Awesome, my order from element14 came today, so I can start on my CV board build!

The 1/4w resistors I bought are tiny though, about half the size of normal ones. Anyone else seen those types before?

I’ve also got a x0x-heart pacemaker to build for some acid. I think it will work nicely with the Alf.

Is there a front panel cad file available for the MIDIalf? I want to make eurorack style front panel for it.


The tiny resistors are most likely 0.1 or 1/4 or plain jane 0.4 watt metal film resistors. I use those all the time on boards designed to hold the bigger 0.6 watt type. The only time you have to look out is if the resistance is lower than 100R since that means it might be part of some high-current/power circuit.


They are certainly 1/4W parts, I was just a bit shocked they were so small. Lowest value on the CV BOM is 220R so shouldn’t be an issue.



There are a couple of manufactures that make 1/4 watt parts (Stackpole in particular) that are the size of normal 1/8 watt parts. Very handy in circumstances where people have the “90 degree to the board” resistor which I am not a fan of and you can get those to lay flat in the same footprint


dotlogic .. I also use these a lot. You get those when you order the cheapest 1% resistors at farnell/element14 :)altitude That’s great to know! I’ve got to build a yocto and i wa thinking of replacing the 5% resistors with 1%.


@altitude - good call on the '90degree to the board` usage. These would look much neater in those locations.

@shiftr - guilty as charged, they were the cheapest ones I could find. :slight_smile:

A good hint for anyone buying from element14 (and farnell possibly) is to send your shopping basket/BOM to their quote team for a better price. I managed to pay literally half price on my order, all I had to do was ask.


@dotlogic wow! Half is a lot! … They actually called me a few weeks ago to tell me about this option. But they said it’s only for orders above €200 euro or so. How much was your order if I may ask?


Sure shiftr, It was much less than that, originally over $90AUD, but ended up spending just over $45. I even had to add a few LEDs to push it over the free shipping threshold!

I was pretty surprised it was such a good discount to be honest!

I too have received calls from them offering the service, quite a few actually.


Can someone tell me which is D1 and D2 on the CV board? They are not labelled as such.


All the diode’s are of the same type 1N4004 …

They are polarized! And they are here:


Hey shiftr, yeah, I know this much :stuck_out_tongue:

I’m building for eurorack specs, most of the power components aren’t installed, and D1/D2 are jumpered.
The schematic shows the part ID’s, but the board artwork has only values…


@dotlogic - here they are, MidiALF/CV D1 and D2 that need to eb jumpered:


@dotlogic … oh ok didn’t realize the build is different for the eurorack version. I still have to build mine. I’ve been busy for ages with this endless TTSH.


@shiftr – what are you guys using to drive TTSH CVs and 10V gates? A number of people asked me to come up with a small MIDI2CV board that essentially is the MIDI to CV converter built into MidiALF/CV: 4 x freely assignable CVs (note, velo, any CC, after touch, etc), 4 x Gate (gate, strobe, various clocks derived from MIDI clock, etc), however i’m still not sure it’s worth the effort.


I’m not using anything yet because i haven’t finished it. I’m probably going to be using midiimplant if i wil have the midi2cv inside.
Googling ttsh and midi2cv brought me this
Seems to be done by forum member @qp ?
I can’t tell if it will be worth your effort. How many will you have to sell to make it worth your effort? I think most of the first batch ttsh’s are build by now and a new batch is coming quite soon.

If it could work at +15/-15 and +12/-12 it could also double as a eurorack midi2cv. I think there is still some space for a good diy euro midi2cv. Hexinverters one seems to sell out quite fast all the time.


Well, it’s not really about the money (although I don’t want to lose 'em), it’s more about fun to create a useful project without investing a lot of effort: it looks like a weekend project since most of the code already exists in MidiALF/CV, and laying out Atmega328p based PCB with 8 x 3.5mm vertical connectors and MIDI is trivial.


I thought it was probably not about the money. Maybe you can put a post in ttsh build thread at muff to see how much interst there is. I will take one from you if you make one … and 2 if it’s euro compatible too :slight_smile:


thanks @kvitekp
A further question, would a 15V AC supply be suitable to power the midialf/CV in its normal form? I have one spare and am still tossing up whether to eurorack the alf, or put it into its own case…


@dotlogic – yeah, 15VAC should be OK.


15VAC did not work for me … i had to go to 18VAC to get midialf/CV to work (did not have 16VAC handy).