Page 2 of 5

Re: Sound from headphone jack extremely quiet

Posted: Fri 24 Aug 2018 12:47
by Admin
They just ran some test at factory and report that replacing those resistors with 0R increase the headphone volume.
So if with your headphones the volume is too low, you can remove these resistors and bridge them with solder.
I will upload a video of doing so when I get my hand on a solder iron.

Re: Sound from headphone jack extremely quiet

Posted: Fri 24 Aug 2018 17:28
by dr_bunsen
Admin wrote:
Fri 24 Aug 2018 12:47
They just ran some test at factory and report that replacing those resistors with 0R increase the headphone volume.
So if with your headphones the volume is too low, you can remove these resistors and bridge them with solder.
I will upload a video of doing so when I get my hand on a solder iron.
Will look out for the tutorial. Can you also make sure you include good close up photos of the fix. My soldering skills are ok but my knowledge of electronics is limited and I'm not sure enough what is meant by bridging the resistors to attempt it yet. Definately needed in my case though as I can't hear anything through my headphones with volume at max.

Will the audio have problems despite being louder once the resistors are removed? Would a better fix be to replace with different value resistors? I'm assuming you put them there for a reason?

Re: Sound from headphone jack extremely quiet

Posted: Sat 25 Aug 2018 05:45
by suaviant
Well, I have good news and I have bad news.

I tried the mod.

I was initially successful. I removed the resistors and bridged the connections with two big blobs of solder. This resulted in much louder sound from the headphone jack, what I would call a normal level of sound.

Unfortunately, I couldn't leave well enough alone. I wasn't comfortable with the two big lumps of solder almost touching eachother so I attempted to remove some from the right....

Unfortunately I appear to have melted the board and PULLED UP ONE OF THE TRACKS by accident. Woops.

The system boots, but now I only get sound out of one ear with headphones....

So, in short, the mod works!.... if you can pull it off!!... and don't get cocky 8-)
Image
Image

Re: Sound from headphone jack extremely quiet

Posted: Sat 25 Aug 2018 14:03
by Admin
My soldering skills are ok but my knowledge of electronics is limited and I'm not sure enough what is meant by bridging the resistors to attempt it yet.
Yes I'll post good pictures and videos. By bridging I mean it's currently like this for each audio line (L and R) :
L coming from H3 -> Capacitor -> resistor -> sound wheel

And you need it to be :
L coming from H3 -> Capacitor -> sound wheel

Once you removed the resistor the path will be discontinued. So you need to connect the 2 pins of the resistor together with solder. So the sound can pass.

dr_bunsen wrote:
Fri 24 Aug 2018 17:28
Will the audio have problems despite being louder once the resistors are removed? Would a better fix be to replace with different value resistors? I'm assuming you put them there for a reason?
I put them here (those 2 capacitors and resistors) because it was present on other H3 boards (on H3 eval schematic too). So I asked H3 manufacturer about it and they told me it was an audio filter to improve the audio quality (reduce white noise).
So I added them manually on my prototype, checked that it worked (but with my loud headphone unfortunately) then added them to the retrostone schematic.

What is strange is that with another H3 board (opi pc+) which also have this audio filter, the sound can be heard with any phone set. So I am not sure yet why on retrostone volume is too low. I think it might be the sound wheel potentiometer that is adding also some resistance already.

So no the audio will not have problem because I think the wheel potentiometer is already doing the job of this resistor. Also we tested to removed it works without adding white noise.

Re: Sound from headphone jack extremely quiet

Posted: Sat 25 Aug 2018 14:31
by Admin
suaviant wrote:
Sat 25 Aug 2018 05:45
Well, I have good news and I have bad news.

I tried the mod.

I was initially successful. I removed the resistors and bridged the connections with two big blobs of solder. This resulted in much louder sound from the headphone jack, what I would call a normal level of sound.

Unfortunately, I couldn't leave well enough alone. I wasn't comfortable with the two big lumps of solder almost touching eachother so I attempted to remove some from the right....

Unfortunately I appear to have melted the board and PULLED UP ONE OF THE TRACKS by accident. Woops.

The system boots, but now I only get sound out of one ear with headphones....

So, in short, the mod works!.... if you can pull it off!!... and don't get cocky 8-)
Image
Ah that's unfortunate! But it can still be fixed do not worry. Seeing this hole I think your solder iron must be very hot, so try not applying it for too long.

What you can do is take a small piece of wire (stripped) and solder it on the C14 pad (the one closer to the resistor) and the other end of the wire on the sound wheel pin (the most right one, or on the TP5). As on following picture :
fix the audio.jpg
fix the audio.jpg (117.86 KiB) Viewed 1008 times
If it's getting worse you can send it to me and I'll fix for you of course.

Re: Sound from headphone jack extremely quiet

Posted: Sat 25 Aug 2018 23:17
by Bradlydb
I have just completed the mod to remove the surface mount resistors. The mod does correct the volume issue as mentioned with the headphones. I have noticed no adverse impact on the speaker volume either. I will mention that if your soldering skills are not good I would not try this mod as you will likely damage the RetroStone. I would also recommend a very thin tip soldering iron and a magnifying glass if you have it. I used some 22AWG wire to bridge the resistor connections after I removed the resistors. Good luck to everyone else that has this issue.

Re: Sound from headphone jack extremely quiet

Posted: Thu 30 Aug 2018 09:14
by kikone23
Hello there,

still love my retrostone.

but headset issue is also there for me sadly.

anyone who tested this?

thanks

kikone

Re: Sound from headphone jack extremely quiet

Posted: Thu 30 Aug 2018 10:10
by kikone23
Hello Pierre,

I want to send you my retrostone.

How can we that? Can you fix it please it for me?

Regards,

Kikone

Re: Sound from headphone jack extremely quiet

Posted: Fri 31 Aug 2018 13:56
by Admin
The fix works to increase volume.

Yes it's possible, see my email.

Re: Sound from headphone jack extremely quiet

Posted: Fri 31 Aug 2018 15:09
by Nene
Hey Pierre,

I think it would be a good idea to address this issue at the Kickstarter platform, there are many many questions at the comment section why the headphone sound is so quiet...