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DC blocking capacitors audibility.

MaxwellsEq

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I will rephrase it in EIA electron theory terms:
What characteristics apply in AC analysis of coupling capacitors?
What characteristics apply in DC analysis of coupling capacitors?
Other questions fallow:
Is your analysis based on an operating impedance, or a total short? or do you look at both in consideration?
That's nothing like your previous question.

I honestly think you are trying to convince us you know stuff. But I'm not convinced you do. I think you hope you might get by with scraping questions from somewhere, because "nobody really knows anything anyway", but unfortunately quite a lot of people do know real stuff.

Some of this also reminds me a bit like high schoolers placing their homework questions on stack overflow.
 

nutzandvoltz

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That's nothing like your previous question.

I honestly think you are trying to convince us you know stuff. But I'm not convinced you do. I think you hope you might get by with scraping questions from somewhere, because "nobody really knows anything anyway", but unfortunately quite a lot of people do know real stuff.

Some of this also reminds me a bit like high schoolers placing their homework questions on stack overflow.
but you don't answer the question.
And your criticism doesn't detract from you not answering the question.
 

fpitas

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Ken Tajalli

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Can I assume that none of this "comparing" was done with basic controls?
Yes you may.
After all he is not really an engineer of any calibre, with no engineering achievements under his belt.
He has no degree, no industry experience, all his so-called designs don't perform. So yeah . . .
That's what I assume.
 

SIY

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Yes you may.
After all he is not really an engineer of any calibre, with no engineering achievements under his belt.
He has no degree, no industry experience, all his so-called designs don't perform. So yeah . . .
That's what I assume.
Engineering expertise is NOT the same as sensory testing expertise.
 

IAtaman

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Yes you may.
After all he is not really an engineer of any calibre, with no engineering achievements under his belt.
He has no degree, no industry experience, all his so-called designs don't perform. So yeah . . .
That's what I assume.
What does his industry experience and engineering achievements have anything to do with whether those comparisons you mentioned were done with any sort of control or not?
 

SIY

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I will rephrase it in EIA electron theory terms:
What characteristics apply in AC analysis of coupling capacitors?
What characteristics apply in DC analysis of coupling capacitors?
Capacitance and leakage.

Cut and paste is not a substitute for understanding and relevant experimental data.
 

fpitas

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actually, I'm proving a point that you don't know nothing when you reply to a thread like this.

or at least that what appears to be Forum Exposed
Says you!

/;)
 

mhardy6647

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Thought I'd post a synopsis of this thread to date.
1698092911169.png



You're quite welcome.
;)
 

musicforcities

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Well if the source goes kabloui and sends dc down the line and the amp sends it to your speaker, your sound quality might degrade to zero.

I once witnessed an amp without dc filtering at input, when nothing was playing, slowly move woofer drivers to full excursion and stay there for a bit until they slowly returned to center. Thank god the tweeter was not fried. Was it dc at input or the amp itself? Who knows. But I never trusted it again. also had an Adcom 535 pop a transistor and send a spike down the channel before the rail fuse blew.

Give me speaker protection and dc filtering.
 

MaxwellsEq

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Well if the source goes kabloui and sends dc down the line and the amp sends it to your speaker, your sound quality might degrade to zero.

I once witnessed an amp without dc filtering at input, when nothing was playing, slowly move woofer drivers to full excursion and stay there for a bit until they slowly returned to center. Thank god the tweeter was not fried. Was it dc at input or the amp itself? Who knows. But I never trusted it again. also had an Adcom 535 pop a transistor and send a spike down the channel before the rail fuse blew.

Give me speaker protection and dc filtering.
I agree. This is one of these areas where, there may be an audible benefit from not using a capacitor to filter DC (if the df metric guys are right) because of the elimination of phase impacts in the audio band, but the longevity and safety downsides convince me I can live without this audible benefit. Perhaps the answer is to always use a DC servo, but anything that stops DC passing through the chain is essential. I can't afford to keep replacing my kit.
 

SSS

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Have an old Crown DC-300 power amp which is designed to amplfiy audio as well DC by intention. To save my speakers I added between output and speaker a relay box which disconnects when DC voltage is recognized. Many power amplifiers have this function built in like my Yamaha M-85 power amp.
 

Ken Tajalli

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Just a clarification regarding my previous post about Mojo, dc blocking cap and servo.
I did mention for whatever its worth.
What Rob Watts had said was about a particular scenario, involving a particular Device.
I doubt if his reasoning can be applied literary to every situation, i.e. dc servo is better than a dc blocking cap.
In the case of Mojo1, he blamed the rose-tinted tone of it on the dc blocking cap between the DAC output and the analogue section.
When the unit first came out, the early adoptors where existing Mojo owners. Almost immediately, reports came in from various sources regarding the change in sound quality and/or tone.
It was too many, in a short span of time to be accidental.
Rob Watts put up a post (perhaps grudgingly ) that he was aware of it, and offered his explanation .
Mojo 1, is the only Chord DAC with such a capacitor. it was done to save a little production cost.
 

solderdude

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I actually owned the original Mojo for a year before I sold it.
Reason for selling... I did not want to go through the hassle of having to replace the battery after a few years of usage.

There was no 'sound signature' in it.
Did some blind tests with EMU0404 and it was impossible to tell them apart.
I guess the EMU had the same coupling cap in there.
 

Ken Tajalli

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I actually owned the original Mojo for a year before I sold it.
Reason for selling... I did not want to go through the hassle of having to replace the battery after a few years of usage.
Better not buy any cellphones, rechargeable audio gear of any kind, etc, as all would need changing the batteries after a few years.
Didn't you know, you could get decent ones off Aliexpress for $20? or £40 from Chord direct?
They replaced the USB input chip and the battery for me for less than £100, including postage.
There was no 'sound signature' in it.
Did some blind tests with EMU0404 and it was impossible to tell them apart.
I guess the EMU had the same coupling cap in there.
Who knows, perhaps! or you weren't expecting to find any differences, and you didn't.
Isn't that what we call expectation bias? works with blind tests too.
Why did you buy one in the first place? did Rob Watts woo you :D?
We are going off-topic, I shall stop now.
 

solderdude

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Better not buy any cellphones, rechargeable audio gear of any kind, etc, as all would need changing the batteries after a few years.
Didn't you know, you could get decent ones off Aliexpress for $20? or £40 from Chord direct?
They replaced the USB input chip and the battery for me for less than £100, including postage.
Oh I know. I can easily replace them myself.
Decent ones from Ali-express... yeah right.
Have used some of those for other battery fed devices and they are usually really poor quality.
They work fine with decent capacity the first 10 recharges or so and then quickly drop in capacity.

or you weren't expecting to find any differences, and you didn't.
Isn't that what we call expectation bias? works with blind tests too.
You do not seem to understand what blind tests are.

Expectation bias is more likely to let you hear differences by suggestion a circuit was audibly improved.

Why did you buy one in the first place? did Rob Watts woo you :D?
We are going off-topic, I shall stop now.
I did not buy it. I got it as a gift from a company I reviewed and improved some headphones for. Gave it away to someone who wanted it.
I found the interface awkward, the weight a bit high and it did not offer anything I needed nor did it in a better way than other DACs I had.
I did not need the headphone out which is quite decent.

I highly doubt a DC blocking cap (not even an output cap) would change the sound quality in the way Rob described unless they used some really crappy 0508 or smaller Z5U coupling cap that had a too small value perhaps in which case we can put that down to poor engineering or poor component choice.

Anyway that would be very visible with multitones by a rise in distortion at lower frequencies.
Oh... right .... I forgot... that may be -300dB down so not measurable but quite audible and not only to Rob W but obviously also owners and reviewers.
 
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