Axiom Home Page Forums General Discussion Technical Questions Need quick input about amps, interconnects and SQ

I currently have Axiom M60v2s and VP100 center and I need some timely answers to a few questions. I've posted to another forum but sometimes answers from that one are very slow in coming and sometimes not at all so some here may have seen this post elsewhere.

If anyone can help answer a few more questions I think I may pull the trigger later today depending on what those answers are. Again thanks to all that contribute.

I have a Denon 3808 (130W) and am thinking of adding a Sunfire TGA-5200 today. Many reasons but size, cool running, 200W continuous to all channels and quality is the short list.

When using the pre-out section of the Denon hooked up the the 5 channels on the amp does the signal processing work the same as if the Denon was driving the speakers? An example would be that sometimes on certain movies or tv shows the dialog from the center channel is hard to hear so I pop on the onscreen GUI and bump the center from maybe 0 to +3 or +4 for that movie. Would that still work if using the pre out to an amp?

I figure that as of late I do 60% music and 40% HT. When I play music at parties etc. I notice that after playing music loudly for a while the Denon starts to sound "tired" or "fatigued" (someone told me in a different thread that it may just be the "beer" factor). Would using a dedicated 200W per channel all channels driven amp help in that department and in just overall sound quality?

The amp will sit directly on top of the Denon 3808 or vice versa ( I have forced air ventilation) so I won't need long interconnects. Do I just need to get a good set of audio RCA cables? I saw a cable the other day that was 5 ended. It said 3 for composite video and 2 for audio but if they are quality cables would something like that work to connect 5 channels from Denon to Sunfire or is that a bad idea. I don't mind purchasing good cables but I don't want to spend $40 or $50 a cable.

Thanks to all that have answered my somewhat lame questions in the past and to all that contribute here. Timely answers would be much appreciated and very beneficial as I'm looking at purchasing an amp today but if I'm just wasting my money then I wouldn't want to do that.

Edmond,

1) Yes, you can still control channel levels the same when using the Denon as a pre-amp to the new amp.

2) Would using 200W / channel make a big difference? How big is your room and how loud do you typically listen? (in dB if possible) I'm admittedly biased in this department, but I'm skeptical that you're going to notice a big difference going from 130 wpc to 200 wpc. Using a totally back of the napkin estimate, I'd say you're going to be capable of 3-5 dB higher peaks from that increase in power. It gets harder and harder (i.e. requires more and more power) to make small increases in dB levels as you listen louder and louder. If you think you need that slight bump in sound, then maybe the extra $$$ is worth it to you.

3) Cables - yes, the 3 component + 2 audio combo-cable should work fine.

4) General advice: If there is a good return policy on the amp, then buy it and see what you think. A no-risk return makes that idea low risk. However, if it's a one-time deal and you'd be stuck with it, I'd consider spending my money elsewhere.

Jason

Doesn't doubling the power just make for a 3dB increase?

Technically, I can't think of why a well-cooled amp would start off sounding fine at a certain volume and then decrease in sound quality over time when kept at the same volume...unless someone is bumping up the volume a little here and there...

I agree with everything else Jason said regarding cables, etc...but I'm a little hesitant to think that a new amp would make much of a difference unless your were going up to 300-500 watts...

I'm not that familiar with Sunfire, but I quick review of the owners manual for that amp reveals a 0.5% THD. That's 10x the THD of the Denon you have now. A 70W gain from 130W is only about a 1.5db gain. You will not notice that headroom.

I would recommend going for a quality 2 channel power amp rated at least 400W per channel to get a noticeable headroom improvement. Try to get one that is in the 0.07% THD range or better.

I do a lot of multi channel SACD etc. How would adding just 2 channels of 400W affect that?

0.5% THD is negligible and inaudible.
Don't worry about it.

I agree with the advice provided by myrison with one exception. A separate amp will make the peaks smoother at higher volumes as the headroom for separate amps over the all in one receivers is typically much larger.

As for the 'fatigued' sound, i would hazard an educated guess that it is a beer factor (or for that matter a factor of 'new reference'). When listening to a volume for awhile, it may not "sound" as loud as it did when you first turned it on. Adding the beer in there certainly alters the mental perception of it.
There is a friend of mind who actually starts talking louder the more he drinks. He doesn't even realize he's doing it but his wife uses it as a gauge as to when he's done and ready to go.

Even in multichannel, most of the audio is coming from the mains. The surrounds and rears do not get the amount of output that the mains get. 130W/channel for the surrounds is more than adequate, and imo, not contributing at all to the fatiguing sound you are perceiving.

Agreed, but it's still 10x worse than the Denon. Whenever I see numbers like that, it makes me think what corners were cut to get the power rating versus the quality of the amplification.

Of course, it could also make you wonder if Sunfire is just being more honest with their numbers.

Someone else told me also what chesseroo mentioned when I asked about the THD that it was mostly just a number and at all levels mentioned I wouldn't hear it anyway.

From all my research and as far as I can tell the Sunfire is considered a "good" piece of equipment.

If I were to add a 2 channel amp for the mains of around 400W or maybe even some d-sonic 525W would my center channel become lost in the mix. I did have someone tell me that if I went that route I should power all three front channels with the same amount of power but I just don't know about all this stuff, that's why I'm asking.

Thanks again.