[analogsurviver]

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.

It might be that the dreaded driver connectors/connections ( they are not soldered but rely on mechanical contact ) have oxydized on the way from Germany to you, performed as described at your place, on the back journey to its maker sustained some vibration in the plane, just enough to dislodge the oxyde layer - voila, both you and QUAD Germany could be perfectly right and truthful in the claims
 
Which does not provide one bit of a relief for the manufacturer. That connection should have been changed - AGES ago.

 

[songmic]

  It might be that the dreaded driver connectors/connections ( they are not soldered but rely on mechanical contact ) have oxydized on the way from Germany to you, performed as described at your place, on the back journey to its maker sustained some vibration in the plane, just enough to dislodge the oxyde layer - voila, both you and QUAD Germany could be perfectly right and truthful in the claims
 
Which does not provide one bit of a relief for the manufacturer. That connection should have been changed - AGES ago.

 
Sounds somewhat too convenient to be true, but still a better guess than mine.

 

[analogsurviver]

   
Sounds somewhat too convenient to be true, but still a better guess than mine.

The problem with any electronic gear is basically either lack or excess of contact(s). Any gear should have been field tested prior going into "large" scale production. With Float being around nearly four decades, such teething troubles should have been eliminated years ( here I REALLY miss the past possibility with crossed over letters/words ) DECADES ago. 
 
How on earth will copper contact on the driver itself react to steel head of basically nail if not by electrolytic reaction due to potential differences? Add to that kilovolt voltage swings, humidity, oxygen - you get the picture. I used to clean friend's Floats contacts on average every three months, or there was intermittent sound, crackling noise, etc - sounds familiar ?

 

[spritzer]

The bias issues I was talking about can be any number of things, bad contact due to corrosion, the bias supply not working as it should, a parasitic charge(s) sitting on the diaphragm(s) and impeding it's(their) charge/movement or the bias leaking due to a short somewhere in the assembly.  The small change in the input voltage into the bias supply is not a likely problem as it is a very simple affair and just outputs a multiple of what is input.  All of the issues can be miraculously cured simply by shipping the set as people are finding out with their Stax SR-009's.  Still there is an underlying cause so I wouldn't settle for anything but a new unit being sent out. 
 
The amplifier used also has no bearing on this, you can use a 2W unit and get some sound out of them as all you need is voltage swing, very little current.  The load presented to the amp is also managed so that further improves matters.  Also I don't think a high DC potential on the amp output is a cause as it would first of all blow up any speakers connected to the amp and secondly DC doesn't pass through transformers even if it can make the primary rather toasty.  The only possible issue is the use of a bridged amplifier as the shared return inside the Float adapter will make it blow up or enter protection mode if it has one. 
 
In a last ditch effort these could always be tested on an old Jecklin transformer unit or even a Stax SRD-7 though the volume level won't be very high. 

 

[maximuslt]

 what should I do? 

 

 
You had to take your kit and listen to it from a friend on his amplifier.

 

[analogsurviver]

  The bias issues I was talking about can be any number of things, bad contact due to corrosion, the bias supply not working as it should, a parasitic charge(s) sitting on the diaphragm(s) and impeding it's(their) charge/movement or the bias leaking due to a short somewhere in the assembly.  The small change in the input voltage into the bias supply is not a likely problem as it is a very simple affair and just outputs a multiple of what is input.  All of the issues can be miraculously cured simply by shipping the set as people are finding out with their Stax SR-009's.  Still there is an underlying cause so I wouldn't settle for anything but a new unit being sent out. 
 
The amplifier used also has no bearing on this, you can use a 2W unit and get some sound out of them as all you need is voltage swing, very little current.  The load presented to the amp is also managed so that further improves matters.  Also I don't think a high DC potential on the amp output is a cause as it would first of all blow up any speakers connected to the amp and secondly DC doesn't pass through transformers even if it can make the primary rather toasty.  The only possible issue is the use of a bridged amplifier as the shared return inside the Float adapter will make it blow up or enter protection mode if it has one. 
 
In a last ditch effort these could always be tested on an old Jecklin transformer unit or even a Stax SRD-7 though the volume level won't be very high. 

All of the above is true.
 
ESLs can be tricky. I never got to hear the Jecklin PS2 in a certain shop in Germany. HEAVILY discounted - but after trying like fifth or sixth pair , I pretty much understood why soooo low price. None would take charge, producing typical low sound level with no bias applied. We tried all combinations of available HPs and transformer boxes - no luck.
 
Commercial drivers have to use some kind of conductive material on the surface of the plastic fim that is electrically extremely good isolator. This thin layer of conductive material is quite important from the reliability point of view.
 
However, if one frees him/herself of dust covers and other impediments, necessary for reliability/safety to which commercially available ES product must adhere, that conductive layer no longer is absolutely necessary. All what is necessary for the size of the driver(s) used in headphones/earspeakers ( up to and not appreciably above the size of the Jecklin driver ) is gently breathing on the surface of the driver - depending on the construction, it can be on biased or unbiased driver. Humididity left after breath lowers the surface resistance of the film low enough  for the charge normally to spread uniformly  - and if and when it "starts", it also remains there up to the powering the bias/amp down.
 
This method offers least mass and therefore best performance - but for obvious reasons can not be used in a commercial product. I mentioned it so that mechanisms of "ESL now working/now not" are better understood.
 
Resistances with which ESLs work are so high that the only reliable method to measure them is using electrostatic meters - everything else has too low input impedance and will appreciably alter the real value. The higher the resistance, the higher the time constant that defines low frequency corner electrically - and more "rectified" and constant bias voltage, which again contributes to better performance. 
 
My Stax Lambda Pro may well need new - ahem - "everything" BUT the drivers. As I read, there were some issues with Stax after say 1985 ( ? ), but drivers of this pair is still going strong as on day one. It takes some time for the manufacturers to figure out something that not only works well new, but has some staying power as well. Only experience and time can tell the true story.

 

[Hun7er]

Hello,
 
I hesitate to buy this headphone. Can I connect it directly to my speaker amplifier ?

 

[wink]

No....

 

[maximuslt]

It is better to wait until they release their amplifier and not to put experiments

 

[shipsupt]

A recent email I got from Manfred indicates they are ready to sell their amplifier now.  I don't see anything on the web site, but he sent me information. 

 

[complin]

Is he still quoting prices of Euro 3000 +?
 
Quote:

  A recent email I got from Manfred indicates they are ready to sell their amplifier now.  I don't see anything on the web site, but he sent me information. 

 

[shipsupt]

There are two active amp offered, one for 2495, and one for 3595.  
 
Here is the google translation,  I wish it were better:
 
The FLOAT QA always forms a unit with a power supply module ( power supply ) , which is required for operation. There are 3 different edible parts. So that the system can be tailored to a specific requirement.
1)
FLOAT QA power supply :
passive power supply module for connection to an existing amplifier. The edible part provides an interface for 2 sockets FLOAT QA headphones and a pair of passive speakers . Price: 1395 , - €
2)
FLOAT QA active power supply :
actives food supply with integrated power amplifier for use with controlled high- level connection ( precursor , D / A converter). The edible part provides an interface for 2 sockets FLOAT QA headphones and a pair of passive speakers .
Price: 2495, - €
3)
FLOAT QA power supply actice , Transdyn :
actives food supply with integrated power amplifier and built-in preamp incl Transdynschaltung for use in unregulated high-level signal . The edible part provides an interface for 1 FLOAT QA headphones and a pair of passive speakers.
The Transdynschaltung is quite an amazing circuit in the potential volume and dynamics of large concert halls are " living space just" transformed with their help. In certain Transdyn replaces the missing visual perception of the home musician.
Price: 3595 , - €

 

[spritzer]

Given the gigantic markup on the transformer box I'm suspicious about the amps or rather how cheap they are.  They will have all the same guts as the stock box but add a full amplifier for 1000€?  Some off the shelf chipamp? 

 

[shipsupt]

Maybe something form the old Quad stuff... but certainly a chip amp of some kind.

 

[complin]

I have been in conversation with Manfred Stein the owner of Quad in Germany about his new amplifiers for the Float QA. I assumed that they would have a native bias supply driven directly from the integrated amplifier. However he says that in his opinion the Float QA still needs the step up transformers to perform correctly. So his new amplifiers just drive the original step up transformers but are integrated into a single box!
 
Andreas Rauenbuehler in Germany http://www.high-amp.de/html/frame.html has designed a dedicated amplifier which will drive both stax and the Jecklin Float. Below is a copy of the schematic for his 1200/100 volt bias supply
 

©Copyright Andreas Rauenbuehler​

 
 
Quote:

  Given the gigantic markup on the transformer box I'm suspicious about the amps or rather how cheap they are.  They will have all the same guts as the stock box but add a full amplifier for 1000€?  Some off the shelf chipamp?