Jump to content

The Headcase Stax thread


thrice

Recommended Posts

they quote .0008% thd

has to be koss circuit. opamp driving stack of transistors. lots of gain and lots of feedback.

no chip amp driving a transformer can do this.

and nothing else can do 2000 vppss

also remember they are doing this on a total power budget of 15 watts.

 

Edited by kevin gilmore
  • Like 1
Link to comment
Share on other sites

From topping's previous amplifier products, the EHA5 normal amplifier section is likely to be a composite amplifier, just like the amplifiers of jds atom and benchmark things. The common practice is to combine a precision opamp1 with a higher idle current opamp2 which has a specified closed-loop gain. opamp2 is placed inside the feedback loop of opamp1, which is the "feed forward technology" claimed by some manufacturers. In fact, it introduces a huge amount of feedback, the distortion test is usually lower than what the manufacturer's specs , but I don't know whether it can drive the transformer to output such low distortion though...never tried before 😟

Edited by Kung
Link to comment
Share on other sites

2 hours ago, Kung said:

From topping's previous amplifier products, the EHA5 normal amplifier section is likely to be a composite amplifier, just like the amplifiers of jds atom and benchmark things. The common practice is to combine a precision opamp1 with a higher idle current opamp2 which has a specified closed-loop gain. opamp2 is placed inside the feedback loop of opamp1, which is the "feed forward technology" claimed by some manufacturers. In fact, it introduces a huge amount of feedback, the distortion test is usually lower than what the manufacturer's specs , but I don't know whether it can drive the transformer to output such low distortion though...never tried before 😟

So it is basically what Quad was doing 50 years ago?  😉

Now given it is a step up transformer solution, the light weight of it does worry me as good quality iron has to have a certain weight to it. 

Link to comment
Share on other sites

8 hours ago, thebrunx said:

New King?

King of the trash maybe, not much more.  Assuming that it is well made (a big ask for Topping), it made to spec (also something I really doubt) and will not burn up headphones... This will be on par with the Stax SRM-1Mk2/3/313/323 amps in terms of performance.  Might be ahead of the 353 or D50 as they are both trash. 

26 minutes ago, justin said:

this is why it's basically pointless to advertise specs anymore

Indeed and also a small issue with the 2000Vppss voltage swing, if you go much above 1200Vppss... there is a major risk of burning up the headphones.  Completely useless stats. 

Link to comment
Share on other sites

i have never seen a transformer output amplifier ever generate thd numbers like that. Not a single one regardless of cost.

not even the lundhall silver thing thats $5k each.

can't wait to see what a 10khz square wave looks like.

also likely that its not actually a balanced amplifier even though it has balanced inputs.

i think that kingsound made a chipamp/transformer portable. never heard anyone that liked it.

 

Link to comment
Share on other sites

13 hours ago, Timb5881 said:

The old SRD-x Pro was a transformer driven by an amp.  That may be a he best comparison for this amp.

Indeed but I hope the power amp has moved on a bit from the early 80's...  ;)

9 hours ago, thebrunx said:

aren't Topping known for being giant killers?

It's mediocre crap from China, I don't see how that would be the case.  It's one of a host of similar products that don't stand out at all. 

Link to comment
Share on other sites

Hi

I recently got a stax x9000 and am using a placeholder energiser in stax srm727a (modded). I find the bass to be lacking and it to sound shrill. What energisers do you recommend that's around 3k that I can use with the stax until I save up enough for a better buy? Thanks!

Link to comment
Share on other sites

::)Ray samuels the old friend of stax mafia just released a new amplifier B-21, the electrostatic part claimed 1800Vpp voltage swing with 200mA continuous current output performance just shocked me. . . Reminds me of the horribly weak output performance of the A10 he designed before, this new amp is also questionable...

 

B21.jpg

B211.jpg

  • Like 1
Link to comment
Share on other sites

Holy fuck that thing is ugly and yeah... color me skeptical ;) of those numbers.  1800Vpp would point to either +/-450V or +/-500V rails (given the regular losses) so either 900V or 1000V at 200mA.  That's 180-200W, per channel and those heatsinks are not big enough for even a tenth of that. 

I also love that Ray dug out a 20 year old CD player (which I'm shocked still works as I had one of those)... 

Link to comment
Share on other sites

so a darkstar driving transformers.

yep great idea.

no toobs :(

where else have we seen a red knob.

on the brighter side its probably better made than the viva. and cheaper.

possible spoiler:  transformers made by audiostatic, holland.

spoiler is incorrect :D

and ray clearly does not understand how current works.

 

 

 

 

 

Edited by kevin gilmore
Link to comment
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...

Important Information

By using this site, you agree to our Terms of Use.