Does Modulon solve the infamous SCC-FM-PAK-PSG balance problem (NMS 8250)?

By siddy6581

Expert (84)

siddy6581's picture

14-04-2018, 18:41

Hi everyone.
Okay so I probably read all of the old threads about how to solve the balance problem that occues on NMS 8250 (+ other models) when playing games using both PSG sound from the computer and sounds from the SCC or FM Pak in cartridge. I know all the soldering tutorials etc.

What I like to know is if there is any non-soldering solution available for this problem?
I saw someone mentioning that they had no problem with sound balance when using cartridges with Technobytes 4-slot expander. So could a cartridge expander be a possible solotion? And what does the expander do to solve the probelm?

Does anyone know if SuperSoniq's Modulon (3 slot expander) can fix this problem? Would be a wonderful solution

best regards / drop-out-from-the-solder-academy-Sid, Sweden

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By Meits

Scribe (4993)

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14-04-2018, 20:05

That does not solve it. You do have some volumeknobs on the Modulon, but still there are some designflaws within the 8250 which can not be fixed by that.

By siddy6581

Expert (84)

siddy6581's picture

14-04-2018, 20:23

Meits wrote:

That does not solve it. You do have some volumeknobs on the Modulon, but still there are some designflaws within the 8250 which can not be fixed by that.

I've tride the Play "v15c", "v15c","v15c"-test and got only clean sound, no distorition. So luckly my model is not plagued by that problem. But as I understood the PSG sound somehow gets lower in output when sound-cartridges gets connected. I guess he volumeknobs on Modulon can lower the FK PAK output, but now increase the PSG volume.

AN IDEA: The MegaFlashRom may be a solution though. I have not tried it yet, but If i've understood what
wrote correctly about the MFR, the cart can sort of emulate the PSG together with the SCC and therefore transfer the PSG to an "external" sound output, making it adjustable with the volumeknobs in the Modulon.
2ND IDEA: Use Playsonic cartride in a similare way.

Could any of it be possible?

By Hydragon

Hero (615)

Hydragon's picture

15-04-2018, 04:12

Hi @siddy6581, I first went for a tecnobytes expander, that experience was not so good unfortunately. I switched to a Modulon and it works as intended, it even has option on the side, to adjust volume of tha cartridges.
Got it well-balanced working, I stream on regular base on Twitch, using real hardware, feel free to tune in on www.twitch.tv/mrhydragon to experience the output of the sound yourself.

By siddy6581

Expert (84)

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15-04-2018, 10:24

Hi Hydragon.
I've read about that incident. I will probably go with Modulon, mostly because of price (extra EU import costs) and design. Do you use any extension cable btw to connect the Modulon?

What's your expereince with the Modulons effect on the PSG-output on your MSX-computer or do you already have a Philips NMS with the soundcard fixed?

By Hydragon

Hero (615)

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16-04-2018, 20:32

Well siddy, with the volume balancer on the modulon, you can balance the other cartridges so it gets more in sync with PSG, that's what I did though.
I'm not using an extension cable, it's directly in the backslot of my 8245, so far I'm not aware of any soundcard problems, since everything works fine and no distortions. Been streaming with the hardware setup for a few weeks now.

By Wild_Penguin

Champion (460)

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20-04-2018, 10:14

Hydragon has a different MSX model, which does not have similar mixing issues as the 825x/80 (AFAIK!)

Haven't looked at the modulon, but most probably it will only balance the outputs of *cartridges* inserted into it.

The balance issue with the 825x/80 is with the internal (PSG+keyclick) and external (be that scc or whatever). The 825X also just shorts both cart inputs. There is no way any external expander can fix these problems.

(There are other problems that can cause distortion, even without any sound expansions, namely sometimes the reversed caps, IIRC, but this is not the case on all units out of the factory)

By siddy6581

Expert (84)

siddy6581's picture

03-05-2018, 15:44

Wild_Penguin wrote:

The balance issue with the 825x/80 is with the internal (PSG+keyclick) and external (be that scc or whatever). The 825X also just shorts both cart inputs. There is no way any external expander can fix these problems.

Well I just recieved my new Carnivore2 and I seems like it solves the PSG problem for me. The Carnivore uses the PSG/PII in the cartridge and have volume control and whenever I enable it and fix the sound before starting a game using PSG-sound, the volumes get really nice and balanced. Smile

By Wild_Penguin

Champion (460)

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03-05-2018, 21:03

Nice that you found a solution :-).

There are several cartridges who have anoyther PSG inside them and allow re-routing (by patching software?) the PSG to come from the cartridge, specifically for machines with broken mixer circuitry! Also the MegaFlashRomSCC+ has another PSG.

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