kevin gilmore Posted April 11, 2023 Report Share Posted April 11, 2023 (edited) 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 April 11, 2023 by kevin gilmore 1 Quote Link to comment Share on other sites More sharing options...
Kung Posted April 12, 2023 Report Share Posted April 12, 2023 (edited) 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 April 12, 2023 by Kung Quote Link to comment Share on other sites More sharing options...
Kung Posted April 12, 2023 Report Share Posted April 12, 2023 it is topping a90d amplifier driving step-up transformers，just get confirmed by manufacturer. Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 12, 2023 Report Share Posted April 12, 2023 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. Quote Link to comment Share on other sites More sharing options...
thebrunx Posted April 12, 2023 Report Share Posted April 12, 2023 New King? Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted April 12, 2023 Report Share Posted April 12, 2023 so birgir bought a a90d without knowing it. nice. 3 Quote Link to comment Share on other sites More sharing options...
justin Posted April 12, 2023 Report Share Posted April 12, 2023 18 hours ago, kevin gilmore said: they quote .0008% thd this is why it's basically pointless to advertise specs anymore Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 12, 2023 Report Share Posted April 12, 2023 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. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted April 12, 2023 Report Share Posted April 12, 2023 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. Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 12, 2023 Report Share Posted April 12, 2023 Yup that's the M03... it's not good and there are some others on the Chinese market. Quote Link to comment Share on other sites More sharing options...
Timb5881 Posted April 12, 2023 Report Share Posted April 12, 2023 The old SRD-x Pro was a transformer driven by an amp. That may be a he best comparison for this amp. Quote Link to comment Share on other sites More sharing options...
thebrunx Posted April 12, 2023 Report Share Posted April 12, 2023 aren't Topping known for being giant killers? Quote Link to comment Share on other sites More sharing options...
catscratch Posted April 12, 2023 Report Share Posted April 12, 2023 Yeah any headphone giant you plug in is gonna get killed. 1 1 Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 13, 2023 Report Share Posted April 13, 2023 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. Quote Link to comment Share on other sites More sharing options...
Tachikoma Posted April 13, 2023 Report Share Posted April 13, 2023 11 hours ago, thebrunx said: aren't Topping known for being giant killers? https://www.audiosciencereview.com/forum/index.php?threads/topping-l30-headphone-amplifier-review.15226/page-150 headphone killers maybe... Quote Link to comment Share on other sites More sharing options...
thebrunx Posted April 13, 2023 Report Share Posted April 13, 2023 Seems like everyone is still placing an order. Quote Link to comment Share on other sites More sharing options...
greenpips Posted April 13, 2023 Report Share Posted April 13, 2023 GOSH I will sell all my toppings now. Quote Link to comment Share on other sites More sharing options...
kyorakun Posted April 13, 2023 Report Share Posted April 13, 2023 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! Quote Link to comment Share on other sites More sharing options...
mrmarbach Posted April 13, 2023 Report Share Posted April 13, 2023 (edited) Mjölnir KGST Edited April 13, 2023 by mrmarbach Quote Link to comment Share on other sites More sharing options...
Kung Posted April 15, 2023 Report Share Posted April 15, 2023 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... 1 Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 15, 2023 Report Share Posted April 15, 2023 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)... Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted April 15, 2023 Report Share Posted April 15, 2023 (edited) 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 and ray clearly does not understand how current works. Edited April 16, 2023 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
qqiao Posted April 16, 2023 Report Share Posted April 16, 2023 For eha5, you may refer to this thread on erji.net, http://bbs.erji.net/forum.php?mod=viewthread&tid=2300120&extra=page%3D1 Quote Link to comment Share on other sites More sharing options...
nopants Posted April 16, 2023 Report Share Posted April 16, 2023 (edited) What is this? I wonder what's made everyone try their hand at making electrostatic stuff, not that I mind it but it feels like it's everyone rushing all at once Edited April 16, 2023 by nopants Quote Link to comment Share on other sites More sharing options...
spritzer Posted April 16, 2023 Report Share Posted April 16, 2023 It's for the "tube effect", there is one on either side of the amp. Quote Link to comment Share on other sites More sharing options...
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