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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: bozo55 on June 25, 2015, 08:54:06 AM
Title: audio buzz question.
Post by: bozo55 on June 25, 2015, 08:54:06 AM
I notice audio buzz on the Turbo more than my other systems... the turbo is not as loud as my Genesis for example, so I crank the speakers more and thus hear the buzzing more.
I'm using composite cables from GameDoctorHK for my PC Engine Duo. My TG-16 I'm reluctant to judge since I only run it through RF.
Can the buzzing be fixed? If so, how?
Title: Re: audio buzz question.
Post by: Keith Courage on June 25, 2015, 11:09:28 PM
Those AV cables from Game doctor HK are kind of cheap. Meaning the cable wire is too thin. Get yourself a cable with thicker wiring and the buzz will go away. I know from experience with cheaper cables compared to stock cables specifically with the DUOs.
Title: Re: audio buzz question.
Post by: bozo55 on June 27, 2015, 10:29:28 AM
Those AV cables from Game doctor HK are kind of cheap. Meaning the cable wire is too thin. Get yourself a cable with thicker wiring and the buzz will go away. I know from experience with cheaper cables compared to stock cables specifically with the DUOs.
Sweet, thanks for the advice Keith. I might just sacrifice some AV cables and wire them on myself. Also, the top and bottom of the ground ring for the plug are not soldered together, maybe that might help too? Thanks again!
Title: Re: audio buzz question.
Post by: Keith Courage on June 27, 2015, 10:33:41 AM
the top and bottom do not need to be soldered together.
However there should be a wire running from the center ground pin 3 to one of the round grounding plates. if that isn't there then add a wire.
Title: Re: audio buzz question.
Post by: bozo55 on June 27, 2015, 10:37:39 AM
the top and bottom do not need to be soldered together.
However there should be a wire running from the center ground pin 3 to one of the round grounding plates. if that isn't there then add a wire.
Thanks again Keith. You rock.
Title: Re: audio buzz question.
Post by: bozo55 on June 27, 2015, 11:53:37 AM
I took apart the cable and sure enough, pin 3 was not connected to Ground. So I cut the cord back 6 inches and redid the wiring. It seems better now; wiggling the connector does not cause interference anymore. The humming/buzzing (whatever you want to call it) is still there though.
Is it my imagination or is buzzing inherent in some games more than others? I noticed that if the system is idle (no music playing) it buzzes less. When I am in just the CD menu, the buzzing is much less pronounced than say, at the pause screen for Bonk's Revenge. If I boot out of a CD game with Select+Run, the menu sometimes has that buzz I'm talking about. Almost like EMI noise.
For full disclosure, I am using an Everdrive V2 to play the games and I haven't region modded my PCE to play my US Hucards (I have no Japanese Hucard games).
EDIT: I also noticed that when I press Start to load a CD game, I hear 3 pops out of the right speaker (pop... pop-pop).
EDIT 2: I just also noticed that Hucard games are significantly quieter than CD games Redbook Audio.
Title: Re: audio buzz question.
Post by: esteban on June 27, 2015, 06:21:19 PM
I took apart the cable and sure enough, pin 3 was not connected to Ground. So I cut the cord back 6 inches and redid the wiring. It seems better now; wiggling the connector does not cause interference anymore. The humming/buzzing (whatever you want to call it) is still there though.
Is it my imagination or is buzzing inherent in some games more than others? I noticed that if the system is idle (no music playing) it buzzes less. When I am in just the CD menu, the buzzing is much less pronounced than say, at the pause screen for Bonk's Revenge. If I boot out of a CD game with Select+Run, the menu sometimes has that buzz I'm talking about. Almost like EMI noise.
For full disclosure, I am using an Everdrive V2 to play the games and I haven't region modded my PCE to play my US Hucards (I have no Japanese Hucard games).
EDIT: I also noticed that when I press Start to load a CD game, I hear 3 pops out of the right speaker (pop... pop-pop).
EDIT 2: I just also noticed that Hucard games are significantly quieter than CD games Redbook Audio.
Call me crazy, but I observed this:
More intense/greater amount of "white" (lighter colors) on CRT screen --> more pronounced buzz/high-pitched whine.
Buzzing is not just due to the intensity of "white" displayed on screen...but it is a factor, perhaps.
I am sure the gurus can explain why this happens, in addition to crosstalk (and _____ and _____).
Title: Re: audio buzz question.
Post by: Keith Courage on June 27, 2015, 08:38:53 PM
Some hu card games are much quieter than CD games. Especially the original bomberman and Battle royal. Both are very quiet audio wise. On the other spectrum, JJ and Jeff and Keith courage are two of the loudest Hu cards. This is normal.
Title: Re: audio buzz question.
Post by: VenomMacbeth on June 28, 2015, 05:07:55 AM
Bozo, some of that quietness can potentially be remedied if you use the headphone jack for audio out instead of the composite cable. I've noticed on my Duo, hucard games especially are somewhat louder this way.
Title: Re: audio buzz question.
Post by: bozo55 on June 28, 2015, 05:29:39 AM
Some hu card games are much quieter than CD games. Especially the original bomberman and Battle royal. Both are very quiet audio wise. On the other spectrum, JJ and Jeff and Keith courage are two of the loudest Hu cards. This is normal.
Interesting. I noticed that the humming is almost non existent in Keith Courage when paused, and indeed it is quite loud. Battle Royale had much worse buzzing and the quiet audio made the situation worse.
More intense/greater amount of "white" (lighter colors) on CRT screen --> more pronounced buzz/high-pitched whine.
Buzzing is not just due to the intensity of "white" displayed on screen...but it is a factor, perhaps.
I am sure the gurus can explain why this happens, in addition to crosstalk (and _____ and _____).
I think you're onto something here. Maybe when the picture is brighter there is more buzzing. Which probably implies that the composite cable is not shielded well enough.
EDIT: Hmmm. Air Zonk has some annoying background noise on the difficulty select screen, even though it is mostly black. And then when paused in game on a bright screen the noise is mostly gone.
Title: audio buzz question.
Post by: esteban on June 28, 2015, 05:55:55 AM
As I said in my post, there are probably several causes of audio noise...sometimes it might simply be a matter of how PSG routines/subroutines were programmed (ie when to start/stop a sound effect, song, etc.), so pausing a song at different points might result in more/less noise.
Some songs/sound effects are not as "clean" as others...so some audio noise is a result of how songs/FX are generated, independent of anything else.
Title: Re: audio buzz question.
Post by: bozo55 on June 28, 2015, 06:01:07 AM
As I said in my post, there are probably several causes of audio noise...sometimes it might simply be a matter of how PSG routines/subroutines were programmed (ie when to start/stop a sound effect, song, etc.), so pausing a song at different points might result in more/less noise.
Some songs/sound effects are not as "clean" as others...so some audio noise is a result of how songs/FX are generated, independent of anything else.
That explains the weird noise some games generate that others do not.
Bozo, some of that quietness can potentially be remedied if you use the headphone jack for audio out instead of the composite cable. I've noticed on my Duo, hucard games especially are somewhat louder this way.
Sweet, I'm gonna try this!
EDIT: 'Tis true. The headphone jack maxed out is definitely a good bit louder than the AV out. But the buzzing is still there. So I guess it's either my Duo has issues, or the Everdrive might create more EMI noise.
Title: Re: audio buzz question.
Post by: bozo55 on June 28, 2015, 06:56:03 AM
I just realized... :( I have static coming though the right channel and it comes and goes, regardless of whether I have the sound connected through the AV cable or headphone jack with completely different wires and TV... The sound is exactly like that sound a worn volume pot makes when adjusted (scratchy static). This whole time I thought it was the AV cable but now I realize it can't be.
I think either it's a bad trace or Opamp? What should I be looking to reflow?
Video
I posted a video showing the sound problem I have. I cranked the volume on my TV so the mic on my phone would pick it up... So it sounds a little more exaggerated in the video than in real life. This static only comes out of the right channel.
I know I've asked a million questions already, but is the headphone jack supposed to mute the TV audio? My system still outputs sound to the TV with the headphones connected.
Title: Re: audio buzz question.
Post by: Keith Courage on June 28, 2015, 05:47:33 PM
does the system have new caps yet?
Title: Re: audio buzz question.
Post by: bozo55 on June 28, 2015, 10:37:20 PM
Yes. I redid the caps with a console 5 kit. When I removed the old caps, there were 5 caps that had leaked. 1 close to the CD LED, 2 near the headphone jack and 2 behind the VR heatsinks. I cleaned the board as best as I could and even used a fiberglass pen to scrape off any residue. The system was not too damaged since it worked before I recapped it. The only dumb thing I did was I broke the original headphone volume pot, but successfully replaced it with one from a gameboy color.
I'll try to post some pics later today.
Title: Re: audio buzz question.
Post by: bozo55 on June 29, 2015, 10:19:45 AM
Pics (sorry if these pics suck, I had to resize them a lot so that they would meet the forum guidelines):
Title: Re: audio buzz question.
Post by: bozo55 on June 29, 2015, 10:21:55 AM
More pics:
The first one shows what I think is a corroded via? (Right below the C616 text)
The second shows what I believe is one of the opamps for the sound. One of the legs looks very dull.
Title: Re: audio buzz question.
Post by: Keith Courage on June 30, 2015, 06:59:46 AM
There could be broken traces around the caps you have shown or even shorts under the op amp due to old cap goop. Bridge some solder leads through some of those via holes and see if it helps. If not then remove the omp amp, clean up really well, then reinstall.
Title: Re: audio buzz question.
Post by: bozo55 on June 30, 2015, 08:47:17 AM
Thanks Keith. I'm gonna give it a shot ASAP and see how it goes... I really appreciate all your help.
Title: Re: audio buzz question.
Post by: bozo55 on June 30, 2015, 01:16:19 PM
So I cleaned the headphone jack and AV out with contact cleaner and checked points for continuity. All the op amp pins and traces around it have continuity. The via that looked bad had continuity. I didn't check continuity on the underside of the vias yet though.
The thing is, I can't really reproduce that problem I was having anymore :? sometimes I think i hear some static but it's too faint to really say for sure, even at max TV volume.
I did notice why the GameDoctorHK cables suck though. If you look at the attached picture, you can see that on the left cable (official Genesis 1 AV cable) the Ground ring bump is much bigger, and presses better on the ground pin of the AV out jack of the Turbo. The crappy cable has a very puny bump.
Title: Re: audio buzz question.
Post by: Keith Courage on June 30, 2015, 04:35:28 PM
static and crackling can also be caused by old cap goop underneathe the op amp closest to the m5205 chip under the board. Maybe check there.
this problem usually goes away after the system warms up
Title: Re: audio buzz question.
Post by: bozo55 on July 01, 2015, 03:09:12 AM
static and crackling can also be caused by old cap goop underneathe the op amp closest to the m5205 chip under the board. Maybe check there.
this problem usually goes away after the system warms up
I'm afraid to pry off any op amps, so I will try just spraying some of my MG Electronics contact cleaner spray to see if that helps first. The video showing the problem was with the system having been on for well over an hour.
Title: Re: audio buzz question.
Post by: bozo55 on July 01, 2015, 09:09:19 AM
So I was playing Keith Courage for about 15 minutes, and then the sound became distorted and started to slowly fade until there was no sound... hmmm. So this problem gets much worse with heat it seems. I'm gonna pull this board apart and examine it carefully.
EDIT: letting the system rest for a few minutes gets the sound back. This is a pain in the ass to fix since it is so intermittent.
EDIT 2: I drenched the areas around the op amps under the board with alcohol and contact cleaner spray and wiped with a Q-tip as best as I could. I've had the system running for nearly 2 hours straight now on Keith Courage and can't get the sound to glitch out. I'll have to run it for more time to see how things go.
Title: Re: audio buzz question.
Post by: Keith Courage on July 01, 2015, 02:16:21 PM
So the sound went away altogether? Sounds like a bad trace near the M5205 op amp or a bad trace near the AV jack op amp.
Title: Re: audio buzz question.
Post by: bozo55 on July 01, 2015, 03:59:44 PM
So the sound went away altogether? Sounds like a bad trace near the M5205 op amp or a bad trace near the AV jack op amp.
Yeah, well, I could very (very) faintly hear the sword strike sound effect, except it didn't sound correct. It sounded mostly like faint static, and the BGM was completely gone. It faded out slowly over the course of about 1 minute. First it started to distort, then the volume dropped gradually until the sound was gone.
I turned it off and back on right away and the sound was still completely gone. After leaving the system off for 5 minutes, the sound came right back to normal.
There is no sign of trace wear whatsoever on the bottom. I'm hoping that cleaning it fixed it. I am going to keep testing it and report back.
Thanks again Keith.
Title: Re: audio buzz question.
Post by: Keith Courage on July 01, 2015, 04:55:41 PM
If the sound goes away again, leave the system on and double check the 22UF cap to the left of the M5205 chip. Make sure it's getting 3.7 or 3.8V
Also double check that the op amp near the AV jack is getting the same for the positive lead.
both of those areas are notorious for old cap damage.
Title: Re: audio buzz question.
Post by: bozo55 on July 02, 2015, 08:50:57 AM
If the sound goes away again, leave the system on and double check the 22UF cap to the left of the M5205 chip. Make sure it's getting 3.7 or 3.8V
Also double check that the op amp near the AV jack is getting the same for the positive lead. both of those areas are notorious for old cap damage.
So I put the red probe on the + end of the cap and the black probe to the ground plane of the board? This board has no exposed ground plane... Where should I probe for ground?
Which pin on the 4558/2819 op amp is voltage? I think it's pin 2???
Thanks Keith!
Title: Re: audio buzz question.
Post by: Keith Courage on July 02, 2015, 09:14:43 AM
my mistake, you don't want to check the main power lead for the op-amp. You want to check the top right lead which should read close to 3.8 volts.
grounding plate for the power switch works best.
Title: Re: audio buzz question.
Post by: bozo55 on July 02, 2015, 09:50:02 AM
there should actually be two leads on the op amp that have this voltage. also same on the 22uf cap next to the AV jack op amp.
Thanks Keith. I let the bitch loop on demo with Devil's Crush for several hours. Couldn't get it to screw up any more. I almost want it to screw up so I can test it. I'm in denial that cleaning it actually fixed it.
Title: Re: audio buzz question.
Post by: pnauts on July 02, 2015, 10:57:44 PM
More intense/greater amount of "white" (lighter colors) on CRT screen --> more pronounced buzz/high-pitched whine.
Buzzing is not just due to the intensity of "white" displayed on screen...but it is a factor, perhaps.
I am sure the gurus can explain why this happens, in addition to crosstalk (and _____ and _____).
I agree, white is 0.7V level on analog video (the higher voltage) perhaps there is coupling on audio
Title: Re: audio buzz question.
Post by: bozo55 on July 03, 2015, 04:12:44 PM
I just A-B'd the sound between my TG16 and Duo with Ninja Spirit. The TG16 is using the original HuCard with RF and the Duo is using the Turbo Everdrive on Composite.
Both are using the same sound settings on the same TV.
I noticed the Turbo is way way louder than the PCE Duo and has big booming bass in the game. The Duo sounds tame by comparison. Is this another sign my system is jacked or is the Duo a quieter console than the original Turbo?
P.S. I tested the voltage on all those points you recommended Keith. In fact, i started probing just about every cap on the board. The Audio caps all read 3.8-4v, most of the other caps read 5v. Some read 7-8 volts. Most of the op amp pins read 3.8. one read around 8v and pin 4 read 0v. Voltages seemed to check out fine. I triple checked cap orientation and values when installing and I still don't see anything wrong with respect to that.
P.S.S. I ordered a genuine Stereo AV cable for the Duo from fleabay. I will hopefully have it in a week to see if that helps matters.
Title: Re: audio buzz question.
Post by: Keith Courage on July 03, 2015, 04:59:27 PM
there is one more thing to try. sounds like a grounding issue due to old cap goop somewhere. It is easiest to tap this fix elsewhere then it is to find the shorted connection. Will pm you instructions shortly.
Title: Re: audio buzz question.
Post by: bozo55 on July 03, 2015, 05:17:44 PM
there is one more thing to try. sounds like a grounding issue due to old cap goop somewhere. It is easiest to tap this fix elsewhere then it is to find the shorted connection. Will pm you instructions shortly.
Sweet. Got the PM Keith. I'm going to try this ASAP and get back to you with the results. Thanks!!!
Title: Re: audio buzz question.
Post by: bozo55 on July 03, 2015, 05:54:50 PM
Hey Keith. So I did the red line method as you suggested. Here is a pic of the work for your approval/disapproval :)
http://postimg.org/image/gquiiqd1x/
Checked for shorts with an eye loop and for continuity with a meter. Everything seems fine.
Alas, the sound issue was not changed. I am determined to fix this, so please don't hesitate to suggest anything else. Thanks Keith!
Title: Re: audio buzz question.
Post by: Keith Courage on July 04, 2015, 08:12:41 AM
well if that didn't fix it then there definitely has to be shorts or bad traces somewhere.
usually if the chip card volume is being affected as well then it is a problem near the main AV op amp.
try bridging the wire for the ground on the op-amp itself. Sometimes that connection gets sorted out.
I really have a feeling you were going to need to remove said op amp though and clean under it then reinstall. same thing with the op-amp closest to the M 5205 chip.
Title: Re: audio buzz question.
Post by: bozo55 on July 04, 2015, 04:08:54 PM
well if that didn't fix it then there definitely has to be shorts or bad traces somewhere.
usually if the chip card volume is being affected as well then it is a problem near the main AV op amp.
try bridging the wire for the ground on the op-amp itself. Sometimes that connection gets sorted out.
I really have a feeling you were going to need to remove said op amp though and clean under it then reinstall. same thing with the op-amp closest to the M 5205 chip.
Thanks for the insight Keith. Is pin 4 of the op amp Ground? I'm not quite sure.
If I butcher an op amp trying to remove it, will I be able to find a replacement on DigiKey or Mouser or will I be screwed? I really don't know how I am going to remove the op amp other than fluxing the pins, adding more solder on them and then removing the solder with good ol' solder wick. Is that a bad idea?
Title: Re: audio buzz question.
Post by: Keith Courage on July 04, 2015, 09:18:01 PM
Here is a link to get new ones. http://www.taydaelectronics.com/ic-integrated-circuits/audio-amplifier-instrumentation-op-amp/tjm4558-dual-operational-amplifier-wide-band-soic-8-tjm4558cdt.html
Lots of times you can re-use the old ones though. I pry up slightly under them using a small screw driver while de-soldering one side at a time. Meaning all 4 leads on each side at once.
I'd still look for low voltage somewhere. Double check and wright down the Volts you are getting off the The op-amps and caps when the system is working correctly vs when it is not.
Title: Re: audio buzz question.
Post by: bozo55 on July 05, 2015, 07:53:35 AM
Here is a link to get new ones. http://www.taydaelectronics.com/ic-integrated-circuits/audio-amplifier-instrumentation-op-amp/tjm4558-dual-operational-amplifier-wide-band-soic-8-tjm4558cdt.html
Lots of times you can re-use the old ones though. I pry up slightly under them using a small screw driver while de-soldering one side at a time. Meaning all 4 leads on each side at once.
I'd still look for low voltage somewhere. Double check and wright down the Volts you are getting off the The op-amps and caps when the system is working correctly vs when it is not.
Thanks Keith. I think I'm going to order some of these op amps before I try to yank off the old ones just in case :).
Title: Re: audio buzz question.
Post by: bozo55 on July 11, 2015, 07:30:18 AM
I grew a pair of balls and went for it. I used a decent sized chisel tip to drag back and forth on each side while prying gently with a pair of tweezers.
I removed the op amp without incident and cleaned the holy hell out of the board with electronics cleaner spray. I then tested all the traces to make sure that they were good as well as the vias under the chip. Everything was perfect.
I reinstalled the chip and the volume stayed the same. I could still hear faint static on the right channel, but only sometimes and very faint. The audio buzz is still prominent as a result of having to raise the volume.
I wonder if the headphone volume pot is causing it? I'm going to remove it and see what happens. Here's some pics of the work:
Title: Re: audio buzz question.
Post by: bozo55 on July 11, 2015, 07:42:41 AM
Woah, the sound went out again. Happened the same way. Got distorted, then quieter, then the musical notes just sounded like rhythmic crackles, then the crackles mostly faded out.
That 22uF cap gives me 3.6 volts.
Edit: Oh shit. I think I figured out what's going on. The traces under the AV opamp seem finicky. When I pressed on the opamp pins with my meter the sound came back. Specifically around pin 2 and pin 3!
Could this be bad traces or a bad op amp?
I managed to catch this bizarre phenomenon on video, uploading it now:
Title: Re: audio buzz question.
Post by: pnauts on July 11, 2015, 08:19:13 AM
bad traces of bad soldering.
Title: Re: audio buzz question.
Post by: Keith Courage on July 11, 2015, 08:32:21 AM
yep, op amp traces. remove it and clean the area really good. Then re-install.
Also, sometimes it's just the ground pin in which case you can just tap a new ground from elsewhere on the board.
Title: Re: audio buzz question.
Post by: bozo55 on July 11, 2015, 08:45:59 AM
yep, op amp traces. remove it and clean the area really good. Then re-install.
Also, sometimes it's just the ground pin in which case you can just tap a new ground from elsewhere on the board.
But I already removed and cleaned them :( I have pics showing just how well I cleaned under there.
Even with the sound dead right now pin 4 (V- in) has continuity with ground. All the pins have voltage readings even with the sound dead. But when I press on pin 3, shazam it's alive again...
Title: Re: audio buzz question.
Post by: bozo55 on July 11, 2015, 09:42:28 AM
Okay, here's a video of this problem:
Sorry for the lousy one-handed gameplay :)
I noticed something strange... pressing on pin 3 of the op amp only brings the sound back when the meter is on??? Why is that. If I just press on pin 3 with the meter off I get nothing.
Title: Re: audio buzz question.
Post by: thesteve on July 11, 2015, 11:32:14 AM
ok my turn check the 4 via around C323 (directly right of the amp by the AV jack) chances the one on the right of the 3 together is bad
Title: Re: audio buzz question.
Post by: bozo55 on July 11, 2015, 02:07:57 PM
ok my turn check the 4 via around C323 (directly right of the amp by the AV jack) chances the one on the right of the 3 together is bad
Thanks Steve. Gonna clean those vias and flow some solder in them to make sure they're making good contact. I'm gonna give it a go tomorrow.
Title: Re: audio buzz question.
Post by: bozo55 on July 12, 2015, 12:48:52 PM
I think I found a glaring issue.
When I put the board up to the light, the traces look like the + end of C323 is supposed to be connected to pin 3 of the op amp. I have no continuity there.
It's hard to tell if the traces are from the top or bottom layer so I'm unsure. Can anyone confirm before I jumper this trace and blow up my Duo lol.
Thanks everyone.
P.S. I couldn't find any issues with the vias around C323.
Title: Re: audio buzz question.
Post by: thesteve on July 12, 2015, 01:03:34 PM
that is correct
Title: Re: audio buzz question.
Post by: bozo55 on July 12, 2015, 01:08:47 PM
Thanks Steve. I'm gonna jumper it and see what happens :pray:
Title: Re: audio buzz question.
Post by: bozo55 on July 12, 2015, 01:36:27 PM
So I jumpered pin 3 to C323.
The static I get out the right speaker is still there.
However, the sound has yet to distort and cut out. I have to do more testing, but I think I've made some progress here. Thanks to Keith Courage and thesteve for all your help, you guys are like the PC Engine Whisperers :D
Title: Re: audio buzz question.
Post by: thesteve on July 12, 2015, 01:40:24 PM
meter touching pin3 shouldnt have any effect
Title: Re: audio buzz question.
Post by: bozo55 on July 12, 2015, 01:58:53 PM
It only seemed to when I had the black lead on the power switch ground plate and the meter turned on. With the meter off it did nothing. I don't get why it helped. Maybe when I was pressing in the video I was actually reconnecting the bad trace :?. But I pressed firmly with the meter off and it did nothing, turned the meter on right after and voila.
Update: I've been playing Air Zonk for a while now and I'm on the 5th stage with the sound still intact. Before I jumpered the wire the sound cut off on me by stage 2.
Title: Re: audio buzz question.
Post by: thesteve on July 12, 2015, 05:00:46 PM
that pin floating would have the meter complete the circuit
Title: Re: audio buzz question.
Post by: bozo55 on July 13, 2015, 01:37:40 AM
that pin floating would have the meter complete the circuit
That must mean that trace is unreliable since it was having that issue before I removed the op amp.
Title: Re: audio buzz question.
Post by: bozo55 on July 14, 2015, 01:04:04 PM
I started fudging around because, why the hell not I guess. I bypassed the via beside C616 by jumpering the cap directly to pin 4 of the op amp directly below (IC521).
It may be my imagination but I haven't noticed static in the right channel during my last play-through of Zonk. I still am not satisfied with the audio volume. I don't get why my US Turbo is so much louder. My Turbo is unable to work with the Everdrive however, and it is getting recapped soon. Maybe the audio will be different once it's recapped, i.e. quieter.
One thing I notice with my Duo when I compare it to my JVC X'eye is how loud the X'eye is, yet how little hiss it produces. The Duo puts out way more hiss, and is way quieter. I should have the genuine AV cables soon enough so hopefully those will help.
Title: Re: audio buzz question.
Post by: bozo55 on July 16, 2015, 09:02:15 AM
I got my genuine NEC AV cables in today from ebay. They're pretty beefy, especially compared to the lame Gamedoctor cables.
The hissing is definitely way less :). Volume is still the same however. Much quieter than my Turbo.
The static reappeared in the right channel :(
I'm going to remove the 2 op amps on the underside of the board and see if cleaning under those helps.