I was looking to your site and was ready to by some PCB's for amplifiers, but then on the NS webpage I found this:
http://www.national.com/pf/LM/LME49830.html
Is there any interest for you in such an amplifier? PCB's layouts for your other amps are very nicely done so I would like to see if you will do one for the new chip.
Because now I am drooling over that one.
http://www.national.com/pf/LM/LME49830.html
Is there any interest for you in such an amplifier? PCB's layouts for your other amps are very nicely done so I would like to see if you will do one for the new chip.
Because now I am drooling over that one.
The DACs are not listed as kits on my website, there is only short note in Latest News with links to pics: http://audiosector.com/
Contact me directly for current prices.
Contact me directly for current prices.
Yes, it is BNC, you can also install RCA if your cable is terminated that way.
To use Toslink at the DAC input you need to install toslink receiver and wire it p2p including voltage supply. Not a big deal really.
Below is the pic of one of the DACs with Toslink and source selector switch added.
To use Toslink at the DAC input you need to install toslink receiver and wire it p2p including voltage supply. Not a big deal really.
Below is the pic of one of the DACs with Toslink and source selector switch added.
Attachments
Transformer hum in DAC
Peter,
I have assembled your USB NOS DAC and am very happy with its performance.
One question.. there is a fairly audible 60hz hum that comes from the DAC audible from about a foot away. I assume it comes from the transformer. Is this normal, and should I be concerned? There is nothing in the signal path. Speakers are dead quiet when music is not playing. I have the DAC mounted securely to a 1" thick piece of wood which i suspect would dampen any physical vibration.
Peter,
I have assembled your USB NOS DAC and am very happy with its performance.
One question.. there is a fairly audible 60hz hum that comes from the DAC audible from about a foot away. I assume it comes from the transformer. Is this normal, and should I be concerned? There is nothing in the signal path. Speakers are dead quiet when music is not playing. I have the DAC mounted securely to a 1" thick piece of wood which i suspect would dampen any physical vibration.
Yes, the Hammond 50VA transformer is known to produce audible buzz under some circumstances. It may depend on DC content in your mains and also the way the PCB is mounted.
I prefer to keep the mounting srews loose; the DAC sounds better this way and the board tends to resonate less.
You may use some soft padding under wooden board as well.
I prefer to keep the mounting srews loose; the DAC sounds better this way and the board tends to resonate less.
You may use some soft padding under wooden board as well.
re hammond hum
Thanks Peter,
I'm glad to hear that I don't need to be concerned.
I tried loose mounting screws and see what you mean. It does sound a little better.
I also read in an old Black Gate technical report that they recommended gluing radial BG caps to the pcb reducing the vibration transfered to the insides. I had already soldered the caps in place, so I just took a glue gun and put a little glue around the base of the caps and the pcb. I don't know if I imagine it, but I am convinced that there is a significant improvement in the sound. It is like everything is even more precise and defined. Imaging is razor sharp, and more space around individual instruments. I can't say how much the effect comes from the DAC, or the chipamp as I did the same to the caps on the chip amps and power supply at the same time. It would be interesting to know if anyone else has had a similar experience.
Thanks Peter,
I'm glad to hear that I don't need to be concerned.
I tried loose mounting screws and see what you mean. It does sound a little better.
I also read in an old Black Gate technical report that they recommended gluing radial BG caps to the pcb reducing the vibration transfered to the insides. I had already soldered the caps in place, so I just took a glue gun and put a little glue around the base of the caps and the pcb. I don't know if I imagine it, but I am convinced that there is a significant improvement in the sound. It is like everything is even more precise and defined. Imaging is razor sharp, and more space around individual instruments. I can't say how much the effect comes from the DAC, or the chipamp as I did the same to the caps on the chip amps and power supply at the same time. It would be interesting to know if anyone else has had a similar experience.
removed the sleeve from the coupling caps
Right you are again! With the sleeves removed from the coupling caps there is yet another improvement in clarity. This mod combined with securing the BG caps to the pcb is enough to make you listen to all your music as if on a new system. The renewed transperancy is causing me to reevaluate favorate cuts.
Right you are again! With the sleeves removed from the coupling caps there is yet another improvement in clarity. This mod combined with securing the BG caps to the pcb is enough to make you listen to all your music as if on a new system. The renewed transperancy is causing me to reevaluate favorate cuts.
I got my lm4780 kit and it looks great. Sorry to change topic but... I think my input resistors are 220 instead of 270?? red red brown black brown. I metered them at 220 aswell(crappy multimeter). should i go ahead and use them? I just checked my other kit and they have 220 also. Thanks for the help in advance!
premium parts for chip amp
Peter,
Is it possible just to buy premium parts such as,
caddock resistors,
riken resistors
panasonic caps
mur diodes
for the LM3875 chip amp?
if yes how much, email me prices for stereo pair to me tean_tan@hotmail.com
Peter,
Is it possible just to buy premium parts such as,
caddock resistors,
riken resistors
panasonic caps
mur diodes
for the LM3875 chip amp?
if yes how much, email me prices for stereo pair to me tean_tan@hotmail.com
Can anyone provide any additional location dimensions for the 6 mounting holes in the gold DAC board? ie definition of the hole pattern?
I waded through a zillion posts to find that the holes are 22 mm from on end of the PCB and 25 mm from the other end, but I'm still in need of the width spacing as well as the location of the center holes.
Thanks in advance.
I waded through a zillion posts to find that the holes are 22 mm from on end of the PCB and 25 mm from the other end, but I'm still in need of the width spacing as well as the location of the center holes.
Thanks in advance.
The sizes of the SPDIF and USB DAC boards are exactly the same: 187 x 68mm and the assenbled board will fit into standard 2 x 3 aluminum tubing.
The front of the board is where RCAs are mounted. The hole spacing is 18, 94 and 170.5mm from the front. The side to side distance (on center) is 61mm
The front of the board is where RCAs are mounted. The hole spacing is 18, 94 and 170.5mm from the front. The side to side distance (on center) is 61mm
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