Thank you! I'll do another video and take the power up. Just being timid as this is an expensive card and I have 5 voltage rails going to it (kind of a complicated power system).
@@KissAnalog Yeah, 5 rails, I dig that...back in the days of yore when I was young(er) and just as smart as I am today, I did a hybrid ttl/cmos/24v relay/12v stepper bit of business, cobbling together whatever I had to do a greenhouse climate control thing on the cheap. +-5v,+-15v,+12v+24v...crazy, but low voltages and currents for the most part. Was always paranoid about ground loops and the like, it all worked out though, for over 2 decades. Mebbe stop at 40watts or so, I would be really REALLY reluctant to be playing +-60v especially on 45yo power supplies!
I love class D amps there very underrated. These are very expensive for what they are though, I understand Gan fets are expensive and they will be low volume production amps, but still there way to expensive for me to consider, but still a very nice class D amp, one of the best I've seen.
@@KissAnalog That would be awesome, I would certainly give it a try, I have my own made class D amps all around my house, I mostly just use one of the TI class D chips though.
Thanks for the video, hope you're feeling better. The trouble with GaN fets is they don't improve sound quality so what's the benefit to the listener? They only enable smaller boxes which benefits the manufacturer and since they are so costly I think audio equipment is better off without them until the prices drop. The other thing is the bode plot, I think you ran the db scale with too much separation (probably because of the phase problems). I'd like to see the bode plot with .5 db separation instead of 3 or 4 db separation. It will give a better indication of linearity. You can buy a completed Purifi class D amp for $1k and they get very good reviews, I'm thinking of getting one. I did build and ICE amp that I'm using and it sounds very good with my DIY tube preamp.
Less components gets you closer to the source. I have it and would not trade it for purifi despite it measuring better. No heat 90+% efficiency means longer life that would be the selling point for me. Cost 500 more than a purifi though complete not diy prices. Subjectively sound wise I think it's better than all the class a class d , class ab I encountered/ heard.
@@wric01 Who cares about Heat & it measuring better. Listening to a good class a/b / A amplifier against the GAn is a no brainer, The GaN is all hype but poor sound.
Thanks for the suggestion! I will increase the resolution next time on the bode plot so we can see the actual resolution down to the best scale that is possible. I like the great comments on this. I am not sure about class D yet, I like the idea, and as a power supply engineer, I really like the idea;) I think the feedback on the flatness or sound stage not being 'live' (as I think is the feedback), I think it might be more due to the amp feedback design versus the Class D nature. In regards to the GaN improvement in Class D, if done right, it theoretically should improve it as the rise/fall times are faster so less deadtime between pulses in comparison to MOSFETs. Make sense?
@@wric01 I don't know that GaN's use less components though, you still need the class D typology. As for heat, I'm running the ICE modules and they get barely warm. If we're going to do listening comparisons they have to be DBT's (double blind tests), that's science and I still maintain that the sound of class D can be made very neutral, the component that you want to use with it to create the sound you like is the preamp like PS audio does with their monoblocks. The other thing I found is that other components in the chain make a big difference. What speakers and preamp are you using to evaluate the modules? When I upgraded my speakers I could hear differences in my old amp and my class D.
Thanks RM! It is true, if there's switching - then there needs to be care. As a power supply engineer, I can say that a proper design should be free of RFI/EMI:)
Good video. Glad to see you back on the bench with the test gear out. Thousand dollar amps, heck yeah, let's see what they can do. At least push 100 watts per channel and let's see what kind of heat they pump out and their distortion.
Thanks Tron! I have a box full of boards to test - and amps waiting to get built and tested. I've fallen way behind and will get some time in between now and the end of the year. It would be great to break 15k subs;)
Hi there…. Most of the discussions on your videos I feel are over my head but appreciate what I learnt to date from you. I’m wondering if there is a GaN FET headphone amplifier design out there that you can recommend. I like what is the promised GaN technology and plan to buy the Orchard Audio duel mono blocks for my two channel system. I understand that Purifi sells GaN FET Class D Modules, for 2 channel stereo amplification as a kit, do you have any experience or thought with about it?
Thanks for your feedback! I don't know of a headphone amp yet with GaN, but I wouldn't be surprised if they are out there. I did do a project with a board that I really like. Here's the link: th-cam.com/video/hDI1azLY6wo/w-d-xo.html
For you Bode plots, what load/impedance were you using on this amp? That peaking at 100kHz should not be there for standard 16/8/4 ohm loads. Great video BTW!
Good video I know this is a old video. Has anyone compare this to the Nad M23 master series class D power amp? Audioholics gave the Nad M23 an excellent Review, thats why im curious. Or has anyone tried both with real world listening to both? Thank you in advance
@@JasonLeaman He would only loan these but he did approach me;) I have a theory that too much feedback can have that flat response. Great for low distortion but makes it too tight. Thoughts?
The human hearing is a funny thing, if you get to perfect specifications on an audio component, do we perceive it as boring, flat and unmusical. Nobody would perceive a tube-TV as superior, but many think that tube-audio is. :-)
@@KissAnalog Yeah he loaned me a unit to then hounded me every hour to know my thoughts and when it will be back, its like he wanted me to bragg about them and help him sell because of my review, i deleted my 5 hours of footage and testing and told him to pound sand.
Thank you very much for taking the time to look at these and make the video.
Thank you for the loaners;) BTW, I should have mentioned that the THD is only as high as it is because that is the level of my signal source;)
You're like a surgeon with power delivery. Wow. Cool video man
LOL big thanks!!!
MOAR POWAH! Yeah, 100W tests would be great:-) Thanks for all the work you do, very educational!
Thank you! I'll do another video and take the power up. Just being timid as this is an expensive card and I have 5 voltage rails going to it (kind of a complicated power system).
@@KissAnalog Yeah, 5 rails, I dig that...back in the days of yore when I was young(er) and just as smart as I am today, I did a hybrid ttl/cmos/24v relay/12v stepper bit of business, cobbling together whatever I had to do a greenhouse climate control thing on the cheap. +-5v,+-15v,+12v+24v...crazy, but low voltages and currents for the most part. Was always paranoid about ground loops and the like, it all worked out though, for over 2 decades. Mebbe stop at 40watts or so, I would be really REALLY reluctant to be playing +-60v especially on 45yo power supplies!
I love class D amps there very underrated. These are very expensive for what they are though, I understand Gan fets are expensive and they will be low volume production amps, but still there way to expensive for me to consider, but still a very nice class D amp, one of the best I've seen.
Thanks for this feedback! I agree, the price of the GaN fet should only increase the price by a few dollars... I'll have to do a design of my own;)
@@KissAnalog That would be awesome, I would certainly give it a try, I have my own made class D amps all around my house, I mostly just use one of the TI class D chips though.
Thanks for the video, hope you're feeling better.
The trouble with GaN fets is they don't improve sound quality so what's the benefit to the listener? They only enable smaller boxes which benefits the manufacturer and since they are so costly I think audio equipment is better off without them until the prices drop.
The other thing is the bode plot, I think you ran the db scale with too much separation (probably because of the phase problems). I'd like to see the bode plot with .5 db separation instead of 3 or 4 db separation. It will give a better indication of linearity.
You can buy a completed Purifi class D amp for $1k and they get very good reviews, I'm thinking of getting one. I did build and ICE amp that I'm using and it sounds very good with my DIY tube preamp.
Less components gets you closer to the source. I have it and would not trade it for purifi despite it measuring better. No heat 90+% efficiency means longer life that would be the selling point for me. Cost 500 more than a purifi though complete not diy prices. Subjectively sound wise I think it's better than all the class a class d , class ab I encountered/ heard.
@@wric01 Who cares about Heat & it measuring better. Listening to a good class a/b / A amplifier against the GAn is a no brainer, The GaN is all hype but poor sound.
Thanks for the suggestion! I will increase the resolution next time on the bode plot so we can see the actual resolution down to the best scale that is possible.
I like the great comments on this. I am not sure about class D yet, I like the idea, and as a power supply engineer, I really like the idea;) I think the feedback on the flatness or sound stage not being 'live' (as I think is the feedback), I think it might be more due to the amp feedback design versus the Class D nature. In regards to the GaN improvement in Class D, if done right, it theoretically should improve it as the rise/fall times are faster so less deadtime between pulses in comparison to MOSFETs. Make sense?
@@KissAnalog Good point Eddie, I didn't think about the rise/fall time factor. I'd like to see the comparison, that might be fun!
@@wric01 I don't know that GaN's use less components though, you still need the class D typology. As for heat, I'm running the ICE modules and they get barely warm.
If we're going to do listening comparisons they have to be DBT's (double blind tests), that's science and I still maintain that the sound of class D can be made very neutral, the component that you want to use with it to create the sound you like is the preamp like PS audio does with their monoblocks.
The other thing I found is that other components in the chain make a big difference. What speakers and preamp are you using to evaluate the modules? When I upgraded my speakers I could hear differences in my old amp and my class D.
Also check it for RFI/EMI. If one shares Amateur/SWL radio with the Audio hobby, you might find these switch mode amps don't mix well. Thumbs up!
Thanks RM! It is true, if there's switching - then there needs to be care. As a power supply engineer, I can say that a proper design should be free of RFI/EMI:)
Good video. Glad to see you back on the bench with the test gear out. Thousand dollar amps, heck yeah, let's see what they can do. At least push 100 watts per channel and let's see what kind of heat they pump out and their distortion.
Thanks Tron! I have a box full of boards to test - and amps waiting to get built and tested. I've fallen way behind and will get some time in between now and the end of the year. It would be great to break 15k subs;)
Hi there…. Most of the discussions on your videos I feel are over my head but appreciate what I learnt to date from you.
I’m wondering if there is a GaN FET headphone amplifier design out there that you can recommend. I like what is the promised GaN technology and plan to buy the Orchard Audio duel mono blocks for my two channel system.
I understand that Purifi sells GaN FET Class D Modules, for 2 channel stereo amplification as a kit, do you have any experience or thought with about it?
Thanks for your feedback! I don't know of a headphone amp yet with GaN, but I wouldn't be surprised if they are out there.
I did do a project with a board that I really like. Here's the link: th-cam.com/video/hDI1azLY6wo/w-d-xo.html
At this time I am the only manufacturer that sells GaN FET Class D modules.
The price tag is crazy. I cannot see anything even remotely approaching exotic - not even the eGAN MOSFET's.
Nuts.
Thanks! I have to agree - it seems a bit steep.
Hi Eddie, THIS IS A GREAT video. Thank you for the detail information. I appreciate you sharing you immense knowledge.
Thanks so much! I appreciate you!
I bought them but don't have the chassis ready, later I'll assemble them and try.
Thanks! I'd love to hear your thoughts on how they perform!
Thank you for your support.
Nice video , thanks for this I have a question but I will hold off till a bit later . So much to learn !!! 😊
Thank you! I'll be happy to hear it when you are ready.
For you Bode plots, what load/impedance were you using on this amp? That peaking at 100kHz should not be there for standard 16/8/4 ohm loads. Great video BTW!
Thanks for the feedback! I'd have to double check but I think it was 8 ohms.
Brett? Brett Favre?? WOW!
LOL Thank you - that's perfect! I've heard that before;)
Hi, great video. Did you ground the outputs on that amp? This is a balanced amplifier so the output should not be grounded.
Thanks for the great question! No, I only tied them to the 8 0hm load an differential probes to the scope;) I appreciate your feedback!
@@KissAnalog Thanks :)
Good video
I know this is a old video.
Has anyone compare this to the Nad M23 master series class D power amp?
Audioholics gave the Nad M23 an excellent Review, thats why im curious.
Or has anyone tried both with real world listening to both?
Thank you in advance
That's a great question. Unfortunately this was a loaner so I had to return it.
that's all you got for heat sinking "pretty darn cool" :)
So cool;) LOL Thanks Paul!
Great review! Have you seen my mails to you? :-)
Thank you Fried Mule! Always a treat to see you post;) I'll check my email now!
oooooooo
LOL
Sad face :( Canadian friend no like :(
Don’t like Class D?
@@KissAnalog NO class d & Leo spams a'lot of groups about how his stuff is the best of the best of the best, but the sound is so flat and boring..
@@JasonLeaman He would only loan these but he did approach me;) I have a theory that too much feedback can have that flat response. Great for low distortion but makes it too tight. Thoughts?
The human hearing is a funny thing, if you get to perfect specifications on an audio component, do we perceive it as boring, flat and unmusical. Nobody would perceive a tube-TV as superior, but many think that tube-audio is. :-)
@@KissAnalog Yeah he loaned me a unit to then hounded me every hour to know my thoughts and when it will be back, its like he wanted me to bragg about them and help him sell because of my review, i deleted my 5 hours of footage and testing and told him to pound sand.