Kung

wow~ brass housing... I just simulated it on solidwork, the weight of each is over 300 grams, it is a disaster to wear this stuff on the head 😶

it seems very odd，do you mean that the sound of 007 is different after 717 modification? for all I know，only 727 negative feedback modification, never heard of 717's（CCS mod?），717 is pretty a kgss and should be no problem driving 007. Providing headphone frequency response or some amplifier tests should make it easy to find the cause of the problem.😶

Here are more pictures of PCBs that may be an early version. They look identical in terms of layout.

I saw a portable estat amplifier on a Chinese e-commerce platform and it looks very similar to kevin's amplifier, Is this the commercial version ?

From the picture you posted, there are some flocs have been inserted into the driver house，yea, it is more difficult to clean up for the mesh stator...😬

SR-X MKIV lol..

hell，so far as I know，tokyofansile is a japanese distributor of JR Audio on taobao，JR Audio has built many clone version of spritzer amplifiers and shipped them to japan，vietnam and thailand🙄

bk version sounds similar to the standard SR-009, maybe a little bit more distant and tighter bass due to the new thicker earpads.

no servo at all

agree agree

I have made a t8k input stage board for my bh，with a little bit tweaking，they've been working for 4 months，and T2 input stage can work fine as well. ?

chinese bhse from taobao jr audio。。。

rare and expensive audio equipments are popular in china and people are willing to own a machine like singlepower as their audio collection，and I'm sure vertek now is ready for the copy of headamp's bhse.

the jr audio on taobao? i know you，you're a fan of spritzer.

‘FOTM’，what's the meaning of that？

http://webcache.googleusercontent.com/search?q=cache:_8k5_bjQSfUJ:stax.xsrv.jp/products/sr-009s/+&cd=13&hl=en&ct=clnk&gl=hu SR-009s

I try 02N120P as output fets，this time fr(-3db) can run up to 74Khz，and (-6db) about 114Khz. circuit works much better now.

10m90s

it's good to see more es amp designs. The thd+n is really low about 0.005% fr(-3db)only reach about 11.6Khz and -6db at 19.9Khz from multisim ac analysis when gain is set at 46db，higher the gain the lower fr will be，not sure the circuit works properly ，btw it's easy to run kgsshv fr(-3db)over 110khz or even higher，and 2nd harmonic distortion of -79db and 3rd harmonic distortion of -61db at 1Khz

nicely done ！

rumor from edifier dealer said that sr-009s is ready to launch

great job! kerry

yup，T8000 is another 727 like amp，still haven't enough power.

I see Carbon removed the output buffer stage from KGSS ，So... for es amp，is the output impedance no longer important ?

wow，that's a lot of money