Sound Quality Vs. Measurements

[Wavebourn]

Originally Posted by SY

Peter Walker didn't write the Wikipedia entry.

Lucky he is. I tried to contribute to the "Tube Sound" Wiki page, to discover that my contribution was called barbarism and deleted.

[CopperTop]

Originally Posted by SY

Peter Walker didn't write the Wikipedia entry.

Tomorrow I'll have a look in my copy of that huge book about Quad by Ken Kessler to see if there's a more definitive reference for you.

[Pano]

Originally Posted by revboden

I suppose that the search for the "better" amp is really the search for the amp that incorporates the effects that evoke an emotional response, for example 'warm' sound could be relaxing.

That's only one dimension, and an overused one, at that. There are many other qualities that are sought after and heard in amp - real or imagined. The old "effects box" and "tube warmth" clichés are pretty tired. Not to say they don't exist, but they are far from a complete picture.

[benb]

Originally Posted by abraxalito

Yeah I liked your ideas. We could do with some way to measure sensitivity to interference on input grounds and on speaker and power leads. Not sure how to quantify those effects but I reckon they're important. Perhaps the CE tests for fast transient immunity would be a start, but they need to be conducted while playing a real signal, preferably music, and the input and outputs diff'd.

Bill Whitlock has written about a test he came up with, injecting a 60Hz current between an input's ground connection and the chassis, and measuring how much of it appears on the output. This was specifically to measure ability to reject ground loop currents, but no doubt the idea can be expanded to RF susceptibility as well.

Originally Posted by SY

Too true. A few nights ago, I had a long conversation with a recording engineer about my mike preamp. He just couldn't "get" the notion of a box of gain that simply amplified without coloring or why in the world someone would want to build such a thing.

Originally Posted by Pano

Of course not, that's not how recordings (or even live) work. Mics and preamps are chosen for their "sound". They are tools to achieve and end, an artistic end. If that were not the case, all you'd ever need would be a pair of B&K measurement mics. Record anything and everything with those.

Photographers use filters, odd exposures, Photoshop and printing tweaks to achieve the look they want. Straight forward photos are often pretty boring.

I've seen it all (or so it seems, and heard a lot) on rec.audio.pro. Market it as having the "SY signature sound." If someone finds the sound too boring or whatever, say it also works well with a transformer on the input and/or output.

And something that most people know, different pre input impedances change the sound of dynamic micrphones. Add an input impedance switch and label it "tone" or "coloration select."

I take that back. Make two models, one with higher input impedance than the other. Sell them as two different "flavors."

[Wavebourn]

Originally Posted by benb

I've seen it all (or so it seems, and heard a lot) on rec.audio.pro. Market it as having the "SY signature sound."

Absolutely right. I can argue here among DIYers, but I stopped arguing on gearslutz.com about this matter: if people want to believe that my amps and microphones "add warmth and transparency", so mote it be.

[abraxalito]

'Adding transparency' - that one I like. Perhaps we could though say it adds 'negative opacity'?

[Wavebourn]

Originally Posted by abraxalito

'Adding transparency' - that one I like. Perhaps we could though say it adds 'negative opacity'?

Does it matter?

When people getting rid of some nasty distortions as if hear some nice coloration added, it is their right to believe. They need to call the sound somehow.

[Wavebourn]

Originally Posted by a.wayne

Wave do you have a better copy than MP3 ...?

Why? I expected Scott to ask, it is a song about Boston.

Sounds more like an spring reverb ......

Don't you like it? They did.

[vanderpol4]

Has anybody tried this test by Nelson Pass on a PP tube amp? Perhaps a way to measure/ monitor tweaks of the Global feedback loop?

[Wavebourn]

I did that back in 1979 when played with thick film 50W amp ICs designed in our laboratory, when tried to make a bridged amp without frying them.