Topic: Random spikes and static on SPC4->UA5->JB3 (Optical In). Help.

[tbrown4]

Helping a friend with this issue and we can't figure out where in the chain the problem occurred. Spikes sound like static and are not isolated to one specific channel.

Here is a picture of the wave form.



It is not a consistent problem...just seems to be on a few recordings from this summer. The only common factor we can find is that it was hot/humid and/or raining/wet the nights these recordings were made. He would have been in the pavilion, so the only direct contact with water or beer would be from spillage on or near his gear bag. Could that be the cause? If so, how? And...how can it be avoided in the future.

Just baffled....help.

[drewloo]

Every time I've had something like that it's been a bad cable/loose connection.  The first thing I'd check is your optical cable since they are rather fragile.  Maybe try using a different one next time. 

[JackoRoses]

also if you are using a right angle adapter those have been known to introduce that kind of randomness as well.

[tbrown4]

Every time I've had something like that it's been a bad cable/loose connection.  The first thing I'd check is your optical cable since they are rather fragile.  Maybe try using a different one next time. 

Thats what I thought it could be, the optical cable...but....he hasn't had that issue too often...only a few isolated recordings. I figure when the cable goes bad or is busted....that it's done and you'd see that problem every time after. Some shows he recorded last that same month are pristine.

[tbrown4]

also if you are using a right angle adapter those have been known to introduce that kind of randomness as well.

He does has a permanent right angle on one end of his mic cables, but they aren't adapters.

[JackoRoses]

also if you are using a right angle adapter those have been known to introduce that kind of randomness as well.

He does has a permanent right angle on one end of his mic cables, but they aren't adapters.

sorry I meant an adapter just on the optical cable.

[Chuck]

I have a recording that has that same type of spiking. It was C 481 > V3 > iHP120.
I have never had it again. I suspected it was because I had the iHP-120 resting on the top of the wally world battery I use to power the V3. Since I stopped putting the iHP-120 in that location, I haven't seen that problem again...

[Bernd Out]

Be sure that it's not happening in your transfer to the DAW.
Listen on the headphones on the JB3 and see if the static is on the recording, or if it happened in transfer.
I had a bad Firewire card that caused this... drove me crazy until I realized that the noise kept "moving" within the song.
I listened on the 'phones from the recorder, and viola' no noises!

[terrapinj]

its likely the C4 caps - they are very prone to moisture and humidity and will produce those types of results - Studio Projects (PMI Audio) will tell you to bake the caps at very low heat in your oven for a few minutes, but i had a card cap that had to end up being replaced as the baking would only be a temp solution

as I understand it a bad optical cable can cause drops outs and spikes but it shouldn't cause static

[SmokinJoe]

I second tj's response.  Bad optical cable will cause dropouts/skips, not spikes.  The guy next to me at Mountain Jam had his C4s crap out in the rain... static-ky, then eventually died.  He dried themout under a bare lightbulb that night, and they worked the next day.

[chunga1]

I had the exact same thing happen to me at a show...Only happened one time and only during one bands set....I fixed it with soundforge8..But never had it happen again (so far)..it was a weird static noise but it only happened in the last 20min of the recording of that specific band....It was on the recording and not in the transfer if i remember right..the rig used is in my sig....

tim

[jibooer]

i'm for the opinion of the humidity in the caps only because i've had probs w/ the optical cable before. the sound that was introduced was more of a random ticking....

[Rockinman59]

Thanks guys for all the responses. I'm the new taper with the issue.  I'm thinking at this point that it could have been either the optical cable OR the card caps (only because of the humidity/rain that is the common denominator here) having moisture.   My last 2 shows taped had excellent weather(no humidity to bother the caps) and I also had the optical cable connection to the UA5 out in the open(I turned the UA5 sideways) instead of the cable pressing up against  the inside of my gear bag which could have caused less than a tight connection. Anytime I did have the cable pushed in against the inside of the gearbag, I noticed I couldn't get a signal on the JB3 and when I turned the UA5 around to inspect the connection, the line was disconnected. 

Also, I looked into an optical line with one end as a right angle connector and I'm told they don't make such a thing? I checked with Cablestogo.com and The Guitar Center store.  I need to get another optical line anyway in case I have problems getting a signal.

Thanks again for everyone's advice!  Still learning all this technical stuff but did pretty well in my rookie year.

[JackoRoses]

Thanks guys for all the responses. I'm the new taper with the issue.  I'm thinking at this point that it could have been either the optical cable OR the card caps (only because of the humidity/rain that is the common denominator here) having moisture.   My last 2 shows taped had excellent weather(no humidity to bother the caps) and I also had the optical cable connection to the UA5 out in the open(I turned the UA5 sideways) instead of the cable pressing up against  the inside of my gear bag which could have caused less than a tight connection. Anytime I did have the cable pushed in against the inside of the gearbag, I noticed I couldn't get a signal on the JB3 and when I turned the UA5 around to inspect the connection, the line was disconnected. 

Also, I looked into an optical line with one end as a right angle connector and I'm told they don't make such a thing? I checked with Cablestogo.com and The Guitar Center store.  I need to get another optical line anyway in case I have problems getting a signal.

Thanks again for everyone's advice!  Still learning all this technical stuff but did pretty well in my rookie year.

soundprofessionals had a right angle optical cable for sale at one time.
I'm not sure if they still do or not.
Good luck in tracking down your issue it can be a bit frustrating at times.

[willndmb]

welcome tom