Written on: 19/07/2009
I have owned my MC-10L for over 2 years now and have had no problems. The thing about valve amps is that they are like owning a new pet, you have to know how to treat them in order to keep them happy. As a retired (crinkled) electronics engineer, I know quite a bit about valve technology and maybe this has helped me to keep my Yaqin in first class order. You must regularly check the bias on the output valves to ensure all is well. Well the first thing I did after unpacking the very well packed amplifier was to inspect the valves, after all they are the most delicate items in the package. I personally did not like the way the valves had been manufactured, the internal rivets and metal work did not look quite as good as I had expected and I decided there and then that I would eventually replace all of the valves at a later date. This was an early model, to check the bias meant removal of the top plate which is a pain, thankfully not necessary now as the updated versions have easy access test points and even a trimming tool is provided. There was no handbook with these early units so I checked each valve in order to establish their correct operating points and found all were set very close to each other, that gives you confidence in the manufacturer for a start. I also checked that the alleged 220V - 240V input was happy running on 240V here in the UK and was surprised to find the voltages were spot on for the valve heaters. I run the amplifier into Tannoy speakers and have made my own remote control volume/switching box for the amplifier. The switching arrangement on the Yaqin does introduce some small amounts of cross talk between inputs which is why I made an external unit providing more isolation plus the beauty of remote control. For the money, I don't think you can really go wrong and the cost is far less than trying to build your own amplifier which is how I found the Yaqin in the first place. I was going to build my own but the cost of just the transformers alone was horrific and I doubt if I could have made an amplifier that looks as good. There are issues with some of this manufacturers other amplifiers but the MC10-L appears to be good and I certainly can recommend it. For the more technical reader, I fitted JJ/Tesla EL34's biased at 35mA and replaced the original 6N1's with Svetlana Golds. The difference in sound quality was immediately apparent and certainly made the extra cost worth while. I am currently trying the larger glass enveloped Elecro-Harmonix 6CA7's in the output and they also sound great!