Doubling up the MN3008 as an MN3005

[aballen]

Sent out this morning to Jimi and Ian.  I'll keep the third for testing since no-one seems to need it.

[chordball]

Sent out this morning to Jimi and Ian.  I'll keep the third for testing since no-one seems to need it.

Works for me. You should enjoy your hard work. If you do another run, I do want in on that one.

[aballen]

I'll let you know.  After looking a little closer I think I may stick with the "offset" layout since the "centered" version may cover up the trimmers.

Different boards will have a different layouts of course.

[chordball]

I'll let you know.  After looking a little closer I think I may stick with the "offset" layout since the "centered" version may cover up the trimmers.

I agree on that point. And thanks!

[jimilee]

Very cool, can't wait. Are there boms for the boards?

[ichilton]

Cool, thanks!

[aballen]

I labeled the board with the values needed.  It's a self documenting board

The values and the calibration procedure are also in the aquaboy 2012 document.

Very cool, can't wait. Are there boms for the boards?

[Neurowork]

hey,

If you do another batch, I'd want in. I'll be starting to work on my aquaboy deluxe pretty soon since I just received the 4 MN3008s from smallbear.

[aballen]

I have one set left, and I'm leaving for vacation tomorrow... PM me your address and I'll try to get in in my outbox tonight.

[handlefras]

Hi Aballen,

Registering my interest: if you have any of these boards left, or you are still planning to get some more done, but I'd love to buy a pair from you at some stage if possible?

Thanks

[aballen]

I have one left... Was saving for my dirtbag, but if you need it now I can send this pair to you.  PM me

[handlefras]

Hey guys,

So a grabbed a couple of these double delay boards from aballen (thanks again!) with the intention of completing the Dirtbag using 4x MN3008 (MN3005 fakes). For reference, the final layout and schematic is on page 2 of this thread. It looks to me as though the component values on the double delay boards have been designed/optimised for the Aquaboy and my question is - are these values suitable to use for the Dirtbag circuit? Looking at the Dirtbag schematic, it looks as though the more appropriate values to use would be those in the smallbear schematic:https://www.smallbearelec.com/HowTos/MN3005/3005_to_2x3008_SCH.pdf e.g 2k4 resistors and a 100k trimmer etc. Anyone got any hints for me? I've already had some fun desoldering parts of the Dirtbag board and don't plan on having to redo these double delay boards too. 

Cheers!

[handlefras]

Answering my own question - I soldered up these two double delay boards using the values aballen had conveniently noted on the pcbs themselves. The only modification was that I used 20k trimmers instead of the 22k trimmer specified. I ended up using header pins and mounting these directly to sockets on the main board (saved offboard wiring, but obscures the bias trimmers). If anyone else is considering doing this - be aware that some of the electrolytic caps on the main board will need to be folded flat and check the overall height of your enclosure is enough - mine just fit with 1-2mm to spare.

Aaaannnd Bingo! The Dirtbag works with double delay time. So I guess that means these boards are VERIFIED.

Caveats - I don't know if I'm truly getting double delay time - but it is certainly longer than it was without these boards. I do have the an old big box DMM to compare with, so I'll be sure to do an A/B shortly.

Build report will follow when I get the enclosure tidied up.