fretburner
Well-known member
Hi! I recently bought a used dynacomp and noticed it was extremely noisy. When I touched the footswitch, it was grounded. Would you folks have an idea on what's wrong with it?
MXR DynaComp Issue
- Thread starter fretburner
- Start date
F
Funkfingers
Guest
Re: MXR DynaComp Issue
Dry/cold solder joint(s) on one of the jack sockets would be the first thing to check.
Dry/cold solder joint(s) on one of the jack sockets would be the first thing to check.
J Moose
New member
Re: MXR DynaComp Issue
You'll have to be more specific... what kind of noise?
IMO the dynacomp is a somewhat noisy pedal which is why when I use mine, I leave the volume all the way up. There's not much of a boost there to start with, and even less after compression.
All the metal parts are grounded, no surprise there.
You'll have to be more specific... what kind of noise?
IMO the dynacomp is a somewhat noisy pedal which is why when I use mine, I leave the volume all the way up. There's not much of a boost there to start with, and even less after compression.
All the metal parts are grounded, no surprise there.
Vasshu the humanoid typhoon
Unseen
Re: MXR DynaComp Issue
Is everything tight??
Is everything tight??
fretburner
Well-known member
Re: MXR DynaComp Issue
It's your typical humming noise like having a bad power supply/adapter. The noise was unbearable even at bedroom volumes -- none of my pedals do that. I was going to remove it from the chain and touched the footswitch and it's grounded -- none of my pedals do that as well. The "hum" goes down when I touch the grounded switch though, kinda like when you touch the strings of a poorly grounded guitar. There is that hissy noise though, typical of noisy pedals like the Boss GE7, but that "hum" is what bugs me the most.
Thanks!
It's your typical humming noise like having a bad power supply/adapter. The noise was unbearable even at bedroom volumes -- none of my pedals do that. I was going to remove it from the chain and touched the footswitch and it's grounded -- none of my pedals do that as well. The "hum" goes down when I touch the grounded switch though, kinda like when you touch the strings of a poorly grounded guitar. There is that hissy noise though, typical of noisy pedals like the Boss GE7, but that "hum" is what bugs me the most.
Thanks!
F
Funkfingers
Guest
Re: MXR DynaComp Issue
One other obvious question needs asking. What guitar are you running through the compressor? Single coils + make-up gain stage = increased noise levels when not playing.
One other obvious question needs asking. What guitar are you running through the compressor? Single coils + make-up gain stage = increased noise levels when not playing.
fretburner
Well-known member
Re: MXR DynaComp Issue
^ it's an RG2550 with DMZ Steve's Special and Air Norton. It's quiet. I take out the DynaComp and no hiss nor hum. It's definitely the pedal.
I'm going to open it up this weekend. Wish me luck!
^ it's an RG2550 with DMZ Steve's Special and Air Norton. It's quiet. I take out the DynaComp and no hiss nor hum. It's definitely the pedal.
I'm going to open it up this weekend. Wish me luck!
Re: MXR DynaComp Issue
Hellion's was a good question - are you using batteries or a PSU. In my experience problems with "hummmmm" are normally associated with ground loops, and using multiple pedals and non-regulated/isolated PSUs.
If you using a PSU, try using a battery.
If that’s not the problem, take a look inside the pedal. Start by looking at the wiring to the pots, power connector, jacks and switches. Look for dry, dull solder joins. Also where wires may beginning to break away i.e. hanging on by a thread!
If it’s nothing obvious then it’s a component problem. If it’s an older Dynacomp you've got more of a chance because the newer ones use TINY surface mounted components. Worth having a cursory look for any evidence of “modding” that may have gone wrong.
If you’ve still no luck – post on Freestompboxes.org with some pix. The chaps there will be more than willing to help with any possible debugs.
Hellion's was a good question - are you using batteries or a PSU. In my experience problems with "hummmmm" are normally associated with ground loops, and using multiple pedals and non-regulated/isolated PSUs.
If you using a PSU, try using a battery.
If that’s not the problem, take a look inside the pedal. Start by looking at the wiring to the pots, power connector, jacks and switches. Look for dry, dull solder joins. Also where wires may beginning to break away i.e. hanging on by a thread!
If it’s nothing obvious then it’s a component problem. If it’s an older Dynacomp you've got more of a chance because the newer ones use TINY surface mounted components. Worth having a cursory look for any evidence of “modding” that may have gone wrong.
If you’ve still no luck – post on Freestompboxes.org with some pix. The chaps there will be more than willing to help with any possible debugs.
fretburner
Well-known member
Re: MXR DynaComp Issue
So, I opened the MXR DynaComp looking for cold solder/shorts or whatever sort of defect I can find, and I found NONE! Took pictures, looked some more, finally gave up and put it back together again without the back cover to be able to alternate between battery power and PSU quickly. Alas the "grounding" issue is GONE! It's voodoo!
I did have a problem putting it back though. 2 washers with "teeth" fell, and I can't remember where it came from. Definitely not from the switch. I just placed it on top of where the pots/knobs are at. Would you folks know where these washers with "teeth" (on the "inside circle") is supposed to be?
And btw, it is one noisy pedal. Probably noisier than a GE7. And I'm not sure if I like compression pedals in general. I'm giving up a LOT with my tone and attack.
So, I opened the MXR DynaComp looking for cold solder/shorts or whatever sort of defect I can find, and I found NONE! Took pictures, looked some more, finally gave up and put it back together again without the back cover to be able to alternate between battery power and PSU quickly. Alas the "grounding" issue is GONE! It's voodoo!
I did have a problem putting it back though. 2 washers with "teeth" fell, and I can't remember where it came from. Definitely not from the switch. I just placed it on top of where the pots/knobs are at. Would you folks know where these washers with "teeth" (on the "inside circle") is supposed to be?
And btw, it is one noisy pedal. Probably noisier than a GE7. And I'm not sure if I like compression pedals in general. I'm giving up a LOT with my tone and attack.
Re: MXR DynaComp Issue
I'm getting the same problem with my M-102 (i'm guessing recent model) MXR DynaComp. any updates here?
-I've tried comparing with power from PSU and Battery. the low-crackle noise is less with battery. but still there.
-I've tried cleaning the input and output jacks using simple cloth
-happens even when the SENSITIVITY is at zero(Volume at around 3 o'clock).
-happens even when no input signal (no jack connected [Only for PSU powered]).
-starts happening after a minute or two from turning on the pedal.
the noise sounds like someone blowing into a microphone.
if it matters, theres a SLIGHT ground when you gently touch the output jack or the footswitch.
please tell me how i can fix this without having to change my PSU or using batteries everytime(because it's costly).
I'm getting the same problem with my M-102 (i'm guessing recent model) MXR DynaComp. any updates here?
-I've tried comparing with power from PSU and Battery. the low-crackle noise is less with battery. but still there.
-I've tried cleaning the input and output jacks using simple cloth
-happens even when the SENSITIVITY is at zero(Volume at around 3 o'clock).
-happens even when no input signal (no jack connected [Only for PSU powered]).
-starts happening after a minute or two from turning on the pedal.
the noise sounds like someone blowing into a microphone.
if it matters, theres a SLIGHT ground when you gently touch the output jack or the footswitch.
please tell me how i can fix this without having to change my PSU or using batteries everytime(because it's costly).
Jonathan Conder
New member
Re: MXR DynaComp Issue
I'm having this issue with a 102 version also; I suspect the CA3080 IC chip is the cause, and why I think that is, the one I'm working on wasn't seated straight in the socket. I reseated it, and everything was running normally for about 4 minutes (PC board on an anti-static surface, 9-volt battery), then the same noise came back - it took a lot longer, but the same symptoms. I have those chips on order, and hopefully that'll fix the problem once they arrive.
I'm having this issue with a 102 version also; I suspect the CA3080 IC chip is the cause, and why I think that is, the one I'm working on wasn't seated straight in the socket. I reseated it, and everything was running normally for about 4 minutes (PC board on an anti-static surface, 9-volt battery), then the same noise came back - it took a lot longer, but the same symptoms. I have those chips on order, and hopefully that'll fix the problem once they arrive.
