VOGONS


First post, by dulu

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It was only after a few attempts to activate the card that I realized I could hear doom music. Before that, I couldn't hear it because it was very, very quiet in relation to the noise the card emits. When I plug in headphones and set the volume to max, the noise is very loud. Immediately after turning on the computer, I hear the sound of the spinning disk in my headphones (more precisely - sound that has exact frequency like a hdd motor), sound of moving mouse in windows and various murmurs. I've been trying to pull out all the chips, and it doesn't help. How could I find out what is corrupted on this card? I tried to desolder one large capacitor and replace it with a new one, but it did not help. The sound in one earpiece stopped and the noise in the other was as before.

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Reply 1 of 11, by Joakim

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I have this issue on a laptop. Bitwranger gave me some hints, maybe it is useful. Idk.

Best thing I can think of right now would be to get two sets of headphone, plug one in and just have it on one ear, then with the other one on the other ear, ground the sleeve and poke around with the tip and see if you can find the same noise but louder.... maybe a 1 kilohm or so resistor in series wouldn't be a bad idea though so that you're not rebooting it every time you ground something sensitive.

Reply 2 of 11, by Tiido

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The "thinking noises" are basically normal on these early SB cards. Creative didn't do a good job on the design on analog side. You can replace some of the power supply capacitors for modern types but it will only soften the problem, to cure it there's a need for substantial modifications to reroute the grounding related aspects.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 3 of 11, by cyclone3d

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What are the rest of your system specs?

What power supply are you using? How old is it?

Sounds to me like you are hearing ISA bus noise which can be caused by bad caps or insufficient filtering on the motherboard. I have a Wang branded 386-sx desktop that has very little filtering on the motherboard and quite a bit of noise comes through the CT1350B that came with it when I bought it.

Swapping that same card into a different system and the card has much, much cleaner output.

I will mention that the larger capacitor to the left of the volume knob on the card looks like it is damaged.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 4 of 11, by TheMobRules

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That is one of the few cards that requires the -5V line in the power supply, if that line is not present (like in a modern PSU) it would cause symptoms similars to the ones you're experiencing.

Reply 6 of 11, by cyclone3d

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dulu wrote on 2021-09-09, 20:46:

psu - ocz modxstream pro 500W (currently it`s only one i have)
mobo - aopen ax6bc - my only one with isa
PIII-550

Probably because of the PSU not having -5v
Re: Is a ATX PSU with -5V really essential?

There are options though.
Minus 5 Volts for ISA Slots on ATX Board

Used to be a person on eBay that sold adapter cables with the -5v added but they have not been there for at least a year now.

I'm pretty sure you are going to have issues with the OPL2 chip on there not working properly because of the CPU speed as well.... or rather because of the system sending the commands to the card too fast for the OPL2 chip to handle. Some industrial motherboards most likely don't have this issue.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 8 of 11, by dulu

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Okey, just watched phills video about -5V converter, there is a recording with noise on sb 2.0 and they sound identical xD

After all, I am very happy that the card is rather working 😀

Reply 9 of 11, by canthearu

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dulu wrote on 2021-09-09, 21:52:

How could I check at home if it is actually -5V? Power supply conversion?

Checking the PSU label normally indicates if it has -5V output.

If the PSU label says it supplies -5V (with some amperage figure), then it supplies -5V.

If it doesn't mention -5V, it doesn't supply -5V.

Reply 10 of 11, by Cbb

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I put the money on "no -5V" because of too modern PSU.
Just check the voltage at white wire (against black one) on ATX connector with voltmeter and you'll be sure if there is -5V or not.
At first you may check for +5V (red to black wires) to check right voltmeter connection polarity 😀

Reply 11 of 11, by Tiido

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Without -5V the card should be only producing very very distorted sound as negative half of the signal is clipped off due to lack of the power rail.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜