The Headcase Stax thread

[spritzer]

There is nothing wrong with DIY and we try to make the PCB's as simple as they can be but it is a whole other matter to sell that DIY design after butchering the basics... 

[dripf]

Report it.

[jose]

Where does he get the signal for the level meter? From the output connector? No a good think... 

[RudeWolf]

Is this the same @thuytn selling the amp? Maybe he can chime in?

[Zern_c]

@spritzer Hey spritzer, could you let me know how to change the voltage on my stax 323s from 110V to 220/240V?

[spritzer]

Post some pictures of the inside towards the back of amp as there is no single way to convert them. 

[Mach3]

In the new 353X they cut the wires so you can't change the voltages. 

Did they just cut the wires connecting to the transformer terminals or they removed the winding altogether.

It's annoying using a step down transformer.

[spritzer]

It's worse on the 006tS I just got, there is only a 100V winding and nothing else.  The cut wires can usually be restored with some precision surgery but with just one winding, nothing can be done except a new custom made transformer. 

[bwck2000]

6 minutes ago, spritzer said:

It's worse on the 006tS I just got, there is only a 100V winding and nothing else.  The cut wires can usually be restored with some precision surgery but with just one winding, nothing can be done except a new custom made transformer. 

There is also one winding only on my friend's 007ta. No any other copper wire sticking out. Seems bridging the cut winding for voltage change is not possible on those latest models anymore.

[spritzer]

Yup, that is the same as on mine.  I'm just going to order a custom made transformer which will also allow me to have some fun with the amp over all. 

[Timb5881]

Has any one seen a Stax SRM-1/MK2 like this before?

[spritzer]

I wasn't sure about posting this but it kinda had to be done.  Pic is from HF and the usual nonsense in the peanut gallery there: 

So this is the Sirrah V3 from high-amp.de...aka yet another slight twist on the Stax SRM-1 Mk2 or derivatives.  For me it is just the build here and well... the total shitbox we have here.  First off, what's up with all the hotglue?  As somebody who has built hundreds of amps at this point... I don't even own a hotglue gun nor would I ever think of using this crap.  Some other goodies, top of the transformer sanded for it to fit in the chassis, no insulation on the mains plug which means this would fail even the basic CE tests, nice bit of cloth underneath the pot there to presumably stop it from shorting something on the board and I just love all the transformer leads, not twisted in any way, coming really close to the input wiring.  The hand cut heatpads on the output transistors are also nice and I very much doubt that tiny ballast resistor for the bias supply is rated to 600V.... 

On top of that, look up the design of this thing.  Basically a SRM-212 with a full size power supply and some things changed.  +/-200V rails, no CCS for the VAS stage and very little power. 

[sillie]

I am a owner of such a shitbox that spritzer seems to like so much. I don't understand much about electronics and maybe the assembled construction has some flaws, but who cares in a closed box? Much more important is, how it sounds. I had owned many amplifiers from stax before, but the sirrah sounds just great. Very strong bass, neutral sound and fine resolution. And the power is enough even for hearing loud. I think it is made for people with normal hearing, not for hearing impaired.

[Sherwood]

41 minutes ago, sillie said:

I don't understand much about electronics

Neither do I, so I listen to those who do.  I suppose the other approach is to just not care about things you don't understand.

[billqs]

2 hours ago, sillie said:

...who cares in a closed box? Much more important is, how it sounds. 

Well, if an electronic component is put together in a slapdash manner such that a cursory inspection reveals faults, what does that say about electronic issues that might pop up down the road that don't show up right away? Also, if a company/person doesn't show a lot of competence in building the amp correctly, how competent are they about how they install circuits? I'm glad it sounds good to you. I just hope it lasts.

[ktm]

The whole shaving off the top of the main transformer scares me. 

Insulation is there for a reason. 

1st order of business, try NOT to kill the user.

[jamesmking]

On 9/10/2020 at 1:51 PM, ktm said:

1st order of business, try NOT to kill the user.

try not to kill the user until AFTER they have finished paying for it

Equal rights for electrons! they should be allowed to travel freely and not be constrained by insulation... If they want to travel through your heart it just their way of being loving and friendly.... they are so misunderstood. 

Edited September 12, 2020 by jamesmking

[Pars]

1 hour ago, jamesmking said:

try not to kill the user until AFTER they have finished paying for it, and posted their inflated review on HF...

FTFY...

[gepardcv]

9 hours ago, sillie said:

maybe the assembled construction has some flaws, but who cares in a closed box?

Anyone who doesn't want to be injured. That photo shows a device which is a hazard for (1) electrical shock, and (2) a fire.

[spritzer]

It's been quite a while since somebody has come in and told us to just ignore everything even close to negative because it "sounds good".  Sure, good for you but those of us who have been here a while know that was also said about other amps which turned into an absolute clusterfuck so yeah, keep that in mind. 

So a couple of things things, this amp doesn't swing enough voltage to really work.  Even the SRM-252S has +/-250V rails and that is really the absolute minimum for this role.  Only the utter dog turd that is the SRM-D10 uses +/-200V rails but then again, the off the shelf opamps it uses can't handle any more.  Now the issue is just how much volume are you using and is the amp clipping.  Setting aside the issue of headroom, can the amp handle normal transient swings? 

Second, what does it bring to the table that a SRM-353X doesn't do and better? 

[sillie]

You made me feel insecure with all your comments. I searched the internet for the inside of other amplifiers from stax and other brands on the market. What I found was:

No insulation on the mains plug

No twistet transformer cables

Glue to fix parts and cables.

And now I wonder what ist different there from the sirrah?

[morphsci]

^^^  ^^^

[swt61]

Que sirrah, sirrah.

[Oak Forest Audio Dood]

On 9/3/2020 at 1:48 PM, spritzer said:

I wasn't sure about posting this but it kinda had to be done.  Pic is from HF and the usual nonsense in the peanut gallery there: 

So this is the Sirrah V3 from high-amp.de...aka yet another slight twist on the Stax SRM-1 Mk2 or derivatives.  For me it is just the build here and well... the total shitbox we have here.  First off, what's up with all the hotglue?  As somebody who has built hundreds of amps at this point... I don't even own a hotglue gun nor would I ever think of using this crap.  Some other goodies, top of the transformer sanded for it to fit in the chassis, no insulation on the mains plug which means this would fail even the basic CE tests, nice bit of cloth underneath the pot there to presumably stop it from shorting something on the board and I just love all the transformer leads, not twisted in any way, coming really close to the input wiring.  The hand cut heatpads on the output transistors are also nice and I very much doubt that tiny ballast resistor for the bias supply is rated to 600V.... 

On top of that, look up the design of this thing.  Basically a SRM-212 with a full size power supply and some things changed.  +/-200V rails, no CCS for the VAS stage and very little power. 

AHHHH It's 650 EURO's for the shit box! An I've owned some shit boxs of DOOOOOOOOM [no relation to the BAD Mother F****** Drag Car under the same name] and I've lost a few headphones to said shit boxs. So I can't say I'd want to get into eStats with something so poorly built... Plus That's the same USD cost as a SRD-7 from @spritzer I guess yea you'd need get a power amp to put behind it. An the one I see recommend alot is like what... $150-200ish? So total cost of $900 or so

But apparently you can still get a SRM 323S for like $525ish plus shipping so still cheaper than that thing...what's the consensus here around the 323S?

[naiy8oaY]

14 hours ago, OakForestAudio said:

AHHHH It's 650 EURO's for the shit box! 

With a little patience, that's enough for a 2nd hand SRM-727. That really makes that Sirrah a bad deal.