@Mike:
Don´t forget to put your lamp headset on when you visit BAF…..
This is no lamp headset. It's a machine of some extinct civilisation, located on a forbidden planet. I would say, this is unobtainium by now...
Headset with light
An externally hosted image should be here but it was not working when we last tested it.
Attachments
LuminAria @10ppm
So I tidied up and twisted the cables, grounded the board and the 50Hz lowered to around -87dB, still a bit high I think. After more troubleshooting, I realized the unshielded QA400 cable actually pickup a -104dB signal from the environment (even when LuminAria is off) which are then amplified by 17dB by the LuminAria and hence the -87dB, so I assume it's OK for now, unless I can hear some real hum later.
Then I tried to search the sweetspot, and easily lowered the THD to 10ppm @1Vrms (B+: 114V, Vds: 80V, Id: 73mA, Rd: 600R). First picture is the QA400 measurement after the optimization, second one showing the initial hum, and third one the test setup after tidying the cables.
Time to solder the production channel boards, and thanks Michael for this nice design.
So I tidied up and twisted the cables, grounded the board and the 50Hz lowered to around -87dB, still a bit high I think. After more troubleshooting, I realized the unshielded QA400 cable actually pickup a -104dB signal from the environment (even when LuminAria is off) which are then amplified by 17dB by the LuminAria and hence the -87dB, so I assume it's OK for now, unless I can hear some real hum later.
Then I tried to search the sweetspot, and easily lowered the THD to 10ppm @1Vrms
(B+: 114V, Vds: 80V, Id: 73mA, Rd: 600R). First picture is the QA400 measurement after the optimization, second one showing the initial hum, and third one the test setup after tidying the cables.Time to solder the production channel boards, and thanks Michael for this nice design
.Attachments
Last edited:
On a not so audio-related note:
My team finished our 100-mile relay this past weekend. I had a 16-mile night leg through the woods. The logistics and prep took a lot of time, so if you sent me an email in the past couple of weeks and I haven't replied, send it again.
"Burning River" is done, now I can get ready for "Burning Amp"!
My team finished our 100-mile relay this past weekend. I had a 16-mile night leg through the woods. The logistics and prep took a lot of time, so if you sent me an email in the past couple of weeks and I haven't replied, send it again.
"Burning River" is done, now I can get ready for "Burning Amp"!
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Power 
Congratulations
What about some teaser that tells us about your design for "Burning Amp"
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