[Swampwalker]

Ok folks, sorry if this is an obvious question, but I do not have a very strong electronic background like many of you folks. I have a pair of Stax Lambda Pros that I am presently driving w/a Berning Microzotl tube amp via an SRD-7 Pro adapter. Now the question is, am I wrong in thinking that the microzotl provides the current and voltage amplification of the line level signal from the CDP (CAL CL-10) and then the SRD-7 provides the energizing (high) voltage for the diaphragms in the Lambdas? If so, does the SRD-7 have much of an effect on the sound? Now i am thinking that I should probably upgrade the wires that take the speaker level output from the micro, but other than that, will I really see a big improvement going to a more modern Stax amplifier? The micro is a great amp and does triple duty right now, driving the STAX, HD-600s and a pair of Sequerra monitors I bought from Orpheus (they are awesome, dude, you were right!!). BTW, my tastes do not go to ear-bleed volumes, orchestral stuff, or head-banging metal. The micro has some real nice NOS Tele ECC81s and Sylvania Chrome Dome 6SN7s. The sound is very nice, but as usual, I am trying to max it out. TIA for your help in educating me.

 

[ServinginEcuador]

The Stax units not only need a whole lot of biasing voltage, but signal votage as well. The KGSS puts out something like 400v worth of that, and the Weebl/Blue Hawaii about 500+volts.

My guess would be that the SRD-7 is also stepping up the signal voltage to the much higher signal level necessary for driving the earspeakers.

 

[eric343]

Your guess is correct, Doug.

The SRD-7 contains step-up transformers that allow your amp to drive the voltage-hungry Staxes. (Low volumes on electrostatic headphones are about 10-20 volts (measured stator to stator), with peaks in excess of 300V on loud passages, at least according to my Fluke 189)

Unfortunately, transformers are a very inoptimal way to drive electrostatic headphones and as such a dedicated electrostatic headphone amplifier will give you a major increase in sound quality.

 

[Tachikoma]

The Stax units not only need a whole lot of biasing voltage, but signal votage as well. The KGSS puts out something like 400v worth of that, and the Weebl/Blue Hawaii about 500+volts.

Quote:

Originally Posted by eric343 The SRD-7 contains step-up transformers that allow your amp to drive the voltage-hungry Staxes. (Low volumes on electrostatic headphones are about 10-20 volts (measured stator to stator), with peaks in excess of 300V on loud passages, at least according to my Fluke 189)

So... how do I check how much signal voltage an amp puts out (on a spec sheet, I mean)? *I can't afford anything more expensive than a transformer for driving stax headphones*

PS: can the signal voltage be calculated by something as simple as (Output Power x Resistance)^0.5?

One more thing to add: Does anyone know whats the "step up" ratio of an SRD-7/SB MK2?