[illkemist]

Mods, if there is a better place to post this, please do not hesitate to move it. But I figure the CS300 is a tube amplifier with a headphone output, so this should be okay.

I bought this amplifier a few months back from another head-fier. Great transaction, no problems whatsoever. Lately, it seems that the amp is only outputting to one channel reliably. The left channel works consistently. The right channel is intermittent. I haven't thought to check how long it goes in and out, but it almost sounds like someone is switching the balance of the music. Only, the amp has no balance controls set and my DAC has not been adjusted in this way.

The sound is the same through my speakers (Usher S520) and all of my headphones, so I don't think it is a problem with the speaker outputs or the headphone jack. The amp has a pair of GE 5751s. I switched these and heard no change. In other words, the problem still existed in the left channel. I also tried swapping the EL84s, moving the two leftmost tubes to the right, and vice versa. This did not help either.

Can anyone offer any advice? I can buy a new set of EL84 tubes here from my local vinyl shop. But I don't want to spend the money (US $100) unless I can confirm that the problem lies with the 4 Sovteks that I am using. I'm currently in Taiwan, so shipping to Japan for repair might be costly. I'm really unsure of what to do.

Thanks in advance for your help!

 

[Baimi]

Hi.

There are a couple of audio equipment sellers I know in Taipei that sells the Leben CS300. But I can't guarantee that these sellers would be willing to take a look at your unit, given the fact that you acquired your amp elsewhere.

Another option is to take your unit to be tested by a reputable audio equipment seller that I know of in Taipei. Although he does not sell the amp, he should be qualified to make the diagnosis for you for free (if not, he would be able to point you to the right directions).

I would be glad to help you out but I am afraid I won't have much free time till July. If you aren't in a terrible hurry, PM me and we will see how things work out.

 

[illkemist]

Quote:

Originally Posted by Baimi /img/forum/go_quote.gif Hi. There are a couple of audio equipment sellers I know in Taipei that sells the Leben CS300. But I can't guarantee that these sellers would be willing to take a look at your unit, given the fact that you acquired your amp elsewhere. Another option is to take your unit to be tested by a reputable audio equipment seller that I know of in Taipei. Although he does not sell the amp, he should be qualified to make the diagnosis for you for free (if not, he would be able to point you to the right directions). I would be glad to help you out but I am afraid I won't have much free time till July. If you aren't in a terrible hurry, PM me and we will see how things work out.

Thanks! YGPM

 

[PhaedrusX]

Quote:

Originally Posted by illkemist /img/forum/go_quote.gif ...The left channel works consistently. The right channel is intermittent. I haven't thought to check how long it goes in and out, but it almost sounds like someone is switching the balance of the music. Only, the amp has no balance controls and my DAC has not been adjusted in this way...

the CS300 does have a balance control. it's the knob marked as "Balancer."

 

[illkemist]

Quote:

Originally Posted by PhaedrusX /img/forum/go_quote.gif the CS300 does have a balance control. it's the knob marked as "Balancer."

Sorry for the miscommunication, but the word "set" was supposed to be in there. I edited the post to make this clearer.

 

[PhaedrusX]

that makes sense :] i was wondering how you could've missed it.

i recently acquired a CS300 as well, but am still waiting for a proper voltage transformer to run it off of. so in any event, i hope you update the thread with info about the cause and cure when you end up getting it sorted out.

another idea might be to take a picture of the innards from both the top and bottom. it might be an obvious problem that an experienced DIYer could spot and advise about.