The Headcase Stax thread

[Ali-Pacha]

Ah, remembering your old fights with Anax 

Ali

Edited February 5, 2016 by Ali-Pacha

[3x0]

I'll have to hunt those down for entertainment. I remember a minor fracas with that guy when I said I believed the Omega to be more detailed and resolving than the face tweeter.

[spritzer]

Ahh yeah, the mighty detail machine that is the HD800.  Now let's pair it with an amp that has the transparency of a puddle of mud and we are golden. 

[DolphinG]

Is there anyone who opened recent STAX amps (727A, 323S, 353X.. etc) and tried to change its voltage?

I heard that some 727A amp do not support voltage change. (You need to get a transformer)

Is there anyone who know if STAX started to prevent individual customers from changing their amp's voltage?

How about SRM-353X? I'm now currently in consideration to move from 727A to 353X, and I don't want to use transformer. (220V to 100V)

[spritzer]

I've heard that they use 100V only transformers on the Japanese gear but haven't verified it.  On the cheaper amps it was usually just a matter of missing leads but on the 007/727 they cut the actual winding's. 

[DolphinG]

1 hour ago, spritzer said:

I've heard that they use 100V only transformers on the Japanese gear but haven't verified it.  On the cheaper amps it was usually just a matter of missing leads but on the 007/727 they cut the actual winding's. 

 

Yes! That's what I heard about voltage change of 727A.

Then as 353X is cheaper than 727A, is it possible that they use voltage-changeable transformers?

[spritzer]

No idea. 

[luvdunhill]

I've heard that they use 100V only transformers on the Japanese gear but haven't verified it.  On the cheaper amps it was usually just a matter of missing leads but on the 007/727 they cut the actual winding's. 

Been dealing with that with Esoteric. I hopefully will have something to show for my work soon

[spritzer]

That will be fun to watch.    I'll tackle Accuphase in the near future as I want one of their Class A  integrateds but I believe that they are multi winding as a standard.  

[luvdunhill]

That will be fun to watch.  [emoji4]  I'll tackle Accuphase in the near future as I want one of their Class A  integrateds but I believe that they are multi winding as a standard.  

It is (was) a Bando as well. Also, turned me on to JST connectors which I quite like.

[DefQon]

On 07/02/2016 at 7:22 AM, spritzer said:

That will be fun to watch.    I'll tackle Accuphase in the near future as I want one of their Class A  integrateds but I believe that they are multi winding as a standard.  

 

Some of the Accuphases (depending on region purchased and the preamp and amp I had) have multi windings but no wires are soldered to the taps. Something akin to the older Stax Bando transformers.

[spritzer]

I'l get something like the E-560 or E-600 to play with from Japan.  Only issue is shipping them as they are...ehh..hefty to say the least. 

[luvdunhill]

Can anyone post a picture of what you are referring to with the Bando? They are used in he Esoteric gear as well, but I suppose I might not have looked closely enough?

[spritzer]

On the Stax stuff they cut the lead wires into the transformer.  On the more expensive amps they actually cut the winding's as they are connected to the terminals on the transformer. 

[DefQon]

Yep, for the models I had the transformers were mounted in a fashion where the windings was not very accessible (unlike Stax amps they are on the top) and there is a white plastic clip in compartment box where the windings are soldered to the taps secured to the trafo then a wire comes out to the mains. The Japanese companies really like to stop grey imports and people taking advantage of buying cheap from Japan then changing the primary to suit their country, obviously most cases there is a work around.

[luvdunhill]

So, do you have to disassemble the transformer to tell? I didn't go that far, because I would have to permanently remove the shielding / belly-band. Instead, I designed a new transformer

[spritzer]

Just open up the plastic cover on top of the transformers.  I did look at some pics and I don't think the Esoteric units have those covers. 

What component are you using Marc? 

[luvdunhill]

I will post some pictures when I get back. I wanted to get some extra current capability though for a new output stage, so all is well. Also, the next model up markets a toroid as an "upgrade". It's the K-07x which I can tell you is a completely different beast from the K-07. Once I drop in the new transformer, then I will plan where and how to integrate the output stage in, which should be fun.

The new APL in the making here

[spritzer]

Clearly!! 

I found some pics of the K-07x and since the primary is just two wires next to each other then I bet it is a single primary transformer.  When Stax do 100V only they still have to use 4 wires.  Actually 5 since the thermal fuse is on its own wire. 

[DefQon]

Not sure about modern Esoteric, but you would find similar "tactics" used by some Accuphase, Luxman, old school Teac Esoteric, Victor (Kenwood), Stax and Sony amp/preamp's.

[DolphinG]

Hello another question here about STAX headband.

I wonder which tool should be used to remove small pins that hold 'case holder' to arc assembly.

I know that I should push it to other side, replace case holder and replace those pins... but I think that these pins don't want to get away from their place.

Is there specific tool size that can remove these small pins?

[Quagor]

After using my srm717 for years, on a hot humid (35* 90+% humidity) day when powering down I noticed arcing and minor smoke from near Q34. After powering down for several days I tested it again, the amp seems to be working correctly but powering on or off will reproduce the arcing. A close inspection noticed the fault between the two traces (see the attached picture). 

 

I've been told told to clean between the traces with a scalpel / hobby knife, clean the board with cleaner or isopropyl alcohol and then resurface with circuit board lacquer. What I am unsure of is if this is likely to be a freak occurrence or if I have some kind of underlying issue with the amp.

 

[spritzer]

It is just a freak thing due to the age of the amp and the crappy circuit boards Stax use. 

[Mr.Sneis]

I've been dumbing down my Stax rig and this week I received a pair of "very nice" conditioned Lambda Nova Sigs with 507 pads.  Unfortunately they arrived somewhat damaged and their age is not helping.  Tried calling Yamas/Accutech but no answer.

The case holder for one side came broken in transit; luckily the seller is offering to pay to replace this (https://www.staxusa.com/stax-case-holder.html).  Is there a certain tool and size of tool I need to be able to remove the securing pin?  Tugging by hand has been fruitless though I don't want to break it.

The outer facing foam WAS intact prior to the shipping; seems the same side's driver has come unglued from the frame, this agitated the foam and it's now flaking everywhere.  I believe standard op. procedure is to remove the foam and call it a day but I will also need to secure the driver back to the frame.  Is there a certain glue or adhesive I should be using here?

Kinda bummed to get them like this but since the LNS is unobtanium now I want to make sure I can put it back together proper, thanks!

 

 

 

Edited February 17, 2016 by Mr.Sneis

[spritzer]

I just use a center punch to remove the pins but something like that would work in general. 

As for the glue, if you want them to stay put forever then use some polyurethane based glue.