As a audio pro I hear many Dacs (and Adcs), or use them according to their individual properties and sound. But as a music loving private person I almost exclusively listen to the PD-DAC alone. It sounds relaxed and non-boring at the same time, musically exiting and non-artificial. I - and you will understand what i mean - more often forget what I am listening, just follow the music. I really appriciate that very much. Many thanks.
kotau
kotau
Peter,
From the pictures, it looks like the Patek uses a single dual secondary transformer with one rectifier board. Is that correct?
If that is the case, then I understand the 3 pin (wire) XLR connecting cable. What is the forth wire/pin used in the SE version? Maybe a separate chassis/mains ground? Something else?
In the LM3875 Kit you provide two dual bridge rectifier boards. Are most people using them in complete dual mono configurations with two transformers? Is there any point/use to connecting both rectifier boards to the same transformer?
From the pictures, it looks like the Patek uses a single dual secondary transformer with one rectifier board. Is that correct?
If that is the case, then I understand the 3 pin (wire) XLR connecting cable. What is the forth wire/pin used in the SE version? Maybe a separate chassis/mains ground? Something else?
In the LM3875 Kit you provide two dual bridge rectifier boards. Are most people using them in complete dual mono configurations with two transformers? Is there any point/use to connecting both rectifier boards to the same transformer?
DAC etc.
Hi,
DAC
The DAC seems like a great project for me, can anyone give me an indication of what the total building cost would be, excluding chassis?
Dual rectifiers and one transformer:
I have the PD LM3875 kit running with two rectifier boards and one dual sec transformer. I got rid of a humming type sound by connecting the two CHG-connectors on the amp PCBs. It works nicely, but I'm not sure if it is the best way though, any potential drawbacks doing this?
Peter?
M.A.
Hi,
DAC
The DAC seems like a great project for me, can anyone give me an indication of what the total building cost would be, excluding chassis?
Dual rectifiers and one transformer:
I have the PD LM3875 kit running with two rectifier boards and one dual sec transformer. I got rid of a humming type sound by connecting the two CHG-connectors on the amp PCBs. It works nicely, but I'm not sure if it is the best way though, any potential drawbacks doing this?
Peter?
M.A.
If it works without hum, it should be alright, I wouldn't be switching to one board then.
The DAC info was posted here: http://www.diyaudio.com/forums/showthread.php?postid=609968#post609968
The DAC info was posted here: http://www.diyaudio.com/forums/showthread.php?postid=609968#post609968
Peter Daniel said:
Is there any interference or interaction between channels if the two PS rails are bundled together into one cable, even if they have separate grounds?
I've always been curious about this and I know that the 47Labs Gaincard has two separate PS cables (one for each channel) connecting the Humpty to the Gaincard. I don't know if the effect of bundling everything into one cable is actually audible or not. Just wondering if you've tried both and notice a difference.
Also, I really like the look of a cleanly wired point-to-point tube amp, but I've always wondered how the mass bundling of the cables together might affect the channel separation, PS noise pick up, etc. I'm sure the science behind figuring this out is pretty basic, but it's still beyond a non-engineer like me at this point.
Best,
KT
So I blew am LM4780 chip and I'm trying to figure out what happened.
When I plugged in there was a audible pop and spark and a large chunk of the ceramic (?) on my LM4780 blew off. I think I may have connected the power supply board to the amplifier backwards (ie. V+ and PG+ on the PSU to V- and PG- on the amplifier). Would this have done it?
Peter, how much do you charge for a single LM4780 including shipping to Vancouver?
When I plugged in there was a audible pop and spark and a large chunk of the ceramic (?) on my LM4780 blew off. I think I may have connected the power supply board to the amplifier backwards (ie. V+ and PG+ on the PSU to V- and PG- on the amplifier). Would this have done it?
Peter, how much do you charge for a single LM4780 including shipping to Vancouver?
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I found when building one of the LM4780's, I measured a short between the heatsink and chip even though it had a mica washer. It turned out to be one the the screws touching a metal part of the chip body at the screw mounting slot. Added heatshrink over the screw in this section and all was well.
The LM4780 isn't the most friendy chip to mount and I found it best to use a plate over the face when mounting like the one in the pic.
You should always check for shorts to the heatsink before adding it to the case and firing up.
The LM4780 isn't the most friendy chip to mount and I found it best to use a plate over the face when mounting like the one in the pic.
You should always check for shorts to the heatsink before adding it to the case and firing up.
Attachments
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