crusher wrote on 2026-09-14, 05:52:

@matze79:

Would it be able to add another switch to enable/disable HDD clicker in case you want to (temporarily) disable the sounds?

It would be better to add it to the power wire. Otherwise, how would you reach the PCB inside the computer to push it?

matze79 wrote on 2026-09-14, 10:16:

It would be better to add it to the power wire. Otherwise, how would you reach the PCB inside the computer to push it?

For me personally that wouldn't be a problem. Depends on where you mount the HDD clicker.
This way it woul be easier than to remove the HDD clicker completely and mount it back when you want the sounds again.

A switch on the power wire is also a great idea and even more easy to reach.
But wouldn't that disable the HDD LED passthrough because the HDD clicker is not operating due to missing power?

Hm yeah didn't think of that.
You can wire it in parallel then
A mute button also would be possible.

matze79 wrote on 2026-09-15, 07:14:

Hm yeah didn't think of that.
You can wire it in parallel then
A mute button also would be possible.

A mute button would be perfect for this scenario 😀

crusher wrote on 2026-09-15, 05:50:

A switch on the power wire is also a great idea and even more easy to reach.
But wouldn't that disable the HDD LED passthrough because the HDD clicker is not operating due to missing power?

Could the (optional) mute switch go on a speaker lead instead of power?

Would the amp tolerate an open load? There would possibly be a little pop when switching while playing, but that's probably not a big deal?

Well, it won't get damaged — I just don't like leaving the amp running into no load. Either way, mute is now driven by the MCU instead of being left floating, so the Amp can't end up in an undefined state.

The new unit works well, and exactly as expected 😀

A few test units have already gone out to friends.

Probably worth saying how this differs from HDD Synth, since the two are bound to get compared. HDD Synth plays samples from an SD card, so what you hear is a recording of a real drive, and you can swap sample packs for a different model — the MKIV can even stand in for the drive itself over CompactFlash.

Mine goes the other way round: everything is synthesised on the fly, so there is no SD card, no sample ROM and nothing to load at power-on. The biggest advantage is that it stays cheap to manufacture — no Pico, no SD card, no SD slot, no fancy DAC, and nothing on the board that is hard to source.

Synthesising it live also means the spin-up starts the instant the PSU does. Activity is taken straight off the LED header — the one signal every machine has, whether the drive hangs off MFM, IDE, SCSI or something onboard. Two drive profiles are selectable on the DIP switch, with more to come, so you can change the character without reflashing.

The flip side is that you can't just drop in a recording of your own drive — matching a particular model means dialling in parameters rather than copying a file. Different trade-off, not a better one.

That are great news!
Can't wait to buy this 😀

This new model sounds awesome! Any sound samples or videos of it yet? Any ETA of public availability?

ViTi95 wrote on 2023-03-23, 21:57:

ST-225 simulator 😂

Soo you made that joke 2 years ago, and I just learned today about actual ST-225 simulator .. well, ST-506 simulator 😀 and as bonus points it also implements clicking directly inspired by matze79s Clicker!
https://github.com/kuba2k2/pico506