=== jta_ is now known as jta === Lump|AFK is now known as LumpOfCoal [22:00] zequence: im not an electornics expert [22:00] so we dont have to talke about taht in the main channel [22:00] zequence: i dont care [22:00] im just saying, i ge more noise at lower latency [22:00] why? im assuming something is doing more at lower latency [22:01] is it power? [22:01] i dont know/care [22:01] hypothesise away, but i assue you im not tyring to be "correct" [22:01] im just stating what i have seen [22:01] I'm not making any claims that are "hypothetical" [22:02] Just narrowing down what could and what could not be the cause [22:02] sure [22:02] I'm only interested in solving the problem [22:04] I've sometimes experienced that a screen can cause noise to audio devices. The whiter the color, the more noise [22:04] And it has happened that a hard drives activity has leaked into the audio signal as well [22:05] In both cases I would think it's some sort of ground problem [22:05] yup [22:05] i would hypothesise a power issue there as well [22:07] If the CPU activity is audible, then it kind of sounds like the same thing. I was jusr surprised that low latency would be that audible, as it's not really that much more CPU intensive. If it is a ground problem in this case, it would make sense that anything CPU intensive, at any latency would give noise [22:07] Just that there might be more noise at lower latencies when the PC is idle [22:08] i dont think its cpu activity [22:08] its a constant noise [22:08] you start jack at that latency, and its pretty steady [22:08] i high pitch whine [22:08] its odd [22:09] i solved it much the same way though.. by looking into grounding [22:09] holstein, The PS for the FW unit may be a switcher. [22:09] holstein: You said that the noise increased in volume at lower latencies. Does the pitch change too? [22:10] zequence: i dont remeber that.. but i dont think so [22:10] i think it ws the same pitch and louder [22:11] Sounds like the power supply [22:11] Small switching power supplies have gotten cheaper... I see them even in wall warts [22:12] It's just that I don't see how the latency would affect the FW power supply [22:12] if it causes the device to pull more power [22:12] *if* [22:12] If it is an old unit, I would think the caps are drying out. [22:12] But, how would it do that? It's a constant stream of data, no matter which latency [22:13] The FW unit fills a buffer and sends it every so often, low latency means the cpu in the FW unit has to deal with that part of things more often [22:14] len-1304: Isn't that done in the CPU? [22:14] the buffering, I mean [22:15] zequence: i think you are assuming a constant stream of data.. maybe its not constant? [22:15] in not sure [22:15] It is a constant stream, but it's also buffered [22:16] lower latencies means smaller buffer sizes [22:17] I'm just assuming the buffering is done in the CPU, and not in the audio device. === LumpOfCoal is now known as Lump|AFK [22:24] AFAIK, an audio device sends and receives one sample at a time, following the clock [22:24] i wish i knew more about it [22:25] If you increase samplerate, the rate at which samples are sent/received increases [22:44] zequence, (just had lunch) the FW unit also buffers (as does the ice1712) and sends a bufferfull of data at a time. The driver tells the IF how big the buffers are that it wants. [22:44] That is why there is a lower limit to buffer size for any IF. [22:46] len-1304: How about a higher limit? [22:46] While jack has a limit of 4096, OSS can go higher [22:47] But perhaps the sound server makes up for it [22:47] That would be a jack limit then. [22:47] I wouldn't expect audio devices to be limitless anyway [22:47] The bigger the buffer used the more shared memory must be set aside [22:49] But I have three audio interfaces, the lower limit on each is different (-p128, -p64, and -p32) Jack will not even start if I try to use less... because jack tells alsa to ask the device to set a smaller buffer size than it can and the device refuses (sends an error back)