Recent content by Lightrock

Well done test of the properties by means of the continuously varying signal amplitude! You could make the residual gain mismatch and offset error visible by subtracting the (suitably scaled) original excitation signal. Overall, the algorithm seems to be well implemented, avoiding any audible...

That's right. What you need is an adaptive offset difference detector and an adaptive gain difference detector between the two (or more) input channels to seamlessly stitch the signals together in the digital domain as they transition from one gain range to another. The convergence speed of...

Yes, the LM7705. I had considered it, but the negative voltage it generates is slightly too low (in absolute terms). The other problem is that its charge pump frequency is not synchonizable (as with most small CP ICs). So the switching frequency (in this case, around 92 kHz) would be visable in...

Of course, everyone is still interested! Very nice performance, IVX! Are these numbers achieved with the H2 / H3 overtone compensation activated or bypassed? I get slightly inferior numbers near fullscale (without THD compensation), but I am working with the 4-ch version ES9842. One thing that...

To polish the PCB to avoid any crosstalk is certainly the better option. And 4 layers are the absolute minimum to achieve this - 6 would be better to include two solid copper planes. Bear in mind that the crosstalk is frequency-dependent - if it´s capacitive, it´s rising with 6 dB/oct, whereas...

Very likely, indeed! The AD797 can be a bit picky with purely capacitive feedback. I wouldn´t use it as I/U stage for a current output DAC - far too expensive and just one opamp per package. I have used OPA1602, OPA1612, OPA1678 and OPA1692 with the ESS DACs - all yielding satisfactory results...

I always suspected that the "ESS hump" in reality has to do with this property of non-totally-vanishing non-linearity at mid levels. I have never used a resistor is series with the feedback-C in the I/U stages - and continue to consider this a bad idea because this way, you´re flattening out the...

The AK5394A really was a milestone with surprising longevity and has been deployed not only by AP in top-notch audio measurement equipment. They must have had their reasons to continue using it in their latest flagship (and hopefully stocked enough with their last-buy-order)! But it is limited...

Sorry, your SYS2522. I thought it was the 555 because of the way too small characters at the x,y axis, but now I realize that the SW suffers the same disease on older models.

I don´t think the buffer amp is the culprit because its noise is getting shorted by the C across the analog IN_P/M pins.

Indeed! A slight increase by about 10 dB up to Nyquist, as it seems - however, much gentler than the noise shaping slope of PCM4222 or AK55xx, for instance. I have only tested the ES9842Q with 96 kHz SR so far where the noise floor really looks perfect. Remarkable the absence of any spurs in...

For quite a long time, I reckon. Regarding DACs, even the venerable ES9018S, with which ESS started its success in the high end audio business over a decade ago, still outperforms all competitor´s DACs. Now the ES98x2 seems to be the next hit, after the first trial and failure with the...

And now, with the ES98x2, also pretty much the best ADC chips on the market performance wise!

Agreed on the attractiveness of Double-MOSFETs due to their low price and RdsOn! Unlike typical analog MUXs, they can be used as real current switches without causing terrible distortion. Instead of SOT23-6, you´ll also find a lot of suitable candidates in SOT363 package with additional drain...

Well, that´s kind of noble understatement! Substituting relays with a bunch of N-ch MOSFETs, maintaining a THD < -120 dBc even for signal voltages around 10 Vrms, is certainly not a trivial task, especially because you might run into Vgs max (usually +/-20 V) issues at these high levels! As a...