Help troubleshooting Ibanez SRFF806

[EMoneySC2]

Hello everyone,

I've got an Ibanez SRFF806 that has an electrical problem. With the blend biased all the way to the bridge pickup the sound is fine...clean and clear. When I start to blend in the neck pickup though, there's this weird static sound in the signal. Check this sound clip: [Invalid or Expired Link Removed]

The first group of notes are full bridge, the second group is full neck. You can clearly hear the static sound I'm talking about.

I've cleaned the pots out with DeOxit, and the static is still there.

When the bass is active and I roll off the treble pot to zero the sound mostly goes away but is still quietly present. When the bass is passive if I roll off the tone pot (which acts as the treble pot in active mode) the sound seems to completely disappear. I've messed around with the other pots and the switches, but I can't make the static sound go away.

Does anybody have any thoughts on what the problem might be?

 

[Aidil]

have you tried putting in fresh new battery?

just my 2 cent...

 

[EMoneySC2]

The static sound is present in active and passive mode, so I don't figure it's a battery issue but I'll replace it later today and check.

 

[khutch]

Not sure how Ibanez switches out the preamp in passive mode so it is possible that changing the battery will help in passive mode. It is not the expected result since you can easily switch out preamps in a way that will totally prevent battery issues from affecting the sound but does Ibanez do it that way? If it is not the battery then my best guess would be a dodgy solder joint somewhere in the neck pickup or its wiring to the blend pot.

 

[Aidil]

Yup, engaging passive switch doesn't always mean completely ruling out the preamp or the needs of battery. IIRC, it happened when I still had Bart MK1 preamp in one of my basses: even if the switch was in passive position, but if there was no battery working, then it wouldn't be any sound output from the bass. So... that preamp uses battery despite engaging passive switch.

if the preamp in SRFF806 works the same way and the problem is caused by a dying battery, then switching the switch from active to passive wouldn't fix anything.

 

[EMoneySC2]

Yup, engaging passive switch doesn't always mean completely ruling out the preamp or the needs of battery. IIRC, it happened when I still had Bart MK1 preamp in one of my basses: even if the switch was in passive position, but if there was no battery working, then it wouldn't be any sound output from the bass. So... that preamp uses battery despite engaging passive switch.

if the preamp in SRFF806 works the same way and the problem is caused by a dying battery, then switching the switch from active to passive wouldn't fix anything.

But if that was the case wouldn't the static sound be present all the time? The signal is clean on the bridge pickup, so I don't understand how the battery could be the problem. Once I'm home a bit later tonight I'll try it with a fresh battery anyways.

 

[EMoneySC2]

Alright, I put in a fresh battery and the static noise is still there. The sound is there in active and passive modes, and only present when I blend in signal from the neck pickup.

So am I correct in assuming it has to be a bad connection somewhere or a faulty/damaged pot? Keep in mind that I just cleaned all the pots out with DeOxit yesterday.

Some time ago I did take out the neck pickup and check it...there was no visual issues, but it was hard to tell because the wires go straight into the Bartolini pickup.

 

[EMoneySC2]

Here are some pictures of the insides.

I tried switching the input molex plug into the +6dB connector, and the static sound is still present, but still ONLY in the neck pickup.

The only suspect thing I can find in the electronics cavity is the unshielded tiny gauge wire that connects everything to ground. Though if that was the source of the static sound I have no idea why it would only impact the signal coming from the neck pickup.

Thoughts, anybody?

 

[RobbieK]

I'm guessing it's a dodgy blend pot or connector. If the pickups are connected with molex-type connectors, try swapping the neck and bridge pickups. (Your blend pot will act in reverse.) If the bridge pickup now distorts, I'd suspect the blend pot. If the neck pickup still distorts, I'd suspect the pickup.

If the pickups are directly soldered to the blend, I'd wind the blend all the way to the neck, then use an audio probe to test the circuit from the pickup connection, to the output of the blend. If it turns out to be the blend, before replacing it, I'd reheat the solder joints. A dry joint can make this noise.

If it seems to be the pickup, also try reheating both its hot and earth solder joints.

Oh and fwiw, I'd also remove the connectors one by one, and give them a squirt of contact cleaner as well.

 

[EMoneySC2]

I'm guessing it's a dodgy blend pot or connector. If the pickups are connected with molex-type connectors, try swapping the neck and bridge pickups. (Your blend pot will act in reverse.) If the bridge pickup now distorts, I'd suspect the blend pot. If the neck pickup still distorts, I'd suspect the pickup.

If the pickups are directly soldered to the blend, I'd wind the blend all the way to the neck, then use an audio probe to test the circuit from the pickup connection, to the output of the blend. If it turns out to be the blend, before replacing it, I'd reheat the solder joints. A dry joint can make this noise.

If it seems to be the pickup, also try reheating both its hot and earth solder joints.

Oh and fwiw, I'd also remove the connectors one by one, and give them a squirt of contact cleaner as well.

The pickups are not connected via molex, but I could swap the neck and bridge pickup connections to the blend pot easily enough to see if that would reverse the issue. Then I'd have a good grasp on whether or not it's a pickup or blend pot issue. Thanks for the pointers!

 

[DiabolusInMusic]

In my experience static electricity discharges are stopped with a proper shielding job, which this bass appears to be lacking.

 

[EMoneySC2]

In my experience static electricity discharges are stopped with a proper shielding job, which this bass appears to be lacking.

I think I have been misusing the term static. It's not like I'm getting shocked by the bass, I'm just hearing a static type noise...like a mid-pitch white noise kind of distortion. I'm not really sure how to describe it more accurately. The sound cloud sample above has a DI recording of what I'm hearing.

 

[DiabolusInMusic]

Ahhhh, the notes are distorting. When you put a new battery in was it fresh out of the package? A bad/low battery is the only thing I can think of causing such a noise.

 

[EMoneySC2]

Ahhhh, the notes are distorting. When you put a new battery in was it fresh out of the package? A bad/low battery is the only thing I can think of causing such a noise.

I tried a fresh battery last night and it didn't make a difference. I'm thinking the blend pot is bad, or the neck pickup may have an issue.

 

[RobbieK]

Google on "audio probe". There'll be a million pages and youtubes to check out. It's basically a guitar lead with one jack removed, an aligator clip to attach the braid to the guitar's earth, and a cap (usually around 100nf) to probe the circuit. Just avoid the 9v rail, and don't have your amp turned up too loud.

If it turns out to be the pickup that's suspect, if possible, remove the cover and check for loose material inside. A loose coil may be causing this, and potting or even re-wrapping might be the cure. More likely, a loose piece of metal might be around the magnets. I've heard this sort of distortion from a few hairs of steel wool being attracted to a pickup magnet.

 

[tubedude]

Re-heat the pickup solder joints.