Strange noise from Ibanez ATK

[geoham]

Hi all,

Wonder if any of you can offer any advice. I am experiencing an intermittent issue with my Ibanez ATK 200. I suspect it's related to the pre-amp, but I'll describe the symptoms below, and you can come to your own conclusions.
[list]
[*]Sometimes, I'll hear a noise while I'm playing (in time with what I'm playing) - that I can only describe as distortion meets a white-noise like hiss. A bit like a pre-amp being overloaded, clipping sound. This is behind the sound of the notes, rather than the notes themselves distorting
[*]It goes from being very faint to being almost as loud as the notes I'm playing
[*]When it occurs, it's there constantly - but will typically be gone the next day. I can't replicate right now for example.
[*]The noise is far more apparent when pressing the 'bright' switch on my amp (Ashdown Mag 300), but is still there when the EQ, compression, deep and bright switches are off. I can also hear it on a little Peavey Microbass amp.
[*]The noise is not present when using my Fender Jazz
[/list]
Some things I've tried:-[list]
[*]Replaced the battery - I thought this was it, because the battery was only reading 8v on my multi-meter. The new one reads 9.4v and I still have the problem.
[*]Using the 'Active' input on my amp
[*]Reducing the input gain (amp) - the VU meter never goes in to the red
[*]Reduced volume of bass
[*]Set EQ on bass flat, and also cut each frequency individually and together.
[*]Tried different cables
[/list]
The next time the problem occurs, I'll try to make a recording of it and post it here.

Any advice you can offer would be much appreciated!

[MarkBassChat]

This is clearly related to the preamp. Either there is something wrong with the preamp itself, or with wires soldered,or plugged into the preamp. In any case you can take a look at the preamp with a magnifying glass. If there are plugs (from pots to the preamp), check that they are OK. If you cannot see the problem, ask a tech to service it.

Mark

[icastle]

[quote name='geoham' timestamp='1361534185' post='1987046']
Replaced the battery - I thought this was it, because the battery was only reading 8v on my multi-meter. The new one reads 9.4v and I still have the problem.
[/quote]

Strange as it may sound, and without going into a long nerdy explanation, you can't judge battery life using a multimeter.

If you've replaced the battery with a brand new, never been used before, one - then the battery isn't the problem.

However, if you've dug around and found a battery from somewhere and assumed it was OK because of your multimeter, then you've not eliminated 'duff battery' from the list of possibilities.

[geoham]

[quote name='icastle' timestamp='1361557097' post='1987593']
Strange as it may sound, and without going into a long nerdy explanation, you can't judge battery life using a multimeter.

If you've replaced the battery with a brand new, never been used before, one - then the battery isn't the problem.

However, if you've dug around and found a battery from somewhere and assumed it was OK because of your multimeter, then you've not eliminated 'duff battery' from the list of possibilities.
[/quote]

The battery may well be questionable! It's an unknown brand (gold coloured with chinese text!) and was supplied in an effects pedal I bought (new!), but removed straight away as I use a PSU. Anyway - I've no idea how many people tested the pedal, or how long the battery was in it for. It has also sat in my drawer for a couple of months too. So, I'm going to replace it with a shiny new one tonight.

Being an intermittent fault, it's tough to know when it's resolved, but I'll report back here ASAP. (By intermittent - I mean it's happened a handful of times over the past month, but never before that)

In any case, are the symptoms I'm describing typical of failing battery? I've been a Fender man all my days - this is my first active. I've only had it for about 18 months and gigged it once.

Mark - I've had a look at the pre-amp and can see nothing of concern, pretty simple set-up, few pots, a switch and PCB. All in good condition, no duff soldering etc. Doesn't mean the there isn't a component on its way out though...

Thanks

[icastle]

[quote name='geoham' timestamp='1361563078' post='1987752']
In any case, are the symptoms I'm describing typical of failing battery? [/quote]

I'm an SR505 user, when my battery goes flat it cuts in and out and sounds awful.
It really depends on the design of the preamp as to what happens when the battery dips below a certain point.

Definitely worth changing it, if it doesn't fix the problem then it's one thing you can cross off the list.

[geoham]

I think I've figured it out! (Again!)

Definitely not the battery - brand new alkaline one in there now.

The thing had stopped working altogether today. Had a look at under the control panel again. Just noticed that there is a square of sticky foam attached to the PCB - presumably as insulation. It was mis-aligned, so a couple of pins were visible - and close enough to just touch the input jack.

I've re-aligned this, and tried to move it away from the input jack a little - the bass is back to life now, and I've had no noise issues since.

Fingers crossed!

Edited February 25, 2013 by geoham

[icastle]

[quote name='geoham' timestamp='1361790343' post='1990728']
Fingers crossed!
[/quote]

Well spotted!

Fingers crossed here as well.