Xiang sheng 708b pre amp-valve?

Can anyone tell me what the equivalent valve for the 6N3 is? also any ideas about upgrading this unit, as i`m new to valve amps! Many thanks.

 

Hello,
i bought one of these units in the summer of 2007. I bought it s/h via e-bay and to be perfctly honest with you i sold it very shortly after buying it. I would say that it was not one of my better Hi-Fi purchases and probably one of my worst. I hate giving folk bad news but personally i thought that this unit was really quite poor even though superficially it looks quite good.

The first thing that put me of was that the front valve in the illuminated display window is just that - for display. It is illuminated by some LEDs and plays no part in the ' audio signal processing'.

Most of the chinese valves have direct western or russian equivalents apart from the 6Z4 rectifier valve , i picked one of these up very cheaply off e-bay , it didn't take long to get delivered from China - about 5 days iirc.

There is a thread on Head-fi where one of the more experienced modifiers got the 708B to sing like a bird, unfortunately to do this he had to butcher out major parts of the unit, do some minor circuit re-designing and replace just about everything.

The gain and volume pot of this amp seemed to be particularly insensitive and course in operation.

Sorry but imho this little amp looks fanastic but thats about all .

Here is a fairly good & detailed thread , hope this helps
http://www.head-fi.org/forums/f5/modifying-xiang-sheng-708b-56k-221733/


S&C

 

xiang sheng amp-Sid and Coke

Thanks Sid and coke, even if the information is somewhat depressing I appreciate the time you took to reply and I will check out the links to see if it is worth upgrading. Have a good year! cheers Garry.

 

6N3 may be replaced by 5670, 2C51 or WE396A

I recently tried some NOS Phillips 2C51 in place of stock Chinese
6N3 and they were significantly worse so NOS isn't always an improvement.