Anyone know of any regulars who have posted here recently who own a CT1330A? I could really use a capacitor list and the markings from those ICs.

I have one. I will try to post a list once I am home but not sure how much time I will have before I am on the road again.

cyclone3d wrote:

I have one. I will try to post a list once I am home but not sure how much time I will have before I am on the road again.

It'd be amazing if you had a chance to take a look at this! A simple list of the values (and brand+series) of the caps and the markings from the two ICs would suffice. I really want to get this thing working, and it seems to be in good condition aside from the missing components.

I swapped the capacitors like
1 UST1C220MDD 22uF;16VDC;O5x7mm;Raster:2mm
2 UTT1C101MDD 100uF;16V
3 GT470/16 470uF
4 UPW1C100MDD 10uF;16VDC
5 UPW1H010MDD 1uF;50VDC
6 UVP1H4R7MDD 4,7uF;50VDC (not needed bipolar)
7 UMA1C330MDD 33uF;16VDC
8 UTT1C470MDD 47uF;16VDC
More info http://www.tme.eu

Thanks for the info!

If I understand correctly, those are the caps you purchased to replace the ones on the card. Some of the ones you listed aren't low-ESR\low-impedance capacitors. Is that how the card was originally built?

EDIT: After doing a bit of reading, it doesn't sound like low-ESR caps would have been used for this application originally, and likely wouldn't make a difference now over good standard caps. So, that is good to know. 😀

I'm not an electronics technician, maybe the old ones are better, I can not hear any difference. I provided a list for raster, numbers.

Do you still want the numbers off the orginal caps?

For the U29 and U30 transistors, the markings are as follows:

U29:
MC78L
05ACP
M138

U30:
MC79L
05ACP
M151

cyclone3d wrote:

Do you still want the numbers off the orginal caps? […]
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Do you still want the numbers off the orginal caps?

For the U29 and U30 transistors, the markings are as follows:

U29:
MC78L
05ACP
M138

U30:
MC79L
05ACP
M151

Probably wouldn't hurt, if you have a chance.

Okay, finally had both the parts and the time to fix this card, and it works! It was totally stripped of all its caps and two transistors when I got it, and now it is working! 😀

However, is it normal to only get output from the left channel when playing mono-OPL2 or stereo OPL3 music? I don't have any games that specifically mention dual-OPL2 for FM music. They only specify Adlib, SoundBlaster OPL2 or SBPro2\16 OPL3. Digital sound works fine, and the FM music seems to sound fine when I play it, it's just coming from one side.

I'm waiting on a SB Pro 1 that I ordered to show up, but I think it depends on how the OPL is accessed. There are two sets of registers for the dual OPL2s, so very well could be Left-only when writing to 220-221. Writes to 228, I believe, are copied to both chips. But I could be wrong.

There is no OPL3, so "stereo OPL3 music" isn't a thing on SB Pro 1.0. If it's a driver that's really just using OPL2 backwards compatibility, then ... well, again, it depends on how they're accessing it. 220-221 are for OPL2 backwards compatibility on SB Pro 2 (duplicated on 228-229), and 222-223 are for OPL3.

SirNickity wrote:

I'm waiting on a SB Pro 1 that I ordered to show up, but I think it depends on how the OPL is accessed. There are two sets of registers for the dual OPL2s, so very well could be Left-only when writing to 220-221. Writes to 228, I believe, are copied to both chips. But I could be wrong.

There is no OPL3, so "stereo OPL3 music" isn't a thing on SB Pro 1.0. If it's a driver that's really just using OPL2 backwards compatibility, then ... well, again, it depends on how they're accessing it. 220-221 are for OPL2 backwards compatibility on SB Pro 2 (duplicated on 228-229), and 222-223 are for OPL3.

Seems odd that all of the games I've tried wouldn't be backward compatible with dual OPL2. I was under the impression that anything that can do OPL3 (stereo) would be backward compatible with the SB Pro's dual OPL2 stereo. And anything that is just using mono OPL2 should at least come from both channels.

I've tried the setup programs for Descent, Nascar Racing, Daggerfall and Dark Forces, and I've installed the card (with built in drivers) in Windows 98SE and it still only ever plays FM music from the left side. Definitely something not right here. This will take further troubleshooting I think.

I also get a strange scratching sound when I adjust the volume wheel on the card, and it really only comes from the RIGHT side. If that side were totally dead I'd assume it was something wrong with the right channel in general, but digital sounds come through in perfect stereo. I also just noticed a bit of popping\crackling sound when I shut down the system some times. Not just a single pop, but a series of noises.

EDIT: Ohh... could this be speed related? I just thought about it and this is being used in my tester system, which is a 440BX + 450Mhz P3 system.

Ozzuneoj wrote:

Seems odd that all of the games I've tried wouldn't be backward compatible with dual OPL2. I was under the impression that anything that can do OPL3 (stereo) would be backward compatible with the SB Pro's dual OPL2 stereo. And anything that is just using mono OPL2 should at least come from both channels.

It doesn't work this way. OPL3 chip itself has the capability to generate the stereo sound. OPL2 has no such capability, so the few cards utilizing dual OPL2 chips have one OPL2 chip mapped to left and one OPL2 chip mapped to right channel.

So, if a song is made with OPL3 in mind, it will send its control information to the card, but if the card has dual OPL2, then the OPL3 specific information (including stereo mapping) will be discarded and the rest sent to one of the OPL2 chips. This is why you get your sound only from left channel.

If the song is made with dual OPL2 in mind, and the card has OPL3, it's no good either, as no stereo mapping information recognizable by OPL3 is sent, since for dual OPL2 stereo is done by activating either left or right OPL2 chip. We'll get a mono sound with probably some instruments missing as their info is sent to the non-existing right OPL2 channel.

bristlehog wrote:

It doesn't work this way. OPL3 chip itself has the capability to generate the stereo sound. OPL2 has no such capability, so the […]
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Ozzuneoj wrote:

Seems odd that all of the games I've tried wouldn't be backward compatible with dual OPL2. I was under the impression that anything that can do OPL3 (stereo) would be backward compatible with the SB Pro's dual OPL2 stereo. And anything that is just using mono OPL2 should at least come from both channels.

It doesn't work this way. OPL3 chip itself has the capability to generate the stereo sound. OPL2 has no such capability, so the few cards utilizing dual OPL2 chips have one OPL2 chip mapped to left and one OPL2 chip mapped to right channel.

So, if a song is made with OPL3 in mind, it will send its control information to the card, but if the card has dual OPL2, then the OPL3 specific information (including stereo mapping) will be discarded and the rest sent to one of the OPL2 chips. This is why you get your sound only from left channel.

If the song is made with dual OPL2 in mind, and the card has OPL3, it's no good either, as no stereo mapping information recognizable by OPL3 is sent, since for dual OPL2 stereo is done by activating either left or right OPL2 chip. We'll get a mono sound with probably some instruments missing as their info is sent to the non-existing right OPL2 channel.

Alright, I understand what you're saying, but I guess I'm just surprised. People always talk up the original SB Pro as if it is a great card due to the dual OPL2 having a very unique sound. And yet, every single game that was made for Adlib\OPL2 or OPL3 FM only plays from the left channel? That doesn't sound right. This post states that the card was designed so that anything that is sent to one of the adlib-compatible addresses will play on both chips so that both channels are utilized (even if they are playing the same thing, it's better than having sound only coming from the left channel). This would mean that even OPL3 music should play on both channels, even if it is messed up and missing sounds.

Seems more likely that there's just something wrong with my card. I would expect to find some mention around here of "Don't bother with a CT1330A, it will only have FM music from the left channel in most games." if this were a normal occurrence.

I'll have to dig up a game that actually specifies dual-OPL2 FM to be 100% sure.

Ozzuneoj wrote:

This post states that the card was designed so that anything that is sent to one of the adlib-compatible addresses will play on both chips so that both channels are utilized (even if they are playing the same thing, it's better than having sound only coming from the left channel). This would mean that even OPL3 music should play on both channels, even if it is messed up and missing sounds.

Seems more likely that there's just something wrong with my card. I would expect to find some mention around here of "Don't bother with a CT1330A, it will only have FM music from the left channel in most games." if this were a normal occurrence.

I'll have to dig up a game that actually specifies dual-OPL2 FM to be 100% sure.

Right, I was mistaken about that 'left channel only' thing. Your card should sound mono-ish if used with an Adlib driver, like it was mentioned in that post. If used with an OPL3 driver, it should sound stereo, but in a weird and messed up way. If you only get one channel, it's a sign of something being wrong with the card.

Get yourself the PX Player, and play the aw01.xmi file I sticked to this post (it's from Ultima Underworld). Using 'px aw01.xmi sbp1fm' should give you the stereo (this XMI file is SB Pro 1 compatible). Using 'px aw01.xmi adlib' or 'px aw01.xmi sbfm' should give you the mono sound of Adlib/SB. Don't forget the uw.ad file, it must be in the same folder with aw01.xmi.

For list of games supporting dual OPL2, look here.

I would agree. With standard practices regarding single OPL2 support, you should get mono sound. It seems like it would be possible to get left-only sound by accident, but you (the programmer) would probably have to be doing something dumb to do it.

Ergo, you probably have a bad DAC or capacitor or what-have-you. I will be able to test this more once the Polish postal service tosses my shiny new SB Pro 1.0 across the ocean.

As to the coveted status of the Pro 1.0, I'm not entirely sure. It doesn't seem to have gotten much love back in the day. Probably because it only existed on store shelves for like a weekend before getting replaced with the 2.0. I'm mostly interested in it as an oddity, and because I tend to get a little obsessive about owning "representative samples" of different eras. I expect, for the most part, it will be little more than an expensive Sound Blaster 2.0 clone in my 386DX/40.

SirNickity wrote:

I would agree. With standard practices regarding single OPL2 support, you should get mono sound. It seems like it would be possible to get left-only sound by accident, but you (the programmer) would probably have to be doing something dumb to do it.

Ergo, you probably have a bad DAC or capacitor or what-have-you. I will be able to test this more once the Polish postal service tosses my shiny new SB Pro 1.0 across the ocean.

As to the coveted status of the Pro 1.0, I'm not entirely sure. It doesn't seem to have gotten much love back in the day. Probably because it only existed on store shelves for like a weekend before getting replaced with the 2.0. I'm mostly interested in it as an oddity, and because I tend to get a little obsessive about owning "representative samples" of different eras. I expect, for the most part, it will be little more than an expensive Sound Blaster 2.0 clone in my 386DX/40.

Did you ever get your card?

Yes, I did. I tested it for functionality and then decided to move it to my 486SX alongside a PAS 16 so I could play Wolf3D in stereo. 😉 I haven't spent much time with that computer yet though, so off the top of my head, I don't have much to say about it. Is there something I can do for you?

SirNickity wrote:

Yes, I did. I tested it for functionality and then decided to move it to my 486SX alongside a PAS 16 so I could play Wolf3D in stereo. 😉 I haven't spent much time with that computer yet though, so off the top of my head, I don't have much to say about it. Is there something I can do for you?

I was just curious about the left-channel-only OPL2 music I was getting. I haven't really had time to tinker with this card since posting in this thread and figured I'd just ask again to be sure you didn't have the same problem before spending too much time tearing my card apart and testing things. 😀

I'll try to give that a shot this evening. I don't suppose anyone's ever bothered to make a list of which IO ports particular games use for OPL2 support?

Original AdLib is at 0x388, which all the Sound Blasters support, but they also listen for OPL2 at 0x228.

The SB Pro 1.0 has the left OPL at 0x220 and the right OPL at 0x222, so a game would (presumably) only come from the left channel if it were writing to 220 but should be mono when writing to 228 or 388.

SB Pro 2.0 and SB16 have (mono) OPL2 compatibility at 220 and OPL3 at 222, but still listen for OPL2 at 228 and 388.

So there are a few options, and without debugging, emulation, or bus sniffing, you wouldn't necessarily know which was being used. I guess I just need to get around to setting up my DOS toolchain and compile some of the AdLib demo code for different ports.