TSS Two Chassis Super DAC

Gawdawmighty!

@tedsmith
Forgive me if I’ve already suggested/inquired about this (I don’t remember).
Speaking of modularity, would it make sense for TSS to have an isolated input module (which could still be internal to the digital box)? By that I mean a shielded board, with its own power supply, (and possibly some reclocking, thought that might not be necessary) to which all the digital inputs are attached. This board would then be connected to the digital processing board via a high-speed fiber optic cable. Since the digital board is already going to be connected to the analog box via another fiber optic cable, this completely isolates the digital board galvanically, with respect to RF if the shielding is good enough, and does a rough pass at cleaning up input jitter (again the reclocking might not be necessary because of the design of the DS/TSS).

For that matter, the upcoming PS Audio Music Server could have a similar module for its outputs.

Yeah I did experience some of that early behaviour. I think the USB receiver itself did a scalar multiply on the PCM data before handing it off via I2S.

USB Audio Device Class spec most definitely includes a standard hardware volume property which can be read or set by software. You’ll need to override the behaviour of the XMOS or whatever USB chipset so that instead of modifying the data stream it just passes the values on out of band of the audio. I think the DS doesn’t have any data channels (I2C etc) from the XMOS to send that info on, so the TSS would need to incorporate those somewhere.

I suspected there might be a USB volume property, but I didn’t know for sure, thanks.
There is much more interconnectivity in the TSS so we can send more real time data around as well as more control data.

1 Like

Fantastic discussion on the development of a component before it hits the market. The level of detail being discussed must definitely be a first for any industry. Please carry on, I always want to learn about my products; and, it is fascinating and exciting that I have a chance to witness their development considerations before they are made available.

1 Like

Who is writing the PIC code in TSS, Ted or PS Audio?

I expect that the TSS will be unveiled at an exhibition venue.
Will it be ready for Munich (May 19)?

The TSS has separate (optionally) galvanically isolated inputs and outputs. There isn’t much need to separate things in the digital box from other things in the digital box. Right now there’s more electrical noise (and to a lesser extent jitter) leaking from the digital box to the analog box than we’d like, but the in the TSS the optical connection to the analog box and reclocking there will take care of any such jitter from the digital box.

Gotcha. I just figured that this could be a way of absolutely eliminating electrical noise from input sources (no matter the format), which are of course out of the DAC’s control.

The answer won’t mean what you think it will :slight_smile: There will be a PIC on the digital board with the FPGA, but it will be used to control the FPGA and talk to the outside world. I’ll write the code for the PIC. There will be a link to the display/UI with it’s own processor (which is not a PIC) and PS Audio will be doing that code. Not that I don’t take your point.

Perhaps there’s a misunderstanding but each input will be electrically isolated from all other inputs and the digital box’s ground. The sub systems that need power have (well filtered) isolated power supplies. There will be a configuration to ground any of them for the systems that that may help.

So TSS has a display, right? That is a new tit-bit of information.

No I don’t think it’s new. I have explicitly stated that the analog box won’t have a display. Paul has explicitly talked about the new display technology.

Perhaps a confusion is that the display won’t literally be in the digital box - there will be a wall between it and the rest of the digital box. But to the user the display will be essentially part of the digital box.

1 Like

Needless to say the display in previous products has been a cause of grief for some people. A new display technology that will overcome the previous display problems? I hope the learning curve of a new technology isn’t of itself a potential problem.

I would prefer an app over a display but this implies an Ethernet connection.

The new display definitely addresses many of the concerns and problems of the old display. The prototypes I’ve seen look great. The sensitivity of the touch would be much more consistent. The supported quality of the graphics is much higher. The processor is much faster. There will be more real estate so you won’t have to be so precise when gesturing. We intend to allow more nuanced user control of what’s displayed (if anything) while playing. And not least of all there won’t be any code shared with the old display.

2 Likes

Paul definitely likes the idea of an app as well. There will be an optional Ethernet connection to the display. It will be able to be disabled in the hardware for people that don’t want the associated noise (or hassle.) Conversely there will be an option to use it to upgrade the software, one again optional and controlled by the user. All of this is transparent to the rest of the digital box, e.g. the board with the FPGA, etc.

1 Like

I don’t mean to imply that there definitely will be an app - I don’t know. How the future music server/Octave, what ever interacts with the TSS and how they are all/each controlled is all in PS Audio’s hands.

Some inspiration:

1 Like

Or this…
32