Damn, i hoped that maybe some of the caps with really small leads (0,45mm diameter) would work, but then that is not the case i guess.
Also, what was the recommended ESR value for each of the 4x470u (or 4x560u) to work optimally with "lowresmod"?
Also, what was the recommended ESR value for each of the 4x470u (or 4x560u) to work optimally with "lowresmod"?
Yes, I've disassembled an old SATA cable which had 26 and 28 AWG wire.
Matched perfectly after removing the paint from the vias with a needle.
Some vias are smaller than others, those around the clock were a little smaller than around the shift registers.
I just got finished with the first build of the year!
Rev2 dam1021, powered by a hotrodded DCB1 (~500mA CCS) which also buffers the DAC's raw outputs and provides a muting relay. The DCB1's input impedance is set to about 18k, roughly 30 times the dam's output impedance. Digital inputs are diyinhk Toslink and XMOS USB module, the latter and the dam's isolated i2c inputs are powered by a BIB 3.3V regulator (~200mA CCS). The transitors of the regs are bolted to the chassis' bottom to spread the heat. Neat.
The digital interconnects are made from 10cm CAT5e twisted pairs. Signal interconnects are RG316/U.
The dam1021 is stock for now, but I'm planning on trying different mods some day, we'll see...
It took me about three days to build and it's playing sweet, sweet music as I'm typing. So far I really like what I'm hearing 🙂
Rev2 dam1021, powered by a hotrodded DCB1 (~500mA CCS) which also buffers the DAC's raw outputs and provides a muting relay. The DCB1's input impedance is set to about 18k, roughly 30 times the dam's output impedance. Digital inputs are diyinhk Toslink and XMOS USB module, the latter and the dam's isolated i2c inputs are powered by a BIB 3.3V regulator (~200mA CCS). The transitors of the regs are bolted to the chassis' bottom to spread the heat. Neat.
The digital interconnects are made from 10cm CAT5e twisted pairs. Signal interconnects are RG316/U.
The dam1021 is stock for now, but I'm planning on trying different mods some day, we'll see...
It took me about three days to build and it's playing sweet, sweet music as I'm typing. So far I really like what I'm hearing 🙂
Attachments
hi Guys, need some quick help. I have most of the stuff to start the build (power supply, tranny, input/ selection boards etc). I wanted to see if folks have any success in getting a cable for software interface for updating firmware/ filters etc. thanks
ps: posted on the main forum but wanted to put it here as well to see since this is more geared towards implementation
ps: posted on the main forum but wanted to put it here as well to see since this is more geared towards implementation
You'll do the mods when your honeymoon period ends. Your power supply setup and noise control measures are easily one of the best I've seen on here but its a shame to say that even a transformer fed dam1021 with the mods will be better than a stock one fed with even the cleanest power possible...
I'm using a ATEN USB to Serial RS-232 Converter, Model UC-232A
Bought on ebay.
Wiring info on my blogger page
my dam dac blog
I agree, with mods this dac rocks.
BTW, since you're using the raw output, you can remove the output opamps that you're not using.
That's a pretty simple mod.
thanks Ryssen and randytsuch, appreciate the help. randytsuch, the directions on your blog are very helpful, appreciate the write up
Hello.
My dam1021 are not able to lock usb signal after it have been power off for 2-3 days.
Only way to get it to work again is to reupload the fw (0.99).
I haven't done anything with the dac during power off.
Anyone have seen this problem?
My dam1021 are not able to lock usb signal after it have been power off for 2-3 days.
Only way to get it to work again is to reupload the fw (0.99).
I haven't done anything with the dac during power off.
Anyone have seen this problem?
You can use dime-a-dozen usb to 3.3V TTL serial adaptors since the last firmware update. A no-brainer since they are placed on the dirty side of the 3.3V isolators, unlike the RS232 level serial port which is not isolated in any way. (unless one uses some charge pumped isolated adaptor)
I'm using a pair of these specific ones for my balanced setup.
http://www.ebay.ca/itm/FTDI-FT232RL...200730?hash=item567bfa7bda:g:WpMAAOSwEetWAiow
I don't believe so. I kept mine with my latest balanced incarnation and found that they make a good 300ohm+ headphone amp with plenty of headroom for most things. I wired both buffered +/+ outputs of each balanced dam to a 4 pin XLR jack which I plug my headphones into. Instant truly balanced headphones from independent dac's. The unbuffered balanced outputs go straight into nc400's.
To be honest, I never compared before and after.
I knew I was just going to use the raw output, and I don't like having "extra" stuff on a board that I'm not using, especially active stuff. I know that having those opamps on the dac certainly won't improve things, so off they went.
I do remember someone saying removing the opamps improved performance.
Also, without the opamps, you can use a lower A+ and A- voltage. Without the opamps, you just need a high enough voltage to power the +5 and -5V regulators. +A also powers the +3.3V and 1.2V regs, but they can run from a lower voltage.
Just found in Soekris EU site that the dam1021-02 0.02% rev.3 is about to launch by the end of this month. Could Soren briefly describe what's changed compare to rev.2? Thanks.
I'm having problems with XMOS USB audio replay, there are clicks and pops every other second. Over Toslink (SPDIF) it's working fine.
I've started a new thread here: http://www.diyaudio.com/forums/pc-b...dio-experiencing-clicks-pops.html#post4572320. Maybe someone has had a similar issue or has an idea how to tackle this?
I've started a new thread here: http://www.diyaudio.com/forums/pc-b...dio-experiencing-clicks-pops.html#post4572320. Maybe someone has had a similar issue or has an idea how to tackle this?
Problem solved: http://www.diyaudio.com/forums/pc-b...dio-experiencing-clicks-pops.html#post4575592
It appears that an intended contact between the USB port's housing and the grounded enclosure was the cause. Fixed with some heat shrink tubing 🙂
Another view of my dual mono dam1021 raw balanced setup.
Buffered outputs go into a 4 pin XLR output for headphones.
Raw unbuffered via 3 pin XLR's to NC400 modules.
Dual TTL serial converters for full PC control of both dam boards.
USB hub allows single cable going to the PC for both serial converters and Amanero.
Bipolar +/- 13.5VDC from tracking shunt regulator with LM129AH reference can.
Various mods used:
Transistor super regulators in place of series resistors for 4v vref's
1500uF per vref and 3.3v. 47uF ceramic near clocks.
1200uF for Amanero 3.3v ISO. 680uF for 5V USB power.
I'm extremely pleased with the overall result. These dam boards are nothing short of fantastic, especially when given a bit of modding love.
Buffered outputs go into a 4 pin XLR output for headphones.
Raw unbuffered via 3 pin XLR's to NC400 modules.
Dual TTL serial converters for full PC control of both dam boards.
USB hub allows single cable going to the PC for both serial converters and Amanero.
Bipolar +/- 13.5VDC from tracking shunt regulator with LM129AH reference can.
Various mods used:
Transistor super regulators in place of series resistors for 4v vref's
1500uF per vref and 3.3v. 47uF ceramic near clocks.
1200uF for Amanero 3.3v ISO. 680uF for 5V USB power.
I'm extremely pleased with the overall result. These dam boards are nothing short of fantastic, especially when given a bit of modding love.