Dear Mr. Pass,
I have not build an amplifier of your s yet, but hopefully when my schedule clears up, I would very much like to try one.
However on a different note, the sound quality of the entire system still depends on the rest of the partnering components (DACs, volume control etc) irregardless of how well your amplifers are designed.
Since you also design IV converters why not just merge your IV converter and your amplifier into one. Make it a power DAC. Volume control can be implemented digitally on one of those 24 bit DSPs that upsample from 16 bit. I think there are a few out there. The output of a 24 bit sigma Delta DAC could then be fed directly into your amp (differential input). This could effectively mean the only thing that stands between your DAC chip and your speakers is only one transistor/FETs (or maybe 2).Can't think of anything more direct...
There would then be no ambiguity on how the rest of the components will affect the sound...
Oon
I have not build an amplifier of your s yet, but hopefully when my schedule clears up, I would very much like to try one.
However on a different note, the sound quality of the entire system still depends on the rest of the partnering components (DACs, volume control etc) irregardless of how well your amplifers are designed.
Since you also design IV converters why not just merge your IV converter and your amplifier into one. Make it a power DAC. Volume control can be implemented digitally on one of those 24 bit DSPs that upsample from 16 bit. I think there are a few out there. The output of a 24 bit sigma Delta DAC could then be fed directly into your amp (differential input). This could effectively mean the only thing that stands between your DAC chip and your speakers is only one transistor/FETs (or maybe 2).Can't think of anything more direct...
There would then be no ambiguity on how the rest of the components will affect the sound...
Oon
Many of the suggestions I receive are in the form of how I can integrate
components together to form integrated amplifiers, amplifiers with crossovers
built in, power DACs, and so on.
However I am largely headed the other way, separating out power supplies,
output stages, and front end circuits into separate pieces so that they can
be mixed and matched at will. While it results in many more boxes, it
gives me a playing field to easily listen to the differences in component
sub-circuits and refine them while keeping other elements constant.
But then that's me. Someone else will likely be happy to integrate
components so as to make life easier for customers.
components together to form integrated amplifiers, amplifiers with crossovers
built in, power DACs, and so on.
However I am largely headed the other way, separating out power supplies,
output stages, and front end circuits into separate pieces so that they can
be mixed and matched at will. While it results in many more boxes, it
gives me a playing field to easily listen to the differences in component
sub-circuits and refine them while keeping other elements constant.
But then that's me. Someone else will likely be happy to integrate
components so as to make life easier for customers.
Many of the suggestions I receive are in the form of how I can integrate
components together to form integrated amplifiers, amplifiers with crossovers
built in, power DACs, and so on.
However I am largely headed the other way, separating out power supplies,
output stages, and front end circuits into separate pieces so that they can
be mixed and matched at will. While it results in many more boxes, it
gives me a playing field to easily listen to the differences in component
sub-circuits and refine them while keeping other elements constant.
But then that's me. Someone else will likely be happy to integrate
components so as to make life easier for customers.
Perfecto .........
However I am largely headed the other way, separating out power supplies,
output stages, and front end circuits into separate pieces so that they can
be mixed and matched at will.
funny, the other day I thought about doing that
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Dear Mr. Pass,
I respectly accept your opinions. In a hypothetical state if you were to build such and amp how would you go about doing it (DAC+amp) all in one. What sort of approach would you use?
1) use a combination your Zen I/V converter and your Aleph J amp?
2) use a bipolar to directly amplify the current from your DAC and couple that with a current source?
What sort of approach do you think makes the most sense....
Oon
I respectly accept your opinions
. In a hypothetical state if you were to build such and amp how would you go about doing it (DAC+amp) all in one. What sort of approach would you use?1) use a combination your Zen I/V converter and your Aleph J amp?
2) use a bipolar to directly amplify the current from your DAC and couple that with a current source?
What sort of approach do you think makes the most sense....
Oon
I think that is an outstanding idea!
But how do you keep grounding (loops, etc..) from becoming an issue?
sound more like a class-D Hypex active speaker concept
not quite true, there is no PWM involved.... I think it would be closer to using a gainclone power amp chip for I/V conversion.
I just think it would be cool if by addition of a few transistor we could directly drive a speaker using your DAC...
Oon
Dear Mr. Pass,
I respectly accept your opinions
1) use a combination your Zen I/V converter and your Aleph J amp?
2) use a bipolar to directly amplify the current from your DAC and couple that with a current source?
What sort of approach do you think makes the most sense....
Oon
Try 1) Zen I/V feeding Aleph J / F5 / Zen 9 / F3, or maybe even drop the Zen I/V and look at redoing the input of the F5 to cut one stage.
1) Well, I think one of the small challenges that I have is, that most 24 bit DACs are running from single supply, which means they will always have a DC component. Could probably be solved by adding a capacitor between Zen I/V converter and amplifier. But that would mean adding a capacitor in the signal path.
2) The issue is most 24 bit DAC are sigma deltas I think. This would require a differential amp in between. Having a differential amp would also automatically cancel out the DC component and solve the capacitor problem. However I am looking for single output DAC too. So one logical solution is to use 2 ZenI/V and feed the output to a Aleph J differential input.
I did consider modifying if the firststage of the F5 could be converted to a Zen I/V. After all I think one the wonderful thing about the Zen I/V is to be able to swing a high voltage swings (gain) by just using a higher resistor. The I/V conversion is actually done on the resistor. But unfortunately I think the same resistor is also used to determine bias for the Zen I/V transitors as well as determine the bias of the output stage. So with so many functions handled by one resistor, I doubt we will be getting a resistor value that fulfils so many functions. Plus there is also the problem of DC at the output of the DAC.
Care to comment on this Mr. Pass?
Oon
Goodpoint. However, I figured for those Vout DAC, what is happening inside is they are just incorporating their own Op amp inside the chip (but do correct me if I am wrong), which sort of goes again the philisophy of using minimal active components in the signal path. So basically I have my doubts that those V-out DACs will sound as good as I-out DAC with a Zen I/V converter.
But my knowledge on the internal workings of DAC is limited, so I might be wrong on this matter. I think I should put up a post in the Digital line level to find out the difference. My initial DAC I was thinking about is AD1853, but AD 1852 has a voltage out....
Oon
But my knowledge on the internal workings of DAC is limited, so I might be wrong on this matter. I think I should put up a post in the Digital line level to find out the difference. My initial DAC I was thinking about is AD1853, but AD 1852 has a voltage out....
Oon
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Hi Buzzforb. Thanks for the tip. However I am trying to avoid putting an op-amp in between the DAC and the Pass amp (internal to the DAC or external). Which sorts of defeats the philosophy of the Pass Amp. Do you happen to know if they are native V-out DACs or are they basically I DACs with op-amp outputs? Especially the ESS versions.
Agree that part about messing around with the DACs operation. I think it way too difficult...
Oon
THe ESS Dacs are Vout but are extremely well done. If you want to use the D1, then look at the AD 1865. IT is very highly regarded and used in the Audio Note Dacs. Get a Kit off ebay and change the output stage. From there you can tweak as you like. Take a look at this thread.
http://www.diyaudio.com/forums/pass-labs/190438-ss-120r085-depletion-mode-jfet-3.html#post2603798
http://www.diyaudio.com/forums/pass-labs/190438-ss-120r085-depletion-mode-jfet-3.html#post2603798
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