I'm having some trouble with the sound on the following hardware:

Chaintech 7nif2 motherboard
AMD 2500+ CPU
256 mb DDR 2700 ram
Pinnacle Studio Pro Tuner card

Everything is working fine except for the sound. I get the sound from the channel that is tuned in, but it is accompanied by crackling, hissing... etc. As if listening to a radio that is tuned just off of the station.

I've also tried a Hauppauge WinTV Go and got the same results.

Both of those cards use a line out/line in jumper cable to get sound into the sound card.

Ripped CD's sound fine, so I don't think it's the nvidia sound. I've noticed that the bttv Mini Howto says there is an msp3400 module that can be loaded. Since this Pinnacle TV card is stereo is it possible I need to load that?

Does anyone have suggestions?

I've determined that I should be loading msp3400 since the PCTV Pro has an MSP341G chip. But for some reason I just can't get it to recognize the chip. Here's some output from my dmesg command:

Linux video capture interface: v1.00
i2c-core.o: i2c core module
i2c-algo-bit.o: i2c bit algorithm module
i2c-core.o: driver i2c msp3400 driver registered.
i2c-core.o: driver i2c TV tuner driver registered.
bttv: driver version 0.7.104 loaded
bttv: using 4 buffers with 2080k (8320k total) for capture
bttv: Host bridge is PCI device 10de:01e0 (nVidia Corporation)
bttv: Bt8xx card found (0).
bttv0: Bt878 (rev 17) at 01:06.0, irq: 5, latency: 32, mmio: 0xde000000
bttv0: detected: Pinnacle PCTV [card=39], PCI subsystem ID is 11bd:0012
bttv0: using: BT878(Pinnacle PCTV Studio Pr) [card=52,insmod option]
tuner: probing bt848 #0 i2c adapter [id=0x10005]
tuner: chip found @ 0xc2
tuner(bttv): type forced to 21 (Temic NTSC (4039 FR5)) [insmod]
i2c-core.o: client [Temic NTSC (4039 FR5)] registered to adapter [bt848 #0](pos. 0).
i2c-core.o: adapter bt848 #0 registered as adapter 0.
bttv0: i2c: checking for MSP34xx @ 0x80... not found
bttv0: miro: id=18 tuner=2 radio=fmtuner stereo=no
bttv0: using tuner=21
tuner: type already set (21)
bttv0: i2c: checking for MSP34xx @ 0x80... not found
bttv0: i2c: checking for TDA9875 @ 0xb0... not found
bttv0: i2c: checking for TDA7432 @ 0x8a... not found
tvaudio: TV audio decoder + audio/video mux driver
tvaudio: known chips: tda9840,tda9873h,tda9874h/a,tda9850,tda9855,tea6300,tea6420,tda8425,pic16c54 (PV951)
i2c-core.o: driver generic i2c audio driver registered.
bttv0: PLL: 28636363 => 35468950 .. ok
bttv0: registered device video0
bttv0: registered device vbi0
bttv0: registered device radio0
bttv0: PLL can sleep, using XTAL (28636363).

Here is the contents of my bttv file:

alias char-major-81 videodev
alias char-major-81-0 bttv
pre-install bttv modprobe -k msp3400; modprobe -k tuner
options bttv card=52 tuner=21 pll=1 automute=0 debug=1
options tuner type=21 debug=1
options msp3400 once=1 simple=1 debug=1

What am I doing wrong here? Is it possible my tuner is blown?