Ashly SC-40 Clone
- Thread starter disssa
- Start date
CheapSuitG
Well-known member
Let me know if you have a spare PCB!
Amazing work! I've been working on a dual SC-40 pedal, how are you managing the 9v to 15v step? I was originally looking at using an 18v supply and a regulator down to 15v, are you using a voltage doubling circuit here? Is that the part labelled PS2 (power supply?) on your board?
Looks kinda like a Recom R09P15D
Those are cool bits of kit. I've wondered how quiet they are
Looked in the SC-50 Clone thread, was able to make out that it's a Traco Power, and going thru their products, I believe it's a TEC 3-1213. Looks like a nice piece! I like the integrated unit option.
I used a Traco 2-0923.
If you don't mind me asking, how is the noise levels with these, and what filtering did you use around the module? I know Aion FX uses a 2-0923 in the Eclipse Boost (schematic seen in the documentation here: link), did you set up the filtering around it in a similar way? Love to see the old Ashly gear get some appreciation, I have 2 SC-40s I use for recording along with SC-50s, and want to build myself a dual pre in a stomp box so I don't have to lug the old units to shows.
Great, that's very helpful info! I've been meaning to get around to making these for a while, but had some other projects on the docket first, namely an Acoustic 360+ preamp in a rack (on pause until I can source a good unit with the faceplate done how I'd like). I think I'll do the SC-50 as well, did you do the blue or black version? The original I have on hand at the moment is the earlier blue version with matched metal can transistors, but was looking into making a circuit where it's swappable between those and the black version's dbx chip, though I currently only have the early version schematic.
@disssa out of curiosity, do you happen to know the current draw of your SC-40 build? In planning to build a dual version, I'm looking at the Traco power converters, the 2-0923 outputs 67mA, but wondering how much of that the circuit uses if I need to go with a version like the TMR 4 that produces 133mA in order to supply both circuits from one supply, or if the TEC 3 models at 100mA will be sufficient. Thankss!
The current draw is 120mA.
I would use a TEC 3 because the range of the input voltage is better (4.5V...13.2V). The input voltage of the TMR is 9...18V. Most power supplies deliver just under 9 volts. The Tracos react very sensitively to undersupply.
That's 67mA per rail, so 134mA total for the TEC 2. If current draw of one circuit is 120mA, even the TEC 3 won't work because it's limited to 200mA total.
Edit: Had a quick looksie and TMR 6-0523 will provide more than enough current (200mA per rail). Input voltage is 4.5-9V, so some form of overvoltage protection or voltage regulation on the input would be advisable. Or just use a 12V power supply and go with the TMR 4. Not quite as pricey as the TMR 6 either.
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Bricksnbeatles
Member known well
Ditto ^
The period where Geddy was using a pair of SC-40s is probably my favorite for his live bass tone. Would love to build one or two of these if you offer the boards for sale at some point
Excellent, thank you! Good to know about their sensitivity as well.
That's what I was thinking, if it was under 100 mA I could get away with the TEC 3. Looked at the TMR 6 too, but I think the TMR 4 will work well as my solution.
I did also see this as a possible option: https://www.cdiweb.com/products/detail/mcwi0512d15-minmax-technology/521452/
MCWI05 Series
OVERVIEW The MINMAX MCWI05 series is a range of isolated 5W DC-DC converter modules featuring fully regulated output voltages and ultra-wide 4:1 input voltage ranges. The converters come in a very small SIP-8 package which occupies only 2.0 cm2 of PCB space. An excellent efficiency allows...
www.minmaxpower.com
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