I get by pretty well with the 48Khz sampling but would be happy if I could move to 96KHz.
Maybe someone else makes USB soundcard that will do higher rates, duplex. My spare PC has the 1/2 hight PCI slot, so the Audiophile card won't fit.
I like the USB card and its phantom power, the balanced or unbalanced ins and outs, the SPDIF in and out, the ease of use. I still use my o'scope, but the soundcard is now #1 in the lab.
Maybe someone else makes USB soundcard that will do higher rates, duplex. My spare PC has the 1/2 hight PCI slot, so the Audiophile card won't fit.
I like the USB card and its phantom power, the balanced or unbalanced ins and outs, the SPDIF in and out, the ease of use. I still use my o'scope, but the soundcard is now #1 in the lab.
Sy,
I have been using an EMU1616m with a custom breakout box (several actually) for years.
In fact, I can easily make some measurements with that setup that are difficult using AP2 (like PSU rail noise audio FFT), but there is stuff where even the AP2 does not suffice and stuff where it can measure things the Soundcard based set-up cannot.
A major problem is that all these measurement systems invariably involve a lot of averaging, be it digital or analogue. So there are questions this gear just cannot answer and yet they are the ones that matter IMNSHO.
And for answers to those questions I am back to very blunt tools.
Ciao T
I have been using an EMU1616m with a custom breakout box (several actually) for years.
In fact, I can easily make some measurements with that setup that are difficult using AP2 (like PSU rail noise audio FFT), but there is stuff where even the AP2 does not suffice and stuff where it can measure things the Soundcard based set-up cannot.
A major problem is that all these measurement systems invariably involve a lot of averaging, be it digital or analogue. So there are questions this gear just cannot answer and yet they are the ones that matter IMNSHO.
And for answers to those questions I am back to very blunt tools.
Ciao T
Hate being a grammar cop, but I have seen this mistake so many times in recent days (not just here) that I am compelled to butt in:
"Silicon" is a semiconducting, somewhat metallic-looking, element, bluish in color; devices are now being made from silicon carbide.
"Silicone" is akin to an organic ketone compound, containing hydrogen and oxygen, but with the carbon atoms replaced by silicon. There are many different silicones, all of them oily in nature.
John Atkinson
Editor, Stereophile (and erstwhile chemist)
Yeah, and since we live in modern California where Holly Wood is going to kill Internet, we should use proper grammar.
By the way, I used before Tascam US-122 D/A that is 96 KHz/24 bit, but now had to switch to M-audio because it does not need M$ Windows and stinkin' firmware download each time I power it on.
Hi,
If you run class A and you have a signal just at the edge of class A then one transistor will experience near cutoff, that is it will experience near zero dissipation and the other a doubling of current, that is a doubling of dissipation.
As there is significant thermal resistance between the die and even the heat spreader (have a look at the thermal tracking of the so-called "thermaltrak" transistors) and more of it into the heatsink you can be quite sure that significant temperature changes of the die will be experienced, disregardless of heatsink size.
The precise thermal profile as it relates to the signal will differ for class A and Class AB amplifiers, but both experience significant modulation effects, as do Mosfet's incidentally.
The only saving grace in many cases is that BJT output stages are usually quite heavily degenerated, so the thermal modulation effects are swamped by the emitter resistors... Of course, the lower the emitter resistors, the lower the degeneration...
SE Class A Tubes anyone?
Ciao T
Ciao T
If you run class A and you have a signal just at the edge of class A then one transistor will experience near cutoff, that is it will experience near zero dissipation and the other a doubling of current, that is a doubling of dissipation.
As there is significant thermal resistance between the die and even the heat spreader (have a look at the thermal tracking of the so-called "thermaltrak" transistors) and more of it into the heatsink you can be quite sure that significant temperature changes of the die will be experienced, disregardless of heatsink size.
The precise thermal profile as it relates to the signal will differ for class A and Class AB amplifiers, but both experience significant modulation effects, as do Mosfet's incidentally.
The only saving grace in many cases is that BJT output stages are usually quite heavily degenerated, so the thermal modulation effects are swamped by the emitter resistors... Of course, the lower the emitter resistors, the lower the degeneration...
SE Class A Tubes anyone?
Ciao T
Ciao T
Not so. Averaging drops the analog detector noise floor, but it's perfectly possible (as I demonstrated in another thread and in some of my published research) to use a single impulse to overcome the objections of unspecified artifacts which somehow get averaged out.
Thorsten;
I have both SE class A tube and SE class A MOSFET designs. MOSFET design uses a source follower bootstrapped by another one, and is loaded on counter-modulated CCS. As you can see, variations of power dissipation of the device is minimal. As well as other parameters, such as capacitances.
For SE tube I found the best tube I could, it is 4P1L that is a copy of the tube designed by Telefunken for German army before WW-II. It worth it.
I have both SE class A tube and SE class A MOSFET designs. MOSFET design uses a source follower bootstrapped by another one, and is loaded on counter-modulated CCS. As you can see, variations of power dissipation of the device is minimal. As well as other parameters, such as capacitances.
For SE tube I found the best tube I could, it is 4P1L that is a copy of the tube designed by Telefunken for German army before WW-II. It worth it.
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