Jump to content
thrice

The Headcase Stax thread

Recommended Posts

On 7/28/2017 at 8:38 AM, Dave R said:

Would 007 ear pads work on 009's ?

They are a few (2-3) mm smaller in diameter, and 2-3 mm thicker both in front and back side. You can install them on the 009 by some stretch, but I am not sure they will sound in optimal way. The inner opening of the 009 pads is larger, and the air volume between the ear and driver is slightly larger. But IME the 009 is the most invariant Stax vs pad changes, so there is hope. There are some slight chances one would even prefer the sound with the 007 pads, but IME the 009 sounds best (= most natural and neutral) with the stock 009 pads. With the 007 pads it was more relaxed, but not as neutral any more. If you already have 007 pads to try, just try and see, otherwise better spend the money on 009 pads.

https://www.staxaudio.com/earpad/stax-sr-009-earpad

These pads look very similar to the 009 pads, but synthetic leather?  The originals are mostly leather, with only some flaps from synthetic leather (AFAIK). Maybe the description is misleading?

I've got my 009 replacement pads from the local Stax distributor for 140 euros (IIRC), but I waited 6 months until they arrived. Stax surely should provide replacement pads to 009 owners, maybe they ask the serial number nowadays, I don't know - my dealer managed it.

Share this post


Link to post
Share on other sites

On that other site, someone has been using rubber bands on their 009's headband, which apparently creates more clamping force, but in doing so has broken part of the headband.

Now if I still signed in on that site ( which I haven't done since May ) I could send them a PM explaining the headband I did for my 009's shown in the photo, which feels slightly more tight ( but still extremely comfortable ) than the Stax original headband,  but seeing how I'm not signing in on that site ever again, they'll either have to carry on with the rubber bands, or come up with a different idea. 🤔

IMG_2603.thumb.JPG.34cac6d22e7e71ab31d45212d4985356.JPG

 

  • Like 1

Share this post


Link to post
Share on other sites

Searching on HF for "009 headband replacement" brings up instructions for a nice mod on the first hit. Not the same user name as here, but I'm guessing it's yours. Pretty sure that anyone capable of doing that mod will have thought of doing that search.

Share this post


Link to post
Share on other sites
11 minutes ago, gepardcv said:

Searching on HF for "009 headband replacement" brings up instructions for a nice mod on the first hit. Not the same user name as here, but I'm guessing it's yours. Pretty sure that anyone capable of doing that mod will have thought of doing that search.

On HF my username is David1961, but I came to prefer Dave R. I did try to change it to Dave R on that site but was unable to do so, however now it doesn't matter.

Share this post


Link to post
Share on other sites
49 minutes ago, gepardcv said:

Searching on HF for "009 headband replacement" brings up instructions for a nice mod on the first hit. Not the same user name as here, but I'm guessing it's yours. Pretty sure that anyone capable of doing that mod will have thought of doing that search.

I thought the bright yellow rubber bands did a wonderful job of bringing out the highlights in his eyes. Not sure he needs to improve upon it any further.

Share this post


Link to post
Share on other sites

Latest state of the egmont clone from china:

Pro socket is changed from shitty one to teflon one.

IMG-20170821-WA0015.thumb.jpg.3ef3d4d9010b43f490f13ca1282ea3ac.jpg

Capps on signal path  are changed from mundorf 0.15uf supremes to 0.15uf jenzen copper foils.

IMG-20170821-WA0014.thumb.jpg.e1229d8db5d12c4456f19cf7cc4698ef.jpg

Choke filters in power supply are changed from CRC to CLC. Air core inductors are used.

Diodes are changed to SiCs

IMG-20170901-WA0000.thumb.jpg.1a5b1861b5b093e8505788e4b86aa9ff.jpg

IMG-20170901-WA0001.thumb.jpg.fd5039c0ca7f90737895592bd392a201.jpg

 

You might think "why do you spend so much time and money on a shitty amp?!" But I think "what man is a man who does not make the world better."

:)

Chasis of amp will change and transformator will be torrodial from torody.

Edited by Sechtdamon

Share this post


Link to post
Share on other sites
5 hours ago, Sechtdamon said:

Are jensen's are fake Antonio?

They are bought from hificollective.co.uk

https://www.hificollective.co.uk/catalog/jcs110-015uf-630v-jensen-copper-foil-tube-p-8414.html

I'm probably wrong, sorry Özgür. The font of the "audio capacitor" line seemed a bit larger and bolder than I remember in them. Why do you think the Jensens are better than the Mundorf Silver in Oil? I hadn't said so.

  • Like 1

Share this post


Link to post
Share on other sites

It's okey Antonio. For a moment you got me :) mundorfs were entry level one, not silver in oils. It's in test now, I'm going to listen it next week.

I hope it can drive 007s. :)

Share this post


Link to post
Share on other sites
On 02.09.2017 at 9:41 PM, dsavitsk said:

Those leads look awfully close to shorting

I'll ask my friend for checking them. Thanks for feedback Doug. :)

Edited by Sechtdamon

Share this post


Link to post
Share on other sites

I was just reading HF and came across this "gem". 

59b126d4e73c0_megahertzstaxamp-1.jpg.86f5a44f3da2ea60d5938b54e73f8fe9.jpg

It's not an amp...it's a "musical instrument"!!  Yeah...what the fuck is it with Italian amps being garbage? Rudistor and now Megahertz...  Bask in the glory of this hand built masterpiece:

59b126d6f12e2_megahertzstaxamp.thumb.jpg.13245b122e845dd070b9ab99fda34a7b.jpg

As soon as I saw this it was eerily familiar...  So back in 1968 Stax released two schematics, the SRX and a simpler two tube design with grounded cathodes.  Back in 2013 I released a schematic of a balanced take of that amp and built one unit.  It was ok for a cheapo amp but yeah...nothing that sets the world on fire.  Here is the schematic:

staxAsota.thumb.jpg.0a69f0e70b9d1f6b29b3605be9d156b2.jpg

Ok so let's look into this.  Two 9 pin tubes so ECC83 input (pretty much has to be for enough gain) and any of the high power dual triode noval tubes.  6CG7 would work...  So we clearly have a resistor loaded output stage with a grounded cathode and output caps (the big ones) and high value resistors after the cap to ground.  The input is clearly balanced and not many versions of that possible with interstage caps.  Electrolytic cathode bypass caps for higher gain and those silver things might be the input caps.  Sure as shit there are four of them... 

Now for the PSU and just the parts quality... this sure as shit doesn't look regulated or filled with quality parts at all.  I guess that and the mediocre circuitry makes this worth 1/2 of what Woo ask for the WES and a "musical instrument". 

  • Like 1

Share this post


Link to post
Share on other sites

You missed the best one, the Guerra (Italian for "war"), which has...wait for it....output inductors.  Oh, wait, sorry, here's what the manufacturer says, "Although it may seem like our truncated circuit, it has been designed with great care and the output inductance has been realized as a high level transformer, on two holes, with different splits, just like a secondary output transformer!"

 

Outside:

img_5317.jpg

Inside:

img_0217.jpg

 

Looks like passive power supply.

Edited by JimL

Share this post


Link to post
Share on other sites

why do the 2 pictures not match, specifically the input attenuator hanging out the bottom (or top) and the rotary switch?

definitely gotta love the Mikhail capacitor mounting technique.

Share this post


Link to post
Share on other sites

Yeah, funny that the pics don't match at all.  Also, why 6 triodes to drive the output tubes balanced?  You can do it with 8 but 6?  I very much doubt it... 

Well unless the middle tube is a phase splitter and it's just a two section amp?

Share this post


Link to post
Share on other sites

Definitely unbalanced input only so middle tube is phase splitter and the other tube is a driver.likely just a push pull amp with a really big output transformer

Share this post


Link to post
Share on other sites

Don't know about the pictures.  Copied directly from p12 of the HF thread "Stat SR009 and T2 successors confirmed for spring 2017"

Share this post


Link to post
Share on other sites

Look at the input wiring, the XLR's go to the attenuator but the RCA's (I assume they are RCA's on the right) go directly to the middle tube.  So this is a pretty horrible clusterfuck of an amp... 

Edit:  Yup, those are RCA's on the right:

http://www.megahertzaudio.it/guerra.htm

 

Edited by spritzer

Share this post


Link to post
Share on other sites

one other thing about that single input tube, both channels inside the same tube definitely reduce the channel separation.

and those monster stax transformers are obviously stax stickers attached to something custom.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×