[KR...]

for a very long time

Seriously, you wouldn't believe the difference that I am hearing right now, it is as if I just made a serious upgrade to my system, and all I did was forget to turn off the amp for over 10 hours. They have never ever sounded this good, it's just unreal, it really is night and day. This is hands down the best and cheapest (it's free, other than the bill depending on what amp you are using) upgrade you can make to your Stax system. If anyone here owns a Stax system, please try this for yourself, just leave it on and never turn it off, after about 5 or 8 hours whatever, try listening to CDs that you normally listen to, and you too will hear the amazing difference.

Before I wrote that these amps needed at least an hour to sound great, but now I will change that to say that they really do need to be left on, even if the source is off, always, just never turn them off, you will be glad you did.

 

[bln]

heh, i guess with an amp that you always want to be turned on, one of the major criteria when buying should be 'won't blow up.'

 

[KR...]

Quote:

Originally Posted by bln heh, i guess with an amp that you always want to be one, one of the major criteria when buying should be 'won't blow up.'

The sleep at the wheel amps?

Yeah, stay away from those

 

[Bill Ward]

I agree that there is a marked improvement when a Stax system is left on. I tend to leave mine powered up for a couple of days straight when I know I'm going to be using it. What concerns me is a thread from a couple of months back that suggested that the amp becomes unstable after an extended period and may sustain damage. (No search function, so I can't provide a link.) Anyway, I turn my off overnight every couple of days.

Any thoughts on the subject?

BW

 

[minya]

Yep, I've noticed this too. I leave my KGSS on 24/7 (with my phones plugged in all the time). Even so much as unplugging tends to mess with the sound. It isn't all that bad of course -- sort of like a weird bass suckout -- but it bugs me. I just leave everything on so I never have to worry

- Chris

 

[Nik]

Quote:

Originally Posted by KR... for a very long time Seriously, you wouldn't believe the difference that I am hearing right now, it is as if I just made a serious upgrade to my system, and all I did was forget to turn off the amp for over 10 hours. They have never ever sounded this good, it's just unreal, it really is night and day. This is hands down the best and cheapest (it's free, other than the bill depending on what amp you are using) upgrade you can make to your Stax system. If anyone here owns a Stax system, please try this for yourself, just leave it on and never turn it off, after about 5 or 8 hours whatever, try listening to CDs that you normally listen to, and you too will hear the amazing difference. Before I wrote that these amps needed at least an hour to sound great, but now I will change that to say that they really do need to be left on, even if the source is off, always, just never turn them off, you will be glad you did.

... I'm very sorry, but this is the first thing I have done with Stax eq.... always !!!

Best!
Nicola

 

[edstrelow]

I have a similar SRM-3/404 set-up and agree with the observations about allowing significant warm-up. You don't mention whether or not you unplug the phones between use. I personally think that the phones should be left plugged in at all times, whether or not the amp is on.

I recently had a somewhat similar eureka experience about long hours of use. I plugged my Stax Sigma pro's which I had not used for some months, in place of the 404's. They sounded reasonable for the first day or so with minimal warm-up. Then I started hearing seriously deficient sound, when used within the first half-hour, not just subtle efects but actual distortion with some sounds, usually midrange/upper midrange, generally lessening after 1/2 hour. This reminded me a bit about the way old "self-energizing" stat phones sounded and they were warming up. I also inadvertently left the system on for about 10 hours and then turned it off for about 4 minutes to let the amp cool, it does got hot since it is a class A. When I turned it back on it was really good, several levels of improvement over what I had previously thought was acceptable performance for these phones. Since that time, they have continued to perform oustandingly with only modest warm-up (5-10 minutes).

I don't like the idea of leaving the amp on all that time, because it gets hot and I think you will shorten its life. Also I hear a subtle high frequency veiling effect when the amp has been just sitting and getting warm. I think it pays to let it cool off for a bit. I don't seem to hear the same veiling if the amps is actually used for several hours though.

I am curious as to what is going on. My two general ideas are firstly that the electrostatic diaphragms need to get properly charged up. Unlike dynamic/ magnetic speakers, electrostatics need an additional charge added before they can operate. Many older stat phones used a self-energizing charging circuit in which you could hear the system coming alive, most notably in the first few seconds, sometimes longer. One guess is that even the newer charging circuits are not able to get the phones operating to full spec until after some use.

A second guess is that maybe the amps themselves need to warm up to get to some stable operating condition. Class A amps get quite hot and I wondered if there are not some protection circuits or the like such that the amp only works properly when it gets to some operating temperature. This is just a wild guess. Anyone have any real knowledge on this issue?

 

[fyrfytrhoges]

what about placing a small fan near the amp to keep it cool?

 

[edstrelow]

Re: Fan to cool the amp. This might help somewhat. However possibly not that much. I once opened an SRM3 and found that it was double shielded, i.e. there was a case within a case. It is much hotter inside the inner case than one realizes from touching the outer case. So the fan wouldn't cool the inner section too much.

However, I don't belive that all other Stax amps follow this mode of construction and some have vent holes for which a fan could be useful. Most big class A amps have cooling fans built in.

 

[Glassman]

all you need is to provide the bias for the phones.. running whole amp 24/7 is mighty idea.. biasing the phones won't suck much power and won't make your amp blow.. I will try to make two switches on my soon-to-be Blue Hawaii - bias voltage on/off, tube filament power on/off and whole amp on/off.. running this 120W beast all the time would cost me a fortune!

 

[minya]

Paul, if your amp gets seriously hot, then a fan is a good idea. On the warmer days when my room heats up a lot I turn my fan on and point it towards the amp. It cools it down substantially.

- Chris

 

[KR...]

1st of all, thank you all so very much for your input, I find any opinions and finding onm this subject very helpful, so keep them coming

A few personal notes to add :

I never unplug my headphones. The 1st and only time I ever did was when I took them to the NY meet, and they have been left plug in ever since. As far as leaving teh amp on always or leaving it on for long periods but in cycles, again it's too early for me to know for sure. This is why I posted this thread, to get feedback. I sure do not want to ruin my amp, so I want to see what is the best way to go about using it to both to get the best sound and also to make sure I can enjoy that sound for many, many years to come.

While I have written about warm up times, charging the headphones is another topic that I believe is important to discuss. I mean how many times have you notice that those Omegas only started to really sound great toward the end of these meets that people have? It is normally around 4 to 5 hours after they were plugged in. Also many of us have notice differences between headphones they were just plug in against those they have been plug in for a long time, regardless if the amp is warmed up or not, the sound difference can be heard.

This is all going only by what my ears are telling me, I really do not know just why this is so exactly. Stax never bothers to even mention any of this is their paperwork or website as far as I know.

Can anyone who really knows their electrostatic technology chime in here and give me the 101 on why I am hearing what it is that I am hearing as far as warm up times and charge up times is concern?

 

[fyrfytrhoges]

i am definitely going to check into some small fans for both my kgss and my stax 006t, the stax amp was extremely warm yesterday since it was very warm outside. and the kgss has been warm on occasion too, both amps have venting on the cover and should benefit from a fan i would imagine.

 

[kevin gilmore]

You absolutely positively need to keep the space charge on the
headphones. So for most people that means that the amp has
to be on all the time. If you are building one, you can use a little
tiny switcher to keep the high voltage on all the time.

The impedance of the diaphram is in the 10's to 100's of megohm
range. It really does take a day or more to charge fully.
Same thing with quads and all other electrostatic speakers.

Because i have many more electrostatic headphones than i
do amps I built a box with 6 stax connectors (high bias only)
and the headphones i'm not listening to at the moment stay
plugged into the charger. Very low power.

 

[Ken B]

I see a potential product for electrostatic users. A small inexpensive box that we can plug our headphones into to maintain a constant charge. I would prefer this method than having my tube amp cooking all day.

How about it Kevin?