It's not a good idea to use the digital volume control above 0. Generally filters are made to be as close to the clipping boundary as possible. The same applies to music, the recording level is adjusted so that digital clipping does not occur. In DAM1021 and others, the digital volume control is between the first and second stages of filtering, so by increasing the volume above 0, we can feed the second stage with a deformed signal. The only reason to use the +10 correction are filters that lose a lot on the first stage, e.g. a filter with 1 coefficient which loses 18dB
I think that the designer has assured that the pipeline has the ability to accommodate the +10 dB without compromising the quality... but maybe Sören would like to step in and say how it is...?
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The digital volume control is last, and yes, there are plenty of bit to ensure that when t.ex. it's being used for what it's there for, to increase volume on low level material, there are no quality loss....
OK thanks! The claim was that e.g. a signal of 0,5 dBfs would clip if you set the DAM tp + 10dB gain. Will it?
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OK, so not a compensation for weak gain in your system. If you set it to +10 and play normally produced CD of today, it will clip. Strange, I dont experience this - but I use digital volume in my player before the DAM and perhaps I only max that with low level recorded CDs...
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Last year I bought a dam1021 rev7, I already had the rev1 fully modded.
The new rev7 in stock already sounded better than the old rev1 modded.
Looking at the rev7 board, there's not much to be modified, Soeren already updated the vrefs and the clock PS.
The only thing that I see was adding better caps to the shift registers decoupling,
searching in mouser/digikey I found the new Kemet KO-CAP T520 tantalum-polymer caps.
The 100uF 6.3v in a 1411 package with only 15mOhm is a good candidate,
they can be soldered next to the biggest existing ceramic caps, there are 12 of those.
Attention: those Kemet T520 are polarized, it is needed to check the polarity for each cap (no logic on the PCB)
The new rev7 in stock already sounded better than the old rev1 modded.
Looking at the rev7 board, there's not much to be modified, Soeren already updated the vrefs and the clock PS.
The only thing that I see was adding better caps to the shift registers decoupling,
searching in mouser/digikey I found the new Kemet KO-CAP T520 tantalum-polymer caps.
The 100uF 6.3v in a 1411 package with only 15mOhm is a good candidate,
they can be soldered next to the biggest existing ceramic caps, there are 12 of those.
Attention: those Kemet T520 are polarized, it is needed to check the polarity for each cap (no logic on the PCB)
Attachments
I have dam1021 ver 7, it work well.
Today, when dam1021 power off I used a multi metre and saw that at position j7: Pin 1,2,3,4 are connected. This is unusual, in fact, there are only 2 and 3 connected. The positions j6 and j8 are normal.
ver 7 uses +-9v dc, is it correct?
Thanks
Today, when dam1021 power off I used a multi metre and saw that at position j7: Pin 1,2,3,4 are connected. This is unusual, in fact, there are only 2 and 3 connected. The positions j6 and j8 are normal.
ver 7 uses +-9v dc, is it correct?
Thanks
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Hi diyaudio friends
Just to let you know, I have three dam1021 boards for sale, at the moment they are reduced as an easter offer. Two brand new boards and one used board. If you are interested take a look at the swap meet or pm me.
Kind Regards
Phil
Just to let you know, I have three dam1021 boards for sale, at the moment they are reduced as an easter offer. Two brand new boards and one used board. If you are interested take a look at the swap meet or pm me.
Kind Regards
Phil
I can't send a PM yet because I'm new to the forum so would be grateful if you could PM me about the dam1021 boards, I might be interested in the used board.
Kind regards,
Andy
Kind regards,
Andy
Hello, I am interested in one new board. Could you please PM me about HW version and requested price ? Thank you !
@soekris
A suggestion for your board line DAMs: offer them optional without the resistors of the ladder soldered on the board, but with the unmounted resistors - perhaps with some excess amount of resistors.
So one could match the resistors before soldering.
OK, I know, soldering 100 tiny SMD resistors, tightly spaced, is not fun 🙄
A suggestion for your board line DAMs: offer them optional without the resistors of the ladder soldered on the board, but with the unmounted resistors - perhaps with some excess amount of resistors.
So one could match the resistors before soldering.
OK, I know, soldering 100 tiny SMD resistors, tightly spaced, is not fun 🙄
Hello all!
Does somebody knows where it is possible to take control board for dam2941 something like this:
https://www.diyaudio.com/community/...84-khz-dac-module.327381/page-10#post-5667887
?
Does somebody knows where it is possible to take control board for dam2941 something like this:
https://www.diyaudio.com/community/...84-khz-dac-module.327381/page-10#post-5667887
?