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Leben 300: Glitchy Switch Question

kjb

kjb

Proof reading not always a strength
A quick Question.

My Leben 300xs has developed a glitchy input selection switch. I sometimes lose the left channel when switching between sources or in the middle of listening. A quick jiggle puts in right but its a bit of a PITA.

The distributor recommended using some Servisol Switch cleaner which gives a short term fix but the issue returns after a week or so. It only affects the input selection switch, not any of the others. The amp is under 2 years old so it's not a wear and tear issue.

Has anyone experienced similar? Any suggestions or does it need a visit to an engineer?
 
If the Leben is still under warranty I'd return it to the dealer/distributor and let them sort it out.
 
Contact cleaner is your friend - save yourself the grief and aggravation of sending the amp out by giving the switch a quick spritz(under the hood so to speak) and working it back and forth a bunch and you're good to go.

If you have pets or a wood stove this will happen more frequently than if not. It's a quick and easy fix and you'll be back to enjoying the music in no time.

If that doesn't solve it yes absolutely send her back for a spa treatment at the nearest authorized service center...
 
Regardless of warranty period, if i had paid several thousands of pounds for a new amp i would expect it to last more than 2 years. I would be politely but firmly asking the dealer to repair the fault. I would describe the symptoms not the diagnosis. If they didnt agree to fix it i would remind them of their responsibility under consumer rights legislation and escalate via small claims court if needed.

If it didn't come from a dealer i would buy a like for like switch and get a local repair agent to swap out.

You may need to import the switch
 
And now ...

having had the glitchy switch sorted out via the dealer and by the very lovely @John Caswell who occasionally posts here, the amp has now developed some crackle and pop in the left channel.

When I switch it on there is quite a loud crackle and hiss through the left channel while it warms up - from then on everything is fine. Today it was slightly different in that there was quite a loud pop first thing, then more crackle than usual for 45 seconds or so, then it was fine again.

Any thoughts on what the issue might be and some tips for a fix? Being a non-engineer and valve rookie I'm nervous about tinkering in case I make the issue worse!
 
You could try removing and reseating the valves- symptoms like this can sometimes be down to poor contact between valve pins and the base.
 
I would think it’s one of the phase splitter or driver valves dying.. swap over the small valves on the channels and see if it moves and isolate the dying one.. then replace as a pair..
 
Thanks all

I'll try these things out and let you know how it's gone.
 
Hmm

First of all I swapped round the ECC 83s round and powered up but still had the cracking

I then I swapped out the EL84 for a spare set but again still have the same crackling and popping from the same left side channel. So, it seems it's not the valves...

What might I look at next?
 
Update - for some unknown reason the issue is now resolved.

It wasn't quite "turn it off and turn it on again" level but not far off. Taking out the valves and returning them to their original positions and letting it settle seems to have done the job - hopefully its not just temporary....
 
kjb said:
Update - for some unknown reason the issue is now resolved.

It wasn't quite "turn it off and turn it on again" level but not far off. Taking out the valves and returning them to their original positions and letting it settle seems to have done the job - hopefully its not just temporary....
Click to expand...

Reseating valves often works well. Next time you remove the valves, clean the pins as well.
 
The selector switch on our LEBEN CS300F did exactly the same thing, within 6-months of brand-new purchase: an intermittent problem that sounded like it was trying to play two sources at once!

Our dealer happily took the amp off our hands and got the selector switch sorted - and even gave us a loaner while we waited. All with their compliments.

So, a big shout-out for Neil and Paul at TURNED-ON AUDIO in Auckland’s Onehunga. NZ. They are the real deal.

Other than that, the only hiccup in more than five years of ownership and constant operation of our LEBEN CS300F has been some minor crackly noise that was immediately cured by sanding the tube pins… and we still run the original tube set!

What an amp! :cool:
 
And keep an eye on valve playing life. Are you hour counting their life span?
If it's the XS it's running EL84(SOVTEK) X 4 and 12AX7A(Sovtek) X 2 and both these valves can last years depending on the circuit configuration.
 
My CS300XS did this after about 3 years. It’s the input switch itself. It’s an old fashioned wiper style thing and is a massive pain to replace. I got mine replaced by the Leben service guy in the UK. Not cheap, as I recall.
 
Rockmeister said:
And keep an eye on valve playing life. Are you hour counting their life span?
If it's the XS it's running EL84(SOVTEK) X 4 and 12AX7A(Sovtek) X 2 and both these valves can last years depending on the circuit configuration.
Click to expand...

For an example, I had the original Sovteks checked after 5 years of use when I had my Leben serviced and they were still going strong.
 
Our LEBEN CS300F uses 04 x JAN-6197 (GE) power tubes and 02 x 17EW8(Hi-Fi) preamp tubes.

Still going strong five plus years later. I have no way of testing them, other than listening...

We have a spare set. Perhaps I should pop them in to see if there is any difference?

Anyone care to comment on how a worn set of operationally perfect tubes might sound?

cs300f_4_m.jpg
 
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