Hey Tiido!

That’s a great spot! On mine, it looks like it has been simplified to R70 and R69, with the spot where R68 should be actually being a bridge to ground.

I lifted 70 and 69, and cut the bridge, but alas no change. Odd! I’ve put them back now anyhow.

It may remain an unsolved mystery… at least it does seem to otherwise work, and the SYSex above fixes some of those issues too!

I must thank you for your continued efforts on this, as well as your patience with myself- it’s very much appreciated 😀

I picked another one of these up, and it just so happened to be the earlier revision with the socketed CM-32L ROM. I did the mod again and observed the same results; no SFX on channel 10 unless you load in the SysEx file I made.

I did at least discover that the VPP doesn't need to be tied to VCC - I left it floating and it works absolutely fine.

Hi!
So, is a modded RA-50 totally equivalent to a CM-32L or not? I have found a couple of them at an interesting price and wondered if the modification is feasible and effective.
Thanks

Seems to be possible but whoever did it never posted a detailed guide, hopefully one day we will get one.

Mao wrote on 2024-11-04, 21:27:

Hi!
So, is a modded RA-50 totally equivalent to a CM-32L or not? I have found a couple of them at an interesting price and wondered if the modification is feasible and effective.
Thanks

It is, but to make it so you need to do the following:

• Add the missing SFX sample ROM that is missing (either via an additional 512K chip as I did, or by replacing the existing ROM with a larger 1MB 0ne as per Tiido's post.
• For some reason, the device doesn't initialise the SFX samples on channel 10 as a real CM-32L does. This doesn't affect games that are not expecting this mapping, but for those that do, you just need to send this SysEx file here to set the device up after powering it on.

I haven't posted any guide on how to do the mod as the posts here should cover what's required and some may want to do the neater modification of replacing the ROM entirely, but this does require de-soldering tools.

Cheers,
Rich