[BenF]

Why "easier and safer" ?

No chance of electrocuting yourself or damaging the amp.

 

[Precaud]

No chance of electrocuting yourself or damaging the amp.

It is baseless and irresponsible for you to assume those risks are present for the alternatives I suggested.

 

[BenF]

It is baseless and irresponsible for you to assume those risks are present for the alternatives I suggested.

I guess Stax is an irresponsible company, printing warnings like this one on the back of 252S:

They also include this baseless warning on the first page of the manual:

 

[Precaud]

I guess Stax is an irresponsible company, printing warnings like this one on the back of 252S:


They also include this baseless warning on the first page of the manual:

If someone is not comfortable working with electronic circuits, then it goes without saying that this mod is not for you. Don't undertake this as a "first project".
The mods do not compromise the amp's safety or reliability in operation.
Do you have something besides scare-mongering to bring to the conversation? Sheesh.

 

[BenF]

If someone is not comfortable working with electronic circuits, then it goes without saying that this mod is not for you. Don't undertake this as a "first project".
The mods do not compromise the amp's safety or reliability in operation.
Do you have something besides scare-mongering to bring to the conversation? Sheesh.

I think it's safe to say that most people are not qualified to work on high voltage circuits - hence the "easier and safer" alternative I suggested.
Why are you taking this so personally? I haven't said a single word about your mod.

 

[Precaud]

I think it's safe to say that most people are not qualified to work on high voltage circuits - hence the "easier and safer" alternative I suggested.

Why are you taking this so personally? I haven't said a single word about your mod.

1. Sir, you are the one conflating the issues. Your "easier and safer" suggestion only relates to choosing which 12V power supply to use. The circuit mods are a separate matter. The supply you're recommending is good enough and will work fine but it is not any safer and is frankly overkill in this application. Inside the 252S, the only thing that uses the 12V supply directly is the power LED and the PWM chip. You don't need a Jung-based super-regulator for that.

2. Working on HV circuits does not require any special qualifications. Replacing HV parts is not any different than replacing other ones. It's safe, because one doesn't work on the circuits when they're powered up. And, the fact is, the 252S HV circuit doesn't generate enough power to hurt you. A couple milliAmps at 200V will generate a mild sting, yes; but hurt, no.

It's not personal. It's about keeping the discussion based in facts, not speculation and fears. The clear message I get from your posts is that you're not a candidate for doing these (or perhaps any) electronic mods. But for some reason you're making a big stink about it. I don't get it.

 

[BenF]

... Inside the 252S, the only thing that uses the 12V supply directly is the power LED and the PWM chip. You don't need a Jung-based super-regulator for that.

It doesn't matter which parts of 252 get the 12v directly and which indirectly - feeding a higher quality signal will result in less noise.

2. Working on HV circuits does not require any special qualifications. Replacing HV parts is not any different than replacing other ones. It's safe, because one doesn't work on the circuits when they're powered up. And, the fact is, the 252S HV circuit doesn't generate enough power to hurt you. A couple milliAmps at 200V will generate a mild sting, yes; but hurt, no.

I hope you will understand if when choosing between your recommendation on safety and Stax's, I will choose to follow Stax's advice.
Vast majority (I'd guess well over 90%) of people in this thread use electrostatic amplifiers, but do not build or mod them (unlike headphones, which many people do mod personally). For these people your mod (as great as it may be), is not an option.

Anyway, to avoid derailing this thread, +1 to ignore list.

 

[Precaud]

It doesn't matter which parts of 252 get the 12v directly and which indirectly - feeding a higher quality signal will result in less noise.

Not true. Circuit context does matter. I've tried and tested several of them, and my measurements and listening say that any reasonably-regulated supply is just fine here for the raw -12V. Some of the advantages of using something like a Jung super-regulator (super-low output impedance) are totally lost by connecting it with a couple feet of cable between two barrel plugs.

I hope you will understand if when choosing between your recommendation on safety and Stax's, I will choose to follow Stax's advice.

They put that on there for legal reasons. My advice is common sense. If you're not comfortable modding electronic circuits, don't do it. My toaster oven also says "danger - no user-serviceable parts inside", but it's not going to stop me from fixing it if/when it breaks.

Vast majority (I'd guess well over 90%) of people in this thread use electrostatic amplifiers, but do not build or mod them (unlike headphones, which many people do mod personally). For these people your mod (as great as it may be), is not an option.

That's ok. I've always considered equipment mods to be self-qualifying; people who aren't interested or can't do them ignore them and walk on by. I've also started a thread about the mods in the DIY forum, so perhaps interested modders should go there to discuss, so as not to ruffle any more sensitive feathers here.
Stax SRM-252S Driver Unit Upgrade
We already have one guy who is ordering the parts and hopefully will share his experience with us.

Anyway, to avoid derailing this thread, +1 to ignore list.

Good idea.

 

[greggf]

delete

 

[Kiats]

Picked up a KGST this morning and now enjoying it with the 009.

 

[Kiats]

Lovely pair of early Lambda Professionals came today, courtesy of @spritzer. Gorgeous balanced sound signature.

 

[Kiats]

The Stax X9000 has landed. Big shout out to Jeremy from AV One for making this happen!

 

[prtuc2]

That wooden box just not too appealing and harder to transport, I prefer the Stax SR-007MKA or II plastic carrying case.

 

[oneguy]

You transport your Stax that often?

 

[prtuc2]

You transport your Stax that often?

Not really, other than CanJam but would definitely open to have plastic case as an option.