Giscours malfunction
 

Hi Guys,
woke up this morning and only had music on left channel. checked cc80's and swapped cables around it appears to definitely be the pre-amp.

all six valves are glowing and i have a green light infront of each WE tube.

see pics for evidence. Anyone have any ideas or experience or further diagnostic thoughts or is it back to the factory.

Giscours purchased second had from AA member, been working fine for nearly a year, serial number 003 and after email with shindo san (upon purchase) no service was recommended.

Only change to the set up was the swapping in of some different kt88's in the cc80 (two months ago). Had not got round to biasing the amps, could that affect the pre-amp????

thanks in advance for any help,
Paul. :tears:

Paul,
Sorry to hear of your troubles. I too have had Shindo malfunctions. Best bet is to send it back to Shindo. Although they are very reliable, like anything else
they can have issues from time to time.
Dale

Same here Paul, sorry for the troubles you're having. I would reach out to JH. He should get back to you on Monday. This is not my area of expertise, so other users please back up my following thought. How about just taking those WE tubes, and swapping channels.
Both volume controls on your amps are turned all the way up, Right?

fjn04

good answer:thumbsup:

Sorry to read this Paul.

Swapping the right and left tubes is a good idea but I would swap all of them, not only the WE tubes.
Does this happen no matter the inputs you are using ? Did you try swapping the cables between your source and the Giscours ?
Having a bad bias on a CC80 won't affect the preamp.
If the KT88 come from Shindo, you may not have to adjust the bias.
We have a fabulous Shindo expert in Paris.
If you need service It could be simpler to send him your Giscours than sending it to Japan. Just let me know by PM if you need him.

Just BE VERY CAREFUL WHEN REMOVING AND INSERTING THE TUBES. THE SOCKETS ARE VERY VERY TIGHT.

I assume that by checking cables you also swapped the connections to the amps at the pre?

I assume this is happening both with phono and another source? This would eliminate something in the phono stage as the issue.

If so, then the easiest trouble shooting is to swap the positions L/R of the valves, one set at a time, powering off in between. Start with the rectifiers, then the tubes in the line stage. If you hear the failure switch channels, you know that tube is bad.

If after doing this the problem doesnt flip channels, and all the cable connections are not bad, you know you have another part failure in the line stage that you will have to seek out a reliable repair for. Probably the best place to start with that might be A23.

That's the exact procedure I would follow.
Keith Aschenbrenner will not service a Shindo piece not imported by himself. He has been very fair to stop imports when they became forbidden by RoHS regulations so he does not accept to work for the ones who do not share the same respect for the law.

Guys,

Thanks for the support, group answer in one go!

I only have one source - my MSB DAC but i will move it to another pre-amp input..

Im thinking about the tubes switch.....

I agree with Jerome regarding Keith's view point - i think the real answer is in Japan not A23

Paul,

Sending your gear to Japan will be very expensive. PM me if you want to talk about my technician, I will give you his web site and phone number. He is fabulous. He is also a designer and maker of High end tube amps and cd players, pretty well known in France. Sending your Giscours from Switzerland to Paris won't cost a fortune if it really needs service.
And I bet you that Shindo has no mystery for him. :D
But of course, swap cables and tubes first !!!