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New Jecklin Float QA !!! - Page 41

post #601 of 663

Still better than a transformer box though

Quad in Germany as rumoured to be developing two amplifiers which should drive both the old and new float but sound quite expensive. 

 

Quote:

Originally Posted by spritzer View Post
 

Only one amplifier is compatible with the Floats and that is the old Ergo amp.  It's not something I'd recommend though...  

post #602 of 663

What's the bias voltage/spacer thickness on these?  Also, any pictures of the connectors?

post #603 of 663

 

 

 

I believe you're talking about 1200V bias, but better for someone in the know to confirm that.


Edited by shipsupt - 10/9/13 at 2:27pm
post #604 of 663

Thanks!  Who's pics are those?

 

The shell of the connectors looks a lot like the HE90's.  Are these Stax compatible in pin configuration and spacing?

post #605 of 663

Those are from Quad's site.  I'm not home to take a picture of it, but that's just what it looks like.  Definitely not STAX jack compatible.  Much smaller diameter.

 

I should add that it's built quite nicely and functions well.  If I had to consider a STAX alternative I'd consider trying to source them.  I'm making the big assumption here that they are rated properly for the high voltages they carry.


Edited by shipsupt - 10/9/13 at 2:33pm
post #606 of 663

Those plugs could be Lemo and with PEEK inserts have high voltage potential. 

 

Quote:

Originally Posted by complin View Post
 

Still better than a transformer box though

Quad in Germany as rumoured to be developing two amplifiers which should drive both the old and new float but sound quite expensive. 

 

Far from it actually.  The amp is horrible, two sections of an ECC81 driven in pseudo SRPP (SRPP can never work for electrostatics) and at +900V violating pretty much every rating for the tube.  Then we have the input stage which drifts like mad. 

 

Quote:
Originally Posted by n3rdling View Post
 

What's the bias voltage/spacer thickness on these?  Also, any pictures of the connectors?

 

The Jecklin's varied in bias from 1200-1500V but the PS2 was +1200V.  The Ergo amp was made for the PS2 and it has a 1500V bias tap so that might be the desired bias or just a trick to make the amp behave. 

post #607 of 663
So what amps are people using with the new Floats?
post #608 of 663

Do you mean to drive the power supply?

post #609 of 663
Quote:
Originally Posted by spritzer View Post
 

 

Far from it actually.  The amp is horrible, two sections of an ECC81 driven in pseudo SRPP (SRPP can never work for electrostatics) and at +900V violating pretty much every rating for the tube.  Then we have the input stage which drifts like mad. 

 

 

The Jecklin's varied in bias from 1200-1500V but the PS2 was +1200V.  The Ergo amp was made for the PS2 and it has a 1500V bias tap so that might be the desired bias or just a trick to make the amp behave. 

Bias on Floats is 1200 - 1500 V depending on box that came with it. Spacer thickness is at  least 0.8 mm - or more. Not only bias, but drive voltage has to be considerably larger than for any Stax model - no Stax amp, even if bias is increased to required value, can not provide voltage swing necessary. I do not know capabilities of KGSSHV, Blue Hawai, etc - but it is unlikely to be really enough to drive Floats properly.

 

+900 V supply for the amplifier driving Floats is way too low - disregarding any instability and/or elements driven to the very limit of safe operation. If transformer boxes are meaured, you will arrive at about 3 kV peak to peak - which roughly equals 1 kV RMS. For this an B+ of at least 1500 V is required, leaving for all practical purposes only tubes as possible output devices. ESL amps are basically horizontal deflection amplifier for cathode ray tubes of  (colour) TVs. The necessary high voltage parts are ever more scarce since TVs became pancakes. 

post #610 of 663
Quote:
Originally Posted by shipsupt View Post

Do you mean to drive the power supply?
.... Yes? Clearly I am missing something here. So is the power supply the amp?
post #611 of 663
Quote:
Originally Posted by Audio Jester View Post


.... Yes? Clearly I am missing something here. So is the power supply the amp?

 

No, you have the right idea. You hook the box up to an amp with speaker taps.

 

FWIW, I was impressed with the sound even using a $30 T-amp...

post #612 of 663

The power supply is just two components, a bias supply which is simply a voltage multiplier run off the mains and two transformers used to step up the input voltage from a power amp to the right level. 

 

Quote:

Originally Posted by analogsurviver View Post
 

Bias on Floats is 1200 - 1500 V depending on box that came with it. Spacer thickness is at  least 0.8 mm - or more. Not only bias, but drive voltage has to be considerably larger than for any Stax model - no Stax amp, even if bias is increased to required value, can not provide voltage swing necessary. I do not know capabilities of KGSSHV, Blue Hawai, etc - but it is unlikely to be really enough to drive Floats properly.

 

+900 V supply for the amplifier driving Floats is way too low - disregarding any instability and/or elements driven to the very limit of safe operation. If transformer boxes are meaured, you will arrive at about 3 kV peak to peak - which roughly equals 1 kV RMS. For this an B+ of at least 1500 V is required, leaving for all practical purposes only tubes as possible output devices. ESL amps are basically horizontal deflection amplifier for cathode ray tubes of  (colour) TVs. The necessary high voltage parts are ever more scarce since TVs became pancakes. 

 

The transformers on the Floats are between 1:60 and 1:120 but they are overkill.  Same thing for Stax though at 1:25-1:30.  We have a SS amp design which can swing just about 3000Vp-p and it will have no problem driving the Floats.  KGSSHV will be able to drive them too but it will require some mods given the different load. 

post #613 of 663
Quote:
Originally Posted by spritzer View Post
 

 

The transformers on the Floats are between 1:60 and 1:120 but they are overkill.  Same thing for Stax though at 1:25-1:30.  We have a SS amp design which can swing just about 3000Vp-p and it will have no problem driving the Floats.  KGSSHV will be able to drive them too but it will require some mods given the different load. 

 

Well, I returned my Float QA to QUAD in Germany, but they told me that there is absolutely nothing wrong with it. They said my Float QA works perfectly, without any of the issues I described. This is very strange, because I tried my Float QA not only at home but at various audio stores in Seoul, with completely different amps and setups, and the Float QA posed the same crackling noise problem. You told me this could have been a bias issue, but could bias issue appear and disappear like this?

 

On a side note, I found another guy in Seoul who owns the Float QA through the Korean headphile community, so I asked him if I could come over to his house and have a quick listen. His Float QA sounded spectacular, although he was using an inexpensive amp with it.

post #614 of 663

Your issues sound similar to the ones I was having. Did you send in your headphones or the power supply?

 

There was nothing wrong with my headphones, but the power supply itself had a faulty connection. When they replaced the power supply everything was fine.

post #615 of 663
Quote:
Originally Posted by MuppetFace View Post

Your issues sound similar to the ones I was having. Did you send in your headphones or the power supply?

There was nothing wrong with my headphones, but the power supply itself had a faulty connection. When they replaced the power supply everything was fine.

I sent both my headphone and power supply back to them. However, yesterday they told me that they found absolutely nothing wrong with my Float QA, both headphones and the power supply. According to them, my Float QA is working perfectly. I really don't get it, the Float QA was very problematic when I tested it, not only with my home audio system but also at local audio stores using 4 different amps, and there was always that cracking noise.

Also, I read what your problem was, but I think my problem is different from yours. The crackling noise was the only problem you had, otherwise you found it to be a very good sounding headphone. For my Float QA, the crackling noise was very much apparent and the sound became extremely distorted, making listening absolutely unbearable. On top of that, my Float QA's volume was low, and I couldn't get it to sound satisfactorily loud enough even with my 70W Pathos Classic One amp. Moreover, the soundstage was cramped.

Because of the distortion, it honestly sounded much worse and unbearable to listen than an iBud. It sounded nothing at all like the normal, perfectly working Float QA I listened to at another headphile's house, although he was using a much cheaper amp.

I have no idea why QUAD is saying it works perfectly, while it sounds disastrous with 4 completely different setups and amps I tried in Korea. I even recorded the sound coming out of the Float QA with my iPhone and sent the recorded file to them to prove my point. Right now, I'm very worried that QUAD might keep on insisting there's nothing wrong with my Float QA, and just send it back to me the way it was without repairing anything.
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