Here's my VSPS build. Overall it went very smoothly, and it worked on the first try
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I am getting a slight hum with the volume turned way up. The hum goes away when i disconnect the ground from the power cord. Hum is the same regardless if the power ground is connected to the same terminal as the board ground (as shown in the photo) or if I ground it to the screw for the IEC socket. The hum does not interfere with listening though.
Overall a nice sounding unit.
.I am getting a slight hum with the volume turned way up. The hum goes away when i disconnect the ground from the power cord. Hum is the same regardless if the power ground is connected to the same terminal as the board ground (as shown in the photo) or if I ground it to the screw for the IEC socket. The hum does not interfere with listening though.
Overall a nice sounding unit.
Attachments
This hum is caused by a simple ground loop: the signal return (COM) is connected to earth at the VSPS and again somewhere down the chain, in your amplifier for example.
It doesn't occur when you have the power supply and VSPS in a separate chassis, as only the power supply chassis is earthed, and the VSPS COM / VSPS chassis does not connect to it.
The simple solution is disconnect the chassis from the AC earth connection.
A more rigorous modification would be to keep the chassis connected to AC earth for safety, but insert 47 ohm resistor and a small ceramic capacitor in parallel between the GND pad on the board and the chassis ground lug.
I'm not completely sure that will work as advertised, since the turntable gnd wire connects to the chassis and now they will see 47 ohms back to the VSPS COM, but it's easy enough to try.
It doesn't occur when you have the power supply and VSPS in a separate chassis, as only the power supply chassis is earthed, and the VSPS COM / VSPS chassis does not connect to it.
The simple solution is disconnect the chassis from the AC earth connection.
A more rigorous modification would be to keep the chassis connected to AC earth for safety, but insert 47 ohm resistor and a small ceramic capacitor in parallel between the GND pad on the board and the chassis ground lug.
I'm not completely sure that will work as advertised, since the turntable gnd wire connects to the chassis and now they will see 47 ohms back to the VSPS COM, but it's easy enough to try.
Separate enclosures (Modus Shop) for phono section and power supply.
There are drills on the bottom of phono section allowing to change settings for MM / MC cartridges.
Opamps: LME49860.
Transformer ( Transformatory toroidalne, audio, separacyjne, trójfazowe - sklep internetowyroducent PWPH Lachowski Ksi??yno - Bia?ystok ).
K
There are drills on the bottom of phono section allowing to change settings for MM / MC cartridges.
Opamps: LME49860.
Transformer ( Transformatory toroidalne, audio, separacyjne, trójfazowe - sklep internetowy
roducent PWPH Lachowski Ksi??yno - Bia?ystok ).K
Attachments
I see. Well, the improvement is 16.5%. So now you know.
[Mica sound cleaner than mica.]
Man...that's accurate....how do you calculate Richard.....?
BTW 1000pF Mica arrived yesterday. Will be putting that. I'm curious all of them specially the leads is magnetic. Won't this a no no for signal lines...?