[3X0]

Will write Drew about this ASAP to confirm. So to be safe should I request a 5M resistor on the bias line or a 10M? (remember I'm a electrostat noob so I have no idea on which lines these resistors should even be)
 
What are the long-term consequences in case the Stax termination is without a resistor, out of curiosity? I've read one post about drivers "dying" but I'm just curious.

 

[chinsettawong]

If you are using a Stax amp, you already have at least 5M series resister in your bias line.  If you want to conform to the original Sennheiser's, just add another 5M in your bias line.  

 

[shipsupt]

Got it.  So it's more for safety of the listener than the headphone.  Thanks!

 

[spritzer]

The safety factor is there but the resistor is also part of the charge pattern for the diaphragm.  Change the coating and you change the load resistor.  That's why you can't use the Stax oem's on a Stax amp, very different diaphragm properties. 
 
This also ties into a much bigger picture so yeah, get the ballast right. 

 

[3X0]

Drew responded that he only uses 5M resistors on the bias line when reterminating HE90s. :eek:

Anyway, I responded that apparently it's not in the best interest of the HE60 to run resistorless. Will wait for his response on the matter..


In other news, anyone try to ghetto fix deteriorated pads? I am considering deliberately removing all the pleather from my old pads and then using some kind of nonporous tape to seal the outside (thinking black masking tape or packing tape). I notice the inside pleather is perforated though so I may apply some tape to a laminate, punch out tiny perforations and use that on the inside. Better than being flaky and useless?

Then with a light cleaning, replacement of the screws, nice vinyl dust cover and HD 650 headpad I imagine the baby O would be far less high maintenance.

 

[shipsupt]

I'm pretty good on my 60 pads, the set on there looks good and I have two spare sets 

 but I do worry because I have some HE-90 pads on my Jades and I know eventually they will fall apart.

 

[3X0]

Ya, but that doesn't change the pads being a waste when they're on their way out.

Were you able to identify whether your set had a resistor in line?

The other option is to reterminate to HE90 and have HE90->HE60 and HE90->Stax adapters, with only the very latter having a resistor.. but that gets expensive especially since I won't be using the HE90 termination within the next decade (I'm a young man).

 

[shipsupt]

I haven't had a chance to check it yet.

 

[spritzer]

Quote:

Drew responded that he only uses 5M resistors on the bias line when reterminating HE90s.

Anyway, I responded that apparently it's not in the best interest of the HE60 to run resistorless. Will wait for his response on the matter..
 

 
Anything HE90 applies to the HE60 as well.  Same tech used on both drivers aside from the actual structural materials. 

 

[3X0]

$10 just to add a 5M resistor that apparently should have already been included in the retermination... how much is the actual 600V 1/4W 5M ohm resistor worth as a single piece without bundle pricing?

 

[spritzer]

This is the one I use in most of the stuff I build.  It's 4M7 so close enough but it's the perfect resistor for the job. 
 
http://www2.mouser.com/ProductDetail/Vishay-BC-Components/VR37000004704FR500/?qs=sGAEpiMZZMu61qfTUdNhG5V28IhA8cEfH3sT%252bvWwd%2fk%3d
 
You can buy just one at that price... 
 
I do have some smaller 5M resistors for this role from a similar lineup and they cost even less. 

 

[3X0]

Blargh. Went ahead with the $10 resistor "upgrade" since there's no point not to when they're already in Drew's hands.

At least I can have peace of mind that the diaphragms will be operating in spec out of whatever I can plug it into.

 

[3X0]

Got the retermination but noticed a channel imbalance recently that was also reported by Drew after it was reterminated. Left channel is at least 20% louder than the right (not sure what the dB difference is). In fact when the set is "fresh" from a not being used for a couple of days the left channel can be as much as twice as loud as the right channel, but the right channel seems to get stronger with playback/power-on time.
 
The reterminated HE60s play fine with the SRM-T1 so I believe the HEV70 was what was causing my crackling/oscillation issues earlier. Now I'm just worried whether or not the sometimes substantial channel imbalance could be down to potential damage caused by the HEV70 going haywire. There's nothing that sounds fishy about the right channel except it being quieter.
 
Oh, and the o-ring on the left side finally gave out and snapped. Sennheiser USA still hasn't gotten my replacements from Germany...

 

[chinsettawong]

I use superglue to glue back the o-ring, and it works fine for me.

Wachara C.

 

[spritzer]

Bias issue after retermination that wasn't there before?  Something wrong with the retermination me thinks as the bias wires for both channels are now summed into one pin.