Wednesday, August 19, 2009

GAINCLONE LM1875





Finally..i can build gainclone using LM1875 chip amplifier from National. At previous I build gainclone using TDA chip amplifier series, because it’s difficult to find LM series in my place. I find LM1875 in one electronics store, that’s only one electronics store that sell LM1875. I spend Rp.30.000,- for one pair of LM1875 (RP.15.000,- for one chip).
I build my gainclone in three days, at first I fitting all of component to PCB. The schematic and PCB layout is same with my gainclone TDA 2050. I spend much time for building chassis which made of alumunium material. I finished my chassis in two days.



SOUND TEST
For testing, I choose to play ‘Here I Am’ from Bryan Adams using Winamp. I connect the computer out directly to the my gainclone without pre-amp. The sound is very natural, the best respons of my gainclone at middle and high frequency, low frequency is too warm, its very suitable for playing jazz, so I decide to play ‘ Rahasia Perempuan’ (jazz version) by Muhammad Dhani & The Swinger. Exactly!!the sound is perfect…vocal very natural and open, treble so crispy, bass very warm. I can heard differences significaly between gainclone base of LM1875 and TDA 2050. TDA series….ke laut aje!!!!
My gainclone using chosen components, R metal film, MKM, Audiophiler capasitor as input coupling, ordinary elco (pfiuh…), and 5 Ampere transformator BIG and rotary potentiometer. For the next, I plan to increase my gainclone performance by replacing all elco with better type, replacing the transformator with toroid and replacing potentiometer with passive attenuator. I hope it will come true….cause ….bokek nda…ben dino nggawe proyek terus…hasrat tuk menyolder dan menyolder serta menyolder tak kuasa ku tahan……









Penampakan terakhir Gainclonku:

-Rf diganti Takman
-Rg diganti Prp red
-Audiophiler diganti Solen 4,4 uF
-Caps keramik diganti silver mica 220 pf
-Elko supply diganti Siemens sikorel 2200 uF
Penggantian baru itu, tapi efeknya langsung kerasa....sangat signifikan sekali perbedaanya. Mid lebih open, high lebih nyess.....cukup puas!!!!




UPDATE:
Gainclone-ku kian hari kian ajib....trafo yang semula masih pake trafo roti (kotak) murmer, kini ganti sama trafo donat...disamping suara tambah maknyus tampilanpun kian apik, elko reservoir ditingkatkan kapasitasnya dengan menambah satu pasang elko Selfic 3300 uF/ 50volt.
Nuansa futuristik menjadi kian menarik dengan pemasangan enam buah super bright led biru..






Gainclone kebanggaanku ini saya jodohkan dengan Subwoofer Gainclone LM3886.

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