Mystery trouble with new Shanling Integrated

[markw]

I've always found this to be a diffucult question to answer.

You mentioned that you hadnt noticed it for a while after you got the unit. Was that because it wasnt there before or you just hadnt noticed it?

That's kinda like asking someone that's looking for something they lost where they lost it.

 

[TLS Guy]

I never connect or disconnect anything without shutting it down. I can't afford to replace anything!



It's not actually a tube amp. It's a solid state integrated with a built-in tube buffer stage for the unbalanced inputs. (The balanced inputs go straight to the SS pre section)
And this buzz is there whether I've selected a balanced or unbalanced input, so I'm pretty sure it's not the tubes.

This will turn out to be lay out problem. From the days of building and designing tube amps, I know the layout of the wiring is critical. I bet the LT tube wiring layout is responsible for this somehow. Try and listen to another and see if it has the same slight buzz.

By the way tubes add nothing except trouble and increased risk of background noise.

Which audio equivalent of the National Enquirer persuaded you to buy that thing anyway?

 

[Brett A]

Which audio equivalent of the National Enquirer persuaded you to buy that thing anyway?

I'll try not to be insulted by this question. I bought it because it sounds gorgeous and I like it. Out of the integrateds I took home to audition (Cambridge Audio 740, Music Hall Maven, Krell KAV 400xi), this one sounded by far the best. (It replace my Rotel RA 1060.)

I realize a tube buffer can only add to the signal, but I like its sound. And if I want to run it straight SS, I just use the balanced inputs which bypass the tube buffer so its flexible in that way.

(Nice Gerrard 301's, by the way)

 

[Brett A]

So far, your responses have pointed to any or all of the following:

• Right channel power transformer
• A cracked solder joint somewhere.
• A lay out problem (BTW, what is "LT tube wiring"?)

I think the next thing to do is load it back in my car and go to the shop on a day when it's not too busy there and investigate this with them. (I can also listen to their floor model)

You mentioned that you hadnt noticed it for a while after you got the unit. Was that because it wasnt there before or you just hadnt noticed it?

I really think it was not there before. My house is so dead quiet and I've been curious about background noise in my equipment all along.
Since this buzz has appeared, it has not been intermittent.


.

 

[Haoleb]

I think what TLS guy is reffering to as the LT wiring is what is more commonly known as the heater. This is the part of the tube that glows. Sometimes they are AC heaters and Sometimes they are DC heaters. Ac heaters do induce an amount of noise into the circuitry, I can tell you for a fact that DC heaters are better as the preamp I used to have was originally AC heater and changing it to DC reduced the noise significantly.

That being said I would be pretty shocked if it came down to being a PCB layout issue. Just look at the circuitry it appears to be mirrored. I would also imagine in something as nice as that peice they would be using DC heaters.


I would take it to your dealer and try it in their store and see if you can hear the problem there. Since you said it is such a quiet buzz though it could just be considered normal.

 

[TLS Guy]

I'll try not to be insulted by this question. I bought it because it sounds gorgeous and I like it. Out of the integrateds I took home to audition (Cambridge Audio 740, Music Hall Maven, Krell KAV 400xi), this one sounded by far the best. (It replace my Rotel RA 1060.)

I realize a tube buffer can only add to the signal, but I like its sound. And if I want to run it straight SS, I just use the balanced inputs which bypass the tube buffer so its flexible in that way.

(Nice Gerrard 301's, by the way)

Yes, I love the Garrard 301's I have had them over forty years!

The reason you have to bypass the tube for the balanced input, is that tubes require a transformer for a balanced input. An op amp chip however makes an excellent balanced input amplifier.

I have to say that using a tube as a tone control leaves me scratching my head. I just see no rational point in the exercise at all.

 

[J Guild]

Brett A, I am curious how you resolved the noise with the A3000. I have the same model and am experiencing similar noise with mine.

 

[TLS Guy]

Brett A, I am curious how you resolved the noise with the A3000. I have the same model and am experiencing similar noise with mine.

He probably got rid of the noise by selling it!