OSSC Noisy Output

[SV001]

Hello,

I am testing my 0.76-aud firmware, OSSC v1.5 unit with a self-installed HDMI Audio Upgrade and am noticing a lot of noise (scrolling horizontal lines) with the following settings:

Input: 240p
Type: Scart & Component
Output: Passthru & Line2x

Input: 480i
Type: Scart & Component
Output: Passthru & Line2x(bob)

Input: 480p
Type: Scart & Component
Output: Passthru & Line2x

I messed around with all the settings on the OSSC and only increasing/decreasing the H. samplerate has any effect on the noise.

I have tested the following NTSC consoles with the OSSC: SNES via Scart, PS1 via Scart, Saturn via Scart, PS2 via Scart & Component, and Original Xbox via Component.

I have tested with three different computer monitors, a Samsung LED HDTV, and a Vizio LCD HDTV via DVI and a basic DVI to HDMI converter, all with the same results. I have also tested the OSSC at two different locations. I am using the PSU that the OSSC came with as well as high quality cables for the consoles.

There is no noticeable noise when I use Line3x-Line5x with 240p input. When I hookup the PS2 and Xbox directly to the HDTV’s via component, there is no noticeable noise.

When I received the unit, I did some basic testing mainly with 240p Line3x-Line5x output, but not with 480i or 480p sources. I did successfully install the HDMI Audio Upgrade board and have no issues with the audio.

Is the noise normal? Am I being overly anal? I do not believe that I damaged the OSSC with the HDMI audio upgrade installation, I was very precise. I confirmed that there were no shorts made and all the soldered connections have appropriate continuity. I appreciate any assistance offered!

Pictures of my HDMI Audio Upgrade Installation:
Photobucket – HDMI Audio Upgrade Install

Poor quality examples of noise:
240P 2x PS1 Scart
480i 2x PS1 Scart
480P Passthru PS2 Scart
480P Passthru PS2 Component

[BuckoA51]

Could be that you got a bad PSU, did you buy one from us or are you using your own?

[Harrumph]

I am using the PSU that the OSSC came with as well as high quality cables for the consoles.

[paulb_nl]

That is certainly not normal. Since you have ruled out everything except the PSU and the OSSC, I would try another PSU.

[SV001]

I also tested the OSSC using a PSU that output 5V 2.0A that I got from Amazon after I noticed the noise with the PowerPax 5V 1.2A PSU.

I hooked up my Sega Genesis Model 2 and rgb modded N64 to the OSSC via scart today for the first time and encountered the same noise.

Any other troubleshooting ideas? Downgrading the firmware made no difference. I am starting to second guess myself; would it be worthwhile to uninstall the HDMI Audio Upgrade? I want to reconfirm that I was not overzealous with the knife when cutting the traces between the I2S, WS and SCK solder joints.

[marqs]

All your problematic modes (with default samplerate) use ~27MHz sampling clock. I wonder if some interference is picked from 27MHz oscillator (used for different purpose), especially when one unshielded wire gets hooked from there to audio board. You could try temporarily disconnecting audio board clock and power wires to see if that makes any difference.

[SV001]

I disconnected the audio board clock and power wires and the noise completely disappeared. I reconnected the wires and the noise reappeared. I shortened the wires and tried wiring it similarly to user Kabloui’s pictures. The noise was greatly reduced, almost negligible, but I cannot seem to completely remove the noise with the HDMI Audio Upgrade Board connected. Any suggestions? I am currently using 26 gauge Kynar for the power and clock.

[BuckoA51]

I tested a new PSU with an audio board installed OSSC yesterday and looked very closely for noise, I couldn’t see any, so that’s a mystery. Have you tried a different power outlet? Long shot I know.

[marqs]

A coax wire for the clock with shields grounded on both ends might help if that is causing the noise.

[Anonymous]

Hey guys, I’m having scrolling horizontal lines and a lot of audio noise with a PS2/Component cables in OSSC firmware 0.84a and 0.85a. I’ve hooked up my PS2 directly to my TV and there’s no scrolling horizontal lines and the audio’s clear. I’ve tried other cables with OSSC and nothing changed. Thinking in taking back my money, if there’s no solution.

[Author]

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