Made a prototyping fixture for the footswitch version to do test-fitting, before I start drilling into the real enclosures.
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The Passinwind Open Source Preamp
- Thread starter Passinwind
- Start date
- Dec 3, 2003
- 23,042
- 45,885
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
Hi guys, looking to adapt this for an onboard preamp on one of my next bass builds. Trying to determine what the best configuration would be to do this? I'd like to try just the variable LPF, but I'm a little confused - the Github says its not for standalone use, but the Oshpark description says it can be?
Is the entire preamp compact enough to fit onboard a guitar? Which components of it might be best suited onboard?
Also - I noticed that the link to the breakout board for the LPF gain module seems to be broken on Github - is this intended?
Thank you!
Is the entire preamp compact enough to fit onboard a guitar? Which components of it might be best suited onboard?
Also - I noticed that the link to the breakout board for the LPF gain module seems to be broken on Github - is this intended?
Thank you!
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- Dec 3, 2003
- 23,042
- 45,885
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
Hi,
Thanks for the heads up on the gain breakout link, which I have now fixed. I also edited out the reference to standalone usage of the new inverting LPF board, which serves to give an overall non-inverting response when used with the Baxandall Bass/Mids board. This project has morphed away from onboard installs, as supporting that would be far too time consuming and in the majority of cases one would need to buy at least a dozen custom pots from Omeg in the UK to make it work. Frankly, I've lost interest in this project and in bass in general and will be leaving Talkbass for an extended period of time as soon as the V4 beta testers finish up their initial builds.
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Thanks for the response! Would any of the V1 or V2 boards be better suited for onboard installs?
Sorry to hear that you'll be moving on soon, you're a wealth of knowledge for our community.
- Dec 3, 2003
- 23,042
- 45,885
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
The pot bushing length problem is still the same regardless of which LPF board we use. You could put a separate buffer in front of the V4 LPF board, use it with an active pickup, or configure the Bax board as a higher impedance front end. I may relent and post a share link for the older LPF board eventually, because it's proven useful in the blend pedals I'm doing for guitars with both piezo and magnetic pickups. But I'd recommend just buying an onboard filter preamp from my friends at JTEX or Underhill, in all honesty.
And thanks for the kind words. I've had a blast here on TB for the last twenty years but it's definitely time for me to check out now.
- Dec 3, 2003
- 23,042
- 45,885
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
We are gonna miss you if you do.
Thanks for everything you do Charlie.
Thank you Mick. I'm still working on the V2 pedal and hope to hand that project back to you pretty soon now. It doesn't really like any of the usual through hole opamp suspects that much at the moment (TL072 is stable and "OK", at least), so I'll be trying some more uptown choices the next time I do a Mouser order. I feel it's worth throwing a bit more time at since the build time is so much quicker, and I expect it'll sound fine once we suss the secret sauce. I really want it to work well for acoustic guitar too, which I think it could with a few more tweaks.
Thanks for sharing that, Sanj. It would certainly let someone use whatever chip Charlie came up with for v2 and it's 8DIP format, were that to happen.
- Dec 3, 2003
- 23,042
- 45,885
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
I did one like that, and another one to adapt two single opamps to a dual DIP8 pinout. But from my perspective if someone can solder that up comfortably they might as well build one with SMT resistors too!
You can get SOIC8 to DIP8 socket adaptors for programming chips, they might do the job possibly.
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I have made a footprint just like that for use in KiCad when I make my own PCB's, I wanted to future proof my projects so I have started doing it for all components I use.
Fet's and transistors are all slowly becoming SMD and it won't be long before all other components go that way too.
Plus it gives me more options when I buy components.
- Dec 3, 2003
- 23,042
- 45,885
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
I'll be shooting for a single monthly update for the foreseeable future, but I will still try to respond to posts in this thread in a more timely fashion, just not close to same day as I've always tried for in the past.
So for right now, I just finished this build up for my Dojo a couple of days ago:
I have a couple of onboard preamps to get out this week (maybe the last ones actually), then I'll be wrapping up the V4 Github documentation and trying some different through hole opamps in my two V2 builds. My new acoustic guitar seems to especially to like a couple of my older pedal builds, which happily enough means one less thing to build and/or sell. Really hoping to get all this stuff wrapped up by month's end, and keeping my fingers crossed!
So for right now, I just finished this build up for my Dojo a couple of days ago:
I have a couple of onboard preamps to get out this week (maybe the last ones actually), then I'll be wrapping up the V4 Github documentation and trying some different through hole opamps in my two V2 builds. My new acoustic guitar seems to especially to like a couple of my older pedal builds, which happily enough means one less thing to build and/or sell. Really hoping to get all this stuff wrapped up by month's end, and keeping my fingers crossed!
Making slow progress on the builds, designed and ordered power junction boards to make all the 9V wiring between the jack and boards a bit easier. Also has provisions for a power-on LED. Shared here:
OSH Park ~
OSH Park ~
Really looking good. Both my friend and I are looking forward to giving them a road test!
Really nice looking work, Sanj. Your picture is (I think) the first affirmative picture in the thread for which way is up for the sub boards on the dual pots, for we visual learners.
Are you grounding the enclosure to the circuit? Where in the circuit, the first input jack to the case?
"Making slow progress on the builds, designed and ordered power junction boards to make all the 9V wiring between the jack and boards a bit easier. Also has provisions for a power-on LED. Shared here:
OSH Park ~"
Thanks for sharing your power supply distribution board. It is a really useful board for this project or any other time you're feeding multiple boards. I just got some at OshPark.
Are you grounding the enclosure to the circuit? Where in the circuit, the first input jack to the case?
"Making slow progress on the builds, designed and ordered power junction boards to make all the 9V wiring between the jack and boards a bit easier. Also has provisions for a power-on LED. Shared here:
OSH Park ~"
Thanks for sharing your power supply distribution board. It is a really useful board for this project or any other time you're feeding multiple boards. I just got some at OshPark.
- Dec 3, 2003
- 23,042
- 45,885
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
