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Hi Marco,
As far as I know, there are some manufacturers in China who have a very loose or even non existent quality control. But if Yaqin wanted to join and compete in the world wide market then they should have their products complied with any safety standard. I have used the Yaqin for over a year and it has not caused a single problem. I assume that it is safe enough to use it in U. k. as it indicates on the box it is a 240V version.
King
King,
That's what it said on the box of a few people's Yaqin amplifiers I know of that caught fire...
I don't wish to alarm you unnecessarily, as your Yaqin has obviously worked fine for over a year, but internal components, such as capacitors, overheating due to being incompatible with the over-voltage imposed on the secondary circuits, as a result of some UK mains supplies being rated as high as 248V (not 240V), sometimes even higher, is a real issue.
That extra 8V, or so, may not seem much, but it can be quite critical when the tolerance of some internal components is unable to handle it, and if they 'pop' when the equipment is left unattended for a period of time, the knock-on effect on the primaries can be quite 'spectacular', and extremely dangerous. Someone more technically-minded than me will explain it better.
I just think it's important that you should know this, as the last thing I'd want to happen is for me to say nothing and then find out that something nasty has happened, so I'm sure you can appreciate my concern. If it were me, I would not leave it switched on for any length of time while you are not in the room, and make sure it's switched off at night before you go to bed.
My advice would be to measure the voltage on your mains supply with a multi-meter, and if it is significantly over 240V, then take your Yaqin to a qualified electronics engineer, get it fully tested for safety, and if recommended have some 'over-specified' higher-rated capacitors, etc, fitted to ensure that the circuit can safely cope with any over-voltage. It will probably improve the sound, too, and you'll have piece of mind knowing that you're safe :)
It's always better being safe than sorry where electricity is concerned!
Marco.
Hi Marco,
Thank you for your warning! The voltage in my area is normally 238 volts and seldom goes beyond 240V. But I will take precaution and probably use a step-up transformer to drop the voltage down to220V just in case of any unforeseen happening.
King
You mean a step-down transformer ;)
No worries - like I said it's better being safe than sorry...
I used to have a Yaqin MC-100B valve amp, which I used with a step-down transformer. One day I stupidly unplugged it and ran the raw mains straight through (thinking that it was after all supposed to be safe with 240V UK mains, as stated on the box), and after about an hour, I heard a sizzling noise coming from the amp, and to my horror the power supply caps were bubbling up and smoking in front of my eyes...!!
So I quickly switched off the amplifier - it gave me a real fright! Then after that I had it properly modified to be safe on UK mains by Anthony Matthews, a qualified electronics engineer and equipment designer, here on the forum, and then everything was ok - plus is sounded much better too! :)
Marco.
Over the years I have bought quite a few cartridges, some of them are considered vintage but still very competitive even amongst those latest creations. I have always been passionate with Denon cartridges since 1979 and am still using them now. One of the most popular cartridges of all time and truly a classic, of course, is the Denon 103. The 103D has not caught much of my attention, though I still consider it a better cartridge.
Denon 103
http://i42.tinypic.com/33vbudd.jpg
Denon 103D
http://i42.tinypic.com/2wqej9g.jpg
Close-up of 103D
http://i39.tinypic.com/2zemn8j.jpg
One of my favourite cartridges, the 103R
http://i43.tinypic.com/2zhijo9.jpg
Close-up
http://i40.tinypic.com/2cy2rh2.jpg
DL303
http://i41.tinypic.com/fd6n4l.jpg
Close-up
http://i43.tinypic.com/2igy8mh.jpg
DL304
http://i42.tinypic.com/2lmnb03.jpg
Close-up
http://i44.tinypic.com/szgz0j.jpg
King -
About the safety of the Yaqin MS-12B: Mine was also marked 240V on the box, though the amp itself has 220V on it. I checked the secondary voltages of the mains transformer, and with a 240V AC input they very closely matched the values marked on the circuit diagram - apart from the heater voltage to the 12AU7 valves, which was 1.2V high at 13.8V AC. (Not dangerous, but could shorten the life of the valve a bit). I have since added a power resistor to drop the voltage to 12.6V. The main supply capacitors on mine are rated at 400V, so there's a good margin there.
So it probably is a good idea, as Marco advised, to check the voltages. And I would also agree about not leaving the amp powered up when you're not around. (Come to that, I would probably feel the same about any valve amp.)
Hi John,
I certainly agree that all valve amps should not be powered up when we are not around because of the danger it may cause. Actually I always turn off the Yaqin as soon as the listening session is finished.
Anyway, thank you for your caution!
King
DL301
http://i41.tinypic.com/1clki.jpg
Close-up
http://i41.tinypic.com/5dkq41.jpg
DL110
Close-up
http://i41.tinypic.com/59u8w7.jpg
Another cartridge which I also adore is the Supex 900 Super; I used to partner it with the Grace 707 arm, a classic combination that most of us were using during that period due to the mighty effort and inevitable influence contributed by Linn, I guess.
Supex 900 Super
http://i41.tinypic.com/1zxwizn.jpg
Close-up
http://i42.tinypic.com/91gffr.jpg
http://i39.tinypic.com/2m6ltfp.jpg
Supex 1000
http://i43.tinypic.com/4pa8h.jpg
Close-up
http://i40.tinypic.com/fu5ced.jpg
http://i42.tinypic.com/240yp6o.jpg
Hi King,
Superb photos yet again, and some of the cleanest looking styli I've seen! :)
You are a truly an enthusiast par excellence and have my deepest respect :youtheman:
Marco.
Hi Marco,
Thank you for your kind and bounteous comments!
I will post more pictures when I have time.
Regards!
King