[Towert7]

Hello.

I was wondering if you know who is able to make an adapter to go from the HE60 plug to the Stax pro plug.
(Not reterminating the HE60 cable, but an adapter).

I also have heard people say that a resistor in one of the leads needs to be added, which I can only assume is to lower the gain?

All info would be appreciated.
Thanks!

 

[Jon L]

I have this pic saved from an old thread..

 

[penger]

Looks like apuresound might. APureSound - Where The Music Is Always Pure - APS Audio LLC.

 

[wavoman]

Resistor is to lower the bias voltage from 580 (Stax) to 560 (HE60). At least I think the HE60 is 560 -- some threads here say 540.

Many posters say you don't need the resistors -- bias voltage is so close 580 vs 560 (or 540). Caution: HE90's are 500, a different animal.

Drew at moon-audio makes these adapters. He does superb work.

BTW, good choice of gear -- the HE60 sounds fantastic with Stax amps, esp. the 717.

 

[jigster]

The resistor lowers the bias voltage, some have done the adapter without the resistor. However, some owners have posted that their HE60's drivers had problems and had to be replaced when they used adapters without the resistors, as the difference in voltage may damage the drivers over time. Though there are others who use adapters without the resistors; who believe the resistors have affects the sound. But just to be on the safe side, I did mine with the resistor.

Edit: oops, my bad. As spritzer & Dinan have pointed out, the resistor doesn't lower the voltage. Apologies.

Here's Kevin Gilmore's DIY adapter for your reference of how it may be done.

HeadWize - Project: Blue Hawaii Hybrid Electrostatic Amplifier for Stax Omega II Headphones by Kevin Gilmore

 

[spritzer]

The resistor doesn't lower the bias voltage, for that you would have to have a ground connection (which there isn't since the bias is an open, highly resistive circuit) or another resistor to ground to form a voltage divider. Sennheiser simply spec'd a 10M ballast resistor to match their drivers.

 

[chi2]

Peter Rill who has placed a DIY description in the German HIFI-Forum (Wir basteln einen HE60->Stax-Adapter, Kopfhörer allgemein - HIFI-FORUM) has built one for me. (Mine differs a bit from the one described as it uses an O2 plug.) Peter is well known for his excellent work and he's a nice guy to deal with. If you're interested you can pm me and I'll pass you his email address.

 

[Dinan]

I built 3 of these when I built mine and will NEVER build another so please don't ask me too. They are just far too labor intensive to do properly.

The pinout above looks correct. The resistor goes in the bias line and is 5M ohm for use with STAX amps and keeps the charge even in the transducers, it does not lower the voltage as Spritzer has already pointed out.

I used a combination of the two designs...this one for the HE60 end but I added the bias resistor to the unused side of the board: HeadWize - Project: Blue Hawaii Hybrid Electrostatic Amplifier for Stax Omega II Headphones by Kevin Gilmore

I used the German adaptor as a general guide for the rest but look to the pinout above for the correct connections as there are some pins out of phase in the German post.

A word of caution....after I built the adaptor and heard how amazing the HE60 is on real amps, I did a permanent STAX termination on the HE60 as no one in their right mind would ever go back to the HEV70 after hearing what they really can do.

 

[Michgelsen]

Quote:

Originally Posted by penger /img/forum/go_quote.gif Looks like apuresound might. APureSound - Where The Music Is Always Pure - APS Audio LLC.

I asked him about it some time ago. Alex said he didn't make them anymore, but only does reterminations.

 

[wiktor]

A few of photos of the adapter Sennheiser HE60 to Stax which I made yesterday. Materials: the original Stax extension cable SRE-725, heat-shrinkable tubes and pins from the computer plug ( Motherboard PSU ). I made connectors for Orpheus HE90 to Stax and Stax O2 to Orpheus.

 

[Towert7]

That looks very good. Did you solder the wires directly onto the HE60 cable jack?
Also, did you add in the recommended resistor?

 

[wiktor]

No, pins from the computer plug are soldered to the Stax cable. Everything is for disconnecting.

I didn't apply the resistor, but is OK.

 

[Dinan]

That looks like a good "quick" way to do it if you don't want to build the circuit board.

One thing on the resistor...after comparing HeadphoneAddict's pair of HE60 which we believe to have no resistor to my pair with the 5M ohm resistor, we felt the sound on the pair with the resistor was superior. Both pairs were recently rebuilt so there were no age related issues to explain the differences. So aside from the practical arguments for the resistor, it would appear that there is also a sonic one.

 

[wiktor]

Spritzer wrote me about this resistor. No problem, I will try to improve this adapter asap.

In this connection the HE60 sound isn't so good how from Stax Omega. Of course better than from HEV70.

The bigger improvement in the sound occurred after the Stax connection to the HEV90 amplifier. I made this adapter also. I will try tomorrow to connect headphones HE90 to Stax amplifier.

 

[spritzer]

I figured I'd kill two birds with one stone and post about the resistor here as opposed to a PM. Since the Sennheiser HE's require a 10Mohm ballast resistor unlike the Stax 5Mohm the simplest solution is to just add a resistor (5M) between the bias connector and the bias wire inside the adapter. That resistor simply adds to the one inside the amp creating a 10M total. Care should be taken to use 600V rated resistors, 1/4W is more then enough.