kenratboy Posted June 14, 2005 Share Posted June 14, 2005 I heard some preamps have more or less output at a given volume (as in, between low and full volume) - so how do you 'match' different preamps with amps? Is there a standard or do you need to just be careful? Example - how do I know full volume on the preamp = full amp output? Thanks! Quote Link to comment Share on other sites More sharing options...
Spkrdctr Posted June 14, 2005 Share Posted June 14, 2005 Ken, Full volume on the preamp does not mean full volume on the amp or vice versa. You have the signal strength of your source material which is a major factor. This is why everyone brings up the 1812 Overture for testing an amps clipping point. You can get just about anything to clip on cannon shots!!! What is happening is that the size of your low level signal from the preamp is controlled by the volume knob (generally), then it goes to the amp which brings the size up again and feeds it to the speakers. The amp, unless you have a volume control on it, is amplifying everything a certain amount. You control it by changing the signal size (voltage) with the preamp. If the amp has a volume control or more properly a gain control, than you can control both the preamp and the amp. Usually you want a fairly good signal going to the amp, this keeps you from having your amp, amplifying noise (hiss and hash)which will happen with a very low level preamp signal, on less than the best high end gear. High end gear has extremely low noise levels and this is not as big of a problem. This is a very simple explanation. I hope it helps. If you have any specific questions on this info, please e-mail me directly at Spkrdctr@aol.com Quote Link to comment Share on other sites More sharing options...
Trooper Posted June 14, 2005 Share Posted June 14, 2005 Good info by the previous poster. Most power amps can be driven to full power by about 1.5Vrms. You can usually find this in most good amp specs. You'll want to make sure the preamp you choose can output at least that much voltage. I know of one instance where company X's big 7 channel power amp required about 1.4Vrms to reach its rated 200W output. Evidently the amp designer didn't tell the preamp designer because the surround processor/preamp from the same company only put out 1Vrms before it started to clip. This meant that with this >$7000 pair of components you could never reach maximum output of the amp! Brilliant. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.