Is the heat coming from the opamp board?, it is class A, if so it might be an idea to power that board down. I took a quick look at the Katana manual and it suggests that power can be turned off.....
"Power to the OPAMP stage can be switched off when player is idle for extended periods of time with switch 3 of Micro Controller."
Might be worth trying and check board temperatures to confirm.
"Power to the OPAMP stage can be switched off when player is idle for extended periods of time with switch 3 of Micro Controller."
Might be worth trying and check board temperatures to confirm.
Good to see some life in the Katana thread again!
On cooling, the best thing you can do is to power your RPi/Katana stack with 2-3 5V supplies, one for the RPi (or USBBridge Signature if you have one), another for the Katana Isolator if you have it plus Katana DAC board, and a third one for the Katana Microprocessor Board, combining the latter two if you wish, but make sure it has sufficient current capacity. Then use a separate +-15V supply to power the Katana Output board so you can turn off the +-15V supplies on the Microprocessor board. The main heat-producing parts in a Katana are the DC-DC converters that produce +-15V from 5V to power the Katana Output board.
During my early testing of the Katana I was concerned about how hot it got. My eventual setup using a separate +-15V supply runs nice and cool, very little heat produced above ambient (confirmed that this evening). While the discrete opamp stages do run Class-A, at that signal level they don't produce much noticeable heat.
AND a bonus to my ears is the improved sound-quality.
Of course you'll want well-behaved +-15V supplies to make sure you don't kill the now-irreplaceable Katana Output board. I use a simple DIY'd +-15V raw DC supply into a +- pair of Sparkos discrete regulators. Regulators from Belleson or NewClassD should also work well, I've used them before in other similar applications to good effect. I don't have personal experience with other commercial or DIY options for this application.
An option I haven't tried yet, but plan to do so before I retire my Katana stack, is to use Ian Canada's LiFePO4 supply's 2 13.2V rails configured in +-13.2V to replace my DC-connected supply. Of course for this to work effectively, you need to do a bit of DIY work to bypass the pre-regulators on the Microprocessor board that feed the Output board as they won't regulate fed those voltages. OTOH, in my setup with the Sparkos regulators, bypassing those pre-regulators was a nice sonic upgrade to my ears, as was bypassing the inter-board connectors, all detailed in some previous posts as I remember.
AND yes, as good as it sounds, I am slowly moving to replace my Katana stack with the latest Ian Canada stack, which when coupled to a VG output stage sounds better to me than my Katana setup. I am currently using Ian's OP861 output stage, but I don't see that he has released it to general distribution. His IVStd stage with good opamps (I prefer Sparkos or NewClassD Ultimate discretes, with OPA1612's close behind) or a good transformer output stage work well.
Of course, that comes at a price... the Ian Canada stack costs a bit more than what one could get a Katana stack back when they were available.
Finally I don't remember if I ever posted this, but while the Allo Katana Isolator board provided some improvements when used with a standard RPi, IF you have a USBBridge Signature with a good power supply, try it without the Isolator board. A friend tipped me off that he got better sonics without the Isolator board with that as a source and I agree.
Greg in Mississippi
P.S. Hoping everyone at Allo are ok, they have been quiet for some time, since very early 2022. Anyone have any news?
On cooling, the best thing you can do is to power your RPi/Katana stack with 2-3 5V supplies, one for the RPi (or USBBridge Signature if you have one), another for the Katana Isolator if you have it plus Katana DAC board, and a third one for the Katana Microprocessor Board, combining the latter two if you wish, but make sure it has sufficient current capacity. Then use a separate +-15V supply to power the Katana Output board so you can turn off the +-15V supplies on the Microprocessor board. The main heat-producing parts in a Katana are the DC-DC converters that produce +-15V from 5V to power the Katana Output board.
During my early testing of the Katana I was concerned about how hot it got. My eventual setup using a separate +-15V supply runs nice and cool, very little heat produced above ambient (confirmed that this evening). While the discrete opamp stages do run Class-A, at that signal level they don't produce much noticeable heat.
AND a bonus to my ears is the improved sound-quality.
Of course you'll want well-behaved +-15V supplies to make sure you don't kill the now-irreplaceable Katana Output board. I use a simple DIY'd +-15V raw DC supply into a +- pair of Sparkos discrete regulators. Regulators from Belleson or NewClassD should also work well, I've used them before in other similar applications to good effect. I don't have personal experience with other commercial or DIY options for this application.
An option I haven't tried yet, but plan to do so before I retire my Katana stack, is to use Ian Canada's LiFePO4 supply's 2 13.2V rails configured in +-13.2V to replace my DC-connected supply. Of course for this to work effectively, you need to do a bit of DIY work to bypass the pre-regulators on the Microprocessor board that feed the Output board as they won't regulate fed those voltages. OTOH, in my setup with the Sparkos regulators, bypassing those pre-regulators was a nice sonic upgrade to my ears, as was bypassing the inter-board connectors, all detailed in some previous posts as I remember.
AND yes, as good as it sounds, I am slowly moving to replace my Katana stack with the latest Ian Canada stack, which when coupled to a VG output stage sounds better to me than my Katana setup. I am currently using Ian's OP861 output stage, but I don't see that he has released it to general distribution. His IVStd stage with good opamps (I prefer Sparkos or NewClassD Ultimate discretes, with OPA1612's close behind) or a good transformer output stage work well.
Of course, that comes at a price... the Ian Canada stack costs a bit more than what one could get a Katana stack back when they were available.
Finally I don't remember if I ever posted this, but while the Allo Katana Isolator board provided some improvements when used with a standard RPi, IF you have a USBBridge Signature with a good power supply, try it without the Isolator board. A friend tipped me off that he got better sonics without the Isolator board with that as a source and I agree.
Greg in Mississippi
P.S. Hoping everyone at Allo are ok, they have been quiet for some time, since very early 2022. Anyone have any news?
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@chris14
I havn't checked the opamp board yet as it is difficult to reach. Just noticed the heat at the microcontroller board at the top.
@Greg Stewart
Thanks for the hints. Up to now I'm using only two power supplies, but I have a third one which I could add,
However I don't have a +/-15 V linear power supply (yet).
I noticed that the two red marked silver parts are getting very hot. The one in the lower left part of the photo is even hotter than the other one.
Will it lower the temperature when a +/-15 V power supply will be connected?
@All
Does anybody have a suggestion for a +/-15 V linear power supply, either a commercial one or a diy with an available guide to follow?
I'm fine with soldering, but not with creating pcb layouts from scratch.
Cu
Christoph
I havn't checked the opamp board yet as it is difficult to reach. Just noticed the heat at the microcontroller board at the top.
@Greg Stewart
Thanks for the hints. Up to now I'm using only two power supplies, but I have a third one which I could add,
However I don't have a +/-15 V linear power supply (yet).
I noticed that the two red marked silver parts are getting very hot. The one in the lower left part of the photo is even hotter than the other one.
Will it lower the temperature when a +/-15 V power supply will be connected?
@All
Does anybody have a suggestion for a +/-15 V linear power supply, either a commercial one or a diy with an available guide to follow?
I'm fine with soldering, but not with creating pcb layouts from scratch.
Cu
Christoph
Chris808,
The larger metal plate you have circled is the heatsink for the microprocessor. Heat should not change at all with a +-15V supply. OTOH, mine (as well as I can reach it) just barely feels warm.
The smaller metal plate is the heatsink for the DC-DC converter that provides the +-15V power. Of course mine is off, so cold, but it is as I remember the main heat source when running. As @chris14 mentioned, you can see how much cooler it will run by adding the +-15V supplies by turning off the switch next to the Microprocessor board USB-C connector. I would do this with the power off to the Katana stack, power it up for awhile to check (with your amp off), then power it down to reset the switch on. Just being cautious around the now irreplaceable Output board.
When you do this, the Microprocessor should stay about the same temp, the DC-DC converter should go cold. The black square chip near the smaller metal plate may also get cooler. It is a regulator and I believe it is a preregulator for the DC-DC converter, but I do not have the Katana schematic.
My experience is that adding a good +-15V supply to the typical 2 5V supplies used by most Katana users will not only lower the heat, but also as long as you use a good supply make a substantial improvement to the SQ. Read my posts on this in the older Allo Reclocker thread and at the beginning of this thread. Before the separate +-15V supply, I felt the Katana was roughly comparible to the orginal Boss, but not quite as musical. With the +-15V supply added, it was significantly better (in my setup, to my ears).
A +-15V supply, at its most basic form, is a center-tapped transformer, 4 diodes as a diode bridge, 2 main filter capacitors, 2 regulators (along with any components that may be needed to set the regulator output voltages, though many are sold pre-set), and 2 regulator output and possibly 2 input capacitors. The one I built added an AC filter cap and a transformer ringing suppresion filter, but those are not required. It was fairly simple to DIY and I just did point-to-point, no PCB, though I used a piece of perf-board to mount the regulators, their input and output filter caps, and the connectors to make it easy to integrate into the Katana stack.
I can post pix and more info if you want.
Also there are links to various good-quality commercial options in the first post of this thread.
Let me know how I can assist.
Greg in Mississippi
P.S. Now that it is clear that Allo is not in a position to resolve issues with the output stage, this is a good time to point out that their stage is a typical "Op-Amp I/V stage for an ESS DAC" with just a few Allo-tweaks that could be implemented with a separate replacement board fairly easily. One would have to deal with the interboard connectivity between the DAC and Microprocessor board, but nothing too hard to solve. The only question is whether the typical failure mode may also damage components on the Microprocessor board that are critical to overall operation.
The larger metal plate you have circled is the heatsink for the microprocessor. Heat should not change at all with a +-15V supply. OTOH, mine (as well as I can reach it) just barely feels warm.
The smaller metal plate is the heatsink for the DC-DC converter that provides the +-15V power. Of course mine is off, so cold, but it is as I remember the main heat source when running. As @chris14 mentioned, you can see how much cooler it will run by adding the +-15V supplies by turning off the switch next to the Microprocessor board USB-C connector. I would do this with the power off to the Katana stack, power it up for awhile to check (with your amp off), then power it down to reset the switch on. Just being cautious around the now irreplaceable Output board.
When you do this, the Microprocessor should stay about the same temp, the DC-DC converter should go cold. The black square chip near the smaller metal plate may also get cooler. It is a regulator and I believe it is a preregulator for the DC-DC converter, but I do not have the Katana schematic.
My experience is that adding a good +-15V supply to the typical 2 5V supplies used by most Katana users will not only lower the heat, but also as long as you use a good supply make a substantial improvement to the SQ. Read my posts on this in the older Allo Reclocker thread and at the beginning of this thread. Before the separate +-15V supply, I felt the Katana was roughly comparible to the orginal Boss, but not quite as musical. With the +-15V supply added, it was significantly better (in my setup, to my ears).
A +-15V supply, at its most basic form, is a center-tapped transformer, 4 diodes as a diode bridge, 2 main filter capacitors, 2 regulators (along with any components that may be needed to set the regulator output voltages, though many are sold pre-set), and 2 regulator output and possibly 2 input capacitors. The one I built added an AC filter cap and a transformer ringing suppresion filter, but those are not required. It was fairly simple to DIY and I just did point-to-point, no PCB, though I used a piece of perf-board to mount the regulators, their input and output filter caps, and the connectors to make it easy to integrate into the Katana stack.
I can post pix and more info if you want.
Also there are links to various good-quality commercial options in the first post of this thread.
Let me know how I can assist.
Greg in Mississippi
P.S. Now that it is clear that Allo is not in a position to resolve issues with the output stage, this is a good time to point out that their stage is a typical "Op-Amp I/V stage for an ESS DAC" with just a few Allo-tweaks that could be implemented with a separate replacement board fairly easily. One would have to deal with the interboard connectivity between the DAC and Microprocessor board, but nothing too hard to solve. The only question is whether the typical failure mode may also damage components on the Microprocessor board that are critical to overall operation.
Attachments
Thanks Greg for all the useful information, i try to get a +-15 V PSU.
In the meantime, I would like to figure out how an 3 PSU setup is realised with the isolator board.
The manual contains only the setup for 3 PSU without the isolator, J26 + J30 both open.
Where can I find the description of the jumper settings when the isolator is used?
I assume in this case I have to feed the
I'm new to the Katana, sorry about this basic questions. I will also read the whole thread, however it may take a while...
Cu
Christoph
In the meantime, I would like to figure out how an 3 PSU setup is realised with the isolator board.
The manual contains only the setup for 3 PSU without the isolator, J26 + J30 both open.
Where can I find the description of the jumper settings when the isolator is used?
I assume in this case I have to feed the
- microprocessor board
- Katana board
- Isolator board
I'm new to the Katana, sorry about this basic questions. I will also read the whole thread, however it may take a while...
Cu
Christoph
Christoph,
You actually want to read both this thread AND the Katana-related posts in Allo's Kali thread. BUT here is the info you need.
You can download the Allo Isolator 1.2 Tech Manual and Katana Default Power Source Settings from the links on this page:
https://allo.com/sparky/isolator-1-2.html#downloads
Note that while the manual states Isolator Rev 1.2, I believe most in the field are Rev 1.3, though they are identical in how you configure and connect them.
I found the explanation in the Tech Manual easier to follow.
You actually have to feed the:
- 5V -> RPi + Isolator Primary (input / dirty side)
- 5V -> Isolator Secondary (output / clean side) + Katana DAC board
- 5V -> Microprocessor Board
For the RPi + Isolator Primary, you can either leave the RPi POWER Isolation Jumper (J26, though it is not labeled on the board) open/off and feed 5V into the RPi OR have the RPi Power Isolation Jumper (J26) on and feed 5V into the Isolator USB-C connector.
Either will work, I have generally fed the RPi via a high-current connector with leads soldered to the 5V and ground on the bottom of the GPIO connector and feed the Isolator via the GPIO connector.
If you are feeding the RPi through the USB connector, I suggested trying it either way (power into the RPi/J26 off or power into the Isolator USB-C/J26 on) and see if you can hear a difference. I suspect you won't.
For the Isolator Secondary + Katana DAC board, you have a jumper on the DAC board J30 connector and feed 5V into the DAC board J31 connector.
Similar to powering the RPi, I use a high-current connector for this and have soldered the leads to the bottom of the J31 connector.
For the Microprocessor board (when not also powering the Katana DAC board), you leave the Microprocessor board J26 jumper off completely (see the Katana manual for details on 3 power source) and feed 5V into the Microprocessor Board USB-C.
Similar to powering the RPi and the Katana DAC board, I use a high-current connector for this and have soldered the leads with the positive to positive side of the ceramic cap near the USB-C and the negative to the negative side of the Supercap near the USB-C (and if your Microprocessor board does not have the Supercap, it is easiest to use the open positive and negative leads at it's location).
Once you have a suitable +-15V power supply (please check with us here before you buy it!), we can go over where to connect it (you can either do it the recommended way or a theoretically better way) and what other changes are needed.
Hopefully this helps. Ask questions if unclear.
Greg in Mississippi
You actually want to read both this thread AND the Katana-related posts in Allo's Kali thread. BUT here is the info you need.
You can download the Allo Isolator 1.2 Tech Manual and Katana Default Power Source Settings from the links on this page:
https://allo.com/sparky/isolator-1-2.html#downloads
Note that while the manual states Isolator Rev 1.2, I believe most in the field are Rev 1.3, though they are identical in how you configure and connect them.
I found the explanation in the Tech Manual easier to follow.
You actually have to feed the:
- 5V -> RPi + Isolator Primary (input / dirty side)
- 5V -> Isolator Secondary (output / clean side) + Katana DAC board
- 5V -> Microprocessor Board
For the RPi + Isolator Primary, you can either leave the RPi POWER Isolation Jumper (J26, though it is not labeled on the board) open/off and feed 5V into the RPi OR have the RPi Power Isolation Jumper (J26) on and feed 5V into the Isolator USB-C connector.
Either will work, I have generally fed the RPi via a high-current connector with leads soldered to the 5V and ground on the bottom of the GPIO connector and feed the Isolator via the GPIO connector.
If you are feeding the RPi through the USB connector, I suggested trying it either way (power into the RPi/J26 off or power into the Isolator USB-C/J26 on) and see if you can hear a difference. I suspect you won't.
For the Isolator Secondary + Katana DAC board, you have a jumper on the DAC board J30 connector and feed 5V into the DAC board J31 connector.
Similar to powering the RPi, I use a high-current connector for this and have soldered the leads to the bottom of the J31 connector.
For the Microprocessor board (when not also powering the Katana DAC board), you leave the Microprocessor board J26 jumper off completely (see the Katana manual for details on 3 power source) and feed 5V into the Microprocessor Board USB-C.
Similar to powering the RPi and the Katana DAC board, I use a high-current connector for this and have soldered the leads with the positive to positive side of the ceramic cap near the USB-C and the negative to the negative side of the Supercap near the USB-C (and if your Microprocessor board does not have the Supercap, it is easiest to use the open positive and negative leads at it's location).
Once you have a suitable +-15V power supply (please check with us here before you buy it!), we can go over where to connect it (you can either do it the recommended way or a theoretically better way) and what other changes are needed.
Hopefully this helps. Ask questions if unclear.
Greg in Mississippi
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Not what I see here. Maybe it is region-code based... I am in the US, when I click on the Katana links on Allo.com, it takes me to the Revolution DAC page. AND I cannot get to a Katana page from any link.
On Katana vs Boss V2... with either a 1-2 power supply setup on each, they are roughly comparable sonically IMHO. Add a 3rd to the Katana for a slight lift above the Boss V2. Add any reasonably-good linear +-15V supply to power the Katana Opamp board and then there is no comparison, the Katana is way ahead, again IMHO.
This is not a knock on the Boss V2, it is a very good bang-for-the-bux unit.
I did this comparison with very good power supplies. As with any DAC & player, the better the supplies, the better the sonics, at least to my ears and in my setups.
AND both are improved when used on the currently unavailable USBBridge Signature.
Greg in Mississippi
On Katana vs Boss V2... with either a 1-2 power supply setup on each, they are roughly comparable sonically IMHO. Add a 3rd to the Katana for a slight lift above the Boss V2. Add any reasonably-good linear +-15V supply to power the Katana Opamp board and then there is no comparison, the Katana is way ahead, again IMHO.
This is not a knock on the Boss V2, it is a very good bang-for-the-bux unit.
I did this comparison with very good power supplies. As with any DAC & player, the better the supplies, the better the sonics, at least to my ears and in my setups.
AND both are improved when used on the currently unavailable USBBridge Signature.
Greg in Mississippi
Looks good. Thx!
I'd recommend checking with them on actual stock before ordering.
Also, if you aren't going to go for the 2-3 5V supplies plus a +-15V supply configuration, if not immediately at least at some point, IMHO the Boss Rev 1.2 is a better overall choice.
Of course, YMMV.
Greg in Mississippi
I'd recommend checking with them on actual stock before ordering.
Also, if you aren't going to go for the 2-3 5V supplies plus a +-15V supply configuration, if not immediately at least at some point, IMHO the Boss Rev 1.2 is a better overall choice.
Of course, YMMV.
Greg in Mississippi
I have one I bought used a while back - was a very good deal.
It’s being used via some ceiling speakers in my house - so definitely not at it’s optimum currently!
So really just sharing in case others were interested.
As you say - who know if it’s real stock - or just a mistake in updating the Allo website.
It’s being used via some ceiling speakers in my house - so definitely not at it’s optimum currently!
So really just sharing in case others were interested.
As you say - who know if it’s real stock - or just a mistake in updating the Allo website.
What are the criteria for choosing a suitable +-15V power supply?
I'm located in Germany, so importing a PSU from the US doesn't make much sense because of the import duties & taxes.
From the links on page / post 1 : The sparko labs PSU is suitable I assume ?
https://sparkoslabs.com/product/dual-power-supply/
Any opinion about this German supplier of DIY power supplies (sorry about the German description, but the schematics are also shown there) ?
http://www.thel-audioworld.de/module/NT-HQ/NT-HQ.htm
Cu
Christoph
Not to rain on anyone's parade, but the time when Katana dac was a game changer has IMHO largely come and gone. Have an experimental prototype AK4499 dac (which like katana is also pretty much no longer at the vanguard of dac technology). The custom AK4499 dac blows away Katana (modified or not) as well as many or most other modern commercial dacs. Moreover, pretty sure one of today's off the shelf Holo Spring 3 dacs could make a Katana sound rather dated. Seems to me like we have to keep learning and growing, not get stuck at a certain point in time of dac technology development. Allo seems to have suffered badly from COVID and from global electronics parts shortages. Key people may no longer be there. We don't know, at least I don't. Time to move on unless Allo shows they are back in business enough to be taken seriously. That's my personal opinion anyway.
Markw4,
Great to hear from you, I haven't been doing much audio recently nor on this site, so not aware of what you've posted recently.
I totally agree with you that the Katana is not now (and honestly never was) a top performing DAC in the sense of the high-end audio world. Of course, this thread is about "Getting the best out of..." this unit, so it was never touted as such. My impression is that it WAS the best commercial performer for an RPi DAC Hat as long as one was willing/able to use the best sounding 3 5V and a +-15V supply configuration. Without that, other offerings of that time (including Allo's Boss Rev1.2) were competitive. AND if reasonably good supplies were used, it was hard to justify it on a bang-for-the-buck basis. AND even with the expensive exotic power supplys I used, I had no illusions that it was a world-beater, just the best RPi DAC Hat I'd tried at that time.
AND of course, I'm back here helping someone with questions about a Katana they own, not touting it as a top DAC or suggesting anyone purchase one. Unless I see strong proof-of-life from Allo, there's no way I'd suggest someone try to get one today!
I have not kept up with other commercial RPi DAC Hat offerings, so don't know where it stands today. My gut feel is that the novelty of the RPi DAC Hat has largely passed and other configurations are more popular.
Happy to hear the Holo Spring 3 is a good performer. Its on my list of commercial DACs to consider if I ever decide to go commercial instead of DIY along with the Denefrips Terminator. AND am very interested in how the new Gustard R26 R2R DAC stacks up along with whatever comes out based on the latest AKM offerings.
But at this point, I'm getting sufficiently good SQ that I'm not driven to upgrade, unless someone does a good AKM-based DAC Hat.
Curious about the custom AKM4490 DAC you mention. Have you posted about it here or elsewhere? I'd love to learn more about it.
Also I remember you had high hopes about a new ROLM DAC chip, has that fallen by the wayside?
AND I also agree that Allo seems to be at the very least dormant, if not gone. No responses from CDSGames here since very early this year and they've been absent on other forums too. About the time they went dark Covid was hitting India hard, I fear for the worse. BUT hope they are ok and recover as a company.
Greg in Mississippi
Great to hear from you, I haven't been doing much audio recently nor on this site, so not aware of what you've posted recently.
I totally agree with you that the Katana is not now (and honestly never was) a top performing DAC in the sense of the high-end audio world. Of course, this thread is about "Getting the best out of..." this unit, so it was never touted as such. My impression is that it WAS the best commercial performer for an RPi DAC Hat as long as one was willing/able to use the best sounding 3 5V and a +-15V supply configuration. Without that, other offerings of that time (including Allo's Boss Rev1.2) were competitive. AND if reasonably good supplies were used, it was hard to justify it on a bang-for-the-buck basis. AND even with the expensive exotic power supplys I used, I had no illusions that it was a world-beater, just the best RPi DAC Hat I'd tried at that time.
AND of course, I'm back here helping someone with questions about a Katana they own, not touting it as a top DAC or suggesting anyone purchase one. Unless I see strong proof-of-life from Allo, there's no way I'd suggest someone try to get one today!
I have not kept up with other commercial RPi DAC Hat offerings, so don't know where it stands today. My gut feel is that the novelty of the RPi DAC Hat has largely passed and other configurations are more popular.
Happy to hear the Holo Spring 3 is a good performer. Its on my list of commercial DACs to consider if I ever decide to go commercial instead of DIY along with the Denefrips Terminator. AND am very interested in how the new Gustard R26 R2R DAC stacks up along with whatever comes out based on the latest AKM offerings.
But at this point, I'm getting sufficiently good SQ that I'm not driven to upgrade, unless someone does a good AKM-based DAC Hat.
Curious about the custom AKM4490 DAC you mention. Have you posted about it here or elsewhere? I'd love to learn more about it.
Also I remember you had high hopes about a new ROLM DAC chip, has that fallen by the wayside?
AND I also agree that Allo seems to be at the very least dormant, if not gone. No responses from CDSGames here since very early this year and they've been absent on other forums too. About the time they went dark Covid was hitting India hard, I fear for the worse. BUT hope they are ok and recover as a company.
Greg in Mississippi
Christoph,
Others can chime in too, but I'd start with good regulation, sufficient current capability (at least 1A per rail), and a reasonable base of installations so you can be assured it works as presented without introducing other issues.
The one from Sparkos Labs you linked is very similar to what I am using in my setup if built with their regulators, so I can comfortably say it should be ok. Just in case you missed this, the + & - regulators are purchased separately.
Thel has been around for awhile and when I searched DIYAudio, I found a lot of references to their products (not only the linked regulator), so it sounds like a worthwhile option to vet too.
Again, ,there are others in the 1st post of this thread, including one that some had some issues with and how they rectified them. So other options, but not a lot from EU sources.
I hope this helps.
Greg
Others can chime in too, but I'd start with good regulation, sufficient current capability (at least 1A per rail), and a reasonable base of installations so you can be assured it works as presented without introducing other issues.
The one from Sparkos Labs you linked is very similar to what I am using in my setup if built with their regulators, so I can comfortably say it should be ok. Just in case you missed this, the + & - regulators are purchased separately.
Thel has been around for awhile and when I searched DIYAudio, I found a lot of references to their products (not only the linked regulator), so it sounds like a worthwhile option to vet too.
Again, ,there are others in the 1st post of this thread, including one that some had some issues with and how they rectified them. So other options, but not a lot from EU sources.
I hope this helps.
Greg
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Hi Greg,
The custom AK4499 dac started out as an evaluation board, which was modified a little. Another board was designed to work along with the eval board so as to allow a lot of experiments with ultra-low close-in phase noise clocking and with hardware conversion of PCM audio (such as CD rips) to DSD256. That's because listening tests seem to show that many dacs sound subjectively better operating in DSD256 mode (or higher, such as DSD512 or DSD1024 for certain dacs). Why that is something we could talk about, but as a practical matter I would just suggest to try it. Good clocking may more necessary for DSD than for PCM, however. Also, most people operating dacs in DSD256 mode are using software to do the PCM -> DSD conversion. Most popular program for that is HQ Player.
Anyway, some other things about the custom AK4499 dac include a custom discrete dual Vref (AVCC) power supply. That was done because Vref gets multiplied into the analog audio output. How the voltage regulator sounds is therefore critical. Another thing is that the dac has is a custom discrete output stage (although there is still one opamp per channel for I/V conversion). The dac sounds pretty good, better than any commercial dac I have heard so far. Of course, it would have to cost more than most dacs if it were commercialized because of complexity and because of passive component quality.
Regarding Rohm BD34301EKV, I still think it has some promise but it hasn't really taken off in commercial dac designs. For one thing it doesn't measure as well as AK4499 or as well as the ES9038 dac chips. As it happened I was asked to help a friend with some other stuff so the Rohm project sort of got put on a back burner. In the meantime AKM announced the new AK4499EX (the replacement for the now obsolete AK4499 in use here). So the next dac project will probably either be AK4499EX or else a discrete resistor dac. Still thinking about it.
Mark
The custom AK4499 dac started out as an evaluation board, which was modified a little. Another board was designed to work along with the eval board so as to allow a lot of experiments with ultra-low close-in phase noise clocking and with hardware conversion of PCM audio (such as CD rips) to DSD256. That's because listening tests seem to show that many dacs sound subjectively better operating in DSD256 mode (or higher, such as DSD512 or DSD1024 for certain dacs). Why that is something we could talk about, but as a practical matter I would just suggest to try it. Good clocking may more necessary for DSD than for PCM, however. Also, most people operating dacs in DSD256 mode are using software to do the PCM -> DSD conversion. Most popular program for that is HQ Player.
Anyway, some other things about the custom AK4499 dac include a custom discrete dual Vref (AVCC) power supply. That was done because Vref gets multiplied into the analog audio output. How the voltage regulator sounds is therefore critical. Another thing is that the dac has is a custom discrete output stage (although there is still one opamp per channel for I/V conversion). The dac sounds pretty good, better than any commercial dac I have heard so far. Of course, it would have to cost more than most dacs if it were commercialized because of complexity and because of passive component quality.
Regarding Rohm BD34301EKV, I still think it has some promise but it hasn't really taken off in commercial dac designs. For one thing it doesn't measure as well as AK4499 or as well as the ES9038 dac chips. As it happened I was asked to help a friend with some other stuff so the Rohm project sort of got put on a back burner. In the meantime AKM announced the new AK4499EX (the replacement for the now obsolete AK4499 in use here). So the next dac project will probably either be AK4499EX or else a discrete resistor dac. Still thinking about it.
Mark
Long live the Katana.
After four years of use and a presumably heat-related defect in the OpAmps AND the controller, I have now added a simple linear power supply (780x,790x). Thank you for the encouragement, it was worth it.
The only question left for me is whether a fourth power supply would actually bring audible improvements. With 4 power supplies, would the RPi itself need a high-quality one or would allo's plug-in power supply suffice? At the moment I use a Shanti on the RPi and on the controller/DAC.
I wanted to retire the Katana, but a Topping E50 that I bought on a trial basis was significantly worse in terms of resolution, bass and precision. Luckily I could get replacement boards from allo.
After four years of use and a presumably heat-related defect in the OpAmps AND the controller, I have now added a simple linear power supply (780x,790x). Thank you for the encouragement, it was worth it.
The only question left for me is whether a fourth power supply would actually bring audible improvements. With 4 power supplies, would the RPi itself need a high-quality one or would allo's plug-in power supply suffice? At the moment I use a Shanti on the RPi and on the controller/DAC.
I wanted to retire the Katana, but a Topping E50 that I bought on a trial basis was significantly worse in terms of resolution, bass and precision. Luckily I could get replacement boards from allo.
