The Passinwind Open Source Preamp

[Passinwind]

So you're mentioning that this now-finished bass came out a pound lighter than the bass in post 1582?

I misunderstood you to have done something to lighten this bass.

How much does it weigh?

With the new body it weighs 7.4 pounds, 7.7 if you include the 4 pin right angle XLR and the hanging part of the cable. The body swap was done so I could try a new control layout and play with the outline, while keeping the ability to revert to the post 1582 config if necessary. The weight loss was not necessarily expected, but I'll take it !

 

[Passinwind]

Is that swamp ash? The grain makes it look like it'd be light and resonant.

I had lunch with the luthier the other day and he told me it's actually some frou frou type of bog ash. He seemed very happy that I was able to rehab it to the point of being usable.

 

[dcoyle]

" frou frou type of bog ash"

 

[Jim C]

I had lunch with the luthier the other day and he told me it's actually some frou frou type of bog ash. He seemed very happy that I was able to rehab it to the point of being usable.

But was it vintage?

 

[Passinwind]

But was it vintage?

Carbon dating puts it roughly on par with Keith Richards, so pre-Cretaceous.

 

[Passinwind]

Hey all, I just stumbled on some bad news re. Wima film cap availability: Link Removed

In most cases involving my designs there are readily available alternatives that will work and look just fine, and I assume Wima won't just throw in the towel on these popular parts. I'll revamp the open source boards as needed, but doing that and revising the Mouser BOMs might take a while to get to, and who knows what else may happen in the interim.

On a happier note, I just bought a Spark 2 amp and it works really well with acoustic guitar and the open source pedals. I got it mainly as an electric guitar practice solution, but I think in standalone mode I could play open mics and the like with it perfectly happily, at least with my electric, and it does have a line out should I need a little more stick. It sounds pretty nice with bass but won't get all that loud, as one might expect. For use with a PW3B-LPF pedal I found the Flat Acoustic amp model to work best, and a little better for my purposes than my favorite of the four bass amp models, the G-K based one. Haven't tried muting the onboard speakers and going line out to one of my bass rigs, but I expect it might work pretty well.

 

[dcoyle]

Hey Charlie,

With what you said about the caps, I was just now trying to buy a set of R's and C's for the three board's at Mouser, and the site will show the BOM's but won't let me buy. Is that at my end or is something going on?

Thanks

 

[Passinwind]

Hey Charlie,

With what you said about the caps, I was just now trying to buy a set of R's and C's for the three board's at Mouser, and the site will show the BOM's but won't let me buy. Is that at my end or is something going on?

Thanks

I’m not sure how it all works right now, I’ll take a look presently.To get the 1uF 50v caps I had to go to a past order andclick that line item, which said not currently available but ~1700 in stock (huh?). So I entered qty 100 and hit “add to cart”, then checked out quickly. I figured it might not work, but my full order shipped yesterday I’m going to buy some TDK subs on my next order and see if the extra 1mm width causes any issues, but I think the 1.5 uF ones I use a lot might be more of a problem in some of my other boards.

 

[dcoyle]

When you get to it, it won't let me buy the complete BOM for, say, the HPF. Previously it would respond to "buy selected items", but show a line item as backordered. Has the sharing ability changed?

 

[Passinwind]

When you get to it, it won't let me buy the complete BOM for, say, the HPF. Previously it would respond to "buy selected items", but show a line item as backordered. Has the sharing ability changed?

Not on my end. Did you hit "select all"?

While I was in the HPF BOM I noticed one backordered part number: the 0.68uF 50V caps. The 63V part is the same width and only 1mm taller, so I deleted the 50V part and substituted the 63V / 5% one, using the version with the most in-stock parts. As always, please let me know if you find other backordered or otherwise unavailable parts and I'll try to find workarounds.

 

[dcoyle]

"Not on my end. Did you hit "select all"?

Duh.

Thanks, that was the problem, I hadn't hit "select all" on the left before I tried to "buy selected items" on the right.

I think my purpose has been to help idiot-proof this thread.

 

[Passinwind]

"Not on my end. Did you hit "select all"?

Duh.

Thanks, that was the problem, I hadn't hit "select all" on the left before I tried to "buy selected items" on the right.

I think my purpose has been to help idiot-proof this thread.

All good, you got me to update a back ordered part at least!

 

[Passinwind]

I've been working through rehabbing some old failed and/or unloved builds recently, and yesterday I decided to tackle one that I bailed on 2 1/2 years ago:

The idea was to adapt the HPF/PEQ sections from my DIY amps to a 9 volt single supply format, but retain the ability to use +/- 15V supply rails where appropriate as well. Using a DC-DC converter daughter card seemed straightforward enough, but somehow I never saw the expected substantial headroom gain and eventually I moved on to other windmills to tilt at. But every once in a while I'd order a component or two with this build in mind, and I finally got around to putting in another concerted effort to make this design fork work. It took all afternoon, but a fresh set of eyes eventually paid off and I now have a solid baseline to work off of. On to listening tests this afternoon, then if all goes well I'll whip up the first v5 pedal prototype. More knobs...yay!

My concept was to replace the very simple switched mid section with a one band full parametric equalizer, covering any and all frequencies that most of us would remotely call "midrange." For now that equates to 66Hz-3.6kHz, +/- 15dB at something like 1/10th octave to 2 octave bandwidth. Line level in, up to +22dBU out, so able to drive any commercial power amp with headroom to spare. DI and mic preamp to follow, just maybe.

 

[Lo-E]

I think my purpose has been to help idiot-proof this thread.

Every time I try to idiot-proof a procedure I learn that I’m a much better idiot than I give myself credit for.

 

[Lo-E]

My concept was to replace the very simple switched mid section with a one band full parametric equalizer

Which is a great concept (as you and I have discussed offline). I would counter that the 3-position switched mid actually works pretty effectively and is fast and simple.

A full parametric mid is a wonderful thing (and I use them a lot) but in a gigging situation, if you really felt like adding more knobs, having two bands of switchable mids with just a little overlap between the bands might be even more powerful a tool - and simpler to dial in quickly.

The beauty of modular construction, of course, is that one could mix/match their preferred mid EQ section; simple one-band, simple two-band or full para one band.

Just my brain running laps….

 

[Passinwind]

Which is a great concept (as you and I have discussed offline). I would counter that the 3-position switched mid actually works pretty effectively and is fast and simple.

A full parametric mid is a wonderful thing (and I use them a lot) but in a gigging situation, if you really felt like adding more knobs, having two bands of switchable mids with just a little overlap between the bands might be even more powerful a tool - and simpler to dial in quickly.

The beauty of modular construction, of course, is that one could mix/match their preferred mid EQ section; simple one-band, simple two-band or full para one band.

Just my brain running laps….

My DIY amps use one fixed mid band and a full PEQ. It would be very easy to make the fixed band switchable though...hmmm.

And this "new" board has patch points for both the HPF and PEQ sections, so a two band PEQ and second dedicated HPF for EFX or DI is on my radar as well.

 

[Passinwind]

Initial listening tests on the new HPF / PEQ were very encouraging. One more round of fine tuning this morning and into a test box it goes. The highest PEQ center is now right at 4kHz, which was often a magic bullet notch setting with the four Ashly PEQs I used for monitor mixes in the rock club I used to work in. And it turned out that just running one of my Simple Gain boards off the +15V rail worked fine as a front end and didn't bottleneck headroom at all.

So it works great, let's fix it some more. New board layout nearly done, did catch a little side eye from my wife at 2AM though...

 

[SteveCS]

did catch a little side eye from my wife at 2AM though...

I heard it on the grapevine that retirement is when you stop the day job and start doing the things you love. How blessed when they are one and the same!! Best to you and yours!!

 

[BQFS]

I heard it on the grapevine that retirement is when you stop the day job and start doing the things you love. How blessed when they are one and the same!! Best to you and yours!!

When I was a kid, my mom wanted me to be a dentist, about the furthest thing from my mind. I was into music and electronics. My dad told me to ignore my mother and find something I loved to do and the money would take care of itself. Some of the best advice that younger version of me ever received. My electronics hobby turned into an electronics repair business. I never lost my love of it, and always felt blessed to have followed my dad's advice. Nothing seemed better to me than to do something I loved and getting paid to do it. Now, retired at 76, it's back to being a hobby, although I am currently making preamp boards and pedals for resale.

 

[-Asdfgh-]

I still need to build mind. Hopefully, I can find the right instructions. The bits I have neatly labelled, at least.

Have I mentioned that I (a) don't like soldering and (b) I am rubbish at it? My wife's amazing at it, though...