• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Tube integrated amp in China.

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Unless you like to listen at low levels I think you will find a 300B SE amp will perform quite poorly with your speakers due to their relatively low efficiency. You might want to look at SE amps that utilize the 211, 845 or GM70 instead, alternatively you could consider a 300B PP amplifier if there is one within your targeted price point.
 
If you are in no rush, go with one of the more well known talked about amps that you find here on diyaudio. Get yourself a soldering iron (there used to be a rather large computer and electronics building in Xujiahui -- subway exit conveniently located in front) and some resistors, caps, and solder. Follow the easy solution instructions here. I am pretty sure that with the gathered experience here, you ought to be able to keep trannies from overheating, tweeters from popping, and remove that annoying hum. And get the schematic so you can swap out the transformer for a 110V if you are going to North America next or 100V to Japan. Heck buy the transformer while you are there*.

I know I wish I had this wealth of info from diyaudio when I was living there. All I got to do was watch friends buy these things and try to enjoy them (at the time, my place came fully furnished and I didn't require much) with the odd blown cap, burnt circuit board (ever try to translate for someone explaining, "this piece of garbage almost caught fire, I want my money back, etc..."? I miss it so...).

Or fly down to Hong Kong and there are some good places in Shumshuipo on the electronics market side. You can find some nicely re-worked Chinese tube amps with proper schematics and the modifications drawn in. I have seen some nice Music Angels and Chinese chassis tube amps with tall 845 tubes, 300B, EL34 (and small for this one), and KT88 tube amps. You will pay a price for this and have to lug it back home to SH, but these guys check it all out prior to your buying it (and listen to the amp on proper speakers in these small stores too). And they will pack it in a box and put it in a giant red, white and blue zippered woven plastic bag for you too if you ask nicely. Even with the overages and never getting stopped at customs on the way in, made it worth it to my friends.

I bought tubes in Hong Kong for friends too from these shops too as they have fair prices and won't have very wildly scattered prices from shop to shop. They had the money and I didn't, but I had some of the knowledge and they trusted me (tubes and a lot of magazines from the bookstore above the McDonald's at the Navy pier -- best view from that McDonald's by the way when you are drinking iced tea).

If you REALLY have the time and gumption, Mong Kok district (where the street vendors are) in Hong Kong. Sai Yeung Choi Street and Dundas Street, that is all I can recall. There are other smaller shops but you will have to walk behind the stalls and look towards the buildings and you will see counters with old men reading newspapers listening to not so loud music and signs. Take a look inside and you will be in amplifier heaven. And tube hell because of so many different tubes (NOS WE 300B? It is there, may not be for sale, but they are there). If you ask nicely, they will re-test the tubes that they have spec'd out already with an ancient tube tester form Hickok or something -- never mind their swearing and grumbling, they like doing it if you are buying.

*I'd buy the 110V transformers in Hong Kong or in North America versus trusting one that you can not test. At least the HK guys are trustworthy.
 
Oh yeah, sorry, I don't mean to thread jack your topic, but the point I had and drifted like a cheap electrolytic capacitor from was that the amp dealers in Shanghai have a lot of wares, but in the end, the service was poor and the products were dodgy at times. No sales person knows the info on the amp. Quiz them and ask them some simple questions like what is the failure rate of the product? Or what other tubes are compatible with this amp? Or how do I set the bias? Or what do those characters mean?

You can take your chances, but I would suggest that you go Hong Kong for something reliable and relatively trouble free (no sense in having a house fire at the worst case scenario).

There is also this old thread that I just found here...

http://www.diyaudio.com/forums/tubes-valves/105853-anywhere-hong-kong-2.html

Now, I have had experienced some poor customer service in Hong Kong right from a well known tube amplifier maker in his shop. They had it all, power amp, pre-amp, headphone amp, phono stage, and tubes I was given an address by my friend, a telephone number, and a stack of cash to go test one and bring one back (this buying activity was only a side favour to expat friends who knew I would be in Hong Kong on business once or twice every two months).

Well, I called to make sure that they were open and had some amplifiers in stock. I go to the showroom and what an icy reception by the owner and his girlfriend/wife (fine, I am in jeans and t-shirt and backpack, but they were nice jeans and I wasn't smelly). I said I called prior and if I could take a look and test drive two of their amplifiers.

20 questions later and a pointed finger to where the amps were, I was kind of turned off already. Nice amps to the ear and I asked if I could roll tubes in one of them and i was asked pointedly, if I was going to buy or not.

And that is where I said something along the lines of, "I can see this is too much of a burden on you. I'll go elsewhere. " and left.

But make it an adventure, in the end you will enjoy the music more.
 
Not all dealers or their wares are dodgy. First of all, you need to establish guanxi. I managed to build up some guanxi with the opera consonance dealer here in shanghai. Predominantly because i ept coming back after buying something decent, and when you come back for more, they bcome more honest and more willing to help.
Id be hesitant buying from the electronic markets. First of all, you are lucky to find something, second.y if you find something youll be lucky to get something decent. Go to the hifi plaza near nanjing road. Those are reliable dealers.

As for driving 87db speakers, i used my consonance reference 5.5 mk2 which is an 18wpc integrated amp using 300b tubes on a pair of b&w cdm 7nt speakers, which are 88db. It sounded great! Never a problem with driving the speakers.
 
I don't think that there is any need to build up guanxi. The product that you are buying is rather expensive, specialized, and unique. Most people don't end up buying multiple tube amps like they buy clothes, shoes, or sunglasses -- I'd even go as far as to say that most people don't go back as often to a high end audio shop as they would compared to their favorite restaurant (Di Shui Dong or the local Spirit in the Forest tea shop cafe).

The only way to build guanxi then is to know someone with a friend or relative selling tube amps. That would be great to have a connection like that in a city of 14,000,000.

No offense, but the best policy is to sell the best, reliable, and guaranteed products at a reasonable and fair price. The motivation for the seller is reputation, longevity, and if manger well, profit will follow. The salesmen, owners, and end consumer realize that people with a hobby or interest in tube audio know that these things do not come cheap whether DIY or off the showroom floor.

I don't know how many times I returned to my CD guy in Shanghai on his recommendations (don't buy that, get this one instead, better quality recording and I will take it back if you don't like it) and his service. I told other expats and locals to go there up to the day he closed shop. Japanese music, special jazz recordings, and he recommended Ah-Bing to me. And it sounds awesome through a good amp...
 
Unless you like to listen at low levels I think you will find a 300B SE amp will perform quite poorly with your speakers due to their relatively low efficiency.(snip)

But not a certainty. The key, I believe, is whether your Lspkrs exhibit a resistive (relatively flat impedance curve) load, one where their impedance doesn't swing up and down widely.There are, of course, other factors that come into play: back EMF, phase angles and others. ie: what you consider to be your preferred listening levels and your room size, etc etc.

But Lspkr sensitivity (it is not "efficiency" BTW, ) is pretty misleading IMO as there are a number of Lspkrs that on first blush would seem poorly matches for low-powered SE tube amps

I've driven vintage KEFs, Wharfedales, Rogers, Leaks with published ratings of 82-87 db and with published nominal impedance of 4, 6, and 8ohms with my small EL84 SE amp (9 ohm taps only) with ease and more than enough to satisfy my listening levels, room size etc.

However, Kevin's suggestion to use a beefier version or type of tube amp would seem to cover the range of variables we aren't aware of and which will probably be even more important at determinants as to what kind of tube amp you should be looking at.
 
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