Audiophile USB to PCM

Edsilva - I mod a LOT of different DAC's, and upsampling engines, including the P-1A, Benchmark DAC-1 and the DIP, so I get to hear the output quality of these hardware and firmware upsamplers.

The Secret Rabbit Code (SRC) upsampler with Foobar2000 is simply the best that I have heard, when played through my Off-Ramp converters. Software upsampling will always be more flexible for generating upsampling algorithms. Hardware and firmware implementations have limitations that software does not have. These algorithms are not trivial to implement in hardware, even using DSP engines.

Steve N.
Empirical Audio
Manufacturer/modder

Interesting--glad you chimed in. Maybe I'll look at my Waveterminal again to see if it is capable of something better than 16/44 and give it a go.

I'm still a bit puzzled by the "why," however. In my admittedly simplistic view, you need software and hardware. Sure, PC software is pretty flexible, but so is a lot of firmware; I upgrade various bits of it across my network all the time. And, I think most processors these days are built to be upgradeable with software downloads.

I concur that the collective minds of sourceforge may have built a better algorithm with SRC; I just don't know. But, you still have the hardware issue...

I guess I think of a PC like a good mass market "please everyone" car like a Honda Civic. Sure, you can tack on some upgrades, open up the intake and exhaust, put on better rubber, tweak the CPU, and you might end up with a pretty quick car that might even beat something labeled as a sports car, like a BMW coupe. You can go even further, rip out the excess weight in the interior, implement engine upgrades, install nitrous, tweak the suspension, improve the aerodynamics, and maybe end up with a car that will take a real sports car, like a Carrera. But, I just have a hard time seeing one of those street racers take on something built from the ground up, no compromise, as a sports car like the Lotus Elise or a Dodge Viper.

Anyway, that was my thinking. Perhaps computers and cars aren't a good analogy. Anyway, guess if my WT24 will pass 24/96, I'll find out...

How is transit stock? Pretty good quality?

It only has Toslink out - not so great.

Why is the mod necessary and how do we do it?

The mod changes the Toslink to coax, improves the edge-rates, isolates with a pulse transformer and matches the impedance precisely. It also adds a modified Superclock3. Quite technical, this mod, and a LOT of surface-mount work.

Also, can you explain how to upsample in foobar or itune?

This is explained on the computer audio page of my website:
http://www.empiricalaudio.com

Do they do it automatically, or do we have to do something?

You have to select resampling in Foobar preferences - see the website for instructions and screen-shots.

Steve N.
Empirical Audio
Manufacturer/modder

Edsilva - I look at a PC as a general purpose tool, and a very flexible one. It is like having a set of adapters and sockets with a socket wrench rather than a set of open-end wrenches. The sockets can get into tighter spots and the sockets are interchangeable. You can change the way that the socket wrenches work and their configurations. The open-end wrenches are good, but have limitations. They only work one way with fixed sizes.

DSP processors have certain ways of doing data manipulation. They can be faster at doing some things than software. Software really has no functional limitations, just the size and latency/speed of the code. Hardware is the most limiting for implementing upsampling codes. This is why hardware implementations are usually outdated quickly and do not sound as good. Not that a good code could not be implemented in hardware.

Onhwy61 - I have used and modded the Big Ben. I found it to work exceptionally well for reducing jitter. The effect was immediately noticable. Deciding whether it is worth the price for what it does is up to each individual. It also has the benefit of displaying the input sample rate.