Loud pop when changing formats

[dsm]

Hello everyone,

I just upgraded to the NOS1 G3 and Stealth II with the Lush ^3. I’m using all the same settings as Peter, but I get a load pop when the format switches to MQA or a higher res. It's very much like when the DAC is turned off when the amp is still on, so it's quite unpleasant.

This didn’t happen with my older NOS1 as far as I remember and I can’t find a related topic in the forum yet.

If anyone remembers having this problem and how to fix it, I would greatly appreciate it.

Best regards,

David

[briefremarks]

David,

Jogging my memory. The only thing I remember is a discussion related to the position of Switch #3 on the NOS1.  It was not specifically related to switching to high res formats. I do get a slight "tick" when this happens, but it's very soft.  I may be completely off here, but at one time there was potential for a loud pop related to leaving Switch #3 either up or down (I do not remember) for an extended period of time.  I'm assuming you are using the latest version of XXHE that fixed the "crack" detect issue that could also create a very loud pop.

Ramesh

[PeterSt]

David,

Whether Swich#3 is related I don't even know, but it well could bee because this is about an internal ground connection.
Otherwise it is the same for everybody as far as I know - and like Ramesh said - it is a firm tick and most certainly not something unbearable.

The tick is not ground related that I know of, but it is a very brief mismatch between the sampling rate setting (from the one base clock (44.1) to the other (48)). I think you can mimic it by changing the sampling rate manually in the NOS Driver Control Panel (e.g. switch from 176.4 to 192 and back).

What theoretically could happen is that your amplifier is way over powered, seen by the relatively high attenuation you must apply. Thus, say that you attenuate in XXHighEnd in the realm of 48dBFS, then you have a theoretical ~20dB too much power, which would make your "tick" 20 dB unnecessary loud(er) as well. Could that be the case ?

Peter

[dsm]

I do have switch #3 down and have XXHE 2.11. I also need to have the volume set to around -42 because of the sensitivity of my speakers.

I did not have this happen with my non-upgraded NOS1 so I was wondering if there were changes to the G3  which might be throwing something off for me. Today, I was able to play a playlist with 44.1 and 48, with both 16 and 24 bits without any trouble. When I mixed in an 88, I heard a pop and the right side channel cut out. Sound was very faint from that speaker and that continued as I skipped to songs which were other formats.

I turned off the NOS1 from the front switch (not the back) and started another playlist with 44.1 and all went back to normal.

The only thing I can think to try, if it isn't an XXHE setting, is another USB cable. 

David

[dsm]

I took out the Lush^3 and put in  a generic USB and the popping stopped. There is no noticeable click between tracks that change sample rate and all is working great.

I have Peter's latest Lush^3 settings but may revert to the original ones that it was sent with. I don't know if the connector is not fitting properly  or it is the settings.  I also have the Lush^2 which I can try.

Peter, do you know if removing one of the wires in the Lush^3 could cause a problem?

[dsm]

I took out the Lush^3 and put in  a generic USB and the popping stopped. There is no noticeable click between tracks that change sample rate and all is working great.

I have Peter's latest Lush^3 settings but may revert to the original ones that it was sent with. I don't know if the connector is not fitting properly  or it is the settings.  I also have the Lush^2 which I can try.

Peter, do you know if removing one of the wires in the Lush^3 could cause a problem?

Shoot. Disregard all that, I was able to get another pop and channel cut out with a 24 bit 48.


Edit-  After more testing, it seems like if I start with a 44.1 in a playlist and add a 48k after and play in unattended, all works fine.  The problem may only be from starting a 48k track

Also, if I reboot and start the Phasure driver control and change from 352, 800 to 384,000 I'll get a pop, so it isn't related to XXHE

[dsm]

One more thing, I went to the full OS to backup things in case they got screwed up but now on my USB control panel, the NOS1 is connected but streaming is down.

I've turned off the DAC  and restarted the computer but it still is the same. It's been so long since I've had this happen that I cant quite remember how to get the device to show up again in XXHE. It is still the primary sound driver.

David

[briefremarks]

David,

Any time you reboot the Audio PC OS, you can lose connection to the NOS1.  Generally, the following has worked for me.
- Close XXHE
- Restart NOS1, either using the on/off switch at the back or resetting Switch #2 (I always mix us if this is #4 or #2--it is the one that turns the DAC off/on, not the battery switch)
- Make sure your DC offset is set correctly.
- Relaunch XXHE

You may sometimes need to reboot the Audio PC as well.

[PeterSt]

David (I assume you are up and running again) - all you describe is perfectly normal. But your required attenuation is not (at all). So it is anticipated that this matches or else you have poor sound to begin with (you would loose too many bits).
It is also true that prior to the latest NOS Driver, things were different - the hardware was also different. So it matches the hardware.

The fact that your channel stopped working, tells us (me, but also you) that you push through a too large current. This is again thee attenuation thing, but merely : your power amp is too much over powered (you could say that your speakers are too sensitive, but this would be non-sensical).

I have never ever given the advice to use a pre-amp, but it would solve your problem. But don't do that ... try an other power amp instead.

Best regards,
Peter

PS: The faint sound from one channel came from even the DC Offset went "off" because of it. Or maybe I should say that you *always* need to check that (also please look what Ramesh wrote).

PPS: Ask (more) if needed.

[dsm]

David,

Any time you reboot the Audio PC OS, you can lose connection to the NOS1.  Generally, the following has worked for me.
- Close XXHE
- Restart NOS1, either using the on/off switch at the back or resetting Switch #2 (I always mix us if this is #4 or #2--it is the one that turns the DAC off/on, not the battery switch)
- Make sure your DC offset is set correctly.
- Relaunch XXHE

You may sometimes need to reboot the Audio PC as well.

Unfortunately, I was not able to get the driver working and switched to a backup RAM OS in order to get things running again.

As far as the pop and channel loss, I was able to try another NOS1 G3 and the pop when switching sample rates became tolerable but most importantly, the right channel did not go out. Everything now is working great with this other DAC.

I still haven't been able to test the DAC with the channel trouble on a different system to see how it behaves.

David

[PeterSt]

Right channel : You have the Driver settings wrong in the NOS Control Panel (should be Multi Channel 4.0) and/or you have Switch #5 in the wrong position (should be down).

[dsm]

Right channel : You have the Driver settings wrong in the NOS Control Panel (should be Multi Channel 4.0) and/or you have Switch #5 in the wrong position (should be down).

Hi Peter,

No those were set correctly and I checked them many times.

David

[PeterSt]

Hi again David,

Then you'd have a dysfunctional NOS1. Everything is possible, but it would be the very first time. The person you got it from should know about it, right ? 

Regards,
Peter

[dsm]

Hi Peter,

Then you'd have a dysfunctional NOS1. Everything is possible, but it would be the very first time. The person you got it from should know about it, right ? 

Yes, but I still want to test it with a different amp but have not had time. I do feel like it was unlikely that something could be defective and maybe just something with my situation knocked it over the edge.  I'm in a new studio and when I can test it, I'll set up something in the house so all will be different.

Best,

David

[PeterSt]

Did you swap output cables ? then you can prove whether it is that NOS1.
What I am thinking of is that it is possible that at such an earlier louder pop situation a fuse in the amp blew (a plop is a high current high transient burst). Thus, inputs at the amp can be protected by fuse, and this is then per channel.

Also, when you don't check the DC Offset and one channel is completely off (a 1 or -1 shows), that channel may be completely silent.