That's a 47k Pullup resistor to Pin 20 of the DAC (note: you also need to connect pin 20 at the chip itself to pin 20 on the adaptor board. It's not connected by a trace on the board itself.).
This changes the mode of the PLL in the 8416 to optimise the jitter performance for delta sigma converters.
It's described a few pages back in this thread. Post 53 onwards.
Kevin
This changes the mode of the PLL in the 8416 to optimise the jitter performance for delta sigma converters.
It's described a few pages back in this thread. Post 53 onwards.
Kevin
I'm using an AD826 at the moment but I'm planning to compare a few Op Amps now the filter circuit is behaving and see what sounds best.
Regarding the phono stage do you mean following the Op Amp filter? I have only a volume control between the output of the filter Op Amp and the input to my valve power amps.
Kevin
Regarding the phono stage do you mean following the Op Amp filter? I have only a volume control between the output of the filter Op Amp and the input to my valve power amps.
Kevin
Hi fred,
There is no DC offset (well, no more than a couple of millivolts) on the output of the first stage if you use the correct filter components.
The second Op Amp stage seemed unnecessary to me. A couple more electrolytics in the path and the Op Amp was configured to give only a tiny bit of gain IIRC. I just figured "less is more". Might as well take the output from the first stage.
Kevin
There is no DC offset (well, no more than a couple of millivolts) on the output of the first stage if you use the correct filter components.
The second Op Amp stage seemed unnecessary to me. A couple more electrolytics in the path and the Op Amp was configured to give only a tiny bit of gain IIRC. I just figured "less is more". Might as well take the output from the first stage.
Kevin
Kevin, this is a geat help for new modders of this DAC!
Everything looks OK to me, except who you wrote:
I guess you mean "coupling capacitors", meaning the electrolytics.
You haven't done the changes to R2/C22/C23. This change will improve the PLL. I found it to improve detail and sound stage on some (couldn't notice a huge different on most) music material I 've listened to. But since I only have one DAC I can't make any proper AB-testing, so the difference may of course only be in my imagination!
Everything looks OK to me, except who you wrote:
I guess you mean "coupling capacitors", meaning the electrolytics.
You haven't done the changes to R2/C22/C23. This change will improve the PLL. I found it to improve detail and sound stage on some (couldn't notice a huge different on most) music material I 've listened to. But since I only have one DAC I can't make any proper AB-testing, so the difference may of course only be in my imagination!
gabrielbecheanu said:
Cs8416 in hardware mode will indicate on pin16 state low, if sample rate is under 48K and in state high if sample rate is over 88.1K. You can use this to drive a LED trough a bjt.
For more input info you need to run CS8416 in software mode and use GPO ports pin 18,19,20 and decode them trough a microcontroller.
For HDCD you need a decoder like PMD100.
Regards,
Tibi
luxury54 said:
Well, in fact LM4562 is by far superior to AD826 especially in this application. There are other applications where AD826 will do a better job, but not here.
In my opinion to associate huge slew rate with great sound and detail it's a mistake.
The proof are tubes who have, compared to SS, a lower slew rate.
Regards,
Tibi
tvicol said:
Well, in fact LM4562 is by far superior to AD826 especially in this application. There are other applications where AD826 will do a better job, but not here.
In my opinion to associate huge slew rate with great sound and detail it's a mistake.
The proof are tubes who have, compared to SS, a lower slew rate.
Regards,
Tibi
Tubes control electron flow in a vacuum. Transistors control either holes or electron flow in semiconductor - I think this may be unfair comparison. Tubes may sound "better", but properly implemented 3-gainstage-only transistor amplifiers hard wired can do fantastic job as well.
The slew rate is only one area where AD826 is better compared to LM4562.
I think that many people go straight to operational amplifiers and start replacing them. 90% of the time, the equipment in question sounds harsh, sterile with cheap components, bad grounding topology and noisy power supply rails. It is completely understandable that LM4562 will sound "better" in such equipment – because it really masks and rounds the sound to be more listenable – and that’s all! AD826 OP will emphasize harsh sound and will be immediately labelled as "not suitable for the job" or "bad sounding".
However, if you pay attention to low ground plane noise, low power supply noise, high quality components - than AD826 is one of the best out there. In fact, AD8066 is even better properly implemented.
Just my $0.02
Boky
I think all this talk of LM4562 vs. AD826 is - at the end of the day - purely a matter of taste. Everyone has different hearing, different listening rooms, speakers and so on. I love the LM4562, but don't doubt that in some systems it might not sound as good. That's the beuaty of DIY no? We can tailor the sound exactly to our tastes/systems.
I'm having major problems desoldering the components on my board. I had the 'bright' idea of using nail-clippers, and snipping one end of all the resistors. Holding a soldering iron to the joint and pulling out the end holding most of the resistor was a piece of cake - so easy. However trying to get the tiny bits of component wire out on the other side is causing me to invent new swear words! If i'd been intelligent I would have got a Dremel and cut the resistors neatly in half, then it would have been easy to heat each side and pull out each half of the cut components. I've tried flowing new solder into the clogged up holes and poking enamalled wire (so it doesn't stick) through to clear the holes but that only works 50% of the time. I have a feeling one of the holes is ruined. I may have to build a perf board substitute and take the output directly from the DAC chip legs....
- John
I'm having major problems desoldering the components on my board. I had the 'bright' idea of using nail-clippers, and snipping one end of all the resistors. Holding a soldering iron to the joint and pulling out the end holding most of the resistor was a piece of cake - so easy. However trying to get the tiny bits of component wire out on the other side is causing me to invent new swear words! If i'd been intelligent I would have got a Dremel and cut the resistors neatly in half, then it would have been easy to heat each side and pull out each half of the cut components. I've tried flowing new solder into the clogged up holes and poking enamalled wire (so it doesn't stick) through to clear the holes but that only works 50% of the time. I have a feeling one of the holes is ruined. I may have to build a perf board substitute and take the output directly from the DAC chip legs....
- John
johnm,
I managed to get the components out by pulling on side of the component with a pair of pointed pliers and heating on the solder side with a 50W soldering iron, tip 3.2mm. Like you, I didn't manage to clean all the holes as some of them are connected to a (massive..) ground power plane.
When mounting the new components in the still filled holes I heated the pad from the solder side while gently pressing on pin at the time from the component side. In a couple of hoes I had to heat from the component side so I could heat the leg of the component at the same time.
It took me close to 2 hours to do the mod's, which is 4-5 times longer than it would normally!
Cutting off components completely is a well proven and usually well working method, at least for IC's. I believe one cause for our difficulties may be that the holes are just a tad too small for the legs of resistors and capacitors.
I agree with you re. LM4562. I have completed my comparison between NE5532, LM4562 and OPA 2134 and believe the LM4562 sound perhaps a fraction "better" than NE5532. But it's nothing I would enter a new argument about....
I managed to get the components out by pulling on side of the component with a pair of pointed pliers and heating on the solder side with a 50W soldering iron, tip 3.2mm. Like you, I didn't manage to clean all the holes as some of them are connected to a (massive..) ground power plane.
When mounting the new components in the still filled holes I heated the pad from the solder side while gently pressing on pin at the time from the component side. In a couple of hoes I had to heat from the component side so I could heat the leg of the component at the same time.
It took me close to 2 hours to do the mod's, which is 4-5 times longer than it would normally!
Cutting off components completely is a well proven and usually well working method, at least for IC's. I believe one cause for our difficulties may be that the holes are just a tad too small for the legs of resistors and capacitors.
I agree with you re. LM4562. I have completed my comparison between NE5532, LM4562 and OPA 2134 and believe the LM4562 sound perhaps a fraction "better" than NE5532. But it's nothing I would enter a new argument about....
Hi Segren - many thanks for the advice. In hindsight it would be so easy if I just cut the resistor in half, then heated and pulled each half out. I may order another board to be on the safe side, but then again I don't like to be wasteful. I guess if I do end up damaging any holes I can just create a perf-board with the op-amp and resistors on that as I said above. Would be easier to mod. the perf board as well should the dreaded upgraditis strike
I've decided to just clear 2-3 holes per day now. Any more and I get 1) stressed and 2) might start pushing too hard and damage the board. Approaching this with the gently-gently attitude now.
Fingers crossed!
P.S. These DACs appear to have gone up in price on Ebay now... I wonder why
I've decided to just clear 2-3 holes per day now. Any more and I get 1) stressed and 2) might start pushing too hard and damage the board. Approaching this with the gently-gently attitude now.
Fingers crossed!
P.S. These DACs appear to have gone up in price on Ebay now... I wonder why
I also ordered a second one and have been waiting over 2 weeks for it. Previous one was here in a week so I wonder if demand has been a little high.
It looks like the picture on the current auctions is a subtly different board. The pulse transformer for the SPDIF input has gone and it appears there is (unpopulated) space for the USB interface.
I will let you all know what turns up...
Kevin
You can actually order the DAC with the USB interface populated. It was offered on eBay about 6 weeks ago, but run out of stock.
I have informed Lawrence Chan about this thread and the percieved improvements done, but I don't know ih he is interested in our findings.
Will order a USB version soon, for my son.
there are plenty available with or without the usb interface
i bought mine from the guy in the first link and everything went out fine,but it was the previous version which we all have and as i see this new one also has an upsampling chip (which i don't like) together with 2 crystalls fed by the same reg as the spdif and usb receiver chip (1 for the usb and 1 for the upsampler)
http://cgi.ebay.com/Hi-End-24-192-u...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
http://cgi.ebay.com/CS8416-CS4398-1...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
since we don't use the second opamp anymore i think it would be better and cheaper to consider the 1 opamp version of the board which is much cheaper (35$) and also comes with the CS4397 (better than cs4398 for my tastes)
http://cgi.ebay.com/24bit-192Hz-HI-...4|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
and here is another seller selling the big one a little cheaper
http://cgi.ebay.com/NEW-BIG-24bit-1...4|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
i bought mine from the guy in the first link and everything went out fine,but it was the previous version which we all have and as i see this new one also has an upsampling chip (which i don't like) together with 2 crystalls fed by the same reg as the spdif and usb receiver chip (1 for the usb and 1 for the upsampler)
http://cgi.ebay.com/Hi-End-24-192-u...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
http://cgi.ebay.com/CS8416-CS4398-1...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
since we don't use the second opamp anymore i think it would be better and cheaper to consider the 1 opamp version of the board which is much cheaper (35$) and also comes with the CS4397 (better than cs4398 for my tastes)
http://cgi.ebay.com/24bit-192Hz-HI-...4|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
and here is another seller selling the big one a little cheaper
http://cgi.ebay.com/NEW-BIG-24bit-1...4|66:2|65:12|39:1|240:1318|301:1|293:1|294:50
