IanB

Hi @daveb22, just looking at the service manual it looks like the keybed PCB is split into three parts with jumpers between them? Is that correct? Is the octave that kinda-works on its own PCB? Does the CZ work okay controlled by MIDI? cz1.pdf

Hi TonyR, you can always put a video on YouTube so we can all see it?

Fascinating video. My own conclusion was that claims about one being more "lively" or "dynamic" than the other seem somewhat redolent of audiophile claims- these are very vague and subjective adjectives. Side by side, as you demonstrated, the two keyboards sounded the same, or at least very similar. At some points I closed my eyes and was unable to distinguish the keyboards as you alternated notes. Regarding the oscilloscope traces on the square wave being more sloped on one than the other, that could be down to as little as a single capacitor value in the signal path having a lower value, either by design, tolerance or ageing. It means the more sloped one is passing a bit less bass end, which might be audible in the very low register.

@HAILHAILIt's certainly repairable, it isn't a "beyond economic repair" situation, any reasonably competent technician should have no problem with it. Doesn't even need any parts beyond solder and superglue

I'm just wondering, do these keyboards have any software that allows their functions to be controlled via MIDI? Then a laptop connected by MIDI could be used with functions mapped to its keyboard or some other input device.

Agree with @pianokeyjoe, the controls board has a lot of cracks in it it. If you can solder, you can fix it by soldering jumpers across the breaks; you'd also want to to mechanically repair the board too. The battery doesn't matter right now, the 6500 will work without it. Also, as and when you do get it working, you might be interested to know it's possible to fully edit the current patch (though not save it to a preset) via MIDI. I wrote some software specifically to achieve that; see the link in my signature.

I just had a look at the download stats for VZV CZ, and the breakdown of where people are downloading it, and seeing I have downloads from Canada to India, from Finland to Cote d'Ivoire. There's something immensely gratifying at the thought of people all over the world using a bit of software I wrote. And knowing CZs are still in use all over the globe! With international tensions on the rise, it just feels like a pleasing reminder that music is a global community.

It might be switched to Quasi Mode 0?

@Chas I will be interested to know what results you get. Nyquist says that different DACs shouldn't make a difference to timbre, "the science" says the only difference might be noise levels if one DAC has poorer linearity than the other. But "the science" isn't always right in that there may be other factors! We have to remember also that the CZs use the "fake bits" system where they kinda-sorta extend the resolution of the DAC by scaling the DAC output as the amplitude goes up and down. That uses some really bog standard 4000 series parts as analogue switches, nothing fancy there. Casio were quite inventive with their circuits back then! It interests me what people hear in vintage stuff, often attributing exaggerated claims about circuits which, when you look at the board, are made from common off the shelf components. This is notable in my opinion in the "mystique of Moog". Look on the schematics and it's dime-a-dozen transistors and op amps. One extreme example was that it got around that the capacitors in Fender Stratocaster tone controls were some kind of special sauce and they started selling for silly money; ordinary buy'em by the bucket-load ceramic capacitors! Of course there may be other factors, such as board layout in the smaller CZ101 compared to the CZ1000, etc. Looking forward to your results.

Looking forward to this! As observed by @Jokeyman123 perceived differences in patches may just be due to the extra oscillators available (two PD chips rather than one). I don't think any more waveforms were available in the CZ-1, and without distracting myself by poring over the schematics again (every time I do I get drawn down a rabbit hole!) the circuits are in terms of audio circuitry near identical; same DACs, same op-amps, same components, etc. So I'll be interested to hear this.

@Jokeyman123Well, one obvious advantage to me is that modern technology makes recording accessible. In the past, amateurs could not make professional recordings at all; I remember as a youngster recording the various bedroom bands I was involved in with cassette recorders, which doesn't make great sound quality. Then came the 4 track- a major step forward- but then a decade later I remember the sheer power of having Cubase VST running on my Pentium II system. Effectively unlimited tracks and effects became possible in the digital environment for a price that had been unimaginable in the analogue days of requiring very expensive tape recorders and hardware outboard gear for effects. So for me, modernity is a massive improvement on the old days in that regard. But it is complicated, and as I said in my post, MIDI doesn't help by having a whole jargon and complexity of its own. Plus, ignoring MIDI, routing and recording of audio sources on PC can get unnecessarily complex; I honestly think Windows has got far worse in this regard than at the turn of the century. The options are all over the place, very unergonomic. The Windows 98 audio mixer was far better than what replaced it- so I've heard, it was deliberately to make life harder for people to copy copyrighted material, as if that was going to stop those committed to doing so! As you know, I sometimes write a bit of software and I've now got this "how to make MIDI simpler on Windows" thing running at the back of my head, but it hasn't come up with any good answers yet! I'm vaguely thinking something along the lines of this (imaginary) app detecting that a MIDI device is (say) a Casio or similar keyboard and automatically setting itself up to record MIDI from and play MIDI to that keyboard, but even then there are issues with things like Local On/Off to contend with. But some kind of built in library of configurations for particular models of keyboard (that the community can write additional configurations for) might be a way forward. So there's a specific config for a CTK-3500 or whatever.

Reading this thread I wonder if there's an opening in the "app" space for a simpler MIDI/audio app aimed at young people with a very straightforward interface for young beginners. Thinking about it, it seems part of the issue is that MIDI is a very "raw" standard which forces users to understand how it works at the message level, which is pretty daunting at first. SysEx and NRPNs etc are not too easy to understand for beginners...

Just to add, one thing to watch out for is that Windows 10 (if that's your OS) identifies the UCA's input as a microphone rather than a line input, assumes it is mono and "helpfully" switches off the Right recording channel, so if that happens to you you need to go into the advanced Sound Settings and switch it to 2 channel, 16 bit, 48 kHz (or 44.1 if that's your preference) to get Stereo working. It had me thinking the UCA was broken at first! It often seems the easier they try to make things, the more they futz them up...

I have a UCA222 and it's a good little device. You can download an ASIO driver (details with the UCA) for low latency recording (that is, with a very low delay recording and playing back) which you'll want to use with DAW software.

Glad it's going well @Emerson J, it's certainly easier than the onboard editing, that's what I wrote it for I added the ability to change values with the mouse scroll wheel to make editing as quick as possible. Have fun!

@Emerson Jthis is the kind of message I love to read! Thanks so much for posting I have a Behringer UMC and it works fine with my Casio and the software.

@TooSXy Well it does sound like something amiss in the power circuit. I don't have any more info than the textbook unfortunately. Stabbing about in the dark, a first thing to check would be electrolytic capacitors. Do you have an oscilloscope?

Thanks for the information @Chandler Holloway! I am more interested in widths than lengths

Like the title says. What size are the keys used on Casio's small keyboards like the SA76, or classics like the MT65? If any of you fine people has one of these cuties, would you be kind enough to measure the width and length of the white keys and black keys for me? Reason is I'm making a kind of keybed of my own at the moment and I'm just wondering. I've got full size keys to measure, but not the little ones

@the_duckchildGreat, let us know how it goes!

And sincere thanks from me for your kind words, @Syntherclass!

That sounds like the switch may have failed mechanically rather than needing cleaning

I think the metronome might be a red herring at the moment. A visual inspection and a look at the mod section would be a good place to start. It's easier to focus on one issue at a time

Well if you do you'll kick yourself if it's just a loose wire.

Well one thing at a time, have you opened it up and had a look at what state the insides are in?