Akai s900 white noise

I just purchased a s900 and when recording into it the playback has decent amount of added noise to it, this is especially noticeable on samples that have quieter parts like drum breaks. I've tried many different cables and contigurations samoling directly from turntable sampling directly from audio interface) and different bandwidths and different recording levels and I'm always getting back added noise with the sample (I don't hear this noise monitoring through the s900, only after it's recorded in and played back) I would describe the noise a an electrical hum whirly kind of noise. Im assuming this isn't normal. I owned a mpc 60 about 10 years ago and didn't expierence any noise like this. Any feedback would be appreciated

heya,

hard to say, this could be a lot of things. The venerable S900 is now aging, unless it has been serviced regularly.
You could open the S900 and carefully inspects your capacitors (look for leakage, bulged, etc...), maybe post an hi-res picture. Get a multi-meter and double check them, while some may not leak yet, then can still be "tired".

https://manuals.fdiskc.com/flat/Akai%20 ... Manual.pdf


my 2cents..

Thanks for the response. After testing more configurations I realized that if I sample directly into the s900 from my audio interface and then record back the s900 into the audio interface I don’t get that white noise, so now I’m trying to figure out what in my chain is causing the noise. Maybe it’s some of cables or my turntable. Need to do further testing but if I’m getting good results with the audio interface configurations shouldn’t that indicate that the problem is likely not the s900?

maybe, maybe not, it's probably too early to confirm anything, but follow your intuition. the key thing with testing is consistency. Does this noise appears every time no matter what sample ? or does it appears only when samples contains particular frequencies ? It can be a journey to nail down the issue. use some reference you know well, so you can compare easily. you can also use a sine wave, with various frequencies (ie: 80,200,400,600..)

I ve mentioned capacitors, because it's a frequent issue, but again could be anything. let us know, might be usefull for others.

While all electrolytic capacitors naturally age (matter of fact), the S900 is too old to fall in the „get bulky and leak“ era. Quality standards were much higher back then.
I have some broadcast gear from the 70s and never spotted a cap with visually detectable damage inside, which also applies to Yamaha TX-7, SPX90 or Roland SRV2000 to name a few.

Nevertheless I in fact „recapped“ most of my broadcast modules, resulting in significantly improved noise figures.
A single cap is difficult to measure and it must be removed from the circuit to do so.
For this reason it‘s simply more convenient to replace all of them with quality parts in one go. In case you plan something like that, an automatic desoldering station (about $100) is well worth the investment and speeds up things greatly.
These things aren‘t industrial grade, but do the job just fine as long it‘s not your daily profession.

ps: chilom is right, electrolytic caps are the most common source for aging damage, but if there is noise that reminds on „electricity sounds“ most of the time it‘s wire and ground based.
The noise I mentioned in my case was plain white noise.

+1 to mention ground issues..another classic

while we are, there, another thing to look after is the memory (lovely called IC) but their symptoms varies. OP can launch a quick RAM test to valid that.

Appreciate the responses. While it’s still to early to tell I’ve been getting consistently good results with this last configuration (ive tested about 20 different samples and they all sound ok as long as i use this configuration) although not ideal because i would like to go directly from turntable to mixer to s900. It might be a grounding issue or faulty cables. I only have 5 days left on the reverb return policy to make sure the s900 is working so I need to run more tests, but based on me getting consistent good results with the current set up would you think that the problem is more likely from another source and not the s900 itself?

There are a ton of things that can crop up to cause noise issues.

If you've got a process that gets you a reasonably clean, or acceptable audio output... sounds good to me.

I've got a VX-90 that on some mixers sounds terrible, with very high noise floor, and others, it is crystal clear. Honestly, there's too many factors to tell, but it's likely something in your setup combining poorly with the S900.

ABiggz313 wrote:... I only have 5 days left on the reverb return policy to make sure the s900 is working so I need to run more tests, but based on me getting consistent good results with the current set up would you think that the problem is more likely from another source and not the s900 itself?

The easiest way to check the S900 inputs is to use them with a TR plug that bridges tip and ring by a resistor.
Use 200-500 Ohm for the mic side, 10-50 kOhm for line, the exact value doesn‘t matter.
This way the input is terminated and will only pickup noise from within the circuit.

Then record with gain set to zero, to middle and to full. If the latter produces excessive noise, adjust the dial lower in small steps until you find a sweet spot.
Your records will simply capture the noise floor at various gain levels.
Inspect in a DAW for details... best of luck
(if you lack soldering gear, just wiggle the resistor to the plug, it just needs contact)
Or snip off the end of a mono cable and drag one end of the resistor into the core wire and the other end between shield and core...

Hi guys,
Any news in this subject?
I have purchased a s900 myself and have a problem with the white noise. I have opened to recap it but it was already fully recapped. when i sample with the rec knob set to minimum i get only white noise.