Amp for under $300

[slmcdonald7]

Hi all,
I just purchased a Denon 3805 receiver and a pair of Paradigm Monitor 11's. As many of you know, the 3805 pushes 120 w.p.c., but the 11's have a "suitable amplifier range" up to 250 watts.

At this point, I have several questions.

1) Should I bi-wire them (to get 240 watts) or go with a separate amp?

2) If I go with an amp, an electrical engineer (and audiophile) friend of mine suggested that I purchase an older Marantz off of eBay (from a reputable seller of course). I know very little at all about amps and nothing about older Marantz's. He suggested that for what I wanted to spend (not more than $300), this would be my best source for a good amp. Is this a good idea? Would an older amp be compatible with the 3805? Are there better options out there for the money? I know that these are very basic questions, but that's why I'm here!

As a related question:
3) As I previously stated, the spec sheet on the 11's says that they have a "suitable amplifier range" of 15 to 250 watts, but have a "maximum input power" of 180 watts. What does this mean? I've never been a math person, but something seems fishy about these numbers.


Any and all help/suggestions are truly appreciated.

Thanks,
Stephen

 

[JoeE SP9]

Amp power

Just go ahead and play music. If you don't have enough power the system will generally sound harsh and strained at volume. In extreme circumstances of insufficient power you blow up tweeters. Most of the power recomendations for speakers should only concern you if you are on the low end of the power range. To much power will usually cause bottoming of the woofers voice coil. To little power causes the amp to clip thus blowing tweeters.

 

[slmcdonald7]

Thanks JoeE,

You're right on with your power analysis, that's why I went ahead and purchased the 3805 (as opposed to less powerful / less expensive receivers), since I figured that the 120 w.p.c. would be more than suitable for what I wanted to run (in terms of speaker safety) . My question about the discrepancy between the “suitable power amplifier range" of 15 to 250 watts and the maximum input power of 180 watts was purely academic. If anyone could explain why Paradigm’s spec sheet for these speakers would list a lower number of watts for the maximum input power than they listed for the suitable power amplifier range, I would be all ears.

Also, if anyone has an opinion about my previously posed amplifier / bi-wire question, I would be delighted to hear it!

Thanks again,
Stephen

 

[Unregistered]

1) Should I bi-wire them (to get 240 watts) or go with a separate amp?

Bi-wiring does nothing but increase the effective gauge of the speaker wire. It will NOT give you 240 watts. If you determine that you need more power, then yes go for a separate amp - but that is a very big 'if'.

2) If I go with an amp, an electrical engineer (and audiophile) friend of mine suggested that I purchase an older Marantz off of eBay (from a reputable seller of course). I know very little at all about amps and nothing about older Marantz's. He suggested that for what I wanted to spend (not more than $300), this would be my best source for a good amp. Is this a good idea? Would an older amp be compatible with the 3805? Are there better options out there for the money? I know that these are very basic questions, but that's why I'm here!

Don't know what you can get for $300 but I highly doubt anything you find in that range would be superior to simply using the Denon as is. Older amps are compatible with new receivers though if the receiver has pre-outs and I believe the Denon does.

3) As I previously stated, the spec sheet on the 11's says that they have a "suitable amplifier range" of 15 to 250 watts, but have a "maximum input power" of 180 watts. What does this mean? I've never been a math person, but something seems fishy about these numbers.

Speaker ratings should be taken with a grain of salt. The 'suitable amplifier range' is simply the highest amount of power the manufacturer has determined the speaker can handle. Nearly all speakers can take far more than their highest rated power for short periods of time. 'Maximum input power' is the manufacturer's recommendation for maximum continuous power (RMS). Again they can probably take more for short periods of time.

To clarify what Joe E said:
Too little power can be a problem if you try to drive the amplifier near its limits and it is not able to produce a clean, unclipped output. When an amp is driven too hard, the waveform becomes clipped (tops of the waveforms squared off) which produces harmonics that can destroy tweeters. It is highly unlikely you will ever damage the woofers though - they can take huge amounts of power.

If you find that you cannot achieve the level of loudness that you desire, then it is possible that you would want a higher power amplifier. Turning up a lower powered amplifier near its limit may cause the problems mentioned.
However, you would have to try it first. It is unlikely that the Denon will not have enough power to drive those speakers to uncomfortably loud levels unless you have a very large room or the speakers have very low impedance dips (like down to 2-3 ohms).

 

[Rob Babcock]

I believe the Denon '3805 allows you to dedicate the 6th & 7th amp channels to passively biamp the mains. In this instance biwiring isn't necessary.

 

[slmcdonald7]

Ok, now I'm confused.

Rob, you're right, you can use the Denon 3805 to get 240 w.p.c. using the unused channels when listening in 5.1 (according to Audioholics own review). However, when I called and spoke with a member of Denon's tech support staff, he said that to do this I would have to bi-wire the speaker.

Would you mind explaining to me how I could go about doing this without bi-wiring?

Thanks,
Stephen