Cayin A-88T

I am a bit upset with this thing, yesterday, after 3 discs, a loud HUMMM from the left speaker, even switching off everything else, this morning it was ok again, I am trying to return it, lets see what happens next...

 

Before you do that......pull all the valves out carefully and see if all the pins are bright. Replace this time in the same sockets and then play.....does it sound any different?

Next ....does the amp auto bias ?

if yes swap valves round so you split the pairings.

As to valve types tung sol are always quoted for things like the kt's but its like most things you pay for what you get ....so cheaper valves will likely sound worse than expensive ones.

I replaced my chinese el34's with groove tubes these cost as much as the amp ! but they are still happily working a year on with almost no rebiasing. They sound damn good too !

 

I did remove and replace, when I got the amp, still, if there is a problem, it has 1 year warranty, they should fix, not me...

Some places say it has auto bias, others that it doesnt, you need to open it and calibrate from the bottom of the unit, I sure am not going to do that...

I had my prejudice against tubes, gave them a chance, apparentely I was right... :banghead:

 

Monday the store suggested that I connect the speakers to the 8 ohm terminals, even though they are nominally 4 ohms...

The timbre is now correct, no more aggressivity, still a bit nasal, detail and stage are not as refined as with the Tripath TEAC, but on the right track now... :guiness:

I am still worried with the HUMMM from the left speaker, monday after 3 discs, and the occasional THUMP, also on the left speaker, when I switch off the amplier...

 

Do you turn the volume control to zero before switching off?

 

No, but I switch off all the other equipment first...

I have a feeling it depends on how quick I switch it off, if I wait a bit it doesnt THUMP, maybe some capacitors are still charged...

 

Then I suggest that this is a good thing to try

 

Thanks,

But only sometimes it THUMPs, and I never touch the volume...

Another odd thing, yesterday I received a cheap DAC for the satellite box, the LEFT channel didnt work, only cracks and other noises, always the left channel, but I switched to another input and it was ok, then connected the same ICs to the box analog outs and also OK, weird... :inferno:

 

If it 'thumps' or makes weird popping noises on it's own for no apparent reason it sounds like a valve is faulty.

Tony.

 

It happens sometimes, but only when I switch the unit off, I read about similar problems on the net, usually the problem is "bad" ground connection, or bad capacitors, what is odd is that all those happened also on the left channel...

 

I've been fighting off the temptation to buy an A88-T. Just liked the look of it, I suppose, and the fact that it has a remote. I've read quite a few favourable reports in hi-fi forums from people who've bought Chinese amps. The main worry in the UK is using 220v rated equipment on 240v nominal UK power supply, with the risk of over-running the parts and shortening their lives.

I saw that Noel Keywood, in the current HiFi World, gives a very sniffy and nagative account of Chinese amps in a reply to a letter on the topic.

Many say that changing the valves is worthwhile, but buying valves is itself a black art.

6moons gave a very favourable review of this amplifier:-

http://www.6moons.com/audioreviews/cayin/a88t.html

although it hard to find a 6moons review where they are not enthusiastic.

 

If I had to buy it again, I wouldnt... :newbie:

Having said that, if it has no more problems, and the highs smooth a bit with more play, (it is brand new, as well as the Vincent player), then it is good value for money, and very nice looking too... :MILD:

 

no problem at all with 220 on 240

 

I have read some who would disagree!

 

I bought a Chinese headphone amp and I just visited Chelmer Valve Co to buy a valve and was very shocked to see that they want to charge £6.46 to post a small valve!

 

I suggest they are scare mongering.
We produce some medical equipment where i work, rated for european 220v, no problems at all on 240v.

 

Ah, good old NHS cost-cutting. Gotta love it

 

I switched the pre-amp tubes, left with right, to check if the problem is a tube, so far, twice ONN and OFF, no THUMPs or HUMMM, maybe it was a bad contact like Zanash suggested...

Knock on wood...

 

What?
The company i work for produces medical equipment (albeit under another name), what has that to do with NHS cuts?

 

Maybe they just didnt like to be in a cage, I removed it too, hope the cleaning lady doesnt brake them...