Phil has a great, in-depth video about the differences between all the classic Roland MIDI synths:

https://youtu.be/OLvsaJ4h-VY

It covers a lot, but you can easily skip around to the parts covering the MT-32's.

I don't think Phil covers any differences between the revisions within the original headphoneless model. Not much information anywhere about any differences there.

Ah. My mistake. I misunderstood the question. To my limited knowledge I've never noticed a difference between revisions within the "old type" MT-32's in games, and I have had both over the years (as well as most of the other MT-32 compatible Roland synths). That's not to say I couldn't have missed some minor idiosyncratic difference along the way.

Thank you for the responses!

I have found that Roland MT-32 units seem a little harder to come by than SC-55 units on eBay. A few years ago I remember seeing more MT-32's on eBay than I have seen listed on eBay recently. Previously I had bought one as a gift for my cousin. I partly credit various YouTube videos (and sites like this) for the apparent increased/sustained interest in them among gamers. I'm actually happy to see more people rediscovering the old DOS games and wanting to play and hear them as they were intended to be heard, even if it makes my quest for the right MT-32 a little harder today.

I don't know if I should bite the bullet and just get the rev 1 "old type," or if I should wait. Decisions, decisions 😕

If you're not hearing any chatter about the differences, it's probable that there will be no significant differences between the two revisions of the PCB. More information can always be forthcoming, however.

mt-32 rev.0 (old) vs rev.1 (new)
The discussion in this thread seems rather...confused. Rev.0 and Rev.1 PCBs of the Old model are being confused with "Old" (without headphone jack) and "New" (with headphone jack).

SierraGamer wrote:

A few years ago I remember seeing more MT-32's on eBay than I have seen listed on eBay recently. Previously I had bought one as a gift for my cousin. I partly credit various YouTube videos (and sites like this) for the apparent increased/sustained interest in them among gamers. I'm actually happy to see more people rediscovering the old DOS games and wanting to play and hear them as they were intended to be heard, even if it makes my quest for the right MT-32 a little harder today.

As recently as five years ago, MT-32's could be had on eBay for $50~70 USD depending on condition. Within the last couple of years, it does seem MT-32's have shot up 2x in price beyond what could be explained by just inflation/CPI. Supply seems roughly the same. They are not hard to come by, but the price they are demanding seems to continue to creep up.

Thank you for the responses.

Yes, Qbin, I believe you are right. Last week I purchased a SC-55 mkii for $143 (no additional shipping cost) from an eBay seller in Japan. It is supposed to be in excellent condition.

And just now I purchased the MT-32 (described in my original post) from another Japanese eBay seller for $170 (plus $48 shipping). Yes, I probably overpaid. But I'm fine with it. I have had these same model units in the past, though originally I had the rev. 0 "old" type. I still have my old midi cables that I had previously used. I had given the units to family members, and now I want my own units again.

Yep, fitzpatr, good point. I agree and noticed the same thing. In previous discussions there seemed to be confusion at times about whether people were talking about the "new" vs "old" Roland MT-32 or the differences between the two "old" types.

There are no functional or sonic differences between the two "old-type" MT-32 versions - known bugs and bug exploits are equally applicable to both. I prefer the units with the revised PCB due to their use of soldered-in-place mask ROMs (v1.07), where I've experienced bit-rot in at least one earlier, EPROM-based unit.

Cloudschatze wrote:

where I've experienced bit-rot in at least one earlier, EPROM-based unit.

Were you able to repair it ? If this is common, I wonder if those of us with an EPROM based MT-32 should start thinking about sourcing replacement EEPROMs (and programmers) and replacing the original chips .

Yes, but I cheated, and simply purchased a replacement set of v1.07 mask ROMs from Roland, where it would have been easy enough to either program a new pair of EEPROMs, or erase and re-program the existing EPROMs.

I don't think this is a common problem at all, to the extent that I've never encountered anyone else with a similar issue.

Cloudschatze wrote:

I prefer the units with the revised PCB due to their use of soldered-in-place mask ROMs (v1.07), where I've experienced bit-rot in at least one earlier, EPROM-based unit.

How do you know if your MT-32 ROM has bit rot?
Does it totally fail or does it develop off notes?

I don't recall getting far enough with any sort of testing to know if the operation or sound was affected or not. The more immediate and obvious symptom was the display of garbage characters on the LCD.