Yaqin Tube Valve Amplifiers

Comment from Niels Østergaard
Time: June 18, 2008, 8:26 pm

Hi Dan,

I bought a Yaqin MC100b a few months back and I´m very happy with it. It
works wonders with my Yamaha NS1000M´s. I also own the Yaqin MS12B which
I use solely as a RIAA. IMO that too outperforms units costing a whole
lot more. Now, concerning the power supply stage and the voltage: I live
in Denmark and in my area the highest voltage that I´ve messured was
228V. Should I worry?

I hope you will take time to answer my question and good luck with your
service business.

Best regards

Niels Østergaard

Comment from Dan Ashby
Time: June 19, 2008, 9:48 am

Hi Niels,

According to this page:

http://en.wikipedia.org/wiki/List_of_countries_with_mains_power_plugs%2C_voltages_and_frequencies

Denmark has a 230v supply – the same as the UK but in the UK a tolerance is specified that can mean the voltage goes 10% over which is 253v. I’ve regularly seen voltages around the 240 mark. If yours stays at or around 230 then I don’t think you have a problem. I’ve not owned a 100b so I can’t comment on the build. In my experience the more expensive models had more overhead anyway as the components were better specified.

My advice is not to worry and simply to enjoy it.

Dan

Comment from Carl
Time: July 29, 2008, 10:51 pm

Hello there,

I am entirely new to the world of valve amplifiers and have stumbled across the YAQUIN MC-100B which looks like amazing value for money (£380). I live in the U.K and from looking at the information on your site these YAQUIN amplifiers need to be adjusted to work in the U.K. Is this correct or should I be able to order the product without worry? I have virtually no knowledge of electronics! Is this product not for beginners like me?

Comment from Pete from down under
Time: August 9, 2008, 5:54 pm

Great site very informative & supportive. I bought the MC-10L new model a few weeks back. Been using it with the Proac 1sc. Sounds excellent, however yesterday I blown 2 fuses in a row when turning it on. Now I’m too afraid to replace the fuses again. We have 240v over here in Australia. Could it be the surge coming in that too high. Any comments are welcomed!!!

Comment from Dan Ashby
Time: August 11, 2008, 1:02 am

You could try a slow blow fuse instead of the fast blow they are normally supplied with. Look for a T prefix for slow-blow, or F for fast blow.

Cheers,

Dan

Comment from Pete
Time: August 17, 2008, 12:29 pm

DISASTER!!! Changed the fuse to 2A slow and was given a light show of bright lights from the el34 followed by smoke. I’ve order new el34 from russia. I’m certain that the chinese el34 are faulty. Anything else I should look for? Should I check the 10k resister if they are shorted?

Comment from Pete
Time: August 17, 2008, 3:00 pm

I’ve opened up the amp, 10k resister is burnt out on tube label v1 for el34, anyone know if it 1w or 5w resister type. What could have caused this as i’ve always run the amp woth 0.30v bias or could this just be bad batch of china made el34 tube?

Comment from Paul (UK)
Time: August 22, 2008, 9:07 pm

Hi Dan

An interesting and very useful site Dan – sorry but I’m too late to order as a part of batch as I have already ordered an MC10L (being delivered surface mail – so several weeks wait i’m affraid). I notice from the supplier photos the version I have ordered appears to have additional large capacitors alongside the valves mounted on the top surface of the amplifier compared to other photos I have seen. Does this make it a newer or older version/model MC10L?

Regards Paul

Comment from Paul (UK)
Time: August 23, 2008, 7:52 am

Following on from my previous post ………. and if this is an earlier version are there any issues/problems with this model version other than it being more difficult access for adjustment of bias voltages?

Regards Paul

Comment from Dan Ashby
Time: August 23, 2008, 5:46 pm

Pete,

What a shame about your amp. If it’s the resistor that I think you mean, it’s a 2w one – see here:

http://yaqin.slickpepper.org.uk/wp-content/uploads/2008/06/mc-10l.jpg

Let me know how you get on.

Comment from Dan Ashby
Time: August 23, 2008, 5:50 pm

Paul, you can see my comments on the earlier 10L here: http://yaqin.slickpepper.org.uk/amplifiers/mc-10l

I did tame the heater voltage a bit with two 0.33 ohm 5 watt wirewound resistors in parallel for the heaters but it wasn’t that badly out so you will probably be fine. Why not measure the voltage when you are biasing it and decide then…

Comment from Dorell
Time: August 24, 2008, 9:52 am

Hi Dan
I bought a Yaqin MC100b a few months back and I´m very happy with it but I don#t have expierence with TubeAmp , so please tell me what do you think about it, is a positive answer or negative.

Thank you , from Germany Dorell

Comment from Dan Ashby
Time: August 24, 2008, 10:14 am

Hi Dorell, I haven’t had a 100B. If you’re happy with it then it’s right. It’s too easy to be subjective and without hearing or seeing it I’d be a fool to pass judgement (or even comment). Just enjoy it.

Dan

Comment from Dorell
Time: August 24, 2008, 10:32 am

Hi Dan,

have you the schematic from MC 100 B please and I try to find another Tube KT 88 want change it have you something better than China Tube.
best regards dorell

Comment from Dan Ashby
Time: August 24, 2008, 10:37 am

Hi Dorell, I don’t have the schematic at the moment, but if I buy one I will get it. You should ask the person you bought yours from – they normally give them out. I have some old used KT88 tubes but they aren’t tested and I want to keep them, sorry. I would try ebay, but they might be expensive.

Dan

Comment from Stephane
Time: September 1, 2008, 1:51 pm

Hi Dan,
Have you the schematic from MS 6V6? It would be important to allow changing tubes without adaptation problems. If you have not do you know where i can find it? Thank you and best regards
Stephane

Comment from Dan Ashby
Time: September 1, 2008, 1:56 pm

Hi Stephane,

I don’t have that schematic. I would ask your supplier to provide. They usually do.

Dan

Comment from john barton
Time: October 10, 2008, 8:23 pm

my ms6v6 while listening to at rather a loud volume gave out a pop followed by a small bit of smoke , left channel now not working ! looked for fuse , can not see one. do you know where i can take for repair in norfolk? cheers john

Comment from Dan Ashby
Time: October 11, 2008, 9:25 am

Hi John,

Sorry I have no idea of a repair outfit in Norfolk. I am in Bristol and would be happy for you to send it to me, but you would of course have to cover the postage and parts + some labour (cheap as possible I assure you). I don’t have the schematic for this model but will try to source one from the supplier I used in the past. Let me know if you’re interested via email – dan@slickpepper.co.uk

Regards,

Dan

Comment from Stephane
Time: October 19, 2008, 11:01 am

Hi Dan,
Thank you very much for all you do here. Have you the schematic from Yaqin VK 2100? I need this schematic in order to change the tubes (the VK 2100 has tubes only in preamplification). Thank you and my best regards,
Stephane

Comment from Ray Magri
Time: January 18, 2009, 7:25 pm

Hello Sir,
I’ve had the YAQIN MC-100B for nearly 10 months.
I think that MC-100B is a great value for money, it gives pleasant sonic performance with my YamahaNS1000 speakers, but suddenly I have a slight annoying hum heard on the left speaker/woofer.
This is heard on very low musically pieces or no music at all. It does not increase when the volume is increased. I switched the left 12AX7 with the right and also put two new KT-88 on te left channel but the low hum was still present. I also left the inputs free and also tried on the 0.25V & 0.60V FRONT SWITCHING. I also inspected internally (from the bottom side only) to check if there is any component that looks slightly darkened as I thought I could smell like some kind of burning smell behind the 0.25/0.60V switch. But all looks ok.
The sound is not distorted at all, but at very low listening musical pieces the hum gets very annoying.
Kindly note that speakers are free of hum when tried with other amplfication.
I appreciate very much if you can help.
Regards
Ray

Comment from Dan Ashby
Time: January 19, 2009, 11:32 am

Sorry Ray. I have no experience of the MC-100B.

Dan

Comment from Peter
Time: January 22, 2009, 1:01 am

Good news at last, I finally find time to fix my mc-10l. Thank Dan for your help in supplying me the circuit diagram. Bought new 10ohms resister and caps. Turn out the crappy chinese tube was shorting out the resistor. Bought new wing c vavle from russia. Resoldered the new resister and caps that was blown. Sound even better then before on my proac 1sc. I highly recommend ppl with mc-10l to change all the chinese valve to russian one as they offer warmer bass and sharper highs. Thank DAN again for your comments and help!!!

Comment from stephen
Time: February 4, 2009, 8:57 pm

i need wiring schematic for yaqin ms12b preamp anyone got one??
also does anybody know what tubes i should upgrade to?? i need
1 to 1.2 volts output….not .7 volts…thanks in advance.

ps- i like the yaqin Stuff….cheers

Comment from Dan Ashby
Time: February 5, 2009, 11:04 am

Try looking on the links on the right and clicking on the one that says MS-12B. That works for other people.

Dan

Comment from RYAN
Time: April 2, 2009, 2:13 pm

can i purchace tube amps directrly fro u..where can i find a place to buy a tube amp and a tube cd player made in japan im in canada thanks ryan

Comment from Dan Ashby
Time: April 2, 2009, 2:24 pm

Hi Ryan. I’m in the UK and wouldn’t be able to supply you. Sorry,

Dan

Comment from adam
Time: May 21, 2009, 7:38 pm

Hi Dan,please can you help me! I have an mc10l valve amp that i loaned to so called friends,when i got it back nothing worked!They did say one of the valves was not working properly,so i ordered 2 replacment valves el34b.I have just put them in and still nothing,ive checked the leads and its working ok,im not very technicaly minded,and bought the amp because i love the sound from it.Im really gutted its not working and i live in cyprus,please can you advise me of anything i can do myself or who should i take it in to,to look at it.
kind regards adam

Comment from Dan Ashby
Time: May 21, 2009, 7:53 pm

Have you checked the fuse? It’s right where the mains lead goes in, in a sort of clip out section. They often blow on these amps. If literally nothing works this may be it. Obviously if things get hot and valve glow then the electricity is getting through and you will need to take it to a repair centre.

Dan

Comment from breton51
Time: June 18, 2009, 9:27 pm

Hello,

I have a problem on a valve of the amp.
when I turn on the heating lamps normally then after some seconds the sound is active. the problem is that the lamps of the power stage from the right channel red directly (30 seconds) they are glowing and emitting blue sparks.

Comment from stephen.
Time: January 16, 2010, 12:44 am

Hello,
Ive brought a yaqin mc10 l amplifier which I love but a couple days after i first used it, Its developed a noticeable hum in the left speaker side The right side starts to hum slightly about 20 seconds after the amp is first switched on but it then quietens up but the left side stays noticeably louder.
If i remove the el 34’s from the left side; it stops but I’ve tried swapping the right valves over thinking that it maybe faulty el34 valves but its still the same
I was just wandering if you have had any experience with this fault before.
Best regards;
Stephen. (s.rucki@yahoo.co.uk)

Comment from adrian hall
Time: February 1, 2010, 7:47 pm

Hi, Do you have any experience of the MS 11b phono stage? If so what do you think of it.

Comment from stephen
Time: March 1, 2010, 11:30 pm

The mc 10-l I have is a lovely looking amplifier but the mains hum from both channels (mainly right side) Is driving me mad!! I live in the uk my supply measures 244v (quite high but within tolerance) Ive tried changing the capacitors but I’m beginning to think its the actual power supply transformer as its becoming noisier as are the hum from the speakers has anybody had any similar experiences?