Topic: loud high pitched noise with SONY PCM D1 - it was the 9v alkaline batteries!

[noam]

Last night a tape I made started well and then an extremely loud high pitched noise came in only on the left channel going up and down like waves with rhythmic clicks. Did anyone encounter a similar problem? I thought it had to do with the D1 being kept in my pocket when stealthing and getting too warm, because I had a problem with a SONY HiMD getting warm in my suit pocket and malfunctioning, but a friend said he a had a similar problem when he had a poor connection. I use NEUTRIK/SOUND PROFESSIONALS RIGHT ANGLE 1/8” CONNECTORS to connect the lemosax to the SONY PCM D1 through the lemosax’ unbalanced output. I secure them with Velcro straps – I use some force and the right angle connectors bend a bit. The 1/8” connections are a problem.
Noam

[noam]

In last night’s performance in a huge concert hall here in Tajikistan I used the internal flash memory for act I, put the D1 in my pocket and everything was fine. For the second part of the concert I used the memory stick and I put an ice pack over the D1. The first hour was fine. At some point the ice pack fell to the floor. The recording shows that probably around that time the noise starts to show gradually, building to lower levels than on the previous concert when the noise first started to show up. I then picked up the ice pack from the floor and put it back. The noise goes down but does not disappear entirely. Then the ice pack dropped again and I did not bother to pick it up – the noise came back, this time all the way to zero. At the end of the concert I switched off the lemosax but left the D1 on - with no signal coming there was no noise - it was a flat line.



I left the D1 recording all night with the memory stick and it was fine, no noise. Only when attached to my body it warms up enough to malfunction. This makes it very difficult to me to check a new memory card, because to reproduce the exact conditions it malfunctioned I have to dress up the way I do for a concert and sweat up for several hours with the D1 attached to my body – but it never feels as warm in my apartment as it does in a Tajikistani concert hall with 4 thousand people, huge projectors etc. Very strange.

Noam

[SClassical]

Hey Noam,
I know you used the D1 a lot. So this incident only just started recently? It sounds as if your D1 has a problem. If it is still under warranty maybe you should contact the vendor/Sony. I know other solid state recorders can function when slightly hot (eg MT, R-09 etc..).

[noam]

Hey Noam,
I know you used the D1 a lot. So this incident only just started recently? It sounds as if your D1 has a problem. If it is still under warranty maybe you should contact the vendor/Sony.

Hi Simon,

SONY will not be able to reproduce the problem any more than I was able to at home. I had the same problem with a SONY HiMD that malfunctioned when it got warm only when inside my pocket – I sent it to SONY for repair and they returned it to me without finding anything wrong with it.

Just came back from another performance. For the first act I used the internal memory with no ice pack w/o any problems. For act two I used the same memory stick that malfunctioned the last 2 performances, this time with the ice pack carefully tucked inside my pocket – I didn’t drop it this time and the noise did not come up at all. So this proves in my opinion that the memory stick has become heat sensitive, but no other components have, and that for the time being an ice pack solves the problem. A friend suggested that
 the memory stick is “much more limited, esp.on the top end.  (It is, after all, computer-component technology, same restrictions...)” and I think this fits in best with the evidence  at this point.

The D1 is not exactly stealthable. Neither are the lemosax or the Schoeps (in croakies) for that matter. I am able to stealth them by using extreme and unusual methods. I don’t want to go into details here, but let’s assume just as an example that I put on a mountain gorilla costume, with special pockets custom made to fit in the lemosax and the D1; that costume is very warm, especially the head piece. The anxiety of standing in a mountain gorilla costume in orchestra, front row center, amidst proud Tajikistani men in tuxedos and their bejeweled wives when the orchestra plays our national anthem also increases my body temperature, hot Tajikistani man that I am anyway. The stares I get also don’t help – a conductor once came on stage, took one look at me and collapsed (instant double infarcts + triple strokes.) So the equipment operates in extreme heat – I can’t stealth it into our concert halls any other way other than on my body – they check any bags and here in Tajikistan they cut off the ears of anyone caught stealthing (to prevent them from using croakies), so there aren’t many options.


Noam

[noam]

After several experiments it turned out the source of the problem was the cheap alkaline batteries I used for the Sonosax. I noticed that the Sonosax was giving me flashing red light of "over." I checked the readings on the D1 meters and it did get to the stage of loud high pitched noise - the meters were certainly overring. I disconnected the mic active cable from the Sonosax and the overring continued on the Sonosax for a few seconds even with no signal in. The Sonosax was acting crazy and feeding the D1 that noise. My Sonosax gain meters are covered with electrical grade tape to make sure they don't move. This covers the "low battery" light, which I noticed was blinking.

Now everything fell into place - THE PROBLEM STARTED WHEN I STARTED USING EXTREMELY CHEAP BATTERIES I PURCHASED ON AMAZON ("Universal" 9v alkaline)! The Sonosax was acting crazy when the battery power went very low. I replaced the Sonosax batteries with new ones - everyting worked fine, no noise. I then put back the dying batteries - the noise came right back! These batteries must be really harmful if when they die out they make the Sonosax go crazy! Back to Duracel. The voodoo with the heat and the ice pack was a red herring.



 - Noam

[TNJazz]

+t for figuring out your problem and another in 12 for the vivid description of your technique (hypothetically, of course).

[bubbybooshay]

were they to start cutting off the ears of stealth tapers here it may change my opinion on stealthing