Sunday, May 3, 2015

Modding Marshall MS-2 to Get More Gain, Attenuator and Aux-In


 All I have to do is open the mini (micro?) amp obviously. There's four screw to open. 

The board is secured by three knobs and jack at the front so we have to screw it out as well.

After the board is exposed ( :) ), locate the resistors labeled R1, and R4, replace with wire or just create jumper on it.

(There's mod for more gain on Marshall and others forum [more jumper and replace the value of some resistor and caps to get higher treble and remove some noisy high freq] but I don't need gain that much [or that tone] for my bluesy sound, maybe later. For now, I'm pleased with the original Marshall MS-2 tone :) )

The Marshall characteristic that I didn't like (but I used it anyway) is we have to crank the gain up to have an overdriven sound. But that means we have a high volume out from amp.

If we want to practice with full gain in the middle of the night at the normal bedroom (not sound-proof-ed), we could add a 5k potentiometer before speaker (of course we have to cut speaker positive wire) and we could practice in full gain but lower volume.

Next, create additional input, aux-in for iPhone or mp3 player. Locate the resistor next to volume potentiometer (it connected to center of volume pot and a capacitor at the other end). Disconnect the resistor pin connected to the cap. Connect it to one of mixer input (other input is used for aux-in). The output of the mixer (very simple mixer) must go to cap (where the end of resistor previously connected)

Ups, almost forgotten. We have to create holes somewhere in the amp to accomodate three pot (two for mixing guitar and aux in, one for attenuator) and one for aux-in jack.

Well, the result is surprisingly great for two hours work. (I'm very clumsy at soldering thing)


(update: it works well with batterry but the power seems lost while using 9v adapter [I checked it with two adaptors], hopefully it just bad connector. Will check it later)

Modifikasi Ampli gitar Marshall MS-2

Buka ampli dengan obeng, ada empat baut di belakang

Lepas PCB dengan mencopot knob velume, tone dan on-clean-od (lepas juga mur/bautnya). Jangan lupa lepas mur/baut jack input.

Cari resistor R1 dan R4, copot, ganti dengan kabel biasa. Overdrive sekarang jadi super drive, :)

Ciri khas ampli marshall adalah kita harus memutar gain untuk mendapatkan sound dengan overdrive. Namun hal tersebut juga meningkatkan volume secara keseluruhan.

Jika kita ingin berlatih malam-malam tanpa diumpat tetangga atau digebuki orang serumah, tambahkan attenuator berupa potensiometer 5k sebelum speaker. Potong kabel speaker positif, sambungkan masing masing potongannya ke pin tengah potensio dan salah satu pin pinggir. Dengan cara demikian


Tambahkan input tambahan, aux-in, untuk ipod, iphone, smartphone atau mp3 player. Cari resistor yang terhubung dengan pin tengah volume dan terhubung ke kapasitor. Potong/lepas kaki yang terhubung ke kapasitor dan sambungkan sebagai salah satu dari dua input dari mixer (input satunya untuk mp3/ aux-in). Output dari mixer dihubungkan ke kapasitor yang tadinya terhubung ke resistor pin tengan potensio volume.

Saya membuat beberapa lubang tambahan untuk jack mp3, volume attenuator, volume gitar, volume mp3.

Hasilnya lumayan

(PR-nya, jika pake baterry outputnya besar/keras, tapi kalo pake adaptor suaranya sangat-sangat lemah, ada yang bisa bantu? Saya curiga ada yang tidak beres dengan sambungan adaptor ini )