The Slo-Blow mic pre..(DIY)

  • Thread starter Thread starter BigRay
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BigRay

BigRay

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I've been looking at this one but it's a pretty tough project for someone of my experience, nice simple design but a tough build. I've not built anything P2P yet and I don't think a high voltage DC pre like that is a good place to start. :o

I'd be interested to see how you get on with it though. Good luck (especially when poking around inside :eek: :D ).
 
Kevin DeSchwazi said:
I've been looking at this one but it's a pretty tough project for someone of my experience, nice simple design but a tough build. I've not built anything P2P yet and I don't think a high voltage DC pre like that is a good place to start. :o
Click to expand...

Point to point is easier than making your own PCBs :eek: but yes that is a high voltage circuit. The bigger issue is probably cost, with the transformers, big caps, VU, etc., it is a relatively expensive project. The power supply certainly seems like it could be a little less robust. Designed for a plate voltage of 150VDC, it could be made much cheaper. For example compare the power supply for the PRR vari-mu compressor:

http://music-club.rutgers.edu/headfonz/comp5/Comp5.html

Cheaper power transformer, zeners for regulators, much smaller caps. There isn't a need for a separate winding for phantom; use a voltage multiplier off the secondary. In fact since there are no ICs in the Slowblow, the secondary is only needed for heater supplies and phantom, and a heater supply doesn't need to be regulated (losing the giant heatsink).

Let's see . . . a stack of LEDs and a comparator is cheaper than a VU meter . . . that just leaves the input transformer as the expensive part, but I guess that is part of the plan. Sorry I only know how to do cheap :o

With those revisions, I bet it could fit in a 1u box :)
 
mshilarious said:
Point to point is easier than making your own PCBs :eek:
Click to expand...
Yeah but using PCB's made by someone else (screen printed with component value and location) is easiest of all. ;) :D

That's pretty much the level I'm at right now. :o
 
mshilarious said:
Point to point is easier than making your own PCBs :eek: but yes that is a high voltage circuit. The bigger issue is probably cost, with the transformers, big caps, VU, etc., it is a relatively expensive project. The power supply certainly seems like it could be a little less robust. Designed for a plate voltage of 150VDC, it could be made much cheaper. For example compare the power supply for the PRR vari-mu compressor:

http://music-club.rutgers.edu/headfonz/comp5/Comp5.html

Cheaper power transformer, zeners for regulators, much smaller caps. There isn't a need for a separate winding for phantom; use a voltage multiplier off the secondary. In fact since there are no ICs in the Slowblow, the secondary is only needed for heater supplies and phantom, and a heater supply doesn't need to be regulated (losing the giant heatsink).

Let's see . . . a stack of LEDs and a comparator is cheaper than a VU meter . . . that just leaves the input transformer as the expensive part, but I guess that is part of the plan. Sorry I only know how to do cheap :o

With those revisions, I bet it could fit in a 1u box :)
Click to expand...

Kickin' ass as always, ms. :)
 
I actually Find Makeing my own PCB"s Much easier than wireing Point to Point especially were space is at a Minimum and you need everything semi organized looking.....

All I do is Draw the Curcuit Design on to a Piece of Blank PCB useing a Marker and then wait for the ink to dry and then just soak it in some Ferric Chloride for about 30 minutes and wash it off and you are ready to Solder......

For really Complex PCB designs I Copy the design out on some Glossy Photo Paper and then use an Iron to Transfer the Design over to the Blank PCB (Sort of like an iron on for T Shirts) and then I soak the PCB in water and peel the Paper away and I am left with the design Printed on to the PCB and then I soak it in the Chemicals to disolve the Copper and then I am ready to solder....This was for me is the easiest way....Pluss you can get Blank PCB Material for really cheap from a Guy on e-bay who is selling 360 Square Inches of Blank PCB for $10 (10 - 6 x 6in Squares) in Both single and double sided types.....
This is the way I etched the PCB"s for my Green Pre amp and PSU and it was quite easy considering I had never done it before but since I have made several PCB"s , Most rescently makeing PCB"s to Build Mics out of Based on MSHilarius"s Design, and this way I can get about 30 Mics worth of Curcuit Boards with each 6x6 inch PCB and then Just drill the Holes with my Dremmel...
For adding the Artwork and stuffing Guide to the other side of the PCB I just print the design out on Sticker paper and put the stickers on the PCB"s which shows were each part goes....

I can see useing Point to Point for really easy stuff but once you start useing IC"s and hundreds components it isn"t practical anymore to wire point to point

If anyone wants to learn how to make there own PCB"s at home PM me and I"ll send You more detailed instructions....


Cheers
 
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