pre out voltage

[JohnnieB]

You guys are a riot.
Anyhoo, thanks for the review link PENG, I had only ever seen bits and pieces of that article. I guess I don't understand why companies always have to be half-truthed about everything. Sheesh It makes it tough for a guy like me to swim through all the data and really get a good grasp on what I'm reading.
Once again, Thanks e'body. Another few years on this forum and I may figure all this stuff out.

 

[Irvrobinson]

Sheesh It makes it tough for a guy like me to swim through all the data and really get a good grasp on what I'm reading.

It's tough for anyone to be sure about which components will work together well until you actually test them together. Some amps, for example, are so sensitive that some older pre-amps will be restricted to only a small part of their total volume control range, which can be very inconvenient. Poorly-designed input stages can also suffer from overload, like seems to be the case on the balanced inputs on my subwoofer. I had to use 10db signal attenuators to get things working right. Sometimes even big-name companies get electronics wrong.

 

[PENG]

Good enough for government work? Good enough for community college work?

Nope, neither, but enough for me because I just need to confirm the voltage that my system needs to hit >100 dB SPL and that's pretty much the peak SPL I can tolerate as I normally listen at below 80 dB average and no below 75 dB most of the time. Less than 1V preout would get me that kind of peak as confirmed by the Fluke. If I were to measure the preout voltage at clipping then I would need a suitable scope.

 

[JohnnieB]

Well, for now, I will continue to be happy with the sound I get. I'm not exactly torturing myself.

 

[Rickster71]

I got a vintage/old Sony TA 2000F preamp from Walter a few years ago.
It has a nice feature, level adjustments for each source: http://www.gopixpic.com/1920/sony-ta-2000f-hinten/http:||bilder*hifi-forum*de|max|498663|sony-ta-2000f-hinten_16204*jpg/
That sounds like a nice feature. Any thoughts on why it's not seen anymore?
Here's another TA-2000F info link if interested: http://www.thevintageknob.org/sony-TA-2000F.html

 

[Irvrobinson]

Yeah...4 volts is piddly for dynamic range and leaves nothing for headroom. 8 volts is getting there...10-14 volts and now we're talking!

Oh really? So if most amps clip at less than 4 volts, and usually less than 3 volts, how is 14 volts useful?

 

[Ampdog]

Firstly, to agree that '1V' cannot possibly be just before clipping. I have interpreted a given output as referring to given 'sensitivities' for various input signal values. If involving headroom, that should be specified as such.

I must also agree that 'headroom' can lie with the power amplifier and usually does .... unless matters are so wildly out of kilter that the stage(s) preceding the volume control can be overloaded by too high an input signal. In such a case a figure for headroom should be coupled to (as in being above) rated input signal level.

Finally, I have an issue with certain low input-impedance power amplifiers shooting up nowadays. Why? And if mandatory for whatever reason, why not include a buffer in the main amplifier?

 

[djreef]

This is beginning to sound like the 'damping factor' debate.

 

[stanley77]

Alex, You’re absolutely right, I designed a system ages ago with 5V clipping and I had always considered it to be great. I really admire the design mentioned by TLS Guy and I hope I can get my hands on it someday, just to have a look at how it has been designed to try and quantify the difference in quality brought by such a big headroom. This is perhaps one of the most interesting threads on this forum.

 

[PENG]

Oh really? So if most amps clip at less than 4 volts, and usually less than 3 volts, how is 14 volts useful?

Agree, except once again more, higher are better than less, lower REGARDLESS.