6AS7 Headphone Amplifier Hi,i just got my HD650 last week and want to build a cheap good amp to drive it nicely.I have searched for the circuit on the internet and found 2 circuit which is somehow close to my preference.Also,i found the tube amp Darkvoice 336 also use this tube combination.So...

Recently,i got 4 nice pots on hand and wanna build a pot for my PPA to replace the Alps old pot.But,they are different steps and structure.Two are SHALLCO 32 steps with 2 channels and others are ITT Germary 26 steps with 4 channels. After i searched all the threads about stepped pot,i found...

Recently,i have built up a PPA-like 3-channel amp called "Walker"which was designed by a "Hong Kong"er.You can see the original schematic at the 4th pic while i modified it and replaced the buffer by ha2-5002-5 in stead of buf634. It works very well with opa134 and opa627.However,when i...

Guys,what would you do if a company does not ship goods to you after you've paid for them? I am currently suffering from such problem....but i am not the US resident,how i can seek for help from the related department?

Hi all,i am new here from Hong Kong.Above is my PPA1.1 and it would be a "house amp"instead of a portable amp.I still cannot get any ideal for the C1 and C6.I would like to use Black Gate STD for the C1 and Black Gate NX for the C6,yet,it seems so expensive. Besides,i am now looking for a...