be wary of db's

or voltage output...it has occured to me recenty whilst changing valves in the output stage of my audionote dac1.1, how much the differences in volume have coloured my perception of things.

I am pretty convinced now that if you have a demo in shops, speakers too, that usually, the louder sounds more impressive.

I recall years ago, hearing tannoy m2s, mission 771s against each other, the missions being tiny sounded small and dull in comparison, partly due to the volume difference. Bass too, yes, but comparison with kef q15....now kef are clever, they know all about this, and boost the dbs to 91, by lowering the impedance to 4 ohms, ( and possibly making the cone have a higher resonant freqency, ie lighter, or the magnet being stronger, 'pushing' the cone harder,(lessens bass too) so your amp draws much more current.

In the shop, this sounds far louder and impressive.

But if you 'equalise' the volumes( ite make them equal(ise)(, this is really the only way for a fair comparison...in the dac, I tried an ecc82, and a 5814, a military valve of the same type, and it sounds dull against the eikos, I measured the output volts and found it was only about 2/3.
I then put in an ecc 83, and found it was another 1/3 above the eikos, and sounded more like it, much fuller than before, and less anaemic and washed out.

The operating point for the valve is all messed up, so if you measured it, it would not be good, probably lots of 2nd harmonic distortion, as the resistors for the load are set for an ecc82 ie quite small.
But it sounds more full bodied, and more like the eikos, ony the eikos is still more bassy. THough it has a slightly smoothed treble due to that legato link filter.

I think that is what pioneer are trying to do with this, a platter and an altered treble...trying to imitate vinyl?

Anyway I am going off track...so be aware of the output of things before you write them off as crap...it may not be so simple, and may be simply higher outputs makking it sound fullsome. Shades of chord dac64??

I could be stating the obvious, but then again...it may not occur why somthing sounds better in comparison( I won't go down the route saying all that lovely 2nd harmonic valve distortion is responsible.. )

 

This is quite a well known fact re db levels.

Hifichoice, when it used to do its blind listening sessions, would always adjust the level so everything was on a level playing field.

Different speakers can have quite a large variation in sensitivity and as you say some manufacturers may use this top their advantage

Less obvious - to me anyway - is the fact that for instance, power-amps may have noticeably different sensitivity.
Yesterday, I found out my 2 poweramps (from different manufacturers) need approx 2-3dbs adjustment in level....

Best to take a SPL meter and cd test disc with fixed level sine waves to dems.....

 

More Voodoo less science

Cdr Data, we meet again.
high outputs don't just make something sound more fullsome, more often than not, dependant on the sensitivity of the input, overdriving can sound brash or even distorted.
Some manufacturers of amps are good to us by always having the same level of gain on their power amps for instance, even though they may be of different power ratings, so mixing and matching is easy. It is a much misunderstood and more commonly ignored fault of some system mis-matches.
When it comes to the whole acoustic - electro-mechanical relationship between speakers and amps the field is bigger than we can discuss. I think just setting db defeats the object of music reproduction. PLAY IT LOUD and play it quiet. Does it work for you? This is less scientific but you're not running reviews, your deciding in you heart about the reproduction of music or even recreation of the real event. (Wishing) If it sounds less impressive turn it up. Does it sound good now?

I'm intrigued by the valve changes that can change the gain relationships within an amp. I suppose its my excuse for not having one, I would be tweaking forever. Or frying myself.