Moodring White Noise In bypass too

[claytushaywood]

I've found a few threads on this but with no real discussion.  I built the moodring recently and it works and sounds great.  One of the best sounding pedals I've ever played IMO

However,
The white noise i'm dealing with is pretty obscene.  It is pretty hideous with high mix (ring knob) and tone (mood knob) settings.  and this noise occurs exactly the same when its on as when in bypass (i used the non true bypass wiring).  that meaning you can "control" the noise when the pedal is bypassed by making it louder- turning up the ring knob, or making it brighter or darker- turning up the mood knob.  i have messed with the trim pot inside the pedal and it is pretty unbearable with the trim pot turned all the way down.

I could make a demo of this, but first i'd just like to know if this is normal?  The amount of noise is... I said unbearable, but it can be bearable.  However, it is a whole lot louder than the switching between single coil and humbucking positions on my strat.  it actually seems to cover up that hum.  like if I kept the mix below noon it would be perfectly fine, but this isnt the type of pedal that you wanna use subtley.

I used all top of the line components in this pedal.  maybe I have a bad cap somewhere?  this really sucks because I thought this would be an improvement on the EQD ghost echo, which has some typical pt2399 noise with longer delay times (that at least isnt present in the moodring), but it is MUCH noisier than a ghost echo i built.

so first I guess my question is who else has experienced this and is this normal operation?

[madbean]

You need to track down where the noise is introduced in the circuit. Use an audio probe. I would first listen to the outputs of the PT2399 and Belton Brick, then the output of the gain recovery stage which is IC4B.

Any noise coming out of there is going to translate into your bypass signal if you are doing non-true bypass. So, we need to find the source and eliminate it.

[claytushaywood]

Ok.  I'm not getting noise on the input of the brick and I am getting it on the output. 

are noisey bricks common?  I've never built a belton based circuit and had noise be an issue!!

[claytushaywood]

It should also be noted that I used Plastic isolated jacks and thus the enclosure is not grounded.  maybe i should ground the enclosure?  hopefully.... :-

****sorry i dont believe isolated is the right word.  but you get the idea.  enclosure not grounded.

[claytushaywood]

Do belton bricks really fail in this way?  just having some white noise?  otherwise it sounds pretty terrific... like its going to be one of my favorite pedals of all time once I get rid of the noise

[claytushaywood]

Anyone got any experience with this before I go changing out a belton module for no reason?  it seems the brick sounds fantastic but is contributing unusual amounts of white noise... is that a common symptom

[claytushaywood]

You need to track down where the noise is introduced in the circuit. Use an audio probe. I would first listen to the outputs of the PT2399 and Belton Brick, then the output of the gain recovery stage which is IC4B.

Any noise coming out of there is going to translate into your bypass signal if you are doing non-true bypass. So, we need to find the source and eliminate it.

I isolated the nose to the belton brick.  Got another one and this one has less noise (if i remember correctly, started second guessing myself when I turn the tone control up).  Its fine with the tone control down 9 oclock or below, but after that its pretty noticeable with the mix levels I use. 

Stil an amazing sounding pedal.  I would recommend true bypass wiring to anyone about to build this though.

I'm wondering what kind of RC to ground value I could use to get a filter that wouldnt affect my dry tone too much?  Or maybe I could rewire to true bypass and filter out some of the high end?

any help would be appreciated, I've never been good with adding filters

[luks999]

It should also be noted that I used Plastic isolated jacks and thus the enclosure is not grounded.  maybe i should ground the enclosure?  hopefully.... :-

****sorry i dont believe isolated is the right word.  but you get the idea.  enclosure not grounded.

you should definately ground the enclosure. this is propably the reason why it occurs in bypass as well

[claytushaywood]

I grounded the enclosure using metal jacks... I think the noise got worse (probably no change) heh...

it seems like this noise would be very easily filtered out... so maybe i have a bad cap somewhere?  is there anywhere in the circuit that could be responsible for filtering out ultra high end?

I really love this pedal, i wish more people that have built it would chime in and tell me if this is normal operation or not!  and the noise is in bypass too probably because I did non true bypass with tails

[madbean]

If your noise is isolated to the brick then I would do the following:
Socket C24 and try 470pF.
Socket C26 and try 22n or 47n.

This should cut out more of the highs esp. when the tone control is pushed beyond 50%.

[claytushaywood]

Thanks! I will try that.  My audio probe just shows that there isnt noise before the reverb module and there is noise after it.  Is there anything in the stock circuit that would filter out noise that may be bad?  Like maybe I have a bad connection or a bad cap.  Would those be c24 or c26?

[madbean]

I don;t think so. At least I don;t think you have a bad part necessarily. You'd really have to sit down and audio probe every single connection/component to determine that.

If the noise is coming right from the output of the brick (pins 1 and 5) then the brick is definitely the culprit. Or, possibly there is some noise from the brick which is then being amplified or accentuated by either the Muff tone stack or the gain recovery stage at IC4_B.

When you turn the tone control way up any hiss present is really going to pop esp. by higher levels of gain recovery with the T1 trimmer. But, this is mitigated somewhat by the filter formed by R30/C26 to reduce highs. From my own builds what was there was enough but it can certainly be a made a more aggressive filter without  too much compromise in the overall tone.

My point is that whether or not a noisy brick is to blame or not I think it's probably better to just fix it with tweaking values at this point.

[claytushaywood]

okay, i will work on it.  The brick isnt the culprit regardless, unless I got two noisey bricks in a row.  Which Ive never had noise issues with a belton brick.  Ill get back soon with my results

[claytushaywood]

I put 470pf in c24 and 33n in c26.  The noise has definitely decreased, but if i wanted to leave a brighter setting and the mix near 3 oclock or more the noise in bypass would be too much.  I really dont wanna have to do true bypass and deal with popping issues.

the way the board is setup (brilliantly I should say) makes changing these pretty difficult.  and using sockets was near impossible.  I could tack on another cap to c26 to increase it further.  Anybody got a good idea at a cap value to put in parallel with c26 to give me more filtering without ruining my high end or should I just go true bypass?  if i go true bypass I'd still prefer less noise on the effected signal, am i running into danger putting c26 up near 56n?

[toddvirgil]

For what its worth, I'm getting the same white noise -- but It decreased SIGNIFICANTLY when I tried another PT2399. I think I'll still try changing some of these cap values to help reduce, but I read somewhere that PT2399 can sometimes have a hiss issue, and that did make a big difference.