Jump to content

stax mafia circuit boards


Recommended Posts

  • Replies 99
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

I expect to now be able to spend significant amounts of time on new designs  

hopefully i cleaned this up and its the current versions of everything http://gilmore.chem.northwestern.edu/boards/

try this, there should be over 300 files, had to remove a couple of confidential ones   https://drive.google.com/drive/folders/0B7egryukiT7_TFlEQlBRejdVdDQ  

Posted Images

  • 1 month later...

Are the SS DynaFet gerbers available? Couldn't find at the link in spritzer's 5/10 post, nor Kevin's 9/4 post.

Were the balanced Dynahi and FET boards done in 2011 for Lil'Kinghts GB the SS versions? They look like it, but I could be wrong... I attached the schematic I have.

What FETs were these targeted for? The BOM he had showed 2SJ76/2SK213s, but for some reason (availability), I thought the last version used something else?

 

 

 

dynafetschembal.pdf

Link to post
Share on other sites

I doubt that I ever did a ss dynafet.  I will look.

the latest dynahi and dynalo are both super symmetry, not sure which versions are the lil-knight versions

current versions would use either the that340 parts, or a matched quad of linear systems fets

Link to post
Share on other sites

Thanks Kevin,

The SuSy architecture must be fairly subtle in terms of it versus your normal differential balanced.

Here is what I had for a schematic for the dynafet balanced vs. the SS dynalo (input sections only):

I'll quit crapping on the stax mafia thread also.

Dynafet bal input.jpeg

dynalo_input.jpg

Link to post
Share on other sites
  • 2 months later...

When I try to open gerbers, probably of newer version,  in Proteus I get warning about “Bottom SMT Paste Mask” and file won’t open. After deleting corresponding line in the readme file it opens nicely in Proteus. What might the reason be that it won’t open without delating that particular line in readme file.

Link to post
Share on other sites
  • 2 months later...
  • 2 months later...
  • 3 months later...
  • 5 months later...

Looking for opinion from those familiar with the KGSSHV amp.

I am thinking of building an electrostatic amp and acquire suitable headphones.  Never having had electrostatic equipment before I expect a step up in quality from my open ear Beyers with dedicated amp.  I do have the practical experience and technical know how to build and test these amplifiers. 

Assuming that even the most basic electrostatic amp and headphones will outperform my existing dynamic setup, I would not need the very best of the best, just something decent.

Q1  Considering my existing equipment and expectation, would you recommend an alternative amplifier to build over the KGSSHV?

Q2  Should I instead just go and buy a basic STAX system?

Q3  All electrostatics use a high voltage, so why would the Carbon and Megatron be perceived as being especially hazardous to build?

 

 

 

Link to post
Share on other sites

A1. The KGSSHV uses some out-of-production transistors. While you can still buy them, fakes can be a problem, and reputable suppliers (like bdent) charge a premium. The Carbon is essentially a strict upgrade from the KGSSHV, with (I believe) all current production parts. The major advantage of the KGSSHV over the Carbon is the availability of versions with on-board heatsinks, which simplifies the metalworking considerably. You might consider building a KGST instead. It’s a great amp, and aside from matching 6S4A tubes, I found it generally pretty easy to make. Also consider the SRX Plus (though I haven’t made one of those yet). Search here for threads discussing these builds.

A2. Only you can decide that. It pays to try before you buy.

A3. The Carbon and Megatron are no more dangerous to build than any other device operating at comparable voltages.

  • Like 1
Link to post
Share on other sites
  • 5 months later...

I am still in the process of sourcing for a KGSSHV Carbon build. Unfortunately I was send one wrong board and I can´t reach the seller any more ?

So, if anyone has a KG SiC PSU PCB in Landscape with +15V -15V -400V I am happy for your PM. Additionally if anyone needs a +400V + Bias PSU, feel free to contact me.

Edit: I got an 8 Dollar coupon at JLPCB so I thougth paying 8,50 dollar for 5 PCBs is probably worth it. 

So I will give away 4 of the +-15V -400V PCBs for cost of shipping. I am located in Germany.

Link to post
Share on other sites
  • 2 weeks later...
On 2/15/2019 at 11:36 PM, Xenon said:

Q2  Should I instead just go and buy a basic STAX system?

You may be happy with a basic stax system but the problem is that if you are not used to electrostatic sound (I also run Quad 2805 electrostatic speakers) there is a big difference in sound to most moving coils. The electrostatics offer very good transparency and speed but for me bass and overall warmth has been an issue that seems to require throwing money at to solve.... 

I have a stax srm006T and sr4040 which I found to be rather bright and the bass was rather mushy. As the volume is turned up the bass gets mushier but no louder and the treble just dominates. It sounds fast and detailed this way but I am very sensitive to poor bass....

I managed to buy a pair of sr007a second hand but could not afford to upgrade the srm006T. to an srm007T. The overall ballance was a bit better than the sr4040s and there was a more natural, less bright and hard sound, but the bass was still mushy and it just ran out of steam even quicker - I guess it could not drive the sr007a...

I built a alpha centauri (http://www.high-amp.de/html/hybrid-amp_eng.html) earlier this year -  The alpha bettered the srm00t in every way It does not run out of steam, macro and micro dynamics are better imaging is better - it was my first serious diy build and I learnt a lot from building it. I was especially grateful that the power supply has full short circuit protection on the +-400V and was extremely robust.... I managed to "measure" the +400V supply with my multimeter in resistance mode ? . Some sparking at the test probes and the 400V went into over current protection... no damage done and months later its still working fine... (the multimeter survived too - a brymen bm869s which can handle 1000V in any imode). The designer of the alpha claims that you can even short the +400 and -400 together and the psu will survive. My only issue with the alpha is that the sound stage is rather flat and has no real depth and mid and upper bass is a bit lacking. .

I read reviews of the blue hawaii and the descriptions made me think it would be my kind of amp - but there was no way I was ever going to afford to buy a prebuilt.... So I’m up for building one...

To summarise, from my experience the modern stax amps from Stax are not good - and they certainly do not have a good reputation online. I think they are over-priced especially given the build quality - thin bent steel. I don’t think the 6cg7 has enough drive to get the job done. The 6sn7 of the alpha is better and I am hopping the el34 of the blue hawaii will be better still... 

If you have the time, equipment and skills to build a diy amp I highly recommend it. You can get far better sound for far less than the commercial offerings and learn a lot in the process.

regards

James

 

 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...