Jecklin Float Electrostatic troubleshooting

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I just got my hands on a pair of Jecklin Float Two Electrostatic with Jecklin PS2 "Energizer".
The condition is fairly good. The PS2 looks great, but the headphones require some refurbishing. The foam has to be replaced etc.

There is also something wrong with them. I have no experience with electrostatic speakers, so this is quite new to me.
I have connected the PS2 to a Inter-M R600 amplifier, and the headphone actually produces sound, but the level is very low and the sound is a bit distorted. Especially at low frequencies.

There seem to be no change in sound is I disconnect the mains power to the PS2. Yes, this means that I get sound also with the PS2 unpowered. Maybe this is normal, but I kind of thought bias supply was needed to get any sound at all.

The PS2 circuit board is in very good condition. I resoldered all the components, and the wiring between the circuit board and the connectors.

The two connectors by the way; why are there two of them? I noticed that on one of them, bias voltage to both speakers are wired through one 10Mohm resistor, while on the other bias was wired to separate 10Mohm resistors.

Anyway, I believe that the bad sound I'm getting would be caused by some error in the bias supply. Either in the PS2, the wiring, or maybe with the speakers. Would be very happy for some input/ideas on this.
I did not find any schematics for the PS2 so I reverse engineered it (it's very simple). Because of the extremely high output impedance, it's quite hard to measure the bias voltage.

I have tried to find manuals etc. for the headphones and PS2 but without success. If anyone happens to have these, I would be very happy to get them emailed.

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Disassembled the headphones. They need a really good cleaning! There were lots of small pieces of foam stuck to the plastic sheets (only covers?) on each side of the speakers. I cleaned them quite well. Could do better, bust just for a quick test.
Not very surprisingly they sound much better now, but still not perfect. I also feel I have to turn the volume up quite high, but maybe that is normal.

When playing Way down deep by Jennifer Warnes, the bass drum sounds very distorted.
Could "bad" bias voltage be a cause of that?
 
Could "bad" bias voltage be a cause of that?

Yes, probably there is no HV. Check all the components, at least one is bad. If you can measure 220VAC across the input before the caps,
then I'd next check the diode D1 between the two 0.047uF caps, it may be bad. Next check all the other diodes, they should be similar.
If those seem ok, then look for bad resistors.
 
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I have checked all diodes and resistors. They are OK.

I'm beginning to think that the bias voltage is OK. I have to get some really high value resistors to be able to measure it. I also read that the PS2 will go into "auto-bias mode" if the mains power is disconnected. I guess that's why they work without mains.

It seems like they require much more power to drive than I initially thought. Using my tube amp is probably out of the question (KT88 PP, no feedback). Especially since the impedance of the PS2 seems to be very low and would not work well with the output transformers.

My theory at the moment is that all they need is a really good cleaning. I also emailed Quad Music (Germany) to get a price for replacement foam. According to their website (HOME) they have complete sets including adhesive.
 
If you are sure that the energizer is alright, then you should have a look at the diaphragm. Overtime, the coating on the diaphragm can deteriorate. In that case it would take a long time for the diaphragm to charge up properly. You might want to try to charge your headphones with your energizer for a few hours and try to listen to them again. If the sound gets much louder, the coating on your diaphragm might need recoating.

By the way, can you show me your headphones? I make a similar version of my own. 🙂

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Wachara C.
 
Not just coating gone ? If you have a multimeter which can measure resistance of 200 meg or more you should be able to measure some resistance. Use 2 coins placed in the membrane close to each other to not pierce the foil. But this would need you do disassemble the panel itself. Might be tricky if it's glued. You could destroy the foil.
 
Recoating might be the way. I left them plugged in as recommended and I believe the sound quality got better. They also got a bit louder.

Does anyone know the impedance of these, measured on the inputs of the PS2?
Could of course measure it myself... 🙂

chinsettawong: Nice project you got there. I scanned through your images on Photobucket. Seems like you have a lot going on.

I have built the turntable, tube amp and RIAA myself. D/A is a hybrid (partially built/modified by me). The speakers are a pair of old Rauna Njord (have a pair of KEF iQ70 too). I have kind of decided to stay out of the speaker building area but who knows what might happen. =)
 
Haha, thank you Roger. If you happen to live close to Gävle/Sandviken I really recommend you to visit Speed Weekend on Ice which is arranged at the end of February.
Check out :: Landracing.se :: for more info.

Regarding the Floats. Initially, I connected the Floats to my PA amp (Inter-M R600 Plus). I believe this is considered a very good amplifier, and some even use them as main amp in their HiFi setup. I use it when I need more power and/or do not want to burn out the tubes in my tube amp, or when I need something slightly more portable/robust than a 37kg tube amp. 🙂
The Floats sounds great with this amp, but of course I wanted to try them out with the tube amp.

My tube amp is designed/built by me, and uses two pairs of triode coupled KT88 in push-pull configuration (Siemens c3g for phase splitter and pre-amp). Also, it has no negative feedback, which works very well with by current speakers (Rauna Njord and KEF iQ70).
It sounds way better than the Inter-M amp with these speakers.
The Jecklins sounded really bad though, and I think I understand why now. I measured the impedance of the input to the PS2 "energizer" box and would not really consider the results optimal (impedance is the dark green line, phase is the light green one)...

By the way, I ordered a foam kit, including "special" adhesive from Quad-Musik.de. 44€ including shipping to Sweden.
 

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Haha, thank you Roger. If you happen to live close to Gävle/Sandviken I really recommend you to visit Speed Weekend on Ice which is arranged at the end of February.
Check out :: Landracing.se :: for more info.

Regarding the Floats. Initially, I connected the Floats to my PA amp (Inter-M R600 Plus). I believe this is considered a very good amplifier, and some even use them as main amp in their HiFi setup. I use it when I need more power and/or do not want to burn out the tubes in my tube amp, or when I need something slightly more portable/robust than a 37kg tube amp. 🙂
The Floats sounds great with this amp, but of course I wanted to try them out with the tube amp.

My tube amp is designed/built by me, and uses two pairs of triode coupled KT88 in push-pull configuration (Siemens c3g for phase splitter and pre-amp). Also, it has no negative feedback, which works very well with by current speakers (Rauna Njord and KEF iQ70).
It sounds way better than the Inter-M amp with these speakers.
The Jecklins sounded really bad though, and I think I understand why now. I measured the impedance of the input to the PS2 "energizer" box and would not really consider the results optimal (impedance is the dark green line, phase is the light green one)...

By the way, I ordered a foam kit, including "special" adhesive from Quad-Musik.de. 44€ including shipping to Sweden.

I know I am late -but I owned a JJ Float plus PS2 and what you describe happened to me several times. What you need to know is

a) JJ Float has NO auto-bias. EG if the HV is missing, you do almost get no sound and and the sound (with high output from the amp) is utterly distorted since the diaphragm operates outside of linearity

b) PS 2 has broken down at my home always as a consequence of high input AC voltage (induced by the grid) such as after a thunderstom

c) I have after some time asked what they had to replace and the answer was that the diode was gone

So if somebody has a problem - check the HV circuit
 
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:cop:

Miko... I've taken the unusual step of removing the link from your post as it was both non functional and also corrupting the page formatting.

If you want to repost just the link/image again and if it works OK then we can insert it back into the post.
 
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