both amps have identical input impedence and voltage gain. Please respond.

Thank you,

John

Hi John,

The crucial thing is ... do they amps have the same gain? You've said they do, so you're sweet!

The fact that they have different input sensitivities implies they are rated at different powers ... so you should bi-amp "the other way" (with the more powerful amp on the bass).

Regards,

Andy

john1970 · « **Reply #4 on:** 24 Mar 2006, 02:30 am »

To all,

The only difference is the amps input sensitivities. Every other spec (including power, input capacitence, and gain) are identical. Can I vertical biamp?

Thanks,

John

opnly bafld · « **Reply #5 on:** 24 Mar 2006, 02:41 am »

Yes you can, you will probably have to adjust the balance control just a little.

andyr · « **Reply #6 on:** 24 Mar 2006, 04:15 am »

Quote from: john1970

To all,

The only difference is the amps input sensitivities. Every other spec (including power, input capacitence, and gain) are identical. Can I vertical biamp?

Thanks,

John

I believe there is a fixed mathematical relationship between:
* rated power
* input sensitivity, and
* gain.

If the input sensitivities are different and the gain is the same, I believe the output power *must* be different.

Why are you fixated on wanting to use one stereo amp per speaker? If you had two identical amps then go for it but, if you have 2 different amps, it makes more sense to use one on the highs and one on the lows. However, you also need the gain to be the same inthis setup, for it to work properly.

At the very least, even if my statement at the start of this reply is incorrect, and somehow the two amps do have the same power output, input sensitivity and gain, it is unlikely they exhibit the same tonal characteristics as each other - so one channel will sound different to the other.

Regards,

Andy

John Casler · « **Reply #7 on:** 24 Mar 2006, 04:45 am »

Quote from: john1970

To all,

The only difference is the amps input sensitivities. Every other spec (including power, input capacitence, and gain) are identical. Can I vertical biamp?

Thanks,

John

I'd try "horizontal" biamping instead.

That way the power distribution would be more equal.

I would get the feeling that the amp in the integrated would not get the same "juice" because of the power drain to the power supply by the preamp section.

Horizontal Biamping would make for a more equal distribution of power.

John Ashman · « **Reply #8 on:** 24 Mar 2006, 05:23 am »

The other advantage of horizontal bi-amping is that the 372 allows you to adjust the bass relative to the mid/treble. I also am wondering why you are fixating on vertical bi-amping. If the amps were absolutely identical, sure, but horizontal makes far more sense for quite a few reasons.

opnly bafld · « **Reply #9 on:** 24 Mar 2006, 12:50 pm »

I would guess his reason for vertical biamping in this case is each amp would share the current hungry bass section.

john1970 · « **Reply #10 on:** 24 Mar 2006, 02:00 pm »

opnly bafld you are absolutely correct

I am looking to have one amp drive each of the speakers so each amp can share the current hungry bass section of each speaker.

Thanks,

John

andyr · « **Reply #11 on:** 24 Mar 2006, 08:50 pm »

Quote from: opnly bafld

I would guess his reason for vertical biamping in this case is each amp would share the current hungry bass section.

Yes, so the treble in each channel is compromised when a bass "thwack" happens.

At least when you use one stereo amp for the treble and one for the base, the treble is never impacted (negatively) by what's happening in the base. I suggest this is a better arrangement.

Regards,

Andy

opnly bafld · « **Reply #12 on:** 24 Mar 2006, 11:15 pm »

I not commenting on right or wrong (if there is such a thing

)
But the idea to me would be to not overwork your amps, therefore
no problems when the BASS hits. Just like a lot of systems with only 1 amp.