Rockman x100 headphone output problem

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Wolfman
Posts: 4
Joined: Tue Jul 20, 2021 9:06 pm

Rockman x100 headphone output problem

Post by Wolfman »

Hi everybody!
I have a rockman x100 and I have a problem so hopefully someone can give me a tip. When I use headphone output only one of the headphones has sound, the other is silent. What seems to be the problem? Both stereo outputs behave the same... When I wiggle the jack around I can hear guitar on both sides but it is just a mono signal no stereo. How do I fix the issue?
Thank you,
Regards
X100Ver10
Posts: 142
Joined: Mon Sep 18, 2017 2:49 pm

Re: Rockman x100 headphone output problem

Post by X100Ver10 »

2 common issues with these Rockman headphone amps:

1) The solder joints for the headphone jacks get broken from use. Re-solder all the joints. Try this first.
2) One or both of the LM386N-1 IC's is bad. If just 1 is bad, I recommend replacing them both.

I was a little confused about the way you described your issue. If both headphone jacks only have sound coming out of one side of your headphones, it is probably a bad IC. If you get sound out of both sides of your headphones while wiggling the jack, you might have broken solder joints. What is confusing to me is when you say you wiggle the jack and can hear the guitar on both sides but it is mono and not stereo. If you can hear the guitar on both sides, wouldn't that be stereo? :-)
Wolfman
Posts: 4
Joined: Tue Jul 20, 2021 9:06 pm

Re: Rockman x100 headphone output problem

Post by Wolfman »

Thanks man I really appreciate your response, as I havent found anything about it on the internet.
The thing is when I plug headphone jack till the end I hear the sound coming out only from right headphone. But when I push it about halfway(and wiggle it about), I can find a sweetspot and I can hear the sound coming from both headphones. On both headphone jacks the problem is identical. When I can get the sweetspot by wiggling around the signal I get is mono - the same signal on both headphones. By stereo I mean slight difference in sound giving the stereo effect. When I use AUX out and connect it to my pc I get stereo sound, which is awesome, but the signal is so low so I would prefer if I could use headphone out to connect to my PC.
X100Ver10
Posts: 142
Joined: Mon Sep 18, 2017 2:49 pm

Re: Rockman x100 headphone output problem

Post by X100Ver10 »

Wolfman wrote: Thu Jul 22, 2021 6:41 pm Thanks man I really appreciate your response, as I havent found anything about it on the internet.
The thing is when I plug headphone jack till the end I hear the sound coming out only from right headphone. But when I push it about halfway(and wiggle it about), I can find a sweetspot and I can hear the sound coming from both headphones. On both headphone jacks the problem is identical. When I can get the sweetspot by wiggling around the signal I get is mono - the same signal on both headphones. By stereo I mean slight difference in sound giving the stereo effect. When I use AUX out and connect it to my pc I get stereo sound, which is awesome, but the signal is so low so I would prefer if I could use headphone out to connect to my PC.
Sorry, just got back home from vacation and saw your response.

Probably what is happening is, when pulling out the plug halfway and wiggling it just right, contact is being made with one of the contacts inside the headphone jack with both sections of the headphones jack plug. You may be hearing sound out of both sides of your headphones but it isn't really stereo. Both sides of your headphones are getting sound from the right side of the amp, the side that is still working.

Are you handy with a multimeter? If so, I can probably tell you if one or both of the LM386N-1 IC's is/are bad, if you provide me with the voltages on each leg. More than likely, if you replace both of them, it will resolve your issue though (assuming you've already made sure the headphone jack solder joints are good first). The other component that I've seen cause this issue is the capacitor at location C209 but that is rare.
Wolfman
Posts: 4
Joined: Tue Jul 20, 2021 9:06 pm

Re: Rockman x100 headphone output problem

Post by Wolfman »

Alright so how do I measure each leg? Should the Rockman be on? I have a multimeter but I dont know how to use it in this application. Should I measure output from the headphone jack?

Thanks again for helpful advice.
X100Ver10
Posts: 142
Joined: Mon Sep 18, 2017 2:49 pm

Re: Rockman x100 headphone output problem

Post by X100Ver10 »

Wolfman wrote: Fri Jul 30, 2021 11:35 pm Alright so how do I measure each leg? Should the Rockman be on? I have a multimeter but I dont know how to use it in this application. Should I measure output from the headphone jack?

Thanks again for helpful advice.
Black lead of the multimeter (MM) goes to one of the springs for ground. (Follow the black wire from the Primary circuit board back to the battery spring circuit board. The 2 springs in the middle of the top section of the battery spring board should be a spring for ground). Pick either one and connect a wired alligator clip to it. The other alligator clip end gets connected to the black lead of the MM. You can also just touch the black MM lead to the spring while testing but it is a pain.

Touch red lead from MM to each leg of the LM386N-1 IC. Rockman is powered on during the testing. MM is set to 20 VDC.

#1 leg of the IC should be on the bottom right (next to the dot on top). #2 is above #1, #3 above #2, #4 above #3 (upper right), #5 across from #4 (upper left), #6 below #5, #7 below #6, #8 below #7 (lower left).

If you have a side power jack on your amp and an SR&D Regulated Power Supply (RPS), it will be easy to power up your amp for testing. Just plug it into the side power jack and turn on the amp. If you don't have a side power jack, you'll have to figure out a way to power up the amp because you'll need to take the circuit boards out of the plastic case for testing and there won't be a way to connect batteries. If you have a Rockadaptor (RA), you can probably use rubber bands to secure it to the battery spring board. Just make sure you connect the RA correctly. The amp won't power on if you have the RA flipped the wrong way.

Measure all of the legs on both IC's and post them. Let's make IC #1 the one closest to the headphone jack and IC #2 the other one (by the MN3007 IC).
Wolfman
Posts: 4
Joined: Tue Jul 20, 2021 9:06 pm

Re: Rockman x100 headphone output problem

Post by Wolfman »

Man thanks for taking the time to explain this.
I think I can measure it with the help of your instructions,but the problem is I dont have any power supply only batteries :(. I will see if there is a way to power it on somehow because the devise needs a very specific power source.
mavrim
Posts: 8
Joined: Sun Aug 08, 2021 10:26 pm

Re: Rockman x100 headphone output problem

Post by mavrim »

I recently had a X100 with no audio on the left and audio on the right. Found one headphoe jack had bent terminals inside that shorted. I replaced both headphone jacks and one LM386. Then it sounded great again!
GuitarBuilder
Posts: 245
Joined: Sat Aug 30, 2014 7:14 pm

Re: Rockman x100 headphone output problem

Post by GuitarBuilder »

Are you using the OEM Rockman headphones with correct plug? If not, make sure the plug is 1/8" and not 2.5mm or worse, 3.5mm. Otherwise, fix or replace the jack.