Ai do not remember having this issue before. But, seems I am on a roll.
Bought a nifty 40A SSR off the WEB. Hooked it up so USB controls the rest of the stereo. Serious hum in the transformers. Load dependent. Now before, I just had a very light load on a 10A SSR, but did not notice any hum.
So, swapped in the 10A. Still hum, but only when load over an amp.
Drug out the scope. I can just barely tell a switching glitch for the triac, but nothing I woudl think upset the transformers. Anyway, guess I am looking for a relay. I wanted the SSR as it pulls so little from the USB. Best relay I found is 70mA.
Anyone else have this?
Bought a nifty 40A SSR off the WEB. Hooked it up so USB controls the rest of the stereo. Serious hum in the transformers. Load dependent. Now before, I just had a very light load on a 10A SSR, but did not notice any hum.
So, swapped in the 10A. Still hum, but only when load over an amp.
Drug out the scope. I can just barely tell a switching glitch for the triac, but nothing I woudl think upset the transformers. Anyway, guess I am looking for a relay. I wanted the SSR as it pulls so little from the USB. Best relay I found is 70mA.
Anyone else have this?
SSR may be non-symmetrical device and it may distort sine non-simmetrically, so it may do something like additional dc-bias to the transformer.
It is better to use usual relay.
It is better to use usual relay.
Ordered some relays boards. Guess the best tool for putting in a nail is still a hammer.
Odd, the waveform out of the output here looks a bit distorted, but it may be my cheap probes at that scale. I should still have an old P6106 somewhere. Hope it is not my old Tek scope going off, but it is 30 years old.
I want to test further just to understand. The possible DC bias I had not thought of, but it makes sense. I still have an old huge line filter I might play with. Don't have an isolation transformer, just a big autotransformer from back when I built amps. Yesterday was a very frustrating day, so I need to chill a little.
Odd, the waveform out of the output here looks a bit distorted, but it may be my cheap probes at that scale. I should still have an old P6106 somewhere. Hope it is not my old Tek scope going off, but it is 30 years old.
I want to test further just to understand. The possible DC bias I had not thought of, but it makes sense. I still have an old huge line filter I might play with. Don't have an isolation transformer, just a big autotransformer from back when I built amps. Yesterday was a very frustrating day, so I need to chill a little.
There are two types of SSR, triac and mosfet.
The triac ones cause distortion of audio signal at crossover, the mosfets dont.
The triac ones cause distortion of audio signal at crossover, the mosfets dont.
I can guarantee the $10 E-bay are triac. For that matter, the $40 ones look to be the same device with a different sticker. Could you point me to a MOSFET device?
Been reading up on DC blockers. "Sounds" like that was in fact the problem. It was so bad my e-core in my DAC supply hummed, but not like the toroid in the Creek.
My solution is a relay, but I may just incorporate one along with a basic line filter in my buss bar. Seems like good practice.
My solution is a relay, but I may just incorporate one along with a basic line filter in my buss bar. Seems like good practice.