Absolutely love the idea - I already use mixers (two Behringer RX1602) for my vintage machines, but as many have multiple sound cards I'm always running short on inputs - and have to have a complicated sheet of which card on which system is connected to which input. Being able to just have one per system would be a game-changer.

Maybe a bit of a heretical suggestion though, but wouldn't something like this on an expansion slot at the back of the case make more sense?

Putting this on a drivebay at the front means differing cable lenghts depending on case, which would be susceptible to whatever EMI is present in the case. That means you can't ship with cables unless you go for a long default, which would need a lot of management in smaller cases - and potentially drilling holes in some cases. With a slot-mounted solution, no cable would need be longer than the distance from slot 1 to slot 8, so you could supply (or link to) good cables that would always fit. Also it keeps the front of the system period-correct if so desired. The downside to rear mounting means the knobs won't be as accessible, but realistically, these are settings you want to do once only, not fiddle with all the time.

Another advantage is that one size fits all - you already see people asking about 3.5" vs 5.25" (and dare I suggest full height vs half height), some cases don't have any (or any that are free). An expansion slot will work on anything from a 5150 to a modern system. Of course systems with three sound cards needing this sort of thing might be short on expansion slots, but (at least looking at my own systems) chances of all three-five front bays being occupied is a lot higher than all eight at the back, indeed my only system that actually has all filled is an overloaded XT, and that is getting a PicoMem (from your site of course) which should replace three of the cards anyway. Plus: assuming you don't want to drill holes, you need to route cables to a front bay mixer through a spare slot anyway, so putting the mixer in that slot doesn't cost any more.

dionb wrote on 2025-01-03, 15:55:

Maybe a bit of a heretical suggestion though, but wouldn't something like this on an expansion slot at the back of the case make more sense?

I like.

Jinxter wrote on 2025-01-03, 16:24:

Maybe a bit of a heretical suggestion though, but wouldn't something like this on an expansion slot at the back of the case make more sense?

A "mixing card" is in my todo list, with a number of internal connections aswell as external ones, with software control... but there are many other higher priority things in that todo list...

Tiido wrote on 2025-01-03, 22:54:

Jinxter wrote on 2025-01-03, 16:24:

Maybe a bit of a heretical suggestion though, but wouldn't something like this on an expansion slot at the back of the case make more sense?

A "mixing card" is in my todo list, with a number of internal connections aswell as external ones, with software control... but there are many other higher priority things in that todo list...

I can imagine 😜

Not totally sure about the 'software control' bit - that requires it to be a fully-fledged ISA card with support limited to DOS (or OSs that can run the control app). A hardware-only card would also work on newer PCI-only (or in any case ISA-limited) systems and would be OS independent. Just three or four inputs, corresponding pots and one output - and a Molex for power. Nice and simple. Internal connections would be good though 😀

The software control is not just from the ISA slot, but from a frontpanel too, so that there's no need to bring actual audio signals to it and back which is a huge logistical and sound quality related win. On the front panels you have pots or sliders connecting to a little MCU that then relay position info to another on the card, which then talks it to digipots that do the actual signal level adjustments. The talking can also happen over ISA or PCI or something else, provided an interface is made. ISA being the simplest although PCI is not hard either (and PCI is also in that endless todo list 🤣). It will absolutely need that -12V from the ISA or PCI slot however, proper analog stages are much simpler and higher performance without mucking with virtual grounds and all the pains that come with in. Design goal is complete lack of stuff like ground loop issues and that takes proper analog stages to achieve.

Could the Picomem Audio edition have a software controlled Mixer. With physical line in from CD, Speak, Jack etc.

Sorry for going off topic here, but is there still space for Crystal based MIDI expansion card in your busy schedule for 2025?

On the topic - how do you connect the outputs to the bay's internal mini-jacks?
In my case all of the outputs (except CD-ROM, which is not important as it's digital) are at the back of the PC (card or mb), so would I be letting these in via an opening back in again and running across the whole case to connect?
Also an immediate UX thing for me would be using the knobs and headphones output off the front panel, but still have access to line out from the back (ideally stereo and separate L/R) to have fewer visible cabling for speakers.
Both points above kind of hint that a back-side I/O panel to accompany the bay mixer could be a thing...
And as a bonus a digital "PC speaker" emulator with dedicated volume control would be a selling point for me personally.
Good luck with the project.

ludicrous_peridot wrote on 2025-01-04, 11:49:

Sorry for going off topic here, but is there still space for Crystal based MIDI expansion card in your busy schedule for 2025?

Do you mean the crystalblaster - still intending to but probably not before summer - would need to try find a reliable source of chips again

ludicrous_peridot wrote on 2025-01-04, 11:49:

On the topic - how do you connect the outputs to the bay's internal mini-jacks?

I am intending to make a breakout bracket solution
next revision will have some redesign for this

psychofox wrote on 2024-12-30, 13:11:

Most cases have only 2 3.5" bays, so i would suggest to create also an "high end" 5.25" version of mixer, maybe with eq and led […]
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Most cases have only 2 3.5" bays, so i would suggest to create also an "high end" 5.25" version of mixer, maybe with eq and led graphic equalizer.
My project:

Pentium MMX DOS gaming build "Bright Star"

Edit, Dudeface was faster and had same ideas.

yes i will consider a deluxe, larger 5.25 version

yours looks nice !

dionb wrote on 2025-01-03, 15:55:

Maybe a bit of a heretical suggestion though, but wouldn't something like this on an expansion slot at the back of the case make more sense?

yes i am considering this :
1 part at a bracket / an extension slot (connectors)
1 part in a drive bay (controls)

i will rethink the wiring option, thanks for all input, much appreciated,
it has become a much larger project now 😉

dreamblaster wrote on 2025-01-04, 20:02:

yes i am considering this : 1 part at a bracket / an extension slot (connectors) 1 part in a drive bay (controls) […]
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dionb wrote on 2025-01-03, 15:55:

Maybe a bit of a heretical suggestion though, but wouldn't something like this on an expansion slot at the back of the case make more sense?

yes i am considering this :
1 part at a bracket / an extension slot (connectors)
1 part in a drive bay (controls)

i will rethink the wiring option, thanks for all input, much appreciated,
it has become a much larger project now 😉

Much appreciated - but don't let feature creep kill the project (or turn it into a 5-legged sheep). Ignore everything I wrote if it would delay or unnecessarily complicate the project.

Yoghoo wrote on 2024-12-30, 11:34:

For my use case yes. 😀 As I have a lot of retro pc's all using 1 speaker set. I now use a couple of cheap aliexpress 4 port ones but can't find an affordable 8 port (or more) one.

Try searching Aliexpress for "Mini Mixer G-MARK Mix8" for the 8 channel, and Mix1000 for the 10 channel. it's the jump to 12 channels which is when the price jumps doing to moving to DJing equipment that offers many more controls rather than just being a simple mixer based on volume.

As for the drive bay, my only concern would be noise getting picked up in the case. It could be handy in the right use case. But proper cable shielding will be a must.

Bracket prototype ready, it seems to fit.
Comments?

dreamblaster wrote on 2025-01-30, 20:50:

Bracket prototype ready, it seems to fit. Comments? […]
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Bracket prototype ready, it seems to fit.
Comments?

cool design 😀 good option for those that dont have a spare bay, even has the 4pin headers, this will please a lot of people!

i was thinking about the bay version, i like things to be symmetrical having the knobs off centre would niggle me on an OCD level. 🤣, but you'd have to remove or relocate the front jack to compensate, then i was thinking most people not using onboard audio, but using a sound card wont be making use of the front panel audio, if you could add an AC97 header instead people will be able to make use of thier front headphone/mic jacks which otherwise would go un-used.

dreamblaster wrote on 2025-01-30, 20:50:

Bracket prototype ready, it seems to fit. Comments? […]
Show full quote

Bracket prototype ready, it seems to fit.
Comments?

Oh yes, I can see this being very useful!

SScorpio wrote on 2025-01-04, 23:15:

Yoghoo wrote on 2024-12-30, 11:34:

For my use case yes. 😀 As I have a lot of retro pc's all using 1 speaker set. I now use a couple of cheap aliexpress 4 port ones but can't find an affordable 8 port (or more) one.

As for the drive bay, my only concern would be noise getting picked up in the case. It could be handy in the right use case. But proper cable shielding will be a must.

100% this. I remember buying a 5.25 mounted class D amplifier back in the day thinking it would be cool... The EMI pickup was horrendous. Squealing robot farts all day long.

It was un-usable.

https://www.techpowerup.com/forums/threads/sc … plifier.122806/

dreamblaster wrote on 2025-01-30, 20:50:

What if you added one volum knob (with a press function) on the bracket. And added electronics that controlled the volume trough pressing in the volume knob.
No press = master volume
1 press = output no 1 volume
1 more press = output for no 2 volume.
and so on.

I totally agree that a front panel is way cooler, but this would make a very cheap solution, and you would not need a available bay.
But i guess all electronics would have to be moved to the bracket.

Nice project!

dreamblaster wrote on 2025-01-30, 20:50:

Bracket prototype ready, it seems to fit. Comments? […]
Show full quote

Bracket prototype ready, it seems to fit.
Comments?

Hmm, what about connecting the bay to the bracket with a more reliable connector? Maybe Dupont, which would work with standard CD-ROM drive audio cables, or a single multi audio channel connector to connect all audio channels at once? The LiveDrive had a single ribbon cable for example iirc.

Jacks are not very reliable in my experience, especially the 3,5 mm and smaller types, often introducing contact problems. In the current implementation, you would have four jack connectors in series from the sound card to the bay (including the sound card itself), and another three on the way back out of the case, with seven connections in total.

Maybe two more ideas for a deluxe 5.25" bay version:

- include stereo LED Level indicator (like this)
- include simple preamp equalizer (like this)