Have you looked at the sound on an oscilloscope and noticed any harmonics? Have you tried feeding it back through another Lightspeed to see if it excites any audible resonance or causes any strange harmonics?
I know it's not the help you asked for but you could try simulating his environment by borrowing a Sonos and see what happens.
I know it's not the help you asked for but you could try simulating his environment by borrowing a Sonos and see what happens.
Last edited:
As I said it measures and behaves perfectly every time I've had it back. And I've changed everything bar the chassis, just on spec.
It's hard to grasp what's going on as the owner is in the US and I'm in Australia.
Like I said out of 800 units I've never had this sort of problem, just ones that owners have carelessly done themselves by hooking up car batteries wrong polarity and such ect.
I got a PM from another member here said I could post the file on dropbox whatever that is, I give it a go, I'm useless on the puter.
Cheers George
OK, here I hope is the link to the MP4 sound, it is very quiet so you'll have to turn up the volume a bit.
https://www.dropbox.com/s/glyog69s0... Attenuator Noise Heard From Tweeter.m4a?dl=0
Cheers George
https://www.dropbox.com/s/glyog69s0... Attenuator Noise Heard From Tweeter.m4a?dl=0
Cheers George
Listened to it. I'm definitely no expert in this field, but the first thing that comes to mind- cellular or Sonos data interference. George, is your light speed shielded?
Has your client tried the Sonos troubleshooting guide ?
The noise would be more likely an interference within the Sonos set-up than anything to do with the Lightspeed.
(router on top of or next to other electronics perhaps)
https://sonos.custhelp.com/app/answers/detail/a_id/3650/kw/noise between songs
The noise would be more likely an interference within the Sonos set-up than anything to do with the Lightspeed.
(router on top of or next to other electronics perhaps)
https://sonos.custhelp.com/app/answers/detail/a_id/3650/kw/noise between songs
George, I just opened the sound up in an editor and the peaks of the rhythmic noise are about 0.1 seconds apart - so it's something happening at about 10hz, and I too think it is something with the Sonos. Has your client tried a simple pot to see if the noise is still there. Maybe a Bluetooth or streaming resync thing?
I did a spectrum analysis and there is nothing much to see. I can post it if you like, there is a little 60Hz, 120Hz garbage at around -90db. Each of the 10Hz blast has 3-5 cycles - I'll just include some pics.
I did a spectrum analysis and there is nothing much to see. I can post it if you like, there is a little 60Hz, 120Hz garbage at around -90db. Each of the 10Hz blast has 3-5 cycles - I'll just include some pics.
Attachments
Thanks guys, I've pointed the owner to these posts, maybe he will work it out with some of the answers here.
Cheers George
Cheers George
Can he turn the wifi/wireless network off and run a network cable to the sonos?
You could add some caps, silver-mica/cog, across the rca input sockets inside the lightspeed to hopefully shunt any rf to ground?
what cable is he using to connect the system and how long are they, he could try a clamp-on ferrite core around the cable.
regards
james
You could add some caps, silver-mica/cog, across the rca input sockets inside the lightspeed to hopefully shunt any rf to ground?
what cable is he using to connect the system and how long are they, he could try a clamp-on ferrite core around the cable.
regards
james
I'm hoping the owner will chime in and give some info. instead of it being third hand.
Cheers George
Cheers George
A really big thanks guys for helping out on this, I was ready to neck myself, I kept saying all the times in my emails, it can't be the Lightspeed I've virtually rebuilt it. I think he's worked it out that it's not now, re the email I just got.
Hello George. I listened to my vinyl setup last PM....sounded great through the Lightspeed. I am almost certain there is a negative interaction being caused by the Sonos. I will switch to the stepped attenuator. Thank you for your patience troubleshooting this issue, and referring me to the form
Tom
Cheers George
Hello George. I listened to my vinyl setup last PM....sounded great through the Lightspeed. I am almost certain there is a negative interaction being caused by the Sonos. I will switch to the stepped attenuator. Thank you for your patience troubleshooting this issue, and referring me to the form
Tom
Cheers George
Last edited:
Yes, it could rear it's fault when direct coupled through the Lightspeed to the amp/s.
If there was a coupling cap before or after the Lightspeed to limit the LF as in many active preamps, then it may not show up.
Cheers George
the total resistance of the controller potentiometer, or the total resistance of the audio circuit LDR?
The LED part does not have resistance.
The LED part does not have resistance.
Hi George
I followed your instructions to get quartets selected LDR. I took the recommended tester and I performed the measurements of resistance to subsequent treatment have adequate current to the LEDs.
Established the full scale of the maximum resistance at 20 Kohm.
I purchased 15 LDR Silonex NSL32SR2 at Allied El.
These results would say excellent for the first 10 pieces..
I own already 'great satisfaction with a self-made model that food to + 5V DC using a low noise LT3080 regulator.
My construction.... "I have done better" .... but it works perfectly for 3 years until today
I followed your instructions to get quartets selected LDR. I took the recommended tester and I performed the measurements of resistance to subsequent treatment have adequate current to the LEDs.
Established the full scale of the maximum resistance at 20 Kohm.
I purchased 15 LDR Silonex NSL32SR2 at Allied El.
These results would say excellent for the first 10 pieces..
I own already 'great satisfaction with a self-made model that food to + 5V DC using a low noise LT3080 regulator.
My construction.... "I have done better" .... but it works perfectly for 3 years until today
Last edited:
As per my circuit with no mods, it mimics a 10kohm log pot.
So do some A/B listening comparisons against a 10kohm log Blue Velvet Alps pot you will be quite surprised top to bottom about the sound of cadmium sulphide and no contacts in the signal path, especially in bass drive.
Cheers George
Last edited:
George, would you agree that a simple thick wire instead any attenuator would be by far the best solution (with volume control at the source)? If so, I can report I can't hear any difference between a wire and a pot.
I can hear the difference of a source that has digital domain volume used above 75% of full output so it doesn't "bit strip" direct into a power amp (your simple thick wire) compared to an Alps Blue Velvet in the signal path.
And I've always said that nothing beats a direct source to power amp connection that uses a digital volume control, so long as it's used above 75% of full output. The only way that comes close to this is the Lightspeed Attenuator to me.
Cheers George
And I've always said that nothing beats a direct source to power amp connection that uses a digital volume control, so long as it's used above 75% of full output. The only way that comes close to this is the Lightspeed Attenuator to me.
Cheers George
.... if it makes' pleasure to talk