I've had this amplifier for a year now and its my daily driver, I listen to it daily. sometimes all day. it sounds great I've recently changed all tubes but the old one still play just fine. I did some upgrades to the one i have. hitronics in Canada use to have a mods page and i performed their mods and it sounded a tad better. still sounded great like the factory builds it. the parts inside are of high quality it uses nichicon and rubicon electrolytics and nice good quality resistors and rectifier diodes. the outputs are fused. i power tested my amp and get about 49 watts per channel at clip running 120v. a lot of ads show 60WPC but yaquin website shows 50WPC which is about right. plenty of power for most speakers. i run mine on a set of Bose 301's. series II.

ok some things to know, I am an electronics Tech and have had my hands in this amp. B+ runs about 500VDC before warm up, ive changed some of the electrolytics to handle this. donot power this amp on with out tubes installed or pull them out while its on, B+ too high for original caps on pcb board not the large ones on top. It needs to be rebiased occasionally after long use so check that.do not run more than 121VAC to the amp. input is 110+/- 10%. i built a buck transformer that keeps mine about 120v. my house power is 125vac. if you run this amp too high you do so at your own risk and risk blowing your amp due to excessive B+. tube heater voltage runs a lil high about 6.9vac @ 120vac input. my tubes have lasted a year and were still fine i changed them because i wanted to. do not run your amp with no speaker load. tube amps dont like that and can cause damage. Do not try to adjust bass and treble of your amp by constantly tube rollingthe pin sockets are soldered to board and easy to make a cold solder joint contantly doing that, thats like comparing apples to apples. use good speakers that have a full range and i use an eq with mine. amp sound good with out but phenomenal when you can tailor the bass and treble.crap in equals crap out! on any amp tube or not! just sayin. never turn your back on a tube amp ( dont leave unattended while on for long periods of time. tubes can fail at anytime and sparks can fly. there is a reasons we dont use tubes anymore! they still exist in my opinion as novelty for audiophiles and musicians and still best choice for high power transmitter but that's about it. now go enjoy your tube sound!

Power full and nice sound

Sub out put dont have

My first step in the tube world and still no reason to change Yaqin MC-100B. I cannot imagine how many $$$ is needed to get the another amplifier with significant improvement. Switching UL/TR mode + tube rolling possibilities in 3 raws = a lot of fun and music taste! This amplifier is really bargain, highly recommended!

I would like to know transformator quality, however the amplifier sounds admiringly. Only point to real potential upgrade.

I've owned this amp for maybe 8 years now, and while I can only compare it to a couple of solid state Caver receivers I've own for a couple of decades, it sounds outstanding and in another stratosphere from anything I've owned. I have replaced the power tubes several times and found they matter a great deal. mid-price tubes were good, but the Genalex Gold Lion really upped the ante, and now the Psvane TII to me at least produce euphoric sound. Speakers of course are a pre-requisite. For the money, its an explosion for the buck.

Have I to have it serviced every couple of years, as some shorts or blows. The parts are pennies, but in my case, need to get out to someone to take it and fix. The expense is in labor (1-2 hours times say $100 per hour)) and in the time without the amp!

Bought one back in 2006, quite impressed with the sound at this price range, but sold to a friend few years later. Just bought another one from a Hong Kong ebay seller "primeamp" (quite a helpful seller, but be reminded that their ebay listing shipping time is not accurate for their economy mail, he said that the ebay provided shipping time doesn't suit with their shipping method time and they have to choose one the longest one provided by ebay to complete the listing and sent me some of the screen shots to proof, I paid extra for airmail at the end but worth it, as it arrived from Hong Kong to my home in New Zealand in 3 days!). When it's here I found that the tubes been upgraded to PSVANE KT88s and they are much better than the original Shuguang KT88 of the old one that I bought in 2006 also something is changed, now I just have to upgrade the smaller tubes. This time I am sure I will keep this for myself and not selling to friends, will do some mods later when I have free time, but the stock amp sure will keep me happy for a long while. Want to share with the audio friends out there, this amp is worth buying, some of my friends are going to buy it as well after listening to it.

yaqin mc100b (i think it is new vertion of it)
4x kt120 tungso, 0.60 bias
4x 6sn7gtb nos international service master (made in w.germany).
2x 12ax7 black plate rca.
are you ready ?
& a really nice AR-3a.
now i think about ts kt150.
whats your offer?

I never doubted that the Yaqin 100B would prove its wonderful sound after the original tubes were replaced with Gold Lions and RCA NOS tubes. Today it has been a year since I purchased and installed it and it continues to please me with its workmanship, quality and beautiful sound. This from a guy who owns Mc equipment for many years.... Kodos to the Yaqin design and mfg. team in China. Sincerely, Louis A, NYC

Yaqin MC-100b (2013) with 4x Tung-Sol KT150, 4x electro-harmonix 6SN7EH gold pins and 2x JJ ecc803s gold pins.?
Use 4 digital multimeters to bias.? Remove 2 cage rod's for KT150.?
tone - atmosphere - transparency

I purchased this amp online on a recommendation from a musician friend, as he is also an audiophile.
I enjoyed this amp for 4 years recently sold to another friend, very quickly (after blowing up power tubes going cherry red ) realize the right voltage to run this amp is around 94Volts bringing it down from a Variac transformer (10 Amp) it sounded absolutelty amazing.
using NOS TungSol 6550 circa 1963 to 1965 ( 3 quads in stash) it sounded amazing!!!
for 6SN7 i preferred the Ken Rads or RCA Gray Glass but I also used a pair of TungSol black glass it's just they cost more than the amp itself . . .
for the input tubes I used for best results Sylvania 5751 black plates triple mica's best sounding of the bunch including the Telefunken ECC83 and the mighty RCA's and GE's
I used it as an amp feeding ofmr front connectors direct from impedance adjusted (corner frequency to 47K input on the Yaqin) very modifierd Audible Illusions preamp. this amp really sings with this combination.
i also found better (MUCH BETTER) sounding in triode strapped mode (TR)
many things to be said about this amp, maybe quality of materials was nto as great as some of the Europe's and US's best but for the price never anything come as close to a very good amp for a very small fraction of the cost.
Well recommended,
READ THE MANUAL!!!! adjust the bias on teh power tubes regularly (every 4 to 6 months if good tubes)
it's a keeper,
the only thing with more soul is a 45 or a 300B Japanese high end amp that cost probably 10 times this one (used) . . .

Enjoy the music;

Hi,
I love the sound my Yaqin MC100B, I removed all china made tubes and put in 4 Tung-Sol Kt120 (set bias with 4 cheap multimeters to 0.55mV), 4 Electro-Harmonix 6SN7EH gold pins and 2 JJ Electronic ECC803 S gold pins tubes.

I also love the sound and have Yaqin SD-30A tube fidelity output CD player, I also removed china tubes and replace with 2 JJ Electronic ECC81 gold pin tubes.

I get all my tubes from Yen Audio in USA and use tube dampers on Amp.