AVS Forum banner
Status
Not open for further replies.
1 - 7 of 7 Posts

·
Registered
Joined
·
2,747 Posts
Discussion Starter · #1 ·
I hadn't considered purchasing an amp until very recently, and know almost next to nothing about them.


Most people seem to get an amp so they can play at louder volumes, but I am primarily just interested in improving the sound quality. Would an amp provide a massive boost in quality for my set-up? My HK is giving 75 watts to my Infinity Betas, which handle up to 250 watts. I'm guessing the answer is a definite yes, but I'm looking for a little bit reassurance.


Secondly, can someone explain how the gain on an amp works? I am just a tad confused on how gain controls correlate with the volume of the receiver. The gain simply controls how much power is being coupled with that of the receiver, or am I mistaken?


Finally, is it a bad idea to provide amps only for my front soundstage? I am not willing to pay the amount required for a decent 5-channel amp at this point, and plan to begin with 2 Crown XLS402A amps, one for L/R and the other for the center. Would this result in the surrounds to be severely unpowered, making the soundstage very unbalanced?
 

·
Registered
Joined
·
1,727 Posts
Good questions for which I'd like answers too (amp newbie also). Without being scientific about it, from what I was told, when calibrated properly (e.g. to a reference of 75db at a specific volume level), it won't necessarily play louder. It'll be able to handle large swings in dbs better than amps with less power (e.g. internal), thus improving SQ overall. I'm sure there's other benefits, but is this an accurate statement?
 

·
Registered
Joined
·
8,948 Posts
A separate amp may or may not improve your sound quality, depending on many things, and most importantly your own hearing sensitivity. H/K amps are pretty good, so if you like them adding a separate amp is really only helpful if you have a large listening room and/or like to play your system at unusually loud levels, or if you speakers are unusually low in sensitivity/impedance, which I don't think yours are. A separate amp with significantly more power than your receiver will give you more dynamic capability, and will be less likely to clip, which can help protect your speakers. IMO separates are more appreciated with music than HT, but only if the rest of your system is well above average in transparency. OTOH, a quality amp can be a good long-term investment, allowing you to concentrate on upgrading the preamp-processor end of your system rather than worrying about weak amps in a receiver you like otherwise (assuming it has full preouts).
 

·
Registered
Joined
·
6,779 Posts
The most frequently given advice about setting amplifier gain is to provide the amp with the most clean input signal you can without overloading it or introducing other distortion.


One mistake people make with new amps is to turn the gain controls all the way up, thinking this is the only way to achieve its rated output. More likely that will just increase your noise floor (there can be exceptions).


There isn't any magic setting, like "start with the gain at the 12 o'clock position". It all depends on what input voltage is driving it. If you give the amp a good enough signal at the input, you'll be able to lower the noise floor, plus give the amp the maximum amount of headroom. You'll still be able to drive the amp to its maximum rated output without turning the gain controls to their maximum clockwise position.


Though typically not an issue with consumer grade amps, some people are using pro amps in the home. Often these may require a device like the Rolls MB15 Promatch or ART clean box. They will take consumer level unbalanced signals, increase their gain to provide the proper voltage to the pro amp, and deliver a balance signal output---often to an XLR or TRS connector.
 

·
Registered
Joined
·
6,946 Posts
You may want to inquire about the matching box on the big "New Amp Making Me Grin" thread. I've read quite a bit of it and don't recall many indicating a need for a consumer to pro input level matching device.


The Crown spec is 1.025V in for full output. My old Yamaha M-80 amps say 1.55V in for full output - don't see what the big deal is with the pro amp input levels. At least with the Crown XLS402, anyway.
 

·
Registered
Joined
·
6,779 Posts
Very true. All I meant was if the input source didn't provide enough voltage to drive the amp to full output, there is a remedy.


The matching device can also sometimes be used to eliminate ground loops which can be an issue when an unbalanced RCA output is sent to a balanced XLR input. Some people use a cheater plug to eliminate the hum, but that tends to defeat a useful safety feature.
 

·
Registered
Joined
·
6,946 Posts
Yes, I have seen the cheater plug thing used to address ground loops - not good thing in my book either.
 
1 - 7 of 7 Posts
Status
Not open for further replies.
Top