Bateman standardized the test at 1mfd to be able to test other types and compare. In practice, much larger values are used... especially in FB to ground point. A truly critical place. All make things worse. [BTW I have measured much higher with different loading Z and cap values and voltages]
And considering we typically use more than one cap in typical VFB amps (I/O and FB) the situation is compounded. Add to that several pieces of gear in the audio system and it becomes an even greater significant issue. Only by going to direct-coupled and dc servo could the audio system be improved with all polar caps in the system removed.
Again i have more data but DIYAudio file limitation prevents adding here. The effect of DA dominates over thd sine wave tests also.
An addition to the polar model shown above by Bateman, would also include this modelling ... https://hal.archives-ouvertes.fr/hal-00140547/document
Use both in SPICE and begin to see the real world affects. Then add the high DA components of high value of the polar types to the models. What a mess compared to PP film model... A PP can be just a C in the schematic and give accurate results.
Oh and just use ever larger C values and keep the polar type? Really? Thats the answer? Not in the real competitive world of practice.
THx-RNMarsh
And considering we typically use more than one cap in typical VFB amps (I/O and FB) the situation is compounded. Add to that several pieces of gear in the audio system and it becomes an even greater significant issue. Only by going to direct-coupled and dc servo could the audio system be improved with all polar caps in the system removed.
Again i have more data but DIYAudio file limitation prevents adding here. The effect of DA dominates over thd sine wave tests also.
An addition to the polar model shown above by Bateman, would also include this modelling ... https://hal.archives-ouvertes.fr/hal-00140547/document
Use both in SPICE and begin to see the real world affects. Then add the high DA components of high value of the polar types to the models. What a mess compared to PP film model... A PP can be just a C in the schematic and give accurate results.
Oh and just use ever larger C values and keep the polar type? Really? Thats the answer? Not in the real competitive world of practice.
THx-RNMarsh
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Works for a lot of people. Believe it or not there are plenty of reference designs for SOTA DAC's and A/D's that are IC limited on performance using mundane passives (even at the -130dB level). Cell phone guys beat you up on the numbers and achieve them, open up your phone and see what they use the specs on component max height are crazy these days. By this I mean the phones that support a separate hi-end media path. Look what happened to Pono and their bizarre form factor.
Choosing a cost effective solution that achieves a design goal is engineering not fashion.
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If you just crawled out from under a rock, RM, there's chips like the ES9038Q2M that are for mobile apps. With a decent I-V implementation, they have absolutely no one to apologize to. And I'm sure a high quality bipolar electrolytic coupling cap is part of that.
The whole DA thing has been flogged to death, can we move onto something else? Unless you're working on precision DC measurements... (which is the first thing I think of when I think of audio playback electronics
)
The whole DA thing has been flogged to death, can we move onto something else? Unless you're working on precision DC measurements... (which is the first thing I think of when I think of audio playback electronics
)
Did you read, cell phone audio channels that achieve the stated performance numbers of the IC data sheets? BTW I don't consider things like the Pono anything more than a cell phone without the phone. Many cell phone makers now offer a full ESS based DAC + amplifier audio channel. Most if not all the amplifier technology used comes from the now nearly defunct xDSL business (something that actually made serious money for a while).
The papers that are continuously quoted here are engineering exercises like how to repeatably measure X THD. If you don't want to talk about measurable tangible results but rather metadata and interweb chatter that is your prerogative.
Fortunately, there are thousands of people reading this forum from all over the world and I put up info for them as well. I am not going to attempt to change your mind about the thd vs the DA and its' sound impressions. That is for others to listen and decide.
I agree the digitization of audio has been an over-all improvement in S/N and thd/IM and I am all for it. It continues to get refined. I prefer the HD downloads. I also believe from experience that no polar caps in the signal path will 'sound' more accurate; probably due to their high DA.
THx-RNMarsh
I agree the digitization of audio has been an over-all improvement in S/N and thd/IM and I am all for it. It continues to get refined. I prefer the HD downloads. I also believe from experience that no polar caps in the signal path will 'sound' more accurate; probably due to their high DA.
THx-RNMarsh
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Ironic you say that, the intell I got in China was that since the phones often ship at negligible margins the money came from HD downloads. There was also a hope 3D TV would take off but it met with less than stellar acceptance.
I thought you might have a pithy comment about the wonders of 3D TV after all it's hard to argue adding a whole dimension isn't more accurate.
BTW I've been binging Masterchef UK, it's so Brit compared to the US version. It's too bad the the young buff guy who wanted to bring health consciousness to hi-end dining dropped dead running a marathon.
I had a viewmaster as a kid, I knew 3D was rubbish . Actually when I was at uni they were trying to work out how to do goggle-free 3D even in the 80s. Such a long gestation and such a quick failure
I love masterchef. Esp when they complain about presentation then dive in with a serving spoon.
You might like the horrible histories spoof YouTube
Edit: Favourite ever masterchef moment was when Michel Roux Jr asked for seconds. The look on the chefs face was priceless!
. Actually when I was at uni they were trying to work out how to do goggle-free 3D even in the 80s. Such a long gestation and such a quick failure I love masterchef. Esp when they complain about presentation then dive in with a serving spoon.
You might like the horrible histories spoof YouTube
Edit: Favourite ever masterchef moment was when Michel Roux Jr asked for seconds. The look on the chefs face was priceless!
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ditto mp3 et al and highly compressed formats etc. My reference is real music = accuracy.
-RM
same thing happened with surround sound or multi-channel. Most receivers still have multi-channel amps and decoders but few use it that way. Mostly for video systems and not audio. 3D at its best is great IMO. Avatar was first and very good 3D. But a lot of it is faked 3D. Again it depends on the source material.
as for excellent dac used in cell phones.... and using polar coupling caps... they could sound better if the polar types werent used. And, with sources which are compressed and bit manipulated? So, not sure what is gained in over all sound and accuracy. And what do we listen with these cell phones? ear buds? Built-in speaker? One good part/component does not make a great Hi-End sound.
THx-RNMarsh
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Yea, how many of these phones are being used as the source component in a decent playback system (one which is revealing)?
OK. If you like to call that real 3D. I call it faked 3D.
Never-the-less, todays 3D can be excellent. Right out in the room between the screen and viewer/you.
If we are back to Likes again, I cant complain.
THx-RNMarsh
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Maybe you havent seen good 3D. I get excellent results at my house. Adds to realism IMO when done well.
I just attended a 4D movie in Bangkok. There was seat moving in all axis, snow falling from above, water sprayed and wind in your face in sync with movie dynamics.... an extra physical dimension that added realism... even though faked.
-RM
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