Every little thing moves a fraction of an inch closer. It's like we are approaching it asymptotically, which may actually be the case.
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By the way, I wanted to add to the parts list that I use LT1763-3.3v for clock and VCCA power regulation, one each. Each regulator has a .01 C0G cap for noise filtering, a 1uf input cap, and a 10uf output cap. If people want to add those like I did there may be a question of how to mount them, or what kind of parts to use. We could talk about that I guess, but probably some people won't want to do it exactly like I do.
There is the BOM bih started. It is good except the I/V caps should be 330pf if they are not, and if you want to use AD797 for AVCC then you would need two of them and an adapter to solder them to. Here is the one I used: Single to Dual Op Amp Adapter | BrownDog 020302 | Cimarron Technology
Then we would need to add the two 22uf film caps for AVCC: MKS4C052206D00JSSD WIMA | Mouser
Then what I used for clock and vcca regulators: LT1763CS8-3.3#PBF Analog Devices / Linear Technology | Mouser
Up to each person if they want to use LT1763 how to mount them and whether to use leaded or SMD parts. Each LT1763 needs X7R input cap, I used 1uf. Also, a 10uf output cap, I used SMD, and a .01uf C0G noise reduction cap, I also used SMD. Please see the LT1763 data sheet for details on caps.
LT1763 is itself an SMD part, same size at the LT6655. It could be mounted on the same type of adapter and leaded caps used, or it could be done the way I do it which can be seen in pictures of the bottom of my 1st dac board. Same thing again for the new dac.
When I do that I can fit them in a small space on the bottom of the ground plane. Maybe it would be a good idea to look at the high res pics of the bottom of my boards to see of it looks doable or if adapter board would be wanted, or if someone wants to use an LT3045 module(s) instead. Something like that. I don't have a worked out solution everyone will like for that last little bit.
This is the type of epoxy putty I use: Kneadatite Blue/Yellow Epoxy Putty Tape 36" "Green Stuff": Amazon.com: Industrial & Scientific
Also, not sure if bih's BOM included decoupling caps for everywhere. I usually buy lots of those because I will always find use for any extras eventually.
Then we would need to add the two 22uf film caps for AVCC: MKS4C052206D00JSSD WIMA | Mouser
Then what I used for clock and vcca regulators: LT1763CS8-3.3#PBF Analog Devices / Linear Technology | Mouser
Up to each person if they want to use LT1763 how to mount them and whether to use leaded or SMD parts. Each LT1763 needs X7R input cap, I used 1uf. Also, a 10uf output cap, I used SMD, and a .01uf C0G noise reduction cap, I also used SMD. Please see the LT1763 data sheet for details on caps.
LT1763 is itself an SMD part, same size at the LT6655. It could be mounted on the same type of adapter and leaded caps used, or it could be done the way I do it which can be seen in pictures of the bottom of my 1st dac board. Same thing again for the new dac.
When I do that I can fit them in a small space on the bottom of the ground plane. Maybe it would be a good idea to look at the high res pics of the bottom of my boards to see of it looks doable or if adapter board would be wanted, or if someone wants to use an LT3045 module(s) instead. Something like that. I don't have a worked out solution everyone will like for that last little bit.
This is the type of epoxy putty I use: Kneadatite Blue/Yellow Epoxy Putty Tape 36" "Green Stuff": Amazon.com: Industrial & Scientific
Also, not sure if bih's BOM included decoupling caps for everywhere. I usually buy lots of those because I will always find use for any extras eventually.
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For using the big AVCC caps, if mounting them on top the way I did it is important to note that they cover a number of spots where traces need to be cut and wires soldered on. Those things would need to be done before the film caps are installed. Maybe a good idea to put them on longer leads so they could be tipped a bit to access traces and junctions under them.
Had someone else take a listen to the new modded dac vs Katana 1.1 (with 3 power supplies)
He said Katana 1.1 sounds 'scratchy and muddy' in comparison. I would agree, actually, sounds like it to me as well in comparison. The difference is striking with the latest mods. I am happy as a pig in xxxx right now about the sound quality. If only people had more access to low cost dacs this good. Also, I don't see any reason for people to keep messing around with NOS dacs if their reason for doing so is because they think delta-sigma sounds clinical, cold, fatiguing, etc. Not this one. Very natural, yet detailed sound.
He said Katana 1.1 sounds 'scratchy and muddy' in comparison. I would agree, actually, sounds like it to me as well in comparison. The difference is striking with the latest mods. I am happy as a pig in xxxx right now about the sound quality. If only people had more access to low cost dacs this good. Also, I don't see any reason for people to keep messing around with NOS dacs if their reason for doing so is because they think delta-sigma sounds clinical, cold, fatiguing, etc. Not this one. Very natural, yet detailed sound.
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As I have said multiple times, I would be happy to let someone who is equipped to perform comprehensive dac measurements perform measurements on my modded dacs. Have nothing against it at all. However, I am not so equipped myself.
I would also point out that if one looks at the dacs used to mix and master most records we all listen to, very few offer much in the way of measurements. The primary exception is DAC-3. Why no measurements? Because people who listen for a living trust their ears more than they trust measurements. And they are the same people who make the records we all listen to. Call it whatever you want, if you buy records then you are supporting what they do. If you want to protest, then don't buy records might be one option.
I would also point out that if one looks at the dacs used to mix and master most records we all listen to, very few offer much in the way of measurements. The primary exception is DAC-3. Why no measurements? Because people who listen for a living trust their ears more than they trust measurements. And they are the same people who make the records we all listen to. Call it whatever you want, if you buy records then you are supporting what they do. If you want to protest, then don't buy records might be one option.
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Mark,
Sorry - have to say this is frankly a pretty arrogant post and shows you are
pretty out of touch with pro audio people, equipment and practices.
Pro audio converters are extremely spec driven and there are plenty of
measurements available. You have completely failed to recognize the huge
amount of work many pro audio converter designers have done.
I suggest you look at a historic timeline of pro audio converter development
by people such as Apogee, Dan Lavry, Pacific Microsonics, Prismsound,
Forssell, Cranesong etc etc.
Benchmark have, for the most part, put together a DAC from off the shelf
parts and a bunch of sales blurb. It is well implemented and as such
measures well. There are plenty of mastering engineers that don't use
Benchmark because they have found better converters. THD+N is not the
only arbiter of what makes a good converter. Some pro converters are
slightly euphonic and that is not a bad thing, especially for tracking mixes.
I've seen measurements of many pro converters that measure similarly to
the DAC1/2/3. There are some that measure better. They all have subtle
sonic differences and as such engineers have their own subjective
preferences.
T
Terry, I think you misunderstand my meaning. I have a nice Crane Song HEDD. Many of those companies make very fine products, but do not publish detailed specs like Benchmark does. That is not say whether or not they measure, I'm sure they all do. But, to a large extent they seem to keep much of that information to themselves.
Here is a Solaris manual: http://www.cranesong.com/solaris_manual_version_1.pdf
Here is a DAC-3 manual: https://cdn.shopify.com/s/files/1/0321/7609/files/DAC3_Series_Manual_Rev_B.pdf
There is no way they publish the same amount of specs as anyone can plainly see.
Why? I think it is because the pro audio market is not nearly so spec driven as people tend to be around here. Go to GearSlutz and people talk mostly about how dacs sound, and very little in comparison about how they measure.
By the way, you may not be aware of why I wrote that post. The post that elicited it was removed by the moderators. I will say that I did not like its insinuation and was not in a good mood to respond.
Here is a Solaris manual: http://www.cranesong.com/solaris_manual_version_1.pdf
Here is a DAC-3 manual: https://cdn.shopify.com/s/files/1/0321/7609/files/DAC3_Series_Manual_Rev_B.pdf
There is no way they publish the same amount of specs as anyone can plainly see.
Why? I think it is because the pro audio market is not nearly so spec driven as people tend to be around here. Go to GearSlutz and people talk mostly about how dacs sound, and very little in comparison about how they measure.
By the way, you may not be aware of why I wrote that post. The post that elicited it was removed by the moderators. I will say that I did not like its insinuation and was not in a good mood to respond.
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Guys,
If we could get back to thread business, the board I just got finished modding is a v1.07 and for the first time I tried hooking up the display. It seems to act they way bih described when he had J1 and J2 installed. However, this has no audio output and no indication of locking or that it is receiving DSD whenever the display is plugged in at all, and regardless of which if any jumpers are installed. However, the board works fine without the display.
Don't know if there is some trick to it I am missing or what. I may have to pull the thing out of the test box and look at it on the bench again. If the display unit is bad or something, no problem, I can always pin lift or hack traces to get into the dac registers.
By the way, the reason I decided to poke around in the registers is because it still doesn't sound as good as DAC-3 (as fully expected). So it is time to see if I can improve it any more with some register tweaking.
If we could get back to thread business, the board I just got finished modding is a v1.07 and for the first time I tried hooking up the display. It seems to act they way bih described when he had J1 and J2 installed. However, this has no audio output and no indication of locking or that it is receiving DSD whenever the display is plugged in at all, and regardless of which if any jumpers are installed. However, the board works fine without the display.
Don't know if there is some trick to it I am missing or what. I may have to pull the thing out of the test box and look at it on the bench again. If the display unit is bad or something, no problem, I can always pin lift or hack traces to get into the dac registers.
By the way, the reason I decided to poke around in the registers is because it still doesn't sound as good as DAC-3 (as fully expected). So it is time to see if I can improve it any more with some register tweaking.
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Pins are lifted and super glue is drying. Tomorrow will get into dac registers.
Up to you guys what you want to do next. I made a list of changes I could think of to update the BOM. Don't know bih's schedule or availability to work on it. If bih is busy and if it is okay with him maybe someone can chip in to help speed it up. Thanks.
Up to you guys what you want to do next. I made a list of changes I could think of to update the BOM. Don't know bih's schedule or availability to work on it. If bih is busy and if it is okay with him maybe someone can chip in to help speed it up. Thanks.
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Turns out I have to do some other things today through most of the afternoon. Will try to get back to DPLL and HD comp later. Like to make at least a little progress every day, even it is small.
Also, need to knock out that SMD output stage layout. Should go pretty quick.
Then, finally, I can start learning about Spartan 6 chip internals. Presumably, there is a lot to get up to speed on, don't know.
How about out there? Anyone ordered parts at all yet? Anyone started modding? I know a least a few people did Serge's mods. Don't know, at least that I can remember, if anyone got farther than that. Do we have anyone working on an LT6655 AVCC, or though-hole-component output stage? No reason I can think of to wait. I am unable to try every combination of circuits and compare them or determine price/performance. All I know for certain at this point is that the 2nd modded dac board sounds better than the 1st. I thought I *might* be able to be happy with the 1st one if I didn't have a better dac. I *know* I could be happy with the 2nd one if I didn't have a better dac, and I can assure you I am very picky about sound quality.
So, why has everybody sort of gone silent? Not going to go through with it? Waiting for parts? No time now, but might like to do it someday in the future? Where are we at guys? Should I just drop the thread and have the few people who want to mod contact me by PM if any questions? Or, do we have enough interest out there to keep this thing moving?
Also, need to knock out that SMD output stage layout. Should go pretty quick.
Then, finally, I can start learning about Spartan 6 chip internals. Presumably, there is a lot to get up to speed on, don't know.
How about out there? Anyone ordered parts at all yet? Anyone started modding? I know a least a few people did Serge's mods. Don't know, at least that I can remember, if anyone got farther than that. Do we have anyone working on an LT6655 AVCC, or though-hole-component output stage? No reason I can think of to wait. I am unable to try every combination of circuits and compare them or determine price/performance. All I know for certain at this point is that the 2nd modded dac board sounds better than the 1st. I thought I *might* be able to be happy with the 1st one if I didn't have a better dac. I *know* I could be happy with the 2nd one if I didn't have a better dac, and I can assure you I am very picky about sound quality.
So, why has everybody sort of gone silent? Not going to go through with it? Waiting for parts? No time now, but might like to do it someday in the future? Where are we at guys? Should I just drop the thread and have the few people who want to mod contact me by PM if any questions? Or, do we have enough interest out there to keep this thing moving?
Hello Mark
I'm waiting for the rest of my moduls. When the unmodded DAC with all my modules is working fine, then I will order the parts for modding. I'm quite busy with job, the family, the garden and other hobbies like running, rc plane flying and organizing a HP-old calculator event in the next 2 weeks ...
But I'm reading every post and my target is to finsh the modded DAC bevor the year has ended.
Best regards from switzerland
Hans-Peter
Started mocking up physical assembly of a hugh current op amp AVCC using a DIP and LME49600 as well as an LTC6655 module
Practicing bending pins and removing pins on an old disposable NE5534 that sits on top of the LME49600. Two or three leads need to be removed from the LME49600.
The assembly on top of the film cap is a regulated power supply using a 317. This cost a couple bucks and is smaller than I could make myself. The LTC6655 module is on the side of the film cap, I have a 10uF version of the cap but the 4.7 is used just for showing.
Practicing bending pins and removing pins on an old disposable NE5534 that sits on top of the LME49600. Two or three leads need to be removed from the LME49600.
The assembly on top of the film cap is a regulated power supply using a 317. This cost a couple bucks and is smaller than I could make myself. The LTC6655 module is on the side of the film cap, I have a 10uF version of the cap but the 4.7 is used just for showing.
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you don't need to lift the pins if j1, j2 are on, the preamp volume control to max will have sound.
connect the i2c, preamp volume control to 50%,
ssh,
sudo i2cset -f 1 0x48 0x0f 0x30
sudo i2cset -f 1 0x48 0x10 0x30
now hardware Volume control on -24db.
sudo i2cset -f 1 0x48 0x0f 0x00
sudo i2cset -f 1 0x48 0x10 0x00
now hardware Volume control on 0db.
i'm going to post about i2c control green board in a full description, but english is not my first language, so need a bit more time.
cheers
Can I seek help from the group?
I have ver 1.04 of the DAC board, with xmos u8 usb to I2S connected to it. However, been using spdif input as I find it SQ better than usb - jumper J3 is shorted per instruction. I ported the DAC board to another enclusure, WITHOUT the xmos us decoder. Now there is no sound coming from it.
Is my understanding correct that the DAC board using spdif input will work even without the usb decoder board? Anyone tried it before? Any clues as to why no sound is coming from it?
Thanks and I appreciate any input.
I have ver 1.04 of the DAC board, with xmos u8 usb to I2S connected to it. However, been using spdif input as I find it SQ better than usb - jumper J3 is shorted per instruction. I ported the DAC board to another enclusure, WITHOUT the xmos us decoder. Now there is no sound coming from it.
Is my understanding correct that the DAC board using spdif input will work even without the usb decoder board? Anyone tried it before? Any clues as to why no sound is coming from it?
Thanks and I appreciate any input.