Recent content by peufeu

Hi pma! I'm going to apply this test to some circuits, so I'd like some advice: What song gave the best results in terms of ease of hearing distortion for most people who answered?

Here's an experiment that I would find interesting, so I'm suggesting it. - Put opamp in unity gain buffer configuration and ground the input, so it outputs 0V. - Connect output of opamp to output of audio source via suitable resistor, for example 1k. - Play signal and measure distortion at...

There is something I tried: bitumen between two sheets of MDF. The resulting material is very dead, no resonances, constrained layer damping really works, but it is super messy to build and the bitumen stinks. Viscous acrylic caulk (same stuff you put in the cracks around windows) works just as...

Bitumen pads shouldn't provide any damping of acoustic waves. However since it's a lossy material, they should dampen the vibrations of the speaker cabinet wall. This is not just adding mass: when the walls vibrate they deform, so they also deform the bitumen, which requires energy, and that...

That claim is difficult to test, because it depends on the setting. The guy who claims a strong effect from interconnects in his system can always say that's because there's a lot of RF interference in his listening room, but it's not possible to know if that is true over the internet...

What makes me take the claim with a bucket of salt is this: it all happens in digital domain, so the first thing to do would be to substract output from input and see what it looks like. But he doesn't talk about that at all.

Well yeah, but what I find surprising is he seems competent but he didn't mention the obvious: if there is an audible difference that is correlated with a measurement that's a whooping number of dBs down, so low it would be ridiculous to pretend to be able to hear a signal that many dBs down...

Most of what Mr Chord said in the video made a lot of sense...

It's simple: - The AV source tells the AV sink what the audio sample rate is. - This is expressed as a fractional multiple of the video clock. - The sink can use any suitable implementation to synthetize that audio clock, as long as its frequency is what it should be and it is synchronized to...

Basically the HDMI receiver chip outputs an audio clock that it extracts from the incoming multiplexed signal. How it does that depends on the chip: I've seen one case where they did it ghetto style, with a fractional divider from the video clock, which gives a pp jitter of one period of...

Hey, NAD M28 is sold for only 5499€, of course they would customize it to save 50 cents per cap XD Personally I wouldn't change the caps before they break down, which should take many years. IMO if you want it to last longer your money would be better spent on a bit taller enclosure so you can...

I've looked at a few online photos of the module, it seems to use either Rubycon ZL (5000h @ 105°C) or Panasonic FR (10000h @ 105°C). That's very high quality, high ripple current, long life, and low impedance caps, excellent for switching power supplies (or class D amps which are switching...

It's a Technics with an integrated amp on a hybrid chip, top secret schematics, who knows what's in there! It runs cold. Below plot is 1/gm, in other words output impedance, of 3 output stages, the ALFET/EXICON LatFets, the IRFP240/9240 and the famous MJL1302/3281, at various bias. That was...

I use python because I am too lazy to click on things and turn knobs. Scipy/numpy is very good. Also it is easy to use the soundcard to play and record signals. I've just bought 2 USB controlled bench power supplies, and the pcbs for the rest of the setup are cooking. I'm gonna have a hardware...

Nice build! That's a good argument for bi-wiring actually: nonlinear woofer current * wire impedance creates distortion voltage at the speaker, which will be played back by the whole speaker, so if it's a 3 way the midrange driver will output this distortion voltage... With separate wires...