The Passinwind Open Source Preamp

[Passinwind]

I sort of remember that Invalid Link Removed could make a vendor-independent BOMs?

I can port the Mouser BOMs to Excel spreadsheets to accommodate using other vendors.

And right off the bat, the Rubycon electrolytic caps I've been using for the last few years are now at end of life, joining the Nichicon ones I mostly used before that.

 

[dcoyle]

My strategy for ordering parts is to get the board in hand to see the lead spacing/board room, and order better dielectric film caps. Where that breaks down is where there are special (stuff I don't know about ) caps, like for IC bypasses, etc.

"Frankly, my head is no longer in this at all and I just want it to be finished. "

Charlie, perhaps rather than do BOM's, you might specify the type (COG, film, elytic, etc) and/or series you used for groups of caps ( C1-5, C9, etc) and the folks later could figure out what was currently available from that series's spec?

And maybe one of us can publish our order lists when the schematic values stabilize.

Edit While I was typing you posted the above #1321. A previous Mouser order would get the info on type I mentioned here.

 

[Passinwind]

My strategy for ordering parts is to get the board in hand to see the lead spacing/board room, and order better dielectric film caps. Where that breaks down is where there are special (stuff I don't know about ) caps, like for IC bypasses, etc.

"Frankly, my head is no longer in this at all and I just want it to be finished. "

Charlie, perhaps rather than do BOM's, you might specify the type (COG, film, elytic, etc) and/or series you used for groups of caps ( C1-5, C9, etc) and the folks later could figure out what was currently available from that series's spec?

And maybe one of us can publish our order lists when the schematic values stabilize.

Edit While I was typing you posted the above #1321. A previous Mouser order would get the info on type I mentioned here.

So far about 30% of my preferred components are unavailable. And many of the Wima 50V film caps have no equivalent subs, but thankfully all of those still seem to be there. My plan will be to knock out one BOM a day until this is done. Five schematic revisions for just the HPF boards since I started on the BOM this morning, it's a real slog!

 

[dcoyle]

"Five schematic revisions for just the HPF boards since I started on the BOM this morning, it's a real slog!"

Seems you slogged to a little lower frequency on the LPF schemo, que no?

 

[dcoyle]

Make that HPF.

 

[Passinwind]

Make that HPF.

Yep, I did go back to an older, lower HPF tuning as the default for the moment. I've tweaked it a few more times since you posted that though.

The Mouser BOMs are pretty much finished, but caffeination and some careful double checking are still in order. Hoping we can get by with "only" four or five vendors, but it looks like it may still take 5-6 given ongoing parts stocking issues.

 

[Passinwind]

And now, another take on my simple gain/buffer board:

Roughly 1.2" by 1", variable gain trimmer optional. I'll probably build up a couple this morning.

 

[Tassieviking]

I wonder, If this ever comes out as a kit, will you get 3 empty match boxes for the PCB's to mount in ?

 

[Passinwind]

I wonder, If this ever comes out as a kit, will you get 3 empty match boxes for the PCB's to mount in ?

They will be 3D printed, most likely. I've approached some guys on the PPCB forum, several of whom could make it happen given the right motivation. And yeah, this one could be scaled up to fit the native footprint of the three main boards, but I went for relatively cheap and cheerful for now.

 

[Tassieviking]

Charlie, I am thinking of making some onboard preamps to try in the basses at home, is there a quick link to the best version to build ? (SMD)
I can only find the PCB for the TH version and I can't find any schematics for it.
The old Wiki page wont work for me but that might be me not doing it right.
Personally I would love to see all the old versions still available because I like to see & follow the progression that these type of projects go through, I find them educational for myself.
Thanks
Cheers
Mick

 

[BQFS]

Charlie, I am thinking of making some onboard preamps to try in the basses at home, is there a quick link to the best version to build ? (SMD)
I can only find the PCB for the TH version and I can't find any schematics for it.
The old Wiki page wont work for me but that might be me not doing it right.
Personally I would love to see all the old versions still available because I like to see & follow the progression that these type of projects go through, I find them educational for myself.
Thanks
Cheers
Mick

Me too!

 

[Passinwind]

Charlie, I am thinking of making some onboard preamps to try in the basses at home, is there a quick link to the best version to build ? (SMD)
I can only find the PCB for the TH version and I can't find any schematics for it.
The old Wiki page wont work for me but that might be me not doing it right.
Personally I would love to see all the old versions still available because I like to see & follow the progression that these type of projects go through, I find them educational for myself.
Thanks
Cheers
Mick

What flavor preamp would you prefer? The PW1B v6.6 module works great as a standalone two bander with just a few simple component subs, and can can be configured for either Bass/Mids or Bass/Treble. Active Bass/Mids with an added always-on passive tone control is pretty cool, but you can alos add the LPF module instead if you have the room and can make the Tayda or Small Bear pots fit. And then I have a nice new three band one that's well vetted and quiet verastile in terms of tuning options.

I will flesh out the v1 page eventually, thanks for the reminder!

 

[Passinwind]

Me too!

Same question for you, in your case I can probably just send you something, either a bare board or a stuffed one. Mick is a bit far away and shipping logistics are not that swell.

 

[BQFS]

I am interested in both the bass/mids and the three-band. I'd like to compare the 3 band to what comes standard in Ray5s and compare the bass/mid to the Tone Capsule which I use in a couple of my keepers. Thanks!

 

[Passinwind]

I am interested in both the bass/mids and the three-band. I'd like to compare the 3 band to what comes standard in Ray5s and compare the bass/mid to the Tone Capsule which I use in a couple of my keepers. Thanks!

The three bander can be configured Bass/Low Mid/High Mid like the Tone Capsule too, FWIW. I may have an old one done that way kicking around already, even. The three banders can also be upped to four bands with an add on board, or the two banders upped to 3 with the same add on. But the Bass/Mids/Passive is kind of my trademark build, and a lot of those have gone to NAMM over the last five or so years.

 

[Tassieviking]

The bass I borrowed from my daughter is just a plain 4 string Yamaha with 2 knobs on it, Pbass setup.
All she has is 4 string ones, so something simple that is easy for me to use since I am just learning the bass.
My daughter likes melodic death metal but also stuff like Sabbath, Led Zep, and anything up to what is being released tomorrow. I can go for anything.
I think you would be better at knowing what would be a good one for me to start with, I can easily modify the bass if I want to, or make a new bass for myself until I eventually learn how bad it sounds.
I don't need to color the sound much but the option would be nice I guess.
If I build one onboard preamp I will most likely build lots of different ones before I stop making them one day.
Thanks

 

[Passinwind]

The bass I borrowed from my daughter is just a plain 4 string Yamaha with 2 knobs on it, Pbass setup.
All she has is 4 string ones, so something simple that is easy for me to use since I am just learning the bass.
My daughter likes melodic death metal but also stuff like Sabbath, Led Zep, and anything up to what is being released tomorrow. I can go for anything.
I think you would be better at knowing what would be a good one for me to start with, I can easily modify the bass if I want to, or make a new bass for myself until I eventually learn how bad it sounds.
I don't need to color the sound much but the option would be nice I guess.
If I build one onboard preamp I will most likely build lots of different ones before I stop making them one day.
Thanks

For a simple P Bass preamp one nice option might be two concentric pots, one for Vol/Passive tone and one for Bass/Mids. Let's start by making sure there's room for a battery somewhere though, for starters.

 

[BQFS]

I like the idea of one the same as the Tone Capsule, bass, low-mids, upper mids, no treble.

 

[BQFS]

At the moment, I am upgrading a friend's old Carvin fretless. Looks like we're going to change the bridge to Hipshot with Ghost piezo saddles, Tone Capsule Preamp, EMG Active Balance Control, GraphTech Acousti-Phonic preamp, 18 v source. His is a lineless fretless, beautiful bass. I want it to sound at least as good as it looks. I have an almost identical Carvin fretless that I did the exact same thing to.

 

[Passinwind]

New simple preamp/buffer boards are done and tested:

I messed up the power supply filter cap sizing, but was just barely able to fit the right ones in there. Simple board revision for the next batch, already done. 25V pieces in 16V holes, essentially. Oh well!