[Tinkerer]

Just treat it like gain for the most part. Higher impedance means lower noise floor and lower means more volume. As long as it's compatible with the amp's impedance ratings and you don't crank the volume up so loud you blow the drivers, there's really no wrong answer. The old STAX boxes were 8 ohm IIRC.

 

[Bloos]

Bet you dimes to dollars that if you slap a proper power supply on that 252S, it will sound better than most any transformer energizer though.

What makes a "proper" power supply? Is it just:
-12v DC output
-input matching your country's
-center negative
-regulated
-4.5watts or .26amps

anything I'm missing?
what range would be acceptable for the current? Its quite difficult to find one that's 0.26A (or 4.5watts).
Is it just best to keep it as close to 0.26A as possible without going under it?

 

[Tinkerer]

Regulated 12V means you don't have to worry about current as long as it's above the minimum. It's important on unregulated supplies as that rating is what tells you when it's at the specified voltage. Regulated supplies keep the same voltage no matter the draw.

The better the supply, the better the thing will sound as well. So the order is like Unregulated wall wart<<<<Regulated wall wart<Cheap Bench DC Supply<Dedicated low noise full size audio supply like GRLV
Biggest difference is unregulated to regulated though so that jump is easy. Fancier supplies are not that hard to make or get ahold of though.

 

[Music Alchemist]

Back in the STAX club! I have an SR-Λ now. (The original Lambda that began production in 1979.)

I noticed that some prefer the SR-Λ over the SR-207, but I think the SR-207 is better. (Both are quite nice and give you that STAX sound you can't get anywhere else.)

However, I am only using a Lepai LP-2020TI and STAX SRD-6SB to drive it. (I used a STAX SRM-212 to drive the SR-207.) The Lepai distorts badly at a certain point; on average when the volume knob gets to around 12 o'clock. It can power giant speakers, but can barely handle these headphones. lol

Now I'm on the lookout for a Normal bias STAX amp. (It can also be one that has both PRO and Normal bias outputs.) I spent too much money lately, so I'm only pursuing trades and would like to keep its value under $1,000.

Which amps should I be looking for? The SRM-1/MK2 Pro comes to mind.

How much will it scale going from the cheap speaker amp and electrostatic converter to a STAX amp? (Detailed impressions are appreciated.)

How many of you think the SR-Λ is better than the SR-207 when properly driven?

Would I be better off trying to get a different STAX headphone (perhaps a more modern one) in the trade as well?

I'm going to put up a classified, but if anyone reading this has a Normal bias STAX amp you would like to trade, just take a look at the current inventory sections of my profile and PM me.

Alternately, would a better speaker amp give me the type of improvement I could get from a STAX amp? I also know that my speaker amp outputs more power with a better power supply. I just don't know how each option would sound beforehand.

Update: I bought a Kenwood KR-720 vintage receiver.

 

[Bloos]

Thanks for the explanation!

Does this transformer look like a proper one?
http://www.jameco.com/z/DDU120050F0...near-Wall-Adapter-12-Volt-0-5-Amp_162996.html
Well other than the wrong polarity, but I'm assuming I can change it to be center negative by cutting, flipping, and resoldering the plug. Or solder these two backwards http://leeselectronic.com/en/product/21009.html?search_query=2.1mm+&results=111
http://leeselectronic.com/en/product/21008.html?search_query=2.1mm+&results=111
to make a polarity reversal adapter...right?
(Can't find one without paying over $25 in Canada)

Regulated 12V means you don't have to worry about current as long as it's above the minimum. It's important on unregulated supplies as that rating is what tells you when it's at the specified voltage. Regulated supplies keep the same voltage no matter the draw.

The better the supply, the better the thing will sound as well. So the order is like Unregulated wall wart<<<<Regulated wall wart<Cheap Bench DC Supply<Dedicated low noise full size audio supply like GRLV
Biggest difference is unregulated to regulated though so that jump is easy. Fancier supplies are not that hard to make or get ahold of though.

 

[Pokemonn]

@Music Alchemist
I personally recommend to get used SRM-T1. i own SRM-252S which sound very dull and 2D and not hifi. SRM-T1 can sound 3D presentation. SRM-1/MK2 may sound a bit too polite. i used to own T1 and SRM-1 during 80s.

 

[Tinkerer]

Back in the STAX club! I have an SR-Λ now. (The original Lambda that began production in 1979.)

I noticed that some prefer the SR-Λ over the SR-207, but I think the SR-207 is better. (Both are quite nice and give you that STAX sound you can't get anywhere else.)

However, I am only using a Lepai LP-2020TI and STAX SRD-6SB to drive it. (I used a STAX SRM-212 to drive the SR-207.) The Lepai distorts badly at a certain point; on average when the volume knob gets to around 12 o'clock. It can power giant speakers, but can barely handle these headphones. lol

Now I'm on the lookout for a Normal bias STAX amp. (It can also be one that has both PRO and Normal bias outputs.) I spent too much money lately, so I'm only pursuing trades and would like to keep its value under $1,000.

Which amps should I be looking for? The SRM-1/MK2 Pro comes to mind.

How much will it scale going from the cheap speaker amp and electrostatic converter to a STAX amp? (Detailed impressions are appreciated.)

How many of you think the SR-Λ is better than the SR-207 when properly driven?

Would I be better off trying to get a different STAX headphone (perhaps a more modern one) in the trade as well?

I'm going to put up a classified, but if anyone reading this has a Normal bias STAX amp you would like to trade, just take a look at the current inventory sections of my profile and PM me.

Alternately, would a better speaker amp give me the type of improvement I could get from a STAX amp? I also know that my speaker amp outputs more power with a better power supply. I just don't know how each option would sound beforehand.

Update: I bought a Kenwood KR-720 vintage receiver.

The transformer boxes certainly show the character of the speaker amp. You might be happy with the Kenwood. If not, I second the T1 recommendation for normal bias. T1S or T1W if you can get ahold of it.

Thanks for the explanation!

Does this transformer look like a proper one?
http://www.jameco.com/z/DDU120050F0...near-Wall-Adapter-12-Volt-0-5-Amp_162996.html
Well other than the wrong polarity, but I'm assuming I can change it to be center negative by cutting, flipping, and resoldering the plug. Or solder these two backwards http://leeselectronic.com/en/product/21009.html?search_query=2.1mm+&results=111
http://leeselectronic.com/en/product/21008.html?search_query=2.1mm+&results=111
to make a polarity reversal adapter...right?
(Can't find one without paying over $25 in Canada)

I'd spend the extra few bucks for some headroom like 1 or 1.5 amps, but otherwise, yeah.

 

[Bloos]

Ok gonna get this: http://www.jameco.com/z/DDU120100H4...ngle-Output-12-Volt-1-Amp-12-Watt_170245.html (is 12V +/- 5% good enough? If it ever gets to 12.6V how bad is that?)

As the electrical noob I am, I got a few more questions..
Does "linear" or "switching" matter? a tiny bit of research told me that switching has more noise, so linear is better for audio?
Do you guys use surge protectors? does it effect the sound?
what about UPS, since I heard it can only approximate a sine wave AC and might cause issues with some things, does this matter?
Also does a regulated transformer protect the same way as a surge protector? should I use both together?

 

[Music Alchemist]

Do you guys use surge protectors? does it effect the sound?

Also does a regulated transformer protect the same way as a surge protector? should I use both together?

I've briefly compared with and without surge protectors (including recently with my newest STAX rig) and did not hear a difference.

However, surge protectors can only do so much to protect electronics. I had a router stop working once from a power surge even though it was plugged in to a surge protector. And if there's a direct lightning strike (highly unlikely, but it can happen), all bets are off.

 

[Tinkerer]

Ok gonna get this: http://www.jameco.com/z/DDU120100H4...ngle-Output-12-Volt-1-Amp-12-Watt_170245.html (is 12V +/- 5% good enough? If it ever gets to 12.6V how bad is that?)

As the electrical noob I am, I got a few more questions..
Does "linear" or "switching" matter? a tiny bit of research told me that switching has more noise, so linear is better for audio?
Do you guys use surge protectors? does it effect the sound?
what about UPS, since I heard it can only approximate a sine wave AC and might cause issues with some things, does this matter?
Also does a regulated transformer protect the same way as a surge protector? should I use both together?

Linear is better. And you still need something like this and a little heatshrink for a separate polarity adapter without having to cut up what you buy.

http://www.ebay.com/itm/10X-Male-Fe...pter-Wire-Connector-for-CCTV-Pop/172206415625

 

[Music Alchemist]

So does anyone have experience with the original Lambda from various types of amps? (Such as going from an electrostatic converter and cheap speaker amp, to a more powerful speaker amp, then to a good STAX amp.) I'm trying to figure out how much of an improvement I would get with a proper STAX amp. The vintage receiver should arrive in a few days. I don't know whether I'd be better off getting a different STAX headphone or if the Lambda would get closer to the sound of the SR-207 after it's driven well.

 

[Music Alchemist]

@Tinkerer and other experts:

Is this power supply safe to use with the SRM-252S?

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_203036_-1

It's the one that comes with the used SRS-3100 (yay! finally get to hear the SR-L300) I'll have soon. But I read stories online about it frying amps.

If it is not safe, please tell me exactly what I should buy. (Preferably the cheapest thing that will work.)

Edit: Just noticed this post on the previous page indicating it may not be safe. Any help is appreciated.

 

[Bloos]

@Tinkerer and other experts:
Is this power supply safe to use with the SRM-252S?
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_203036_-1
It's the one that comes with the used SRS-3100 (yay! finally get to hear the SR-L300) I'll have soon. But I read stories online about it frying amps.
If it is not safe, please tell me exactly what I should buy. (Preferably the cheapest thing that will work.)

For that exact power supply Tinkerer said in a previous post: "That supply is unregulated and rated for 18watts or 1.5amps at 12V. The Stax amp only draws about 4.5watts or .26amps when in operation. That means that the wall wart isn't having enough power used to draw it down to the proper voltage and that the amp is being overvolted and being fed 16VDC or 17VDC all the time. That's likely what's causing them to fail.
Just get a regulated 12VDC wall wart at the right polarity instead. Or get an regular one like used in external hard drives and make a little polarity reversal adapter out of a couple bucks in barrel connector parts. A regulated wall wart even makes the amp sound better, so it's a good investment of fifteen or twenty bucks, or even much cheaper if you have one laying around."

I've been using that power supply for almost a year now, nothing has gone wrong yet, but after hearing about several 252s failing on reddit and (coincidentally?) using that power supply, I got a different one for peace of mind.
I bought and received this today: http://www.jameco.com/z/DDU120100H4...ngle-Output-12-Volt-1-Amp-12-Watt_170245.html and made my own polarity reversing adapter for it. Tinkerer seems to approve of this power supply + adapter.
Just plugged it in two hours ago and works fine. Enjoy your new stax! I personally prefer them to the 207s for being slightly warmer sounding.

~Others feel free to chime in.

 

[Music Alchemist]

For that exact power supply Tinkerer said in a previous post: [...]
I've been using that power supply for almost a year now, nothing has gone wrong yet, but after hearing about several 252s failing on reddit and (coincidentally?) using that power supply, I got a different one for peace of mind.
I bought and received this today: http://www.jameco.com/z/DDU120100H4...ngle-Output-12-Volt-1-Amp-12-Watt_170245.html and made a polarity reversing adapter.
Just plugged it in two hours ago and works fine.

~Others feel free to chime in.

Yes, I edited my post linking to that post after noticing it.

Can you explain why the one you linked to is safe? (Aside from the fact that it's regulated...or is that it?)

Got any recommendations for a cheap reverse polarity adapter? (No DIY for me.)

What about "a regulated 12VDC wall wart at the right polarity"? Does anyone have links?

I will also be receiving the original Japanese power supply. Would I be better off just getting a voltage transformer? If so, which ones are recommended? (I'd prefer to get the cheapest one that will reliably work.)

 

[Bloos]

Yes, I edited my post linking to that post after noticing it.
Can you explain why the one you linked to is safe? (Aside from the fact that it's regulated...or is that it?)
Got any recommendations for a cheap reverse polarity adapter? (No DIY for me.)
Also, I will be receiving the original Japanese power supply as well. Would I be better off just getting a voltage transformer? If so, which ones are recommended? (I'd prefer to get the cheapest one that will reliably work.)

Ya, its basically that it's regulated, so it'll have some additional circuitry to be more consistent in outputting 12V +/-5%. The unregulated is just a simple transformer (two coils of wires, which reduces the voltage by a fraction) and some diodes to change the ac to dc, so the voltage output is completely reliant on the voltage being feed to it. These can be seen in the data sheets from their product page,
Diagram of regulated (bottom of page three):
http://www.jameco.com/Jameco/Products/ProdDS/170245.pdf
Diagram of unregulated (bottom of page three):
http://www.jameco.com/Jameco/Products/ProdDS/203036.pdf

That's what I understand, but there's also the thing that Tinkerer said: "That means that the wall wart isn't having enough power used to draw it down to the proper voltage and that the amp is being overvolted and being fed 16VDC or 17VDC all the time"

For the polarity adapter, I only made my own because their shipping costs too much to get to Canada. This should work: https://www.sweetwater.com/store/detail/1SpotCYR (free shipping within US with USPS...sigh) but you should still check the polarity with a multimeter before pluging it into the amp.

the original Japanese power supply is still unregulated, or so I've heard.