Sound distortion on a white PCE on a specific spot

[gtsamour]

I wonder if anyone that has the same hardware can help me...

So, I have a white PCE connected on an IFU-30 and a white cdrom2.

When I load Dracula X and the Konami logo comes up, there is a sound distortion at the point where the sound jingles, at the point that the sound becomes the loudest. I can only describe it as a short white noise like hhsssst that is on both left and right channels.
I'm not referring to the regular buzz due to the increased luminescence at this point

The white PCE is RGB modded and there is a connector installed. So I am getting picture from the console itself, and sound from the 2 RCA on the IFU-30. The console and IFU-30 are recapped using panasonic capacitors from console5.

I haven't noticed any distortions playing other stuff, either from a cd or from the everdrive.

I have concluded that the "problem" if indeed there is one, is on the white PCE itself and not on the ifu-30 because if I try the same with a Core II (also getting sound from the IFU-30) the sound is clear at that point. And if I extract sound from the White PCE's jack, the distortion is there too.

Has anyone that has the complete IFU-30 set noticed the same thing on the Dracula X konami logo?

I find it weird that if there is something wrong, the sound seems OK on everything else.
Can someone that has the same hardware please try it out and tell me?

Does all PC Engine consoles "sound" exactly the same quality wise?

Thank you

ps
I checked the traces of right and left sound channel of the connector (and there is also where I get sound from for the jack) and they go straight to the 6280 chip, no components in between except a resistor for each channel that goes to ground. 6280 chip is where the sound is generated right? Can it be a bad 6280 chip?

[NichlasEk]

I feele that the white pc engine is outputting a much clearer audio than the core grafx. This might just be a personal reflection thou.  I Use a rgb modded ifu. And through that, the white one sounds the best on dracula x. Might be that the ifu and the pc engine uses diffrent grounds? And the ifu if connected both to audio and rgb (8 pin din) attenuates this diffrence? Also i think that the core grafx uses another low level filter on audio than the white one. Please correct me if wrong.

[gtsamour]

I feele that the white pc engine is outputting a much clearer audio than the core grafx. This might just be a personal reflection thou.  I Use a rgb modded ifu. And through that, the white one sounds the best on dracula x. Might be that the ifu and the pc engine uses diffrent grounds? And the ifu if connected both to audio and rgb (8 pin din) attenuates this diffrence? Also i think that the core grafx uses another low level filter on audio than the white one. Please correct me if wrong.

I don't think it has anything to do with the rgb mod using the same ground with the sound... Just to test this out I disconnected the +5v feed on the rgb amp and just tested the sound coming out of the ifu and white pce, still the same phenomenon.

To be more specific, I could describe the phenomenon as a distortion that happens if the sound output of the console is too high but I only spotted it at the konami logo jingle of the Dracula X.

I don't know if the core II i tried and didn't have the same phenomenon, has some king of low pass filter for the sound, for the white there is nothing in between the CPU producing the sound and the expansion port sound pins.

I also forgot to mention earlier that I have also performed the jailbar fix using the two 4,7 uF ceramic caps on the digital and analog 5V cirquits.... I doubt it could be that but could it?

The board is completely clean so not a chance of a solder blob somewhere. After the recap the whole pcb was left to soak in isopropyl alcohol twice to remove dirt, flux and possible solder blobs.

[NichlasEk]

Na the ground thing might have been a wild gose chase. But i really think that the white one sounds clearer and a tad louder. Il open a core one up and have a look if there is something between the cpu and expport.

Take a horrible game like browning for example. The gameplay sucks but i like the music. And it sounds louder sort of on the pc engine.

Might it bee that dracula X produces a real clear loud note just at the logo wich is to much for the amplifyer in the ifu?

[gtsamour]

Might it bee that dracula X produces a real clear loud note just at the logo wich is to much for the amplifyer in the ifu?

It might, but not too loud for the amplifier of the IFU. As I said earlier,the sound has the same issue either taken from the IFU or from the white PCE's jack (which audio is taken from the expansion's port sound pins thus the cpu itself). Its just that the whole IFU thing needs to be complete (PCE+cdrom2+IFU) to play the Dracula X so i can't test the white pce as a stand alone for Dracula X.

So the issue is produced on the white PCE that produces the sound effects and its not introduced later on in the IFU. At least thats what I have concluded.

I would say that if the "too loud for" is the issue here, it would be "loud note just at the logo which is to much for the White PCE's cpu"

Have you tried it yourself NichlasEk? Since you have the same hardware I mean... you may have the same issue but haven't noticed it... you may have to turn the volume up to realise... and maybe try it a couple of times.
I would really appreciate it if you gave it a go (cdrom2+ifu30+white PCE) and paid attention to the konami logo "jingle".

ps
The core I is much like the white, it has RF out, you may not see any amplifier in that one.... on the Core II that has a DIN jack (composite and stereo sound out), maybe.

[NichlasEk]

Ok tried it out... and acctuly didnt notice any difference. But i do notice a distortion of sorts. I get a slight hum and also a kind of a ticking on the high notes. But this is on both the withe and the core grafx with blue text. I thought there where no big difference  between core I and II. I only hace the ones woth blue text and they all have a din 5 instead of RF. I whent a head and tried it on the duo and the duo-r (with a white pc 6280 in it) both sounds the same but a little lower kind of filtred. But i think the distortion is there. Could it bee corroded traces in your white one? Iv seen several of those with really dry soldermask and eaten traces.

Or maybee i have bad ears. I give up

[gtsamour]

Ok tried it out... and acctuly didnt notice any difference. But i do notice a distortion of sorts. I get a slight hum and also a kind of a ticking on the high notes. But this is on both the withe and the core grafx with blue text. I thought there where no big difference  between core I and II. I only hace the ones woth blue text and they all have a din 5 instead of RF. I whent a head and tried it on the duo and the duo-r (with a white pc 6280 in it) both sounds the same but a little lower kind of filtred. But i think the distortion is there. Could it bee corroded traces in your white one? Iv seen several of those with really dry soldermask and eaten traces.

Or maybee i have bad ears. I give up

Fist of all I would like to thank you for taking the time to test it for me, I apreciate it

The hum/buzz is to be expected, specially on the konami logo, it has to do with rgb/sound interference and its more or less there on all pcengines with the RGB mod.

What exactly do you mean by "ticking"? How would you describe it more accurately? We are talking about the loudest level on the konami logo right.?

Actually there is a difference between Core with blue (Core I) and core with orange letters (Core II). The blye letters one has RF from factory and the orange lettered one has a composite and stereo sound DIN from factory so the latter might have a sound amp inside...

The blue lettered one resembles the white more so you may not hear a difference between the two.

My White's board is very well preserved, recapped and with no traces of corrosion anywhere, like new.

This "ticking on the high notes" that you mentioned, was it on the white/core only or on the DUOs as well? Would you classify this as a distortion like the sound being too loud and gets distorted?
Is your white jailbar fixed?

[NichlasEk]

Fist of all I would like to thank you for taking the time to test it for me, I apreciate it

---np as i would like to learn more about this to and help if i can

The hum/buzz is to be expected, specially on the konami logo, it has to do with rgb/sound interference and its more or less there on all pcengines with the RGB mod.

---ok maybe it apears on all white backgrounds and bright colors?

What exactly do you mean by "ticking"? How would you describe it more accurately? We are talking about the loudest level on the konami logo right.?

---I could make a bad youtubevideo on thursday maybee, but for now:

---The konami theme on the logo soundes. blingblingBLINGBLINGblingbliiiingeee
----But with the distortion its kind of like: blingbliingBLING(tick)BLING(tick)BLING8tickticktickBliiingeee

Actually there is a difference between Core with blue (Core I) and core with orange letters (Core II). The blye letters one has RF from factory and the orange lettered one has a composite and stereo sound DIN from factory so the latter might have a sound amp inside...

--- I only have blue Core Is and all three have AV and an arrow pointing to the din5 embossed in the plastic, maybe early Core Is had RF?

The blue lettered one resembles the white more so you may not hear a difference between the two.

My White's board is very well preserved, recapped and with no traces of corrosion anywhere, like new.

-- Than this is a mystery indeed, could you maybe make a "bad" youtubevideo?

This "ticking on the high notes" that you mentioned, was it on the white/core only or on the DUOs as well? Would you classify this as a distortion like the sound being too loud and gets distorted?
Is your white jailbar fixed?

--- I can kind of hear it on the duos to, but fainter. and its like the high notes gets garbled right in the middle of the konami theme. Now that i think of it i might remember hearing this on a SNES to (might be a maid up memmory thou il have to check)

-none of my white ones are jailbarefixed as i dont se any/much jailbars on them with my setup. The cores are fixed, and so are the duos.

[gtsamour]

---ok maybe it apears on all white backgrounds and bright colors?

EXACTLY but on white backgrounds its the most intense.

---I could make a bad youtubevideo on thursday maybee, but for now:
That would be lovely, you think that the "distortion" will be audible in the video?

---The konami theme on the logo soundes. blingblingBLINGBLINGblingbliiiingeee
---But with the distortion its kind of like: blingbliingBLING(tick)BLING(tick)BLING8tickticktickBliiingeee

Hmmmmm, we may be describing the same thing (but I'm too anal about it). I would describe mine more like a "scratch" maybe:  blingbliingBLING(tshss)BLING(tshss)BLINGthsthshBliiingeee
but I have the tv exporting the sound signal through optical fiber to a 5.1 Logitech Z-5500 surround system so I may be hearing the issue much much more clear and loud.

--- I only have blue Core Is and all three have AV and an arrow pointing to the din5 embossed in the plastic, maybe early Core Is had RF?

You are probably right about that, but there has to be cirquit differences between Core I and II, who knows... maybe this is why I don't hear it using my Core II, maybe its muffled by filtering...

-- Than this is a mystery indeed, could you maybe make a "bad" youtubevideo?

I don't think the issue is clearly audible though.

--- I can kind of hear it on the duos to, but fainter. and its like the high notes gets garbled right in the middle of the konami theme.

But you can clearly hear a difference between the "distortion" of the white and the DUOs right? The white being definitelly more "scratchy" and high pitched making it more obvious maybe?

-none of my white ones are jailbarefixed as i dont se any/much jailbars on them with my setup. The cores are fixed, and so are the duos.

I am maybe getting paranoid about this... since the board is squeeky clean and like new, I'm starting to think that this could be normal for a white pce.

Here are some pics of the pcb