How much hiss from Distortion Module

[JRjr]

Hi:
I just took delivery of A Distortion Module and I need someone to tell me how much hiss the unit should
generate with the settings turned down?

The unit has a sticker on it from PerfectSoundRockReferbs. I have played with distortion boxes all my guitar life but this
unit seems like it it makes way to much noise to be sound.

I have tried it with and without a ground and with and without mono/stereo guitar input.

Thanks in advance.

JRjr

[X100Ver10]

Hi:
I just took delivery of A Distortion Module and I need someone to tell me how much hiss the unit should
generate with the settings turned down?

The unit has a sticker on it from PerfectSoundRockReferbs. I have played with distortion boxes all my guitar life but this
unit seems like it it makes way to much noise to be sound.

I have tried it with and without a ground and with and without mono/stereo guitar input.

Thanks in advance.

JRjr

The rockmodules all seem to have some noise to them but it sounds like you are having the same problem I had with a DG. See my thread here:

viewtopic.php?f=15&t=479

If you are comfortable with using a multi-meter on the pins of the IC's with the module plugged in, I still have my notes with the voltages. I may be able to tell you which one(s) is/are bad, if any.

[JohnCT]

Rockmans are full of op-amps, and they are a wonder for their time, but they can get noisy.

I've found over the years that hiss from any kind of semiconductor can often be ferreted by quickly changing the temperature of the device while it's in use. If you don't have any freeze spray, a can of air duster turned upside down will do the same.

With no input to the Rockman, put a *drop* or two of freeze spray on each op-amp listening for any change of hiss either more or less, being careful not to let the freeze spray affect nearby components. Often, you can initiate a delta noise by heat or cooling (with spot cooling a bit easier to apply). I've also used a soldering tip directly to the plastic cases to heat transistors, ICs, etc looking for the same result.

Otherwise, a scope is the best way to pick up any unintended sounds.

John

[X100Ver10]

Rockmans are full of op-amps, and they are a wonder for their time, but they can get noisy.

I've found over the years that hiss from any kind of semiconductor can often be ferreted by quickly changing the temperature of the device while it's in use. If you don't have any freeze spray, a can of air duster turned upside down will do the same.

With no input to the Rockman, put a *drop* or two of freeze spray on each op-amp listening for any change of hiss either more or less, being careful not to let the freeze spray affect nearby components. Often, you can initiate a delta noise by heat or cooling (with spot cooling a bit easier to apply). I've also used a soldering tip directly to the plastic cases to heat transistors, ICs, etc looking for the same result.

Otherwise, a scope is the best way to pick up any unintended sounds.

John

I'm not the OP but I wanted to thank you for the tips. I bought some cans of freeze spray and will try your tip when I get my next problem Rockman.

Can you elaborate on using the soldering tip for diagnosis? How long do you keep contact with the component? Temperature of the soldering iron? Etc.

Thanks.

[JohnCT]

Can you elaborate on using the soldering tip for diagnosis? How long do you keep contact with the component? Temperature of the soldering iron? Etc.

Set your temp for about 600F. I use a wide blade tip for this purpose as you want to transfer the heat over a larger area. The case material of transistors and ICs is quite resistant to burning. If you have a hot air station, you can use the smallest nozzle and set your air for lowest air flow, but I've found even at low speed air tends to heat up the surrounding area, so I usually use a wide blade solder tip I keep for that purpose alone.

Now you may find that the hiss (in this case) may go up or down a bit when any particular part is heated and cooled, and that may be normal. Semis change characteristics with temperature so heating or cooling will usually change the gain of the device a bit. What we're looking for is a definitive change in the noise in question.

There of course is no guarantee that the device under suspicion will be thermally sensitive but a lot of them are, and if they are, then a little temperature manipulation either colder or warmer can ferret out a noisy part and save an awful lot of time.

John

[X100Ver10]

Can you elaborate on using the soldering tip for diagnosis? How long do you keep contact with the component? Temperature of the soldering iron? Etc.

Set your temp for about 600F. I use a wide blade tip for this purpose as you want to transfer the heat over a larger area. The case material of transistors and ICs is quite resistant to burning. If you have a hot air station, you can use the smallest nozzle and set your air for lowest air flow, but I've found even at low speed air tends to heat up the surrounding area, so I usually use a wide blade solder tip I keep for that purpose alone.

Now you may find that the hiss (in this case) may go up or down a bit when any particular part is heated and cooled, and that may be normal. Semis change characteristics with temperature so heating or cooling will usually change the gain of the device a bit. What we're looking for is a definitive change in the noise in question.

There of course is no guarantee that the device under suspicion will be thermally sensitive but a lot of them are, and if they are, then a little temperature manipulation either colder or warmer can ferret out a noisy part and save an awful lot of time.

John

Thanks John!