MSX blaster OPL4

Rookie (23)

29-12-2018, 20:22

Hey all,

i finally got my msx blaster yesterday: https://www.8bits4ever.net/product-page/msx-blaster-opl4
It seems to work just fine, but sometimes it makes a distorted/crackling sound.
I think this sometimes happens when samples are used, not with the own wavetable.
Is this an issue that anyone has encountered before?

Things i tried to rule some stuff out:

* tried different cables on the jack output
* tried different msx machines (nms8245 and nms8250)
* tried a different power extension to rule out interference from other hardware connected to the same one
* ran the moonsound memory test, it passed all tests
* tried it with both a normal floppy and the MFR

Por Pencioner

Scribe (1612)

29-12-2018, 21:06

Once in the past i've used wrong replayer and it was bad with distorted ugly sounds. So i was in panic. But it turned out that it was because of samples weren't loaded, and replayer just no worry tries to play it. So probably don't panic and play some original disks which use samples extensively (like Dutch Moonsound Veterans, i remember they were available for download). If everything is ok then it is not a problem of cartridge.=

Por GreyFoxNL

Rookie (23)

29-12-2018, 21:46

unfortunatly the problem occurs when i play the veterans disks.
When i use the arranger 5 demo all sounds great... .. but that demo only seems to use the internal wavetable.

Por meits

Scribe (6577)

29-12-2018, 22:27

Can you play the tune that sounds bad in openMSX? It might be a bad quality sample. There are some tunes which are based on huge samples which were compressed to fit. That didn't do a lot of justice to the two songs (come take my hand and voodoo people). Those two have to be seen as some kind of proof of concept while the mishaps need to be taken for granted.

When did you get your FM-Blaster? The earlier models were badly amplified, so to get it on par with any other OPL4 cartridge you've to crank up the volume of the amp. That amplifies the noise as well. There is a fix for that of which I am not sure it's taken into a newer batch of FM Blasters (if at all).

Arranger 5 only uses a tiny bit of on board wave table samples. The majority is FM.

Edit: MSX Blaster, so I read now. Sorry, the above probably does not apply. I'm not familiar with this one.

Por GreyFoxNL

Rookie (23)

29-12-2018, 22:38

Yeah i tried that , in open msx it sounds fine.
Another disk i used was dreamscape (also has some crackling sometimes).. should ring a bell for you meits

I ordered the msx blaster 2 weeks ago and received it yesterday.
I've been in contact just now with the fella from 8bits 4 ever. and he suspects the cartridge has a defect.
I sent him te dsk image of the one i used and he tested it and found nothing wrong..
So sadly i have to return it. He will send me a new one.

Ah well, these things happen, i have to say that i am very pleased with the response time and service of 8bits 4 ever.
To be continued when i get the replacement.....

Thanks 4 the input guys !!!

Por meits

Scribe (6577)

02-11-2021, 14:00

I was looking for other pages about MSX-Blaster, but I accidentally ran into this one. The crackling sound was caused by a broken opamp.

Por Wierzbowsky

Guardian (3650)

02-11-2021, 15:04

If a tune uses samples, the crackling sound means that the sample RAM is faulty. At least it was like that for me until I changed the SRAM chip. Try to test the sample RAM with the MOONTEST utility.

http://podrezov.com/moontest/moontest.zip