Axiom Home Page Forums General Discussion Technical Questions Denon with external amp

Yeah Rick, I'm pretty sure that is the case with most receivers. As soon as you use the "pre-outs" for any given channel, that bypasses the internal amp stage. However, I guess I've never tried to hook up a pair of speakers to the regular speaker jacks, AND use the pre-outs at the same time.

I can't remember what receiver, but some model had a warning against hooking up speakers when the pre-outs were connected to amps.

I do remember that someone used a Kill-A-Watt on a previous Pioneer Elite flagship receiver. He found that when there were no speakers connected to the internal amps they still drew some power vs. going into the settings and disabling the amps. It wasn't much, like 5 Watts, but that does add up over time. My current Pioneer, while having pre-outs has no setting to disable the internal amps.

Ricky- I'm using the pre outs for five channels that go to a 5X200 external amp, and using the 3808's amp for the surround back channels.

Mike, are the binding posts that you're using the preouts on still active?

Even if a receiver leaves both its internal amps and pre-outs active at the same time, bi-amping is going to be a problem. Adjusting the channel trims will cut both the internal amp, and the signal going to the external. Unless the external has exactly the same gain as the built-in, you're going to end up with half the speaker at a different level. You'd have to use an external amp with it's own trim setting.

I have no plans on anything like this, the question was brought up and I was looking for the correct answer.

Rick, most(all?)HT receivers don't have a device to cut off the pre-amplifier voltage from the internal amplifier output channels when the pre-outs are used. This can be tested on any particular unit by inserting an RCA plug(doesn't have to be connected to anything)into the pre-out and observing whether the regular sound from the receiver to that speaker is cut off.

An example of where a cut off does occur is using the headphone outputs of most HT receivers. Since these units(contrary to some belief)don't use a "cheap" separate headphone amp, but instead the regular amplifier greatly attenuated for headphone use, the output would no longer be suitable for driving speakers. Therefore, inserting the headphone plug moves a mechanical switch which cuts off the pre-amp voltage from the regular output channels, which merely continue at "idle".

Phil, more than connecting a separate amplifier to one section of the speaker is needed for true bi-amping and to have any significant benefits. An external crossover(usually electronic)has to be used ahead of both amplifiers so that each receives only the desired limited range of frequencies to amplify. The internal crossover in the speaker has to be removed, or at least bypassed.

Thanks John.

I'm using the pre outs for SEVEN channels FROM my Denon 3808 to my external EMOTIVA AMP (2). SQ is so dynamic and lots headroom. I will never go back to AVR. The best sound I was missing from my Axiom speakers for a year until I was introduce to me from this forum. The reason I did upgrade was that Denon can not bring out the best of these AXIOM speakers. With external amp,I can hear the musical instrument details and the punch of those Axiom mid-bass sound so good which I was looking for in these AXIOM speakers. But, I would like to share some issue I ran into with EMO amp and my M80V2. Right now I am stucked with the so call distortion and clipping issue with EMOTIVA amp (XPA 2). Believe me with the external amp it's sound very good, but but be careful with external amp make sure it is a 2 ohm stable amp if you are pairing with M80v2. This Issue-DISTORTION AND CLIPPING WHEN EVER I PUSH the volume up. It is not that loud, just when I play above my listen level for demo to friends with heavy rap/pop music. Some how some where the M80v2 impedence dipped below 2ohm. Other than that it sound very good with external amp. I am kinda disappointed with my M80v2. I thought m80s are suppose to be an efficient 4 ohm speaker/easy speaker to drive . O well. I am returning my Emotiva XPA 2 next week from the 30 days in home trial period. Plus,I tried Outlaw amps and Adcom, EMOTIVA amp sound better and cheaper. If you have other Axiom speakers besides the M80 your be fine with any external amp.

At no point in the impedance curve does the M80 dip below 4 ohm.