Having made some electrostatic panels for headphones in the past I thought well lets play, when I saw a pair of Audiostatic ES300R for 100 Euro claiming they needed new panels just 70km from my flat in Hamburg Germany.
When I got home I stupidly plugged them both in and the second one went BANG and set of the circuit breaker in my flat, so I left that speaker to later. The other played but clicked, around about once a minute. After a little while I realized the clicks where coming from the moving coil speaker on the other channel. Removing the electrostatic speaker connections from the amp removed the sound. So some how the Electrostatic speaker is making sound in the moving coil speakers through the Quad 306.
I guess this could be due to the mains voltage direct coupled and arcing (hopefully not in the output trafos), so upsetting the Quad 306 Amp? Any suggestions or tests I can do are very welcome.
I found some circuits here in DIY audio that are approximately correct for the Audiostatic ES300R (Resistor and capacitor values differ in the driver circuit but the voltage doubler is identical). Thanks to bolserst for the doubler circuit and maudio for the Audiostatic ES300 driver circuit that I stole from other threads in DIY audio and attached here.
The speaker that went BANG had a loose connection on the mains wire, and has obviously done it before, and taken out quiet a few of the PCB tracks near the mains connection. This still was not a killer but, sadly on further investigating one of the 2 stator driving transformers is open circuit on its secondary.
So although the Audiostatic ES300R pannel and stators looks rather well made I am not so impressed with the electro mechanical side. No detachable mains lead, no issolation transformer for the high voltages, no fuses, no screw terminals on the PCB, not even PCB pins, just bare mains wires soldered into the PCB.
As for the sound from the one working speaker the sensitivity is much lower than a Quad ESL63. Subjectively it has a similar quality to the highs and midrange, posibly even better, but I am guessing here but 300Hz and lower seem non existent. The capcitors in the Audiostatic ES300R mention west germany so I suspect they would need to be replaced.
So I probably will give up renewing the speakers, unless some one can sell me a driver transformer cheap, and instead I will sell the transformers cheap.
Happy DIY'ing
Owen
When I got home I stupidly plugged them both in and the second one went BANG and set of the circuit breaker in my flat, so I left that speaker to later. The other played but clicked, around about once a minute. After a little while I realized the clicks where coming from the moving coil speaker on the other channel. Removing the electrostatic speaker connections from the amp removed the sound. So some how the Electrostatic speaker is making sound in the moving coil speakers through the Quad 306.
I guess this could be due to the mains voltage direct coupled and arcing (hopefully not in the output trafos), so upsetting the Quad 306 Amp? Any suggestions or tests I can do are very welcome.
I found some circuits here in DIY audio that are approximately correct for the Audiostatic ES300R (Resistor and capacitor values differ in the driver circuit but the voltage doubler is identical). Thanks to bolserst for the doubler circuit and maudio for the Audiostatic ES300 driver circuit that I stole from other threads in DIY audio and attached here.
The speaker that went BANG had a loose connection on the mains wire, and has obviously done it before, and taken out quiet a few of the PCB tracks near the mains connection. This still was not a killer but, sadly on further investigating one of the 2 stator driving transformers is open circuit on its secondary.
So although the Audiostatic ES300R pannel and stators looks rather well made I am not so impressed with the electro mechanical side. No detachable mains lead, no issolation transformer for the high voltages, no fuses, no screw terminals on the PCB, not even PCB pins, just bare mains wires soldered into the PCB.
As for the sound from the one working speaker the sensitivity is much lower than a Quad ESL63. Subjectively it has a similar quality to the highs and midrange, posibly even better, but I am guessing here but 300Hz and lower seem non existent. The capcitors in the Audiostatic ES300R mention west germany so I suspect they would need to be replaced.
So I probably will give up renewing the speakers, unless some one can sell me a driver transformer cheap, and instead I will sell the transformers cheap.
Happy DIY'ing
Owen
Attachments
Nice find!
The transformer was likely killed by overdriving them. The common failure mode is that the membrane coating goes bad, causing sensitivity to drop slowly over time. The owner corrects for this by gradually cranking up the volume until the output becomes too low to be useful if you're lucky. Or until a transformer fails...
They will need new membranes for sure. Don't let the current sound quality of the other panel fool you, with bad coating it will be nowhere near what these are capable of and tonal balance will be way off. In good condition these esl's are among the best out there are. Imho much better than the Quad 63. They are truly worth a rebuild.
It shouldn't be too hard to source a replacement transformer. Try your favorite local internet market place, or place a wanted ad. Or try companies that rebuild them. Maybe Audiostatic itself still stocks them, give them a call.
Replace all diodes, resistors and capacitors in the hv supply and the large electrolytics in the audio path. Replace the membranes with new 4 or 6 um mylar and apply a good coating. For instance ER Audio in Australia can help you with the materials. And I recommend to modify segmentation to make them less beamy, 4 in stead of 8 wires for the center segment makes a huge difference.
To get the ultimate system, add a pair of dipole woofers crossed at 100-150Hz. You will never look back.
The transformer was likely killed by overdriving them. The common failure mode is that the membrane coating goes bad, causing sensitivity to drop slowly over time. The owner corrects for this by gradually cranking up the volume until the output becomes too low to be useful if you're lucky. Or until a transformer fails...
They will need new membranes for sure. Don't let the current sound quality of the other panel fool you, with bad coating it will be nowhere near what these are capable of and tonal balance will be way off. In good condition these esl's are among the best out there are. Imho much better than the Quad 63. They are truly worth a rebuild.
It shouldn't be too hard to source a replacement transformer. Try your favorite local internet market place, or place a wanted ad. Or try companies that rebuild them. Maybe Audiostatic itself still stocks them, give them a call.
Replace all diodes, resistors and capacitors in the hv supply and the large electrolytics in the audio path. Replace the membranes with new 4 or 6 um mylar and apply a good coating. For instance ER Audio in Australia can help you with the materials. And I recommend to modify segmentation to make them less beamy, 4 in stead of 8 wires for the center segment makes a huge difference.
To get the ultimate system, add a pair of dipole woofers crossed at 100-150Hz. You will never look back.
You're invited (in the south of the Netherlands) to come and listen to a properly rebuild set, you'll be surprised.
Thanks, but I actually own a properly refurbished set 63's. And a few sets of Audiostatics. A set of rebuild 57's. So I know quite well how they all compare. All these designs have good and weak points. In the end it's all a matter of personal preference I guess.
The 63 imho severely lacks in the detail and clarity departement. I personally prefer the much greater detail and openness that the Audiostatics offer, because for me it results in a more enjoyable involvement into the music . But on the downside, Audiostatics suffer from the typical resonant low frequency reproduction that most full range esl's have, so they need a good (dipole) sub to really shine. The 63's do better here, although they are no match for a good dynamic dipole woofer system either. But all in all they are quite pleasant allround speakers.
The 63 imho severely lacks in the detail and clarity departement. I personally prefer the much greater detail and openness that the Audiostatics offer, because for me it results in a more enjoyable involvement into the music . But on the downside, Audiostatics suffer from the typical resonant low frequency reproduction that most full range esl's have, so they need a good (dipole) sub to really shine. The 63's do better here, although they are no match for a good dynamic dipole woofer system either. But all in all they are quite pleasant allround speakers.
Hilarious.
Again, please come and listen if you are in the neighbourhood. No subs needed at all. Very deep clean bass.
Yes, high frequencies of quad rolls off well below 20 kHz. Lots of stuff between mylar and ears as well. Audiostatics wire design stator literally opens up. Each his own.pick ofcourse
Not if you do a correct rebuild with 3 micron Mylan and the right coating, not the heavy graphite stuff that makes total diaphragm 9-12 micron thick.
Quad ESL-63 with 1/6 octave smoothing.
Quad ESL-63 with 1/6 octave smoothing.
I seem to remember reading once probably from the library reading back issues of "Wireless World", "HiFi News and Record Review" (And some pre merger), and interview with Peter Walker, saying something along the lines of
Inspecting and comparing construction and design I expect the "Audiostatic ES300R" sounds better.
I think the "Quad ESL 63" is designed with compromise of sound quality to benefit:
The "Column Speakers" effect is rather wonderful, I had not expected to like it as much as I do. Standing up with the "Quad ESL 63" changes the sound balance which is horrid. The "Audiostatic ES300R" is a "Column Speakers" and so when you stand up the sound feels like it stood up too. Problem with Column Speakers, is they have to be almost from floor to cealing, or thier magic deminishes, and that means a tower in the living room.
The "Quad ESL 63" beats out the "Audiostatic ES300R" in:
I think the "Audiostatic ES300R" and the "Quad ESL 63" took different compromises in design.
Inspecting and comparing construction and design I expect the "Audiostatic ES300R" sounds better.
I think the "Quad ESL 63" is designed with compromise of sound quality to benefit:
- Reliability
- Repeatably
The "Column Speakers" effect is rather wonderful, I had not expected to like it as much as I do. Standing up with the "Quad ESL 63" changes the sound balance which is horrid. The "Audiostatic ES300R" is a "Column Speakers" and so when you stand up the sound feels like it stood up too. Problem with Column Speakers, is they have to be almost from floor to cealing, or thier magic deminishes, and that means a tower in the living room.
The "Quad ESL 63" beats out the "Audiostatic ES300R" in:
- Serviceability
- Health reporting
- Plug sockets for power (USA version is fine I have read): A fixed length of mains cable into grommet in a box marked "dangerous! might kill you or your children" is just not ergonomic.
- Add a 1 Euro "Neon bulb" between the diaphragm and the voltage doubler the charges it. This will light up when ever it delivers about 70 Volts. This also give a fair warning about the health of your speakers. So 1 Euro to avoid the common "the transformer was likely killed by overdriving them" problem maudio reports.
I think the "Audiostatic ES300R" and the "Quad ESL 63" took different compromises in design.
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This graph tlooks reasonable as the vertical scale is very compressed. It stills rolls off after 15 kHz like the Stereophile measurement. Maybe yours are slightly better, I have to look up the Stereophile measurement
The Quad uses a practically uninsulated stator design, therefore it depends on the insulating properties of the air to prevent arcing. That makes such a protection circuit a necessity.
An insulated wire design such as Audiostatic (and most diy designs) uses, offers much better insulation due to the excellent insulation properties of pvc. That almost completely eliminates the risk of arcing so these designs have no need for a protection circuit.
In fact, when overdriving an Audiostatic the transformer insulation will fail before the panel will arc. As you found out already...
To the topicstarter; sometimes they offer srcond hand transformers. Currently on the site 'marktplaats'. I guess audiostatic uses the same 1:75 transformer so if they are from an ES100 (like the ones on marktplaats) they should be fine in the ES300 as well. . Bass auto transformers are rarely offered so I hope that it needs no replacement
I noticed them too:
https://www.marktplaats.nl/v/audio-...84293-trafos-voor-audiostatic-esh-200-step-up
https://www.marktplaats.nl/v/audio-...m2180383551-audiostatic-es-100-trafos-2-stuks
But I believe these are from very early Audiostatic models en I don't thnk they are identical to the later ES100/200/300 series transformers. The tranformers in the first ad (ESH200) have a different pin-out spacing. The second one (ES100) seems to have a center tap on one of the windings,
I do know all later ES100/200/300 R/RS/S models use identical transformers, although some series have impregnated coils and some don't.
https://www.marktplaats.nl/v/audio-...84293-trafos-voor-audiostatic-esh-200-step-up
https://www.marktplaats.nl/v/audio-...m2180383551-audiostatic-es-100-trafos-2-stuks
But I believe these are from very early Audiostatic models en I don't thnk they are identical to the later ES100/200/300 series transformers. The tranformers in the first ad (ESH200) have a different pin-out spacing. The second one (ES100) seems to have a center tap on one of the windings,
I do know all later ES100/200/300 R/RS/S models use identical transformers, although some series have impregnated coils and some don't.
Such a neon oscillator gives an indication of the amount of charge current flowing to the panel, which is a good indicator of the amount of leakage of the panel.
However when the coating degrades and loses conductivity, the panel will not leak more and therefore such a neon indicator will not warn you for a bad coating. Better keep an eye on the volume setting.
I think the "Neon bulb" between the diaphragm and the voltage doubler the charges it, provides great benefit on my Quad ESL 63's and I fitted them to my home made headphones. You have an interesting worry that the coating degrading would make this useless maudio.
My experience with Quad 57's and 63's is that the coating does not really degrade? Am I just lucky? Even if the coating did degrade, would it not degrade slower than dirt build up (Causing excessive leakage) in a electrostatic without dust covers like Quads have?
Should I expect Lycron or similar anti static coatings to degrade?
I will hunt down my spare "neon bulb" in my spares and see if it suggests the Audio Static panels need fixing (which they most definitely do).
My other experiment with the workingish audiostatic speaker is if using two transformers to make an isolation transformer can prevent the audiostatic speaker causing clicks to pass via the amp the Kef speaker.
Do not hold your breath waiting though, I have children and may get a new job soon.
My experience with Quad 57's and 63's is that the coating does not really degrade? Am I just lucky? Even if the coating did degrade, would it not degrade slower than dirt build up (Causing excessive leakage) in a electrostatic without dust covers like Quads have?
Should I expect Lycron or similar anti static coatings to degrade?
I will hunt down my spare "neon bulb" in my spares and see if it suggests the Audio Static panels need fixing (which they most definitely do).
My other experiment with the workingish audiostatic speaker is if using two transformers to make an isolation transformer can prevent the audiostatic speaker causing clicks to pass via the amp the Kef speaker.
Do not hold your breath waiting though, I have children and may get a new job soon.
Simply reversing the mains connection can also improve things in case of audiostatics suffering from hum and clicks.
All audiostatics, if never refurbished, will need new Mylar sheets. Not a shame as these speakers will be probably decades old.
All audiostatics, if never refurbished, will need new Mylar sheets. Not a shame as these speakers will be probably decades old.
The original coatings used by Quad on the 63 and later models is indeed very stable, degradation is usually not an issue. Not before they die from other problems 🤣 On older Quads the glue that holds the stator plates degrades, causing the plates to bend towards the membrane, which causes arcing and destroys the membrane. The later Quads suffer from something called membrane rot, that causes the membranes to tear spontaneously.
On Audiostatics it is mainly the original coating that degrades and causes problems, how long it lasts depends on the conditions, levels of air pollution etc. The coating looses conductivity and due to the open construction membranes collect dirt over the years which does not help either.
I also noted that mylar tends to get brittle over time, not only on Audiostatics but on all ESL's. Could be related to ozone production, don't know for sure. I do not think that is really a problem, not until the membrane gets so brittle it tears. But the difference between the eleasticity of an old and a new membrane is quite noticabe. Anyway, I think it's fair to say all ESL's will benefit from fresh mylar and coating every 10 or 20 years.
If reversing the mains plug does not fix the clicks, try an isolation transformer. I use them as well. The transformers can be as small as 1.5VA as power consumption is almost zero. But clicks usually indicate some kind of arcing somewhere. Does not have to be visible arcing, could be a bad hv connection on the membrane, dirty panels or bad coating as well.
On Audiostatics it is mainly the original coating that degrades and causes problems, how long it lasts depends on the conditions, levels of air pollution etc. The coating looses conductivity and due to the open construction membranes collect dirt over the years which does not help either.
I also noted that mylar tends to get brittle over time, not only on Audiostatics but on all ESL's. Could be related to ozone production, don't know for sure. I do not think that is really a problem, not until the membrane gets so brittle it tears. But the difference between the eleasticity of an old and a new membrane is quite noticabe. Anyway, I think it's fair to say all ESL's will benefit from fresh mylar and coating every 10 or 20 years.
If reversing the mains plug does not fix the clicks, try an isolation transformer. I use them as well. The transformers can be as small as 1.5VA as power consumption is almost zero. But clicks usually indicate some kind of arcing somewhere. Does not have to be visible arcing, could be a bad hv connection on the membrane, dirty panels or bad coating as well.