alvin1118

just bought a cheap and good sennheiser HD201. plug in and listen using my USB DAC, surprisingly, no hissing noise at all! wondering is it my DAC only suitable for this kind of headphone. lol

think i should isolate the problem step by step. 1st move away transformer, see is there any noise. 2nd, check on grounding loop. i suspect the noise actually comes from grounding loop issue

yah,now trying to look for mild steel. or rather just live with the low hissing noise. lol Good SMPS & cap filter would be a good solution for DAC as the power source is separated from the chassis. no more worry on electromagnetic interference.haha.. btw,DAC really sound a lot better. almost run-ed in. quite nice

the transformer actually gives me a lot of troubles. HISSING SOUND!!!! the magnetic interference is terrible. very loud hissing noise when plug in high sensitivity headphone >< moral of the story: dont save cost on important part. i should have bought one "good transformer" instead of using an old VCD Player one. sad :lookdown: no choice now, i uses anti static aluminum foil to wrap around the transformer, and ground the chassis and usb connector to somehow reduces hissing noise. it does help a lot XD hissing noise is very low now but still audible when not playing music. maybe when free then change the transformer see how

eh? i drill a hole then use file slowly make it square the power inlet also the casing is thin, can easily file it

yeah, USB DAC + RA1 GRADO CLONE AMP running in. didnt switch off for 72hours already XD thanks bro bring back to poly & drill holes. lol

haha thanks XD power supply is full bridge rectifier + LM317337. PCB get from a taiwan friend. cheap and good for all application manz. but if you want to invest on power supply, there are other higher end type. $$$$ ><

just done my USB DAC. Specification: DAC: PCM2702, 16Bits, Sampling Freq. 48khz Amp Stage: RA1 (Grado Clone!) Voltage Regulator: ROE Gold Cap, LM317337 Signal Cable: MOGAMI 2549 Overview: Voltage Regulator: DAC+RA1: Front: Rear: Running in now. i would say 999% better than built in sound card!! lol now i really enjoy music XD

i have just changed the normal copper wire which i used it for signal part, to MOGAMI NEGLEX 2549 cable. Path: ALPS VR<->Preamp<->Amp. I would say the sound is warm and sweet now! Vocal is clean and transparent! sound stage also improved. A quite impressive cable. good things must share manz XD

yah, the process of DIY is good.quite interesting especially when it works !! can share some experience with friends etc, great XD btw, happy chinese new year!

lol, will start my PCM2702 DAC + RA1 after CNY. most likely on week 11 Feb. yah it's an integrated amp. hehe~ amb lab stuff looks good! too bad that i dont have a decent headphone, else i will be diy-ing one for myself erm, i assume you are asking me right ?hahahah i got all those stuff from a taiwan friend. he is able to supply me audiophile grade components and PCB + advices. a nice person who are willing to share nice stuff XD of course @ acceptable price. lol

hmm, not sure is it appropriate to post my DIY amplifier here. Hope i didnt violet the SGHeadphone' rules and regulation all right, here's time to share with you guys my 1st DIY amplifier. Basically, it is built out of ICUTE as preamp, TDA7294 OP amp. Before i actually started building this amp, i was wondering, why audiophile DIYer keep emphasis on resistors, capacitors would affect the overall sound quality of the system. For me(at that time ^^), a capacitor is a capacitor , what it does is to dc coupling/filtering/rectifying. who cares about the brand? who cares about those 'high-end' cap? you might want to laugh @ this moment, haha. me too ><. yes, i am wrong. Good capacitors and resistors did improve the sound quality significantly!! That is the main reason why good components like Dale resistors; ROE, FRAKO, BC Components capacitors etc are always can be found in high end audio/visual equipment! Those high end components are rarely found in current market product due to the business strategy nowadays(cut cost >.<) so much words, time to show my work XD Preamp: DC-ICUTE w/ dale resistors, FRAKO Capacitors, Epos & OPA2134 TDA7294 Stereo Amp: ROE, Philip AHT118, FRAKO, SILMIC caps. ROE & Philip 118 i like the most! sound GREAT!!! Speaker Protector: Rectifier: Philip AHT118, Vitamin Q Oil Cap(detailed sounding & bass became more Q~!!), Panasonic for Audio cap Full Assembly: Closed up: Icute->TDA7294->SP linked by mogami 2549 high quality signal cable! Mogami 2546 High Quality Cable: 3.5mm to RCA DIY detailed and clear sounding ! Neglex copper EMI shield! it does make a big different as compare with low/mid end cable. try to believe! Tannoy R1 Bookshelf Speakers: Have been working with my DIY about one month. its done! i'm almost content with my audio system now now trying to build USB DAC(PCM2702) & RA1 headphone amp. my source is not so good, laptop built in sound card. lol. hope the DAC would improve my sound in greater stage! p/s: do give my 1st diy comments your comments is my encouragement! hahahaha