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Howard Stone Howard Stone is offline
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Default More than 30W per chanel Class A transistor amps

On Monday, 4 March 2019 12:45:29 UTC, Peter Wieck wrote:
On Sunday, March 3, 2019 at 7:21:11 PM UTC-5, Howard Stone wrote:

Everyone says that I should try it with am Audio Research valve pre -- but how can this possibly be an improvement over no pre at all???


It is called "Gain" and "Transient". For the sake of simplicity and discussion, let us agree on three things:

1. Whatever amplifier is in use, it is rated at its full RMS output against a 2V input at 1,000 hz.

2. It is a well-designed device using quality parts and assembled with great care.

3. The speakers in use are also good, well-made and rated at 90 dB @ 1 meter @ 1 watt. And rated at an 'average' of 50 watts.

Some basics: The transient associated with a snare-drum rimshot is approximately 120 dB. The transient associated with the onset of the organ Bombard pipes in the Saint-Saens organ symphony on a well-made recording very nearly, or actually peaks at 30 dB over average.

Most amplifiers are capable of momentary peaks and transients far above their rated RMS. Most speakers can handle transients and peaks far above their 'average' rating.

If a pre-amp has no gain over the original signal source, which is a nominal 2V, the peaks and transients will not be expressed - unless the actual listening level is a minimum of 30 dB below the average.

Pre-amps are awful things, just like democracy. Except for the alternatives.

Peter Wieck
Melrose Part, PA


Aha, this is an argument for active pre-amps. Passive pre-amps presumably all have no gain.