[ltp] T43 and S/PDIF audio output

[Richard Neill]

Hi Dave,

I think you'd find a digital audio output on a docking station
http://www.thinkwiki.org/wiki/ThinkPad_Dock_II

Otherwise, I recommend the Behringer UCA202 which is a £25 USB audio 
interface. I've used a number of these, either for the optical or analog 
audio out,  This solution is nearly perfect in terms of eliminating 
interference from the CPU and ground-loop hum.

Aside: I have noticed on one very old amplifier (1970's vintage) that 
you can get squeaks - this arises from the combination of a 
high-frequency DAC and an amplifier with too high a bandwidth, combined 
with aliasing. This is a rare issue though.

HTH,

Richard

On 19/11/2020 11:01, Dave Woodfall wrote:
> Hello all,
> 
> I've been looking to see if I can get digital audio output from my
> T43, so that I can run jackd and connect it to my HiFi DAC.  At the
> moment I'm doing it from a desktop PC, which I would like to
> semi-retire.
> 
> According to modinfo snd_intel8x0 there is:
> 
> parm: spdif_aclink:S/PDIF over AC-link. (int)
> 
> What exactly is this AC-link?
> 
> The only audio sockets are the headphone and mic jacks.  Does anyone
> know how to capture (hopefully coax) S/PDIF output?
> 
> In addition, I have a free PCMCIA slot, 2 USB, PS/2 socket, RJ11
> modem socket, RJ45 NIC socket, parallel port, and external monitor
> output.  I do have a USB S/PDIF adaptor, but IIRC it is limited
> quality compared to coax.
> 
> More info:
> 
> Alsamixer does show any controls for S/PDIF out, but it does have an
> extra console driver, which I've not yet found a use for:
> 
> Card: ThinkPad Console Audio Control
> Chip: ThinkPad EC 1YHT29WW-1.06
> 
> Some lspci output:
> 
> 00:1e.2 Multimedia audio controller: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family)
>          Subsystem: IBM 82801FB/FBM/FR/FW/FRW (ICH6 Family) AC'97 Audio Controller
>          Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR
>          Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort-
>          Latency: 0
>          Interrupt: pin A routed to IRQ 22
>          Region 0: I/O ports at 1c00 [size=256]
>          Region 1: I/O ports at 1880 [size=64]
>          Region 2: Memory at b0000800 (32-bit, non-prefetchable) [size=512]
>          Region 3: Memory at b0000400 (32-bit, non-prefetchable) [size=256]
>          Capabilities: [50] Power Management version 2
>                  Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold
>                  Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
>          Kernel driver in use: snd_intel8x0
>          Kernel modules: snd_intel8x0
> 
> It also lists the modem which has a standard RJ11 socket.
> 
> Thanks for any info.
> 
> --
> Dave
> 
> Love is a snowmobile racing across the tundra and then suddenly it flips over,
> pinning you underneath.  At night, the ice weasels come.
> 	 --Friedrich Nietzsche
>