[KR...]

Some follow up questions :

How long does it take to discharge?

In other words if you unplug it and play back in, do you loss the charge? How long would it have to be unplug before losing it's charge? How long can the amp be off before the headphones lose their charge?

 

[bangraman]

This (a 'pre-charger') is something I'd like to see as I've also noticed that it sounds better after a long power-on period.


Since I'm not in all the time and can be away for lengthy periods, it's not really secure for me to keep tube amps cooking (and the 007t really does cook after an all-day session). Fans are not an option unless there's metalwork and silent case fans involved... and that's too much hassle for me. I suppose a fan could be put in place when you're not using the system though?

 

[kevin gilmore]

http://gilmore.chem.northwestern.edu/gammahv.jpg
(warning large)

One of these, a 12 volt wall brick and a resistor and a stax connector.

The power supply does not need to be anywhere near this big, some
of the picobrick units work fine too (and cheap). I use these because
i have a drawer full of them.

How long do the headphones stay charged, that depends on if you
touch the pins when you unplug them. That shorts out the charge
real quick.

 

[Bill Ward]

I would appreciate what Kevin might have to offer on the safety of leaving a Stax solid state amp on all the time. Will such a practice damage the amp or shorten its service life?

This has been a recurrent question, and Stax has been of no assistance when queried. Surely, someone must have an authoritative answer to the matter. Dr. Gilmore . . . if you could assist?

Thanks,

Bill W.

 

[kevin gilmore]

Any amplifier made by anyone, tubes or solid state has components
in it that have a finite life span. The big electrolytics in the power supply
are the prime example. The more you leave the unit on the quicker
the electrolytics go. Usually 24/7 results in leaking electrolytics as soon
as 10 years. The rest of the components generate heat and the heat
will certainly effect the circuit board. If you are going to leave it on
forever then make sure the ventilation is as good as possible.

 

[ayt999]

I'll soon be using my Blue Hawaii (finally!! I ordered it but have been in japan ever since then so haven't even looked at it in person yet) and would prefer not to leave it on all the time.

the small charger unit that kevin gilmore mentioned seems to be what I was looking for. it seems easy to make so I may try making one when I get back to my place.

thanks for the great information guys. maybe a portable unit for use during transportation may be great since then the headphones will be ready for use earlier in meets and anywhere else they may go.

 

[kevin gilmore]

Here is an even better idea, if somewhat large.

2 x model 489 carbon zinc batteries (2 x 225 volt ==450)
plus 2 x 467 carbon zinc batteries (2 x 67.5 == 135)

== 585 volts. At the picoamps of current drawn, this would last
literally years.

http://tes.com/carbonzinc.html

 

[ayt999]

model 489 carbon zinc batteries $85 MSRP
model 467 carbon zinc batteries $30 MSRP

and since you need two each... that comes out to $230 just for the batteries. wow.

 

[cosmopragma]

Quote:

Originally Posted by ayt999 I'll soon be using my Blue Hawaii (finally!! I ordered it but have been in japan ever since then so haven't even looked at it in person yet) and would prefer not to leave it on all the time. the small charger unit that kevin gilmore mentioned seems to be what I was looking for. it seems easy to make so I may try making one when I get back to my place. thanks for the great information guys. maybe a portable unit for use during transportation may be great since then the headphones will be ready for use earlier in meets and anywhere else they may go.

And here is a cheap and convenient solution.Purchase a used SRM-212 or SRM/Xh or similar (less than 100 $, 200+ new).It consumes about 6 W and for the charge during transportation it can be powered by a car battery via the cigarette lighter jack since it is normally powered by a 12 V PS.

 

[fyrfytrhoges]

kevin, what do you think about the external fan idea? you havent commented on that.... good, bad, indifferent?

 

[bangraman]

Certainly for non-listening idle periods I don't see a problem with a fan, but what about when you're using them? EMI + all sorts of electrical nasties.



Will we see a Gilmore Audiophile Fan?

 

[fyrfytrhoges]

i dont know how bad the power is where all you guys live, but i have had air conditioners, fans, tvs, computers, all running while using my headphones, even before i purchased a power conditioner and i never had all these interference issues you guys talk about......

maybe its just the iron ear syndrome??? (non audiophile ears)

 

[fyrfytrhoges]

bump back up to the top for more fan advice please.....

 

[kevin gilmore]

Here is the most simple and cheap always on bias generator i can
think of.

http://gilmore.chem.northwestern.edu/alwayson.gif

As always with high voltage stuff be careful, the .1uf caps won't
store enough energy to kill you but will certainly get your attention.

The transformer is $12.29 and the rest of the parts total will
still bring the total to under $20.

 

[edstrelow]

This thread is just about the most useful I have seen, either on this site or on Headwize, for dealing with a real issue regarding electrostatics, which puzzled me even after owning sets for 30 years. I wish Stax had done something to explain these issues. I suspect that many of the negative views of their products are from listeners who have had less than ideal charge-up of their phones.

My one query is does anyone have any numbers to put to the charge-up/discharge phenomenon, i.e. can you measure how long it takes to get the phones charged up and how the charge drops off under different conditions, e.g. plugged in, unplugged, dry air, humid air.

I would sure like to get my hands on a ready made charge-up unit. I don't trust my building skills.