~5% of packages and letter mail destined to my house via Canada Post go to another address, and we seem to have a new carrier every few weeks.
My entire neighbourhood complains endlessly and they just send out a different moron.
If my neighbour hadn't noticed the package and drove over it, it would have been very expensive. Next time I'll pay a real courier to do it right. Gladly.
Also, Amazon Prime includes free 2-day shipping via UPS, so that is always my first choice for purchases now. They drive right to my door as late as 8pm and smile and hand me the package.
My entire neighbourhood complains endlessly and they just send out a different moron.
If my neighbour hadn't noticed the package and drove over it, it would have been very expensive. Next time I'll pay a real courier to do it right. Gladly.
Also, Amazon Prime includes free 2-day shipping via UPS, so that is always my first choice for purchases now. They drive right to my door as late as 8pm and smile and hand me the package.
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I saw that, but I have no idea what the master/slave stuff means.
The settings for the different frequencies are pretty straightforward, but I have no idea what the advantage of one frequency has over another.
I just read the datasheet regarding the AM avoidance switching frequency. Perhaps I'll try a few different settings later today, but it seems there is no way to avoid the entire AM spectrum.
Although, it seems there is only one AM station in the area, which is 610kHz, so it should be easy enough to avoid.
Wait a second... is the only benefit of this to avoid my amp interfering with reception of AM radio? If so, I do not care. I do not listen to the radio.
Or, is it so that AM radio does not cause noise in my amp?
Or, both?
Although, it seems there is only one AM station in the area, which is 610kHz, so it should be easy enough to avoid.
Wait a second... is the only benefit of this to avoid my amp interfering with reception of AM radio? If so, I do not care. I do not listen to the radio.
Or, is it so that AM radio does not cause noise in my amp?
Or, both?
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I ship the cards with a ~2 second unmute delay, PLIMIT set to the highest setting, 26dB gain, 1MHz switching frequency and BD modulation mode.
AM avoidance just sets the switching frequency of the amp. You'll want to do this to keep the switching frequency or harmonics from landing on or near the AM radio frequency you want to receive... not really a big deal with this card.
Unless you're synchronizing the amp to an external clock (or another clock) use master mode. Otherwise the amp won't output any audio.
AM avoidance just sets the switching frequency of the amp. You'll want to do this to keep the switching frequency or harmonics from landing on or near the AM radio frequency you want to receive... not really a big deal with this card.
Unless you're synchronizing the amp to an external clock (or another clock) use master mode. Otherwise the amp won't output any audio.
I figured you shipped it with the settings at a reasonable "just works" configuration. I guess I was right. I don't know if I'll bother changing anything.
Is there a disadvantage to higher gain settings? I mean, I know the system will play louder with less pre-amp "volume" but will this cause more distortion or greater chance of clipping? Or are there other things I need to consider when selecting the gain? I've read Mr. Pass's article on gain structure, but most of it went over my head.
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Yes more noise like you reported! Try the lowest gain instead
I like to run the lowest gain setting that will play loud enough. I have an Arcam rDAC which prefers spesific impedances to sound dynamic. Changing the input impedance to preferred impedance for that dac usally increase the dynamics. Not very scientific but its seems to hold true for that dac.
White noise also seems to be a bit lower in some cases with low gain.
I like to run the lowest gain setting that will play loud enough. I have an Arcam rDAC which prefers spesific impedances to sound dynamic. Changing the input impedance to preferred impedance for that dac usally increase the dynamics. Not very scientific but its seems to hold true for that dac.
White noise also seems to be a bit lower in some cases with low gain.
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Yes more noise like you reported! Try the lowest gain instead
I like to run the lowest gain setting that will play loud enough. I have an Arcam rDAC which prefers spesific impedances to sound dynamic. Changing the input impedance to preferred impedance for that dac usally increase the dynamics. Not very scientific but its seems to hold true for that dac.
White noise also seems to be a bit lower in some cases with low gain.
Interesting. I will try the lowest gain setting. My pre-amp is active, but through most of the volume range it acts as an attenuator. It will be interesting to see how the sound is affected when I move into the range where the pre-amp is actually amplifying. I suspect this will be worse, but who knows. I might not even get that high on the volume dial before it becomes too loud, even with 20dB gain on the TPA.
switching frequency setting influences THD too, or so does TI say
I've looked through the graphs included in the datasheet, but I cannot see where that data is presented. I cannot find mention of it in the text, either.
Im not using a chassis. And have been testing the wiener with my Heil which are very sensitive tweeters. Im not hearing any noise with my ear pressed against it. Might want to look into your PSU or change the AM avoidance freq on the dip.
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Thanks for the feedback. I will play with it a bit more. I do plan to build a linear, regulated supply at some point.
I do know that the rest of my system is dead quiet because I recently tried a $3 TDA7297 "lunch money" amplifier and I couldn't hear any noise at all. It was quite remarkable, actually. This was with a regulated linear supply that I slapped together for testing. I will build a more refined version of that supply for the Wiener.
Even with the slight bit of noise (which I estimate to be down around -90dB) the amp sounds very, very good.
I've changed the switching frequency to 500kHz. No change in the "noise". I use quotes here because on closer listening, it is much more like hum. As in, 60Hz hum.
I could easily live with this, since I cannot hear it unless I try, but I am really curious to see what a linear supply will do for the sound.
20dB gain is also much better. It allows for finer adjustment on my pre, over a wider breadth of its range, and it still doesn't reach its max volume before my ears reach theirs.
I could easily live with this, since I cannot hear it unless I try, but I am really curious to see what a linear supply will do for the sound.
20dB gain is also much better. It allows for finer adjustment on my pre, over a wider breadth of its range, and it still doesn't reach its max volume before my ears reach theirs.
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Thanks for the tip. I really don't see this as a huge issue. The noise on the recording media of the tracks I am playing is 10 times more audible than the system noise.
Eva Cassidy just hit 97.6dBC on a high note of Fields of Gold. Sooooo daaaaaaamned clean! All of this and the chip is running at 38C.
I have found my "summer amp".
Eva Cassidy just hit 97.6dBC on a high note of Fields of Gold. Sooooo daaaaaaamned clean! All of this and the chip is running at 38C.
I have found my "summer amp".