Audiostatic ES-100 Problem

[Ulf Eliasson]

My right speaker plays louder than my left
I estimate that the right speaker plays about twice as loud as the left. What could be the cause of this?

What I already have ruled out:

1. Nothing is wrong before the speaker, because when I swap the speakers it’s the same speaker that plays louder.
2. Nothing wrong with the 4000V PSU, because now when I use one PSU to both speakers I have the same problem as when I used two separate PSU.
3. I have with air pressure carefully blown away every little dust/hair that could have made some kind of connection between the membrane and any of the two stators on the left speaker.

Other observations:

1. If the speakers have been disconnected from the power outlet for a day or so when I start playing music through the amplifiers the speakers plays very weak of cause but with perfect balance. When I then connect the 4000V PSU to the outlet the speakers plays louder and louder and keeping the perfect balance for about 10 minutes then the sound starts moving to the right and after about an other 10 minutes the middle have almost moved all the way to the right speaker.
2. I have observed the speaker without any input and in total darkness and no visible or sounding sparks.
3. When I disconnect the 4000V PSU from the outlet and continue to play music the balance point starts moving from close to the right towards the middle slowly after about 10 minutes and after about 10 more the balance is perfect. The sound is not super dynamic but it stays enjoyable for hours.
4. I have also added 10 multiplication links to the PSU enabling it to give 6000V. The dynamics, details and sensitivity is vastly improved but the balance problem remains.
5. No observed sparks with 6000V PSU either.

Conclusions so far:
My first thought was that there was something wrong with the coating of the membrane, but to me it looks more like something acts like a slow 3000V zener diode? Please, challenge my conclusion? All ideas are welcome! Could it be the coating anyway?

[Ulf Eliasson]

Testing with a neon bulb probe between the membrane and the 6000V PSU gives different results for left (the faulty one) and right speaker when connected to the mains outlet:
Left: Starts with one spark every 15s then faster and faster until steady state at one spark at every 4s.
Right: Starts with one spark every 2-3s then slower and slower until steady state at one spark every 60-120s.

A result in line with how the speakers perform, but what could be the root cause?

[Calvin]

Hi,

there must be a serious leakage problem within Your left speaker.
The membrane looses its charge (unusually quickly) or the HV-supply is faulty.
In a first step, connect the right HV-supply to the left Panel.
Problem soplved? -->left HV-supply faulty
Problem still existant? --> left panel faulty

jauu
Calvin

[Ulf Eliasson]

Thanks for your interest, Calvin. I agree with you that it must be some kind of leakage problem. I have already ruled out the PSU as you can see above and it is not a normal leakage because the faulty left speaker plays for hours after disconnected from the outlet. The tricky thing is that the leakage starts over a certain voltage level; my guess is about 3kV because with the original 4kV PSU my right speaker plays a bit louder but with a 6kV PSU it plays a lot louder.

[SM7UYJ]

Could it be a problem in the audio trannie - have you tried switching them?

/R

[Ulf Eliasson]

SM7: Switching the audio transformers was one of the first things I tested.

I have just separated the membrane assembly from the MFD-frame and electronics. I connected my 6kV PSU via the neon bulb probe between the membrane and the stators with the same result; first sparks every 15s and then every 2-3s forever.

Anyone knowing if the coating of an ES-100 is water resistant?

[Ulf Eliasson]

Yesterday evening I used a steam cleaner to clean both sides of the membrane. I let it dry over night. But I was waste of time, because when I connected it to the 6kV PSU via neon probe… still exactly the same frequency of sparks in the bulb. I tried to connect the ground to only the back side stator respectively only the front side stator, but still the same result in both cases.

Next I tried to connect the 6kV with a separate wire directly to the membrane on the top of it to see if that made any difference, but unfortunately no.

All ideas are warm welcome!

[chinsettawong]

Hi,

Try leave the power on overnight and see the difference.
It might take longer time for one panel to charge up than the other.

Wachara C.

[Ulf Eliasson]

Thanks Wachara, but as you can see above the steady state was 2-3s between sparks in the neon probe (steady state is the same for several hours). And before I started my “investigation” my speakers were always connected to the outlet.

What I have done since last post was to remove some glue and silicone on the bottom short-end of the membrane frame and where the high voltage is soldered to the copper foil. Finally some change! Now I only get sparks every 15s in steady state. I will connect in to the amplifier tomorrow and see if it works okay now.

[Ulf Eliasson]

Re-coating original membrane?

No unfortunately the left speaker was even weaker sounding now. It looks like I had a combination of two errors; leakage and poor coating. The leakage is now cured but the coating problem must be fixed. What makes it obvious that I had a problem with the coating, probably accentuated by my steam cleaning, was that midrange and treble can only be heard from two small spots of the speaker.

Anyone being successful with re-coating an Audiostatic ES-100 membrane?