Casio CZ-1 sound

[Jackie C]

I just got a Casio cz-1 for free. The sound works with headphones but without headphones, i only hear a low hum but there’s no sound from speakers when I play. How can I fix this?

[Chas]

Firstly, congratulations on acquiring a CZ-1 for free. It's the flagship of the CZ range and still a very powerful and versatile synth even today. They're also quite sought after and fetch good money, so getting one for free, even if needing repair, is very lucky indeed!

 

When you say "no sound from the speakers", I take it you mean when plugged into an amplifier? The CZ-1 has no speakers of its own. 

 

The CZ series use output relays that can sometimes stick, causing problems with the sound output. I thought they would affect both the line outs and headphone out, so it's a bit weird that your headphones are fine. 

 

It's possible that your line out sockets have got damaged (maybe that's why the CZ-1 was given away for free?) Open it up and check the sockets and board traces for continuity. You can also take the opportunity to check the output relays while you're at it.

 

Here's a video showing how to deal with the output relays:

 

 

[IanB]

Ah, the legendary troublesome CZ relay..!

 

To be fair, they have lasted well over 30 years. Considering the continued popularity of "vintage" keyboards, I wonder how long the designers anticipated them being in use for, and indeed how long the electronic musical instrument designers of today expect their wares to last. Acoustic instruments can last indefinitely and can pretty much always be repaired by a craftsman. With electronics, it's a different story. It's sad to think they'll all fall silent in the end however much care they get.

[CYBERYOGI =CO=Windler]

Well, except violins (stradivarius often got puzzled back together from a zillion of tiny wood debris) also acoustic instruments can not last forever. Mouth blown woodwinds rot by moisture, and also many pianos and particularly pedal harps become an economical total-loss after some decades due to worn mechanism. But at least in theory any component of them can be fully understood and remade by craftsmen.

Edited October 15, 2022 by CYBERYOGI =CO=Windler

[IanB]

14 hours ago, CYBERYOGI =CO=Windler said:

Well, except violins (stradivarius often got puzzled back together from a zillion of tiny wood debris) also acoustic instruments can not last forever. Mouth blown woodwinds rot by moisture, and also many pianos and particularly pedal harps become an economical total-loss after some decades due to worn mechanism. But at least in theory any component of them can be fully understood and remade by craftsmen.

 

Yes. I think my point was that any part of traditional instruments can be fabricated by a sufficiently skilled craftsman. The problem with electronic instruments like this is that they rely on the availability of commercial elements which cease production and can't be fabricated without a massively expensive production run, particularly for instance the Casio LSIs. Now currently we do have the option of microcontroller and FPGA emulators... but often we don't even have the specifications of the original device.