calling in ESL expert

[etalon90]

HI everyone

I just got my hand on a pair of audiostatic wing esl

I'm currently investigating the interface and I'm wondering a possible rebuild option

the current setup use 2 step up transformer each feeding one stator.

the stator is electrically segregated in 2 parts.
20-4-20. 44 wires in total with the middle 4 having a separate stator wire.
the middle 4 wire are feed by the transformer sec via a 57kohm resistor (few in serie)
the 2 set of outer wire are feed by the same transformer sec via another resistor string of 162Kohms.

I understand that the segregated section are there to compensate for the ob step loss and provide an effective EQ thru RC coupling, since the primary are fed directly from the amplifier via a serial resistor.

what if I rewire the stator in 3 parts
let say 12-8-4-8-12.
feeding resistor could be 162k,100k and 57K
would that be a good idea?

Also, Is anybody try to bypass the primary serial resistor?
I wonder if theses alter the sound or are there only to prevent the load impedance to become too low at high frequency


thanks for inputs.

[bear]

pix?

brand?

hard to know without more info...

_-_-bear

Edit: oh Audiostatic?? then, Model??

[Calvin]

Hi,

sounds like the Audiostatic ES100 or the ES50.
Of course can You fudge with the segmentation. In this case it might give a slightly smoother or more even dispersion character and a differing amplitude response.
The primary serial resistor functions as part of the HF-response shaping network, of which the serial secondary side resistor is the other part.
Additionally it functions as kind of safety mechanism, because for very low frequencies and DC the transformers alone are close to a shortcut for the amplifier.
At third it is way more safe and convenient to shape the HF-response of the speaker at the primary side using lowvoltage parts, instead of HV-secondary side parts. So, Yes, You may omit with the primary resistor, but there are well grounded reasons not to do so.

jauu
Calvin

[etalon90]

Thanks Calvin for info.
I'll try to segemnt the stator and play a little.
I'll leave the primary resistor a there but will try to fine tune it later when the stator are rewired.

another question for you Calvin. Given that I use SS amplification, would it be a good idea to omit the impedance correction network.
it's a simple serial RLC connected in parallel with the input terminal of the speaker. (I didn't check the value yet)


Bear, I'll come with schematic/or picture a bit later this week (it may only be Easter before I really invest time in theses.
in the meantime, here the ad.
http://www.divertech.com/audiostatic.html
and the schematic of the smaller model
http://www.quadesl.com/pdf/es50_schem.pdf

Mine have no input cap.
the 47K are changed to 162K for feeding the sides
and one 57K feed the middle instead of a straight wire.



Martin