Hey everyone (and particularly Gustav),
I'm putting together a BOM for this project using the schematic and the board itself. I'll be happy to share it with the group once I've got it completed, as I believe (and hope) that it will be helpful for those of us that only have the boards (no full kit), since a published BOM does not exist.
To that end, I have a few questions that would really help me finish it up. Apologies that there are so many, but I hope you can help!
1. What is the value/taper/etc of the blend pot? I don't actually see it anywhere on the schematic, but I might just be blind.
2. The 10nF cap marked "(HP)" has an asterisk associated with it. Presumably this value can be adjusted to affect the frequency of the HPF (I'm just guessing). Is there any reason to include other options or perhaps clarifying information in my BOM, since an asterisk that leads nowhere tends to cause confusion?
3. The XLRS -- is there a product number for the male and female ones that will fit this footprint?
4. Is it alright to use 1n4004 diodes for all 1n400x designations in this design? Seems easier than ordering multiple varieties if a builder doesn't have any of these on hand.
5. Is there a meaningful difference between the FD333 and the more readily-available FDH333? Looking briefly at datasheets, they appear to be interchangeable, but I'd hate to assume and then be wrong.
6. The 2N5457 transistors seem to be a bit tricky to find (I grabbed some from Reverb, but who knows if other builders will have luck). I read that the PF5102 is a reasonable substitute, at least in guitar pedals, and I also found it easier to locate sellers for that one. Would that (or a different one) be acceptable in this design?
7. If substituting the 7912 for the 7910 as recommended in this thread, are any changes required for other components on the board?
8. For the two diode bridges in the PSU, are there any considerations when it comes to choosing one? The ones in the pictures in the build guide seem to be obsolete or otherwise unavailable. Will a W08G work? (I have a bunch lying around, so I'm hoping yes!)
9. Slightly off the topic of the BOM, but since the board is clearly meant to be supported in the rear by the XLR connections and there are no holes for stand-offs on that side, is it possible to get an fpd file or mechanical drawing of the rear panel so that we can have them made accordingly? This seems preferable to drilling new holes in the board lol.
Again, sorry for the numerous questions, and I hope that I'm not asking for redundant information that has already been covered in this thread (I did look, I promise!). Hopefully it is worth the trouble so that we can have a thorough and accurate BOM for these boards...
These were only sold as kits, and when I stopped those sales, I offered the spare boards. There were about 10, and I found a pile of another 20 when I cleared out the PCB storage. I dont think there is a huge need for a shared BOM based on that.
To try and help you.
1. 2 x 10K lin will do.
2. You are correct, it sets the SC HP. Its rather high "stock", but you can change as you wish.
3. They are just neutrik PCB mount XLRs.
4. Yes - 4003 is fine throughout.
5.You can use both.
6. No idea - youd have to try, but again, we dont really need a public BOM, so just find the 2n5457 for your build, and dont worry about universal availability.
7.Up the trimmer values a little - next step in line will be fine.
8. As long as the minimum voltage and amperage rating are fine, you will be fine. Your mentioned part is rated 800V, 1.5a, which is more than enough.
9.Lay board on bottom of case, punch markers, and drill, if you want to add support studs.