I will not use “Ultimate” or “Premium” project since no one knows (even me) the result of this Gainclone project. I would say… “Ridiculous Gainclone”. Is that OK? 😉 To be honest, this more likely a mini battleship (A-Wing?) on the StarWars movie than an amplifier.
A brief view of it, from the top. Powered with Mundorf Supreme Silver/Gold/Oil as input coupling capacitor (2.2 uF), Vintage NOS SCR 22 uF as feedback capacitor, and Black Gate F Series as power capacitor, bypassed with K40Y Russian oil capacitor. Isn’t that “ridiculous”?
Keep reading, I will show some things I have done today to assembly my Gainclone.
First, I need to clean the leads of the LM1875. You can use scissor to clean the leads to remove any dirt (to make a perfect contact? Yeah right!).
Then, add some WBT Solder on the leads. Why? This will create better signal path (because WBT Solder contains silver inside). Oh well, you can pick any solder which you prefer most. Mundorf M-Solder with Gold also quite recommended. But since this LM1875 tends to have “warmer” sound, so adding some WBT here should be perfect.
Make sure everything is OK? I need to check the “health” status of my capacitors. Especially the NOS one. My Sanwa analog multitester is my best friend for this purpose. Perfect and accurate.
Also need to check for the capacitance. Less then 5% is accepted for me.
The feedback capacitors are mounted. Umm… what a size!
Cannon mounted! I mean, the 2.2 uF Mundorf Silver/Gold/Oil 😉
Another shoot from other side. Those tiny LM1875 are mounted directly to the bottom heatsink. Should be enough to deliver about 20 Watts RMS.
Shoot from the back side. I use “cheap” Shark RCA connector. Will upgrade to Cardas Rhodium later.
That’s it! How does it sound?
Ha~~~ I haven’t tested it! It was too late at that time. Too tired, too lazy, and don’t have enough stamina to held a listening session (and I also haven’t finalized my power supply design anyway). So just wait…
GaëtanDecember 7, 2009 05:02
Thank you so much for sharing your passion as you do it so well. Your website is full inspiration for me and you explain thing in the right manner. Would you mind telling me the chosen value of you power supply decoupling bypass capacitor(K40Y Russian) that you will start with. Also are you using an output coupling capacitor as shown in the typical application datasheet named C5?
I was just curious as I’m currently playing around with tda2030 as first project but may want something more serious for later and I’m gathering idea for that.
Cheers again for you time and involvement,
Jimmy AuwDecember 7, 2009 20:45
Decoupling bypass capacitor should be vary between 0.1-0.47uF.
C5 is not an output coupling capacitor, but it’s a RC filter (Zobel).
ArieDecember 8, 2009 17:34
Tunggu apalagi pak Jim…
Fire up!!! 😀
ArieDecember 8, 2009 17:36
Btw, LM1875 nya sampe “ngilang”, belum ditambah pasukan gerbang item, makin “lenyap” tuh chip amp hahahaha… 😀
Maju terus pantang munduuurrr!!
Jimmy AuwDecember 8, 2009 21:25
Hehehe… belum keluar mood untuk ON-in-nya hehehe…
GaëtanDecember 9, 2009 10:00
Cheers for the info.
From this I found that: A boucherot cell (or Zobel network) is an electronic filter, used in audio amplifiers to dampen out high frequency oscillations that might occur in the absence of loads at high frequencies. Named after Paul Boucherot a boucherot cell typically consists of a resistor and capacitor in series, that is usually placed across a load, for stability.
And I am really curious on how to do it good. Any thought?
DonnieDecember 9, 2009 12:06
Gileee ko Jim two thumbs up..hehehe
jd jantung dr amp nya sendiri (lm1875) cuma nyumbang kurang dr 1% dari total cost right ?
Jimmy AuwDecember 9, 2009 20:38
Listening is believing. You can compare with and without Zobel. No best recipe for all.
Jimmy AuwDecember 9, 2009 20:38
Mungkin less than 0.1%…
Damar.NDecember 17, 2009 12:19
pak jim..itu bikin amp. kayak gitu ngabisin berapa ribu??..-rada tertarik nih..hehe..
Jimmy AuwDecember 17, 2009 21:38
Hehehe… silakan diitung aja bro harga per komponennya… Mungkin yang paling mahal ya Mundorf-nya yang hampir 2.5jt sepasang.
p31rDecember 20, 2009 05:37
hahahaha this is most rediculous audio project i have ever seen. well good luck in your mission jim.
yoelDecember 25, 2009 23:55
wuihh.. kayanya benny emerald hrs bikinin PCB sesuai kebutuhan ko Jim neh… hehe… pisss…lanjoot..
Jimmy AuwDecember 26, 2009 00:24
Hehehe… saya lagi coba2 saja. Kalo bagus, mungkin akan bikin ulang dengan P2P atau bikin PCB sendiri yang lebih lega.
sopoikiDecember 28, 2009 02:45
tanya nih. Kenapa pilih gainclone LM1875, kenapa bukan seri yang lain? Apa sih kelebihannya?
Jimmy AuwDecember 28, 2009 21:16
Ah saya tidak butuh watt besar-besar, jadi 1875 mestinya sudah cukup buat saya.
arieDecember 31, 2009 21:15
penasaran, sudah habis berapa duit tuh pak??
AnonymousJanuary 1, 2010 21:58
just like V12 engine with greedy blower! can’t imagine how does the sound blow out from the muffler…:D
Jimmy AuwJanuary 1, 2010 22:27
He he he… bisa diitung sendiri dari harga per komponennya Pak…
Jimmy AuwJanuary 1, 2010 22:28
He he he bisa diitung sendiri dari harga per komponennya Pak.
even silver solder is mostly leadJanuary 9, 2010 23:19
Hi, love the site!!, looks like a great project and I have been looking for ideas for a ridiculous gainclone to use up some spare caps I have around, which were not enough for my builds of late as I only have 2 of each and everything has been balanced lately. I have 2 x VCAP OIMP 3.3uf, 2 x mundorf SIO .67uf (think thats the value), 2 x duelund 3.9uf VSF copper and plenty of blackgates and nichicon KZ.
ridiculous enough?? 😀 one thing I did wonder, your method for tinning the chip leads really doesnt make sense to me, even silver/gold solder is mostly lead/tin and only 5% silver MAX (eichmann is 5% and is highest) the leads on the device will be copper under the tin (so I agree with scraping the coating) and copper is far better than lead, in fact I use solderless connections whenever I can because of this.
the best way is solderless or weld with jewelers solder, only some components as it is a very hot process.
regardless I look forward top seeing the finished amp and your impressions of the sound
jeremyJanuary 9, 2010 23:30
wow I screwed up my name 😀 I made the post above. sorry I had lead on the brain, tin is what I meant not lead. and just saw that this one has a larger amount of silver, but is still only 9% compared to mostly tin, so I would still think that if you scrape off the tin on the lead and leave it like that or perhaps treat with deoxit it would be better. I doi understand the logic though and i’m most certainly not one of these doubting thomas’s 😀
Jimmy AuwJanuary 10, 2010 11:04
Even 0.1% of Gold on MCap Supreme Silver/Gold solder is enough to make your tin looked shining as Gold.
The rest is our preference.
Dan Lo-IFebruary 6, 2010 06:15
AYO!! AYO!! AYO!!
Hihihi.. kompor Meleduk buat tanggal 20 Feb ntar
Jimmy AuwFebruary 6, 2010 15:25
Huahaha… jadi penonton aja deh tgl 20 nanti mah. Uda banyak yang bawa amunisi 😉
fauziFebruary 27, 2010 22:11
Salam kenal nama saya Fauzi, Pak Jimmy mao tanya gainclone LM 1875, kelasnya apa ya, kelas A atau AB. Thanks sebelumnya
Jimmy AuwMarch 1, 2010 22:54
Hampir semua chip-amp biasanya Class AB atau bahkan Class D.
danielDecember 6, 2010 22:35
1)POT(volume control) before input coupling cap, and
2)zobel at the speaker output
required to change the current parts value?
I’m afraid it will effect the gain, frequency cut-off or cause it to oscillate.
Auw JimmyDecember 7, 2010 10:13
You can always add volume control before the amp, since this volume control will act as passive preamp.
1875 should not need any zobel – I think.
AgusDecember 14, 2010 12:30
Belum tes dengar juga koh? 😀
Auw JimmyDecember 14, 2010 18:26
udah, dan uda dibongkarin lagi malah 🙂
AgusDecember 15, 2010 09:03
Waduh… perasaan belum diposting reviewnya deh koh………….. 😀
Auw JimmyDecember 15, 2010 09:19
Biasa aja sih, ga ada yang menarik.
Jadi males bahasnya juga. Uda keburu dibongkarin.
Kalo ga males, nanti mau coba p2p-nya, mungkin itu lebih menarik 😉
andreMay 2, 2011 22:45
kebetulan ada pcb begini nih buat lm1875..cm belum dirakit.. yg pgn saya tanya,,perlu tambah pcb lg gak buat bank cap/psu ? atau lgsg aja.. thanks
Auw JimmyMay 2, 2011 23:50
Tergantung kamu sendiri. Mau pake PCB bisa, mau langsung juga bisa.
andreMay 3, 2011 19:33
btw masi ada lebih gak lm1875 nya ? nyari2 di glodok gak dapet nih om jim..di ayung abis,,di bowo abis.. dokter ada ga ya ? sempat tanya ke tmpt jual sparepart tv sony,,ada yg asli dibungkus sebiji2 gitu,,cm harganya @95rebuu..
Auw JimmyMay 3, 2011 21:58
Halo Pak Andre,
Saya ada untuk pakai sendiri saja.
romiMay 7, 2013 20:50
wow..komponen audiophile pak..
hendyJanuary 27, 2014 00:31
Salam kenal Pak Jimmy,
Wah gak bisa bayangin suara+dana nya pak,
AgungJanuary 27, 2014 11:23
Salam kenal Bang Jimmy, manttaaap dah bang
Boleh minta skema yang digunakan oleh abang untuk bikin GC LM1875, kalo boleh bisa kirim ke email saya
Matur tengyu sebelumnya, salam DIY’er
Auw JimmyJanuary 27, 2014 13:38
Hi Mas Agung,
Saya hanya pake skema asli dari LM1875. Bisa didapat dari website National, di datasheet LM1875.