Best way to power a gamma1 that is builtin to a M3

[m1abrams]

So I am working on an M3 build and I am considering putting a full gamma1 into the same case as the M3.

Now since the M3 will have an external PSU via a sigma11 with 24V output I was wondering how best to supply 5VDC to the gamma1 board. I was thinking of using an LM7805 with a BIG heatsink, I know this setup would generate a good bit of waste heat.

Does anyone have other recommendations? Would it be better to build up a whole other sigma11 for 5v? That of course would be a good bit more expensive. I was also thinking that down the road I may want to build up my own controller board for stepped attenuation and input selection using a microcontroller, so this of course would also need 5V.

[ShinyFalcon]

I was planning on making a TREAD for 5V. I don't really think that the y1 will benefit a whole lot with its own sigma11.

I don't know if this works, but you can put a 5VAC transformer and hook it up with the same IEC you use in the sigma11, hook the 5VAC with the TREAD, and make a special 4-wire umbilical (I plan on using XLR connectors) to power up both the M³ and the y1.

[m1abrams]

Originally Posted by ShinyFalcon

I was planning on making a TREAD for 5V. I don't really think that the y1 will benefit a whole lot with its own sigma11.

I don't know if this works, but you can put a 5VAC transformer and hook it up with the same IEC you use in the sigma11, hook the 5VAC with the TREAD, and make a special 4-wire umbilical (I plan on using XLR connectors) to power up both the M³ and the y1.

Your right a tread would be a better psu over a sigma11 for this. By chance have you priced out the BoM for a tread?
Still not sure if that is worth the cost over a LM7805 and heatsink.

[ShinyFalcon]

A kit for a TREAD is around $17 direct from Tangent's shop, but with Mouser parts it will be around $14. The kit is designed for higher voltages, but you only need to change one resistor to allow adjustment down to 5V.

I'll let you know that a regulator that's dropping 8V (32V -> 24V) gets pretty damn hot. A regulator that's dropping 19V would probably get extremely hot... Play around with this calculator, according to this calculator a regulator dropping 19V (24V -> 5V) would cause the regulator to overheat.

[m1abrams]

Well at only $17 I like the TREAD idea better. You could even bypass the bridge rectifier and filter caps if you power it from the sigma11. Course that adds a load to the sigma11, probably better to just pickup a small transformer to power the TREAD.

[amb]

Originally Posted by m1abrams

Well at only $17 I like the TREAD idea better. You could even bypass the bridge rectifier and filter caps if you power it from the sigma11. Course that adds a load to the sigma11, probably better to just pickup a small transformer to power the TREAD.

No you shouldn't share the trafo, rectifier and filter caps with the σ11. Don't forget that that V- on the σ11 becomes the negative rail on the M³. The γ1's ground gets connected to M³'s virtual ground when you wire it together. It really needs its own PSU that's isolated from the M³'s.

[m1abrams]

Originally Posted by amb

No you shouldn't share the trafo, rectifier and filter caps with the σ11. Don't forget that that V- on the σ11 becomes the negative rail on the M³. The γ1's ground gets connected to M³'s virtual ground when you wire it together. It really needs its own PSU that's isolated from the M³'s.

Ok thanks, so using a small transformer and the TREAD kit set to 5V output will be the way I go.

I did forget about the virtual ground and V-, that would be bad shorting V- to the virtual ground