oh yes but I think those graphs were just examples. If you put the tilt the other way and bring the frequency down why wouldn't it be a resonant high pass? and of course you would not want to turn the q so far so that it oscillates. I think they said past 3:00 you get into dangerous territory on that one.Interesting piece, thanks for posting that. The graphs on the specs page only seem to show resonant low pass as an option. And I can tell you from recent direct experience that self oscillation in an HPF is a very dodgy thing to have available in an onboard preamp.
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The Passinwind Open Source Preamp
- Thread starter Passinwind
- Start date
- Dec 3, 2003
- 23,054
- 45,952
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
From the little bit of info given I think it's probably actually a tilt control plus a resonant low pass via state variable filter, but it's not really clear. But they also mention how sweet self oscillation sounds, and the synth like vibe, plus having a zener diode limiter, which seems like a great idea for that sort of application. Sounds more like a noise toy in some ways really...not that there's anything wrong with that!
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There's a bunch of videos on YouTube about it. mostly with guitar players and it is capable as a noise machine but it also seems to be a very capable parametric
You create the low pass by turning the tilt left and they make a peak at the corner frequency with the gain and adjust the width with the q. You create a high pass by turning the tilt to the right, turn the frequency down to where you want it, and create a resonant peak at the corner by boosting the gain and adjusting the q
- Dec 3, 2003
- 23,054
- 45,952
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
I eventually found a video that implies that could be so, in which case it may be similar to the venerable Anderton Super Tone Control we've discussed previously in this thread. Sounds cool for guitar, I'd love to see a bass centric vid.
I'll let you know how it sounds this week
Somewhere in their marketing I read that they suggest it could be used as a channel strip in the studio for instruments or for the buss mix, so I'm thinking it has good EQ properties, not just a guitar noise machine
- Dec 3, 2003
- 23,054
- 45,952
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
I'll let you know how it sounds this week
Cool, I was working on something similar a few years before I did the open source one and I think I recognize some of his posted curves as being things I just assumed were going to sound terrible. The Anderton STC could sound really awful at certain settings IME, and of course full parametic EQ in general is often like that. I think that's fine in many applications, but for an onboard build it's kind of no bueno to me.
yeah I think it's got way more features than I would use but right now it's the only way I could get that super filter two thing in a pedal format. I plan on using it like the alembic stuff although it's capable of much more extreme stuff than I'll ever need it for.
- Dec 3, 2003
- 23,054
- 45,952
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
Hope it works well for you. My experience with box mounted versions of the OS design with guitar and mandolin make me want to revisit Craig's STC and the tweaks I was working on in Spice models several years ago. Maybe next year...
I was watching some of the demos and now I really want to try one too! My intro to using resonant filters on bass was an old Morley Power Wah Boost that I used to just sit on a particular setting because it sounded so huge. It seemed to work as a band-pass of sorts but with a really strong resonance. I’ve never found quite the same tone in anything else since, but hear some promising potential in the Fairfield demos. I think part of the Morley’s mojo was old components and unintentional clipping happening before the filter that would push it in a pleasing way, and I think I’m hearing that in some of the Fairfield clips.
so the Fairfield pedal came today and i can confirm that it does exactly what i thought it does. with the tilt control at noon its a one band parametric with gain, frequency, and q. with the tilt control all the way left its a low pass filter and with it all the way right its a high pass filter, with the corner frequency being sweepable with the frequency knob. if you add gain and mess with the q you can create fully adjustable resonant high pass, low pass and band pass filters by affecting what happens at the corner frequency with the q and gain. the range of the frequency and q knobs is very large and at the extreme ends of the spectrum you get into guitar noise making effects, but if you find your range its a good eq pedal i think for bass. will need to spend more time with it to dial in my exact tones. this much adjustability can create some pretty bad sounds if you cant fully visualize how the controls work and a graph in your head..
Hi guys!
So I was working on a little project of mine based on a cort GB34A body lately (I fix/tweak cheap basses for fun; pic below), and was thinking of the preamp I'd put in it. All interesting options such as the aguilar OBP-3 semt a bit expensive to me, so I mined TB to try and find a cheap alternative... and I ended up hearing (ok, reading) about your project. Sounds amazing!
I have basic knowledge in electronics and very basic equipment at home (soldering iron, plyers and a multimeter, that is) and am totally into open-source stuff soooo...
Well I might try to put my dirty paws to use, so that I can get a nice (prolly soldered as poopie actually) DIY preamp!
Two issues (so far) tho:
- I have no idea if this specific preamp would feet my needs and ears (got a passive jazz neck PU and passive humbucker bridge PU)... Is there any vid anywhere showcasing the beast?
- Most troublesome is the fact I'm French (no wait- I'm in France. Being French is another issue). and I'm not sure as to who to order the pieces from (if I don't wanna get huge shipment fees). Any idea anyone?
Anyway all of this sounds super exciting, can't wait to try and fail (and maybe eventually do it)!
So I was working on a little project of mine based on a cort GB34A body lately (I fix/tweak cheap basses for fun; pic below), and was thinking of the preamp I'd put in it. All interesting options such as the aguilar OBP-3 semt a bit expensive to me, so I mined TB to try and find a cheap alternative... and I ended up hearing (ok, reading) about your project. Sounds amazing!
I have basic knowledge in electronics and very basic equipment at home (soldering iron, plyers and a multimeter, that is) and am totally into open-source stuff soooo...
Well I might try to put my dirty paws to use, so that I can get a nice (prolly soldered as poopie actually) DIY preamp!
Two issues (so far) tho:
- I have no idea if this specific preamp would feet my needs and ears (got a passive jazz neck PU and passive humbucker bridge PU)... Is there any vid anywhere showcasing the beast?
- Most troublesome is the fact I'm French (no wait- I'm in France. Being French is another issue). and I'm not sure as to who to order the pieces from (if I don't wanna get huge shipment fees). Any idea anyone?
Anyway all of this sounds super exciting, can't wait to try and fail (and maybe eventually do it)!
I was looking at digikey.co.uk - I think they're shipment fee is £12. I'm waiting to see what the best options are! I'll update you when I know. I've just read through the whole thread and I'm really excited - board should be coming from a friend today!
The things I'm considering (in the UK) are best place for the opamps and quality pots - I figure if I'm going to build it into a bass then alpha pots at 80p a go might not be the best option. I'm planning to put them into a rear routed cavity with no pickguard and the 6.5mm threads look like they will work - happy days!
- Dec 3, 2003
- 23,054
- 45,952
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
Please keep us posted, in the past I've occasionally sent your friend care packages for stuff he had trouble sourcing in the UK. I actually just gave him fabrication files for some opamp adapter boards to allow for subbing in more readily available and potentially higher performance parts that are only available in surface mount configs. I should have some concrete recommendations in that regard very soon, just need to build up the new standalone LPF and have a listen and then thoroughly bench test for any stability issues.
Thanks @Passinwind I've spent a lot of time in the past building various synth filters from PCB's and so I know sourcing the right parts can sometimes take longer than the build - it's great to know you're standing in the wings!
These look pretty sweet with the goth PCB option from OSH park.
Got a couple going spare so if anyone in the UK wants one drop me a PM
Gonna be a while before I get to build mine up sadly as I'm in-between moving house. Great looking project though, thanks to PW and all involved!
Got a couple going spare so if anyone in the UK wants one drop me a PM
Gonna be a while before I get to build mine up sadly as I'm in-between moving house. Great looking project though, thanks to PW and all involved!
- Dec 3, 2003
- 23,054
- 45,952
- Disclosures
- Designer/Toaster Tech @ Passinwind Electronics
Thanks for posting that, it's the first time I've seen any of my designs using the black board option. That would be especially useful for prototypes since tracing signal paths out for modifications would be considerably easier.
For my part, I'm still a bit hung up on the woodworking for my tube amp. Currently I'm waiting on some maple slabs for the front panel fascia. As hobby laser rigs become more and more readily available I think this could be a decent alternative to UV printing for pedals and the like. Here's the general idea:
I want that. But I'm in the US.
Well, chop chop! Kidding of course. Those faceplates look great.
I keep putting off building up a preamp. Maybe it'll be a 2021 new year resolution.
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