[jecklin_freak]

I heard that there was built a tube headphone amplifier for the Jecklin Float by Friedrich Dürrenmatt. Has anybodoy more information about this amplifier?

 

[Duggeh]

I've got a few pictures from an auction of one more than a year ago, but I can't help you with any technical information. Thing is that this has the Ergo name on it, not Jecklin, but it follows the Jecklin red colour scheme, the Ergo scheme is blue.

 

[spritzer]

I've only seen some pictures which show the circuit board (through the perforated top) but very little detail. From what I could make out was a tube output stage with a SS front end. It's tiny and with no heatsinking so I have no doubt that it will not provide the power needed to push the Floats. The tubes used look like small B9 types and there are no options there that I'm aware of that can take anything close to the voltage needed let alone generate the current those massive panels need.

The Jecklin transformers work at a much higher ratio then the Stax units so that means more voltage in top of the 1kV+ bias. A Blue Hawaii will be able to drive them though better then anything else out there let alone if you go all crazy on use and fit it with +/-900v power supplies which means it can swing well in excess of 3000V. The EL34's will have to go but I do know of a tube that is perfect for the job... and I have a quad.

 

[jecklin_freak]

Hello spritzer,
thks for your answer. I think the Jecklin works with +- 850 Volts. So what will be your solution for a tube amp? Is it worth for buying one? Next week I will buy a modifitcadet PS1 with the trafo of the last PS2. That will help a lot of the bass qualitiy of the floats. At the moment I only have the PS0 and I think the change will bring a lot to me.
The sound of the Floats is normally warm from nature. So will the "tube sound" really fit?

 

[spritzer]

Now if your were to find one and post some detailed pics with the top off then I'm all for that.

Designing an amp for electrostatic headphones isn't easy though as it needs to be able to not only swing a lot of voltage but also supply ample current so that the voltage doesn't "sag" once the impedance drops into the treble and bass.

As for the different versions of the Floats, there were a lot of changes underneath the skin including different drivers and very different bias voltages. Jurg even used a - charged bias supply on the PS0 which nobody does (since it is not a good idea) so it was changed on the later models. That said the change in bias doesn't matter all that much once you cross the 1kV barrier since it rises with the square of the diaphragm/stator distance.

The standard tube "sound" has very little to do with the tubes but the components that are around them. Most tube amps use capacitors and transformers in the signal path coupled to very simple power supplies since this is the easy way to do it. A well designed tube amp is just as neutral as any SS amp but far more linear. I would contribute most of the warm sound of the Floats on the housing as that is a huge weakness. The plastic is flimsy and the drivers aren't even properly secured. That's why I was so looking forward to the Purtscheller phones as they might fix that tragic weakness.

 

[dub]

I just found and bought this Ergo Tube Amp for my Float — it sounds very well