Here's a question on the Bias voltage. I "accidentally" got a Bertan negative-going high voltage supply from Ebay. That means that it has a GROUND which is positive with respect to the 580 volt bias. @kevin gilmoresaid to make sure it's the "positive" model, so, my mistake. HOWEVER, it seems to me that the only difference between negative 580 volts and positive 580 volts is that the absolute polarity of the acoustic outpuf of the headphone will be inverted. Ironically, I proved that Stax AND Audeze CRBN produce inverted acoustic polarity than the + and - markings on the Stax 5 pin plug! I also have not been able to hear any difference between normal or inverted polarity. Consider that the device is 100% bilaterally symmetrical*. And that's my point. For what reason would Kevin have insisted on getting a +580 volt bias voltage? Personally I can't think of anything that a negative bias would produce other than to invert the acoustic signal from the headphones. And that's easily corrected by inverting the audio wires from the transformer secondary or the active amplifier. Besides, as I mentioned, Stax and Audeze CRBNs have been acoustically inverting from the get go, and no one, no where, no how, has ever noticed that!

* which explains why, conceivably, moving coil and planar magnetic devices might sound different when inverting absolute polarity, as they are not, typically, bilaterally symmetrical in design. 

Edited August 9, 20232 yr by bobkatz

nope, you cannot use this. reverse bias and the diaphram accumulates all the dust particles. a month later and your headphones are trash.

Indeed, the bias has to be + polarity for that reason. 

On 8/9/2023 at 4:45 PM, kevin gilmore said:

nope, you cannot use this. reverse bias and the diaphram accumulates all the dust particles. a month later and your headphones are trash.

Thanks very much! Well, for sure I won't do that!

Slight necrobump!

ZL01-ZL04 are not zeners. They're MOVs. Fujitsu ENB461M-03. 

 

CASEC_ENBXXXM_03A.PDF