[doraymon]

I live in Canada and there are multiple options for Wurth ferrites.

As per recommendation from R.Watts, I used Wurth 74271633 (100Mhz-2.5Ghz) and Wurth 74271131 (1Mhz-1Ghz), both sized to fit well around my USB cable. Dont forget to order the key so you can remove and mix and match for best effect.

Thanks! Would you mind sharing a picture of the final result on the cable?

 

[Savage4]

After owning a black dave for 5 months I discovered a possibility major design flaw (also could just be my unit). Basically if you use Dave in Dac mode and in pre-amp mode with -3db gain there is a strong distortion in just one particular frequency. I don’t have enough training to tell what frequency but I tried multiple sound tracks and I’m sure it is there. The solution I find is that you need to decrease the gain to smaller than -13db and increase the gain of your separate amp. In this way that distortion disappears.
My setup: Aurender N100– usb — Dave — multiple amps — multiple headphones.
Also I guess it could be the output from Aurender has too large a value or has that particular distortion at that frequency.

 

[Triode User]

After owning a black dave for 5 months I discovered a possibility major design flaw (also could just be my unit). Basically if you use Dave in Dac mode and in pre-amp mode with -3db gain there is a strong distortion in just one particular frequency. I don’t have enough training to tell what frequency but I tried multiple sound tracks and I’m sure it is there. The solution I find is that you need to decrease the gain to smaller than -13db and increase the gain of your separate amp. In this way that distortion disappears.
My setup: Aurender N100– usb — Dave — multiple amps — multiple headphones.
Also I guess it could be the output from Aurender has too large a value or has that particular distortion at that frequency.

I would have a strong suspicion that -3db Dave output is simply too high for your amp and you are getting clipping distortion in the amp. In this case it is not a Dave design flaw but merely that your amp has a lower input requirement than normal. Because the issue is solved by turning Dave down to -13dB it sort of confirms the suspicion although that does seem quite low. Leave Dave at -13dB and move on?

 

[Savage4]

I would have a strong suspicion that -3db Dave output is simply too high for your amp and you are getting clipping distortion in the amp. In this case it is not a Dave design flaw but merely that your amp has a lower input requirement than normal. Because the issue is solved by turning Dave down to -13dB it sort of confirms the suspicion although that does seem quite low. Leave Dave at -13dB and move on?

I tried one speaker build-in amp with adjustable input impedance and one headphone amp so I don’t think it’s my amps.

 

[Triode User]

I tried one speaker build-in amp with adjustable input impedance and one headphone amp so I don’t think it’s my amps.

I assume you mean that the speaker with the built in amp has adjustable input sensitivity and not adjustable input impedance.

Your experiment might just mean that the speaker with the built in amp and your headphone amp both have relatively low maximum input voltages and that both are being driven into clipping and are distorting which is what you hear on some notes. Some amplifiers state what their maximum input levels are.

I am afraid I cannot remember what the Dave output voltage is at -3dB but I still suspect it is simply too high for both your headphone amp and the speaker with the built in amp.

 

[lojay]

After owning a black dave for 5 months I discovered a possibility major design flaw (also could just be my unit). Basically if you use Dave in Dac mode and in pre-amp mode with -3db gain there is a strong distortion in just one particular frequency. I don’t have enough training to tell what frequency but I tried multiple sound tracks and I’m sure it is there. The solution I find is that you need to decrease the gain to smaller than -13db and increase the gain of your separate amp. In this way that distortion disappears.
My setup: Aurender N100– usb — Dave — multiple amps — multiple headphones.
Also I guess it could be the output from Aurender has too large a value or has that particular distortion at that frequency.

It is likely to be your particular unit. When I received my first Dave, I used the Hifiman HE1000 and HE6 with the headphone output. After a while, serious distortion on loud passages manifested itself in the right channel. The distortion sounded like clipping. I emailed Chord's customer support who noted that the Hifiman headphones are very power hungry and are probably tripping the current protection on one side sooner than the other. The problem was fixed ultimately and my current unit (a replacement) has no discernable distortion even when driving loudspeakers through the RCA outputs. You may wish to contact Chord to inspect your unit.

 

[x RELIC x]

@Savage4, -3dB is 3Vrms which is very ‘hot’ for most amps. I wouldn’t say it’s a design flaw in the DAVE other than the default fixed output on all Chord DACs is high. Most amps expect around 2Vrms or lower.

Do you have any information/documentation stating the max Vrms Input your amps can handle? Conversely you can contact Chord to rule out / problem solve any fault with the DAVE.

 

[jonstatt]

Why is there a visible PCM plus and DSD mode that is even a user option? Why isn't it just an automatically selected DSD optimal mode and PCM optimal mode? Then that would free up a menu option meaning the crossfeed menu wouldn't be hidden when headphones were not connected.

 

[rayl]

Why is there a visible PCM plus and DSD mode that is even a user option? Why isn't it just an automatically selected DSD optimal mode and PCM optimal mode? Then that would free up a menu option meaning the crossfeed menu wouldn't be hidden when headphones were not connected.

Different code gets loaded onto fpga. Both cannot fit simultaneously.

 

[jonstatt]

Different code gets loaded onto fpga. Both cannot fit simultaneously.

I understand but it could still auto switch couldn't it?

 

[rayl]

I understand but it could still auto switch couldn't it?

It would take 10s of seconds to reboot. Not the best user experience if it were automatic.

 

[Rob Watts]

And that was the reason why I rejected auto switchover - losing nearly 20 seconds of music whilst it switches over was unacceptable.

My initial plan was to do it in 100 mS - but I could not get the DC servo to re-lock - so the delay is down to allowing the DC servo to reset the DC to zero - otherwise one would get loud bangs. And I tried lots of ways around this issue, but none was satisfactory.

 

[hmartin]

And that was the reason why I rejected auto switchover - losing nearly 20 seconds of music whilst it switches over was unacceptable.

My initial plan was to do it in 100 mS - but I could not get the DC servo to re-lock - so the delay is down to allowing the DC servo to reset the DC to zero - otherwise one would get loud bangs. And I tried lots of ways around this issue, but none was satisfactory.

Does this mean that it would be quick to change code in a separate M-Scaler.

It would for example be very nice to automatically pick reconstruction for different inputs, i.e. pick full 1 M taps for the USB and then have a BNC/optical for TV-decoder and Blu-ray and automatically pick minimum phase low latency for those inputs?

 

[jonstatt]

And that was the reason why I rejected auto switchover - losing nearly 20 seconds of music whilst it switches over was unacceptable.

My initial plan was to do it in 100 mS - but I could not get the DC servo to re-lock - so the delay is down to allowing the DC servo to reset the DC to zero - otherwise one would get loud bangs. And I tried lots of ways around this issue, but none was satisfactory.

Thanks for clarifying Rob. Incidentally talking of loud bangs, I have noticed that if I switch off the power at the back of DAVE while music is still playing I get loud static out of the headphone socket. It isn't loud enough to damage anything but it gave me a fright when I still had the cans on my head. Now I always make sure I stop the music first.

 

[Triode User]

Thanks for clarifying Rob. Incidentally talking of loud bangs, I have noticed that if I switch off the power at the back of DAVE while music is still playing I get loud static out of the headphone socket. It isn't loud enough to damage anything but it gave me a fright when I still had the cans on my head. Now I always make sure I stop the music first.

Yeah, I did that once with my power amps still turned on. I thought the speaker cones were going to hit me in the face!! That will teach me to ignore the golden rule of switching off amps BEFORE switching off any source devices (and I didn't have music playing). No harm done though.