dac I/V convertion with very low distortion

[Telstar]

Originally Posted by MiiB

To my knowledge there's no coherence between good sound quality and low or lower distortion. We often seek low distortion as a Design goal, but in realty speakers contribute with so much distortion that the number of zeros in the source component is a non issue.

I disagree. It's not just the thd that influence the electronics sound, but other forms of distortions that most often ignored (imd, tid, phase distortion and just high order armonics). The way these distortions affect the sound is so strong that something like .1% is clearly audible and it can be much worse than a .2% from the speakers.

I believe that the number of junctions really matters.. This we saw this clearly in the Paradise, where the simpler circuit, with on paper inferior performance, was when built vastly the superior performer, Here we have the same, a real simple circuit VS a more complex better specified circuit. I my mind I know the winner. Seems like the reduction of in circuit nodes is a BIG benefit to the music. where as the housekeeping may be rather complex to max out the performance of the simple circuit.

Yes, what we want are simple circuits with short signal path with as few active and passive components on the signal, and yet a good distortion performance.
I personally prefer open loop circuits but between one with 1% thd@1W and another with 0.01% with closed loop, I prefer the sound of the latter.

[Joachim Gerhard]

Here you can test your ability to hear distortion :Listening Test
I scored in the middle ground.Even 1% low order distortion was hard for me to differentiate.
0.1% low order is definitely not audible.
If you can you are an alien.

[Joachim Gerhard]

Here is an older test on how much distortion we can hear :http://www.linearaudio.nl/Miscellane...0recorders.pdf
The test subject was non other then Les Paul.

[Joachim Gerhard]

Designing for ultra low distortion is not hard anyway :http://www.linearaudio.nl/Documents/...ralization.pdf

problem solved !?

[MiiB]

Problem with speakers is that the distortion you measure is steadystate....so you don't even count the Doppler distortion from multi-tone and the fact that magnet systems are very very nonlinear so a 2kHz on top of a 100 Hz may look quite odd.

On a smaller product like a preamp...distortion may be ca. valid measure, as we have somewhat control of impedance's in both ends.
But in the thread where you nailed my quote we were talking amplifiers driving speaker loads, and in that respect Distortion is a non measure. Or it says nothing about sonic qualities of the circuit.

[Telstar]

Originally Posted by Joachim Gerhard

Here you can test your ability to hear distortion :Listening Test
I scored in the middle ground.Even 1% low order distortion was hard for me to differentiate.
0.1% low order is definitely not audible.
If you can you are an alien.

It all depends on the playback chain where it is reproduced. I also scored on the middle (failing at 18/21) with work pc with emu1212 and a pair of Aurvana Live.

[Joachim Gerhard]

I like low distortion too. If it sounds good all the better. I find it just so sad that amp designers do not talk much to speaker designers. I think we should take the interface problems more serious.

[MiiB]

I second that...speakers and AMP interfacing is a key issue, how does an amplifier deal wit return-currents, how does it bleed back through the feedback.. ect ect.

And I must correct myself, your quote was indeed taken from this thread, but was pro or con an opamp circuit vs an simple discrete solution. where i preferred the simple in-spite of an on paper poorer performance. (sorry)

[Joachim Gerhard]

Some work has being done :http://www.cordellaudio.com/papers/i...distortion.pdf
But what is a "proper" design ?

[MiiB]

I know this is not the proper place for it.... and it should have it own thread... bu to be honest the speaker model in Cordells paper is as good as none...
The hardship is including the nonlinear mechanics in the model. It's mainly the masses that creates the Back EMF that the amplifier has to deal-with..currents out of phase with the driving Voltage... I think there's one of the big differences in VFB vs CFB...sorry.. again not to change the thread, but merely a point of view worthy of concentration.