Hacking the Yamaha DX9 to Turn It into a DX7 (2023)
11 comments
·January 19, 2025ajxs
dlbucci
This is right up my alley right now! I bought a busted CZ-1 as my first synth and I’m trying to get it working. I look forward to reading your blog!
elevaet
I'd love to hear what you're doing with the CZ-101. CZ-5000 owner here.
nonrandomstring
Fantastic read! Love that you did this.
I am surprised Yamaha ever created the DX9 given the manufacturing economics. Did they even save a few pennies here and there to create an inferior instrument? I guess even in the early 80s product differentiation was something.
ajxs
Thank you! I agree with you. I find it hard to believe that leaving out the sub-CPU, one RAM chip and removing the velocity sensitive keyboard would've made a big difference to the manufacturing cost. My guess is that they always planned to have a budget offering, but didn't have a good technical idea of how to implement it. My opinion is that the DX9 was too handicapped in the end to be good value. According to this contemporary review[1], at least one person thought the lower price made up for the handicap!
1: https://www.muzines.co.uk/articles/nine-times-out-of-ten/791...
TheOtherHobbes
'Budget' was relative. £900 is almost exactly £3,000 in modern money, and the DX7 was equivalent to £4300.
80s synth enthusiasts were often young and not particularly rich, so a cut down version wasn't an entirely insane idea. And if it hadn't been cut down enough it would have cannibalised sales of the more expensive synth.
Ironically the opposite happened - many people looked at the DX9, thought "No..." and pushed themselves to their limits financially to get the DX7.
I doubt this was deliberate, but it probably wasn't a net loss for Yamaha.
It's maybe more accurate to think of it as the prototype for the much cheaper budget 4-ops that Yamaha flooded the market with, after the DX7-tier was saturated.
simondotau
Evidently, the answer is that the DX7 was already cheap to produce. Engineering new stuff and spinning up a new assembly line would probably cost more than they would save. Remember, market segmentation is often about price discrimination. It's wrong to assume that consumer goods are priced at cost-plus-margin.
brightmood
There have been many times where companies took down the resource. Be aware that they may make a claim against you !
ajxs
I imagine if ever Yamaha start going after the people eating into their FM synthesis profits they'll have a long, long, long list of people to deal with before they get to me! In 1983 this firmware would definitely have upset someone, but right now I think I'm pretty safe.
Author here: Thank you so much for posting the article! I'm happy to answer any questions about the project.
If you find this interesting, I wrote an overview of how I approach these projects: https://ajxs.me/blog/Introduction_to_Reverse-Engineering_Vin...
I'm currently messing around inside the Casio CZ101, another cool 80s digital synth.