Alternatives for the MT-32?

[Glottis]

I've been recording a lot of MT-32 game music lately and although the recording/sound quality is somewhat satisfying it could be better, the module is the limiting factor here. The MT-32 that I've got is rev 01 and it's a bit noisy. Now based on what I've read in this forum a possibly better choice would be a CM-series module. So in a nutshell, how much better will a CM-module sound over a typical rev 01 MT-32? Also how's the compatibility of these modules in older games? I'm thinkin of getting a CM-64 or CM-500 in the near future, but  if you know of a better choice then please do tell me of it.

Thanks for reading this.

[Cloudschatze]

Are you sure you don't have a Rev. 00 MT-32? Purchasing a CM will not provide much of a difference in clarity otherwise.

[Dustin]

I've been recording a lot of MT-32 game music lately and although the recording/sound quality is somewhat satisfying it could be better, the module is the limiting factor here. The MT-32 that I've got is rev 01 and it's a bit noisy. Now based on what I've read in this forum a possibly better choice would be a CM-series module. So in a nutshell, how much better will a CM-module sound over a typical rev 01 MT-32? Also how's the compatibility of these modules in older games? I'm thinkin of getting a CM-64 or CM-500 in the near future, but  if you know of a better choice then please do tell me of it.

Thanks for reading this.

 Most MT-32's are a bit noisy by nature (some say this is due to the Roland Technicians not taking the time to make a better design in the sound processing part of the MT-32) . A CM series is an excellent choice, but I can't say too much about them as I have never heard/used one. However, another alternative exists. You may pursue a MT-32 that has been modified by either L. A. Custom Instruments, or Real World Interfaces. I'm not terribly familiar with the modifications performed by L. A. Custom Instruments, but I do know that the sound has been altered to a considerably higher timbre quality. I own a MT-32 that has been modified by Real Word Interfaces. Included with it is documentation stating the nature of the modifacations. A trim pot has been added to clean up the sound which makes a huge difference. Also, the reverb levels have been reduced dramaticly to help reduce about 8 dBs of noise, and has an adjustment of 1-50 depending on what size room you are in. There has also been 4 more phone outputs added to the back of the unit , allowing more speakers to be hooked up for a total of 6. It also is equipped with a  
brighter backlit LCD display. I highly recommend it to everyone.

They show up on eBay from time to time, and I paid less for my modified MT-32 then I did for "normal" MT-32.

If you find one, it is definitely a worth-while venture to buy it.  


Hope this helps you,

[Alkarion]

I've been recording a lot of MT-32 game music lately

Would be nice if you made it available on the web. Even if it's not optimal in quality.

[Glottis]

Are you sure you don't have a Rev. 00 MT-32? Purchasing a CM will not provide much of a difference in clarity otherwise.

Yes, as sure as you can be by opening the module and watching it on the pcb.  :wink:

That's good to know, because remarkable improvent would've been my opinion some 10-30dB better SNR and a substantial increase in the line output level of the module.  

 

I own a MT-32 that has been modified by Real Word Interfaces. Included with it is documentation stating the nature of the modifacations. A trim pot has been added to clean up the sound which makes a huge difference. Also, the reverb levels have been reduced dramaticly to help reduce about 8 dBs of noise, and has an adjustment of 1-50 depending on what size room you are in. There has also been 4 more phone outputs added to the back of the unit , allowing more speakers to be hooked up for a total of 6. It also is equipped with a
brighter backlit LCD display. I highly recommend it to everyone.

They show up on eBay from time to time, and I paid less for my modified MT-32 then I did for "normal" MT-32.

If you find one, it is definitely a worth-while venture to buy it.

That is definitely something to look for, by the way I'm very interested in hearing your upcoming recordings done with that module.



 

Would be nice if you made it available on the web. Even if it's not optimal in quality.

Doing it already in a somewhat unusual fashion. I'm a frequent visitor in here.

[Cloudschatze]

Yes, as sure as you can be by opening the module and watching it on the pcb.  :wink:

Hmm. Looking may not be the best way to tell.

HondaSIR posted the following picture of his MT-32 a few months back, and despite the fact that it also shows "01", it seems to lack all of the revisions made to the documented 01 board (second picture). The 01 mainboards have a noise level of -80dBm, matching that of the LAPC-I (and probably the CM-variants). Any extra noise could be a sign of component failure, or a grounding issue.

[Glottis]

Hmm. Looking may not be the best way to tell.

HondaSIR posted the following picture of his MT-32 a few months back, and despite the fact that it also shows "01", it seems to lack all of the revisions made to the documented 01 board (second picture). The 01 mainboards have a noise level of -80dBm, matching that of the LAPC-I (and probably the CM-variants). Any extra noise could be a sign of component failure, or a grounding issue.

The board layout of my MT-32 is identical to that of HondaSIR's module. Printed on the board is the following text "MT-32 MAIN BOARD ASSY 79377310 01" the same that is also on the latest board. So I take it that there are two stock rev 01 MT-32 versions. One without headphone output and the other which has it(?). However I still need to measure the noise level of my MT-32 and see whether it comes near to the level you stated.

I don't think that this noise is caused by a grounding issue. Bad or leaky capacitor(s) could cause it, but I seriously doubt this too.

[Cloudschatze]

So I take it that there are two stock rev 01 MT-32 versions. One without headphone output and the other which has it(?).

It would seem so, though the "older" version more closely resembles the original, 00 design. Soldered EPROMs, and consolidated components suggest cost-cutting measures, rather than a functional redesign. It is plausible that it shares the same crippled DAC as the original, accounting for the noise you mention. If so, either the newer 01 mainboard, an LAPC-I, or one of the CM modules will produce an audibly cleaner sound.

[Glottis]

I did some measuring with the module, and the SNR seems to be roughly -82dB in idle mode. Squeeze off a few dB's to account for the noise done by the souncard's ADC. Fairly good readings for a module of this age, and looks like this will have to do for now. A CM module still is a tempting item if not for the better audio performance, then just for the weird pleasure of owning something rare.  

[Laust]

The 01 mainboards have a noise level of -80dBm, matching that of the LAPC-I (and probably the CM-variants).

I would be very surprised if the LAPC-I wasn't noiser than its close cousins, due to noise picked up from the ISA bus.

[Cloudschatze]

The 01 mainboards have a noise level of -80dBm, matching that of the LAPC-I (and probably the CM-variants).

I would be very surprised if the LAPC-I wasn't noiser than its close cousins, due to noise picked up from the ISA bus.

I've never noticed, but you're probably right. Especially the earlier, unshielded LAPC cards.

The dBm value comes from the respective Service Notes. Real-life application causes variance, I'm sure.

[Zemus]

I did some measuring with the module, and the SNR seems to be roughly -82dB in idle mode.

How exactly did you measure it? On my CM-500 module, the background noise varies when I turn the volume knob. I used my Audigy 2 ZS's external box with the soundcard's mixer set to 0dB amplification. When I turn the volume knob from zero to full I get values between -85dB and -63dB. Fortunately the noise is so linear that it's pretty easy to filter out without messing up the music in any noticeable way...

[Glottis]

How exactly did you measure it? On my CM-500 module, the background noise varies when I turn the volume knob. I used my Audigy 2 ZS's external box with the soundcard's mixer set to 0dB amplification. When I turn the volume knob from zero to full I get values between -85dB and -63dB.

I use a ESI Juli@ soundcard with the following mixer settings,



as you can see the input section '1/2' is fixed to 0dB gain. Then with the module connected to the soundcard I just record a standard 44,1kHz 16bit signal with a wave editor, in this case Soundforge 8.0 and analyze the peak level of the recorded signal/waveform. Turning the volume knob on my module doesn't change the SNR notably and the -82dB result is achieved when the volume is at maximum level.

[Zemus]

Interesting... I'll try to get hold of an MT-32 to compare. It might be the cables or the outputs on the CM-500. I've been thinking of replacing them as they're a bit loose. With the CM-500 turned off, I get a peak value of -96-97dB so there shouldn't be any interference in the box itself.