RayBlack
Well-known member
- Joined
- Oct 13, 2009
- Messages
- 50
Hi there,
I'm experiencing several problems with my PSU design, that I combined from this source http://www.barthman.de/rampedphantom.html
and a friend's advise.
The psu is used for racked V276a,V376b or V672 preamps.
My schematics looks like this:
http://www.baziany.de/DIY/PSU_Schematic_030110.pdf
http://www.baziany.de/DIY/V276a_Input.pdf
I'm supplying 2 preamps, with +24V of this psu and also the six relais for 48V, PAD and Phase, plus the LEDs.
The +48V goes to the Mic Ins and is blocked with to 220uF Cs in the direction of the mic pres.
Problems:
- I get a constant 50/100Hz hum and I think what you call HF oscillation on the mic inputs, when using both 24V and 48V circuits.
- Yesterday I connected chassis ground to 0V of the psu and smoked a diode I think.
Questions:
- Is it even possible to get +24V and +48V out of this xfmr ?
- What kind of wiring would you suggest for the two circuits ?
- Would you connect chassis ground, signal shield, ground of preamps and 0V to get rid of the hum ?
- My xfmr supplies 416mA. Is that too much for the 48V phantom ?
Would appreciate some thoughts on this, as it is my first DIY project and I'm very insecure about many things.
Thanks !
Ray
I'm experiencing several problems with my PSU design, that I combined from this source http://www.barthman.de/rampedphantom.html
and a friend's advise.
The psu is used for racked V276a,V376b or V672 preamps.
My schematics looks like this:
http://www.baziany.de/DIY/PSU_Schematic_030110.pdf
http://www.baziany.de/DIY/V276a_Input.pdf
I'm supplying 2 preamps, with +24V of this psu and also the six relais for 48V, PAD and Phase, plus the LEDs.
The +48V goes to the Mic Ins and is blocked with to 220uF Cs in the direction of the mic pres.
Problems:
- I get a constant 50/100Hz hum and I think what you call HF oscillation on the mic inputs, when using both 24V and 48V circuits.
- Yesterday I connected chassis ground to 0V of the psu and smoked a diode I think.
Questions:
- Is it even possible to get +24V and +48V out of this xfmr ?
- What kind of wiring would you suggest for the two circuits ?
- Would you connect chassis ground, signal shield, ground of preamps and 0V to get rid of the hum ?
- My xfmr supplies 416mA. Is that too much for the 48V phantom ?
Would appreciate some thoughts on this, as it is my first DIY project and I'm very insecure about many things.
Thanks !
Ray