Need help troubleshooting CJ Premier 140

[Avadia]

Hi all. This is my first post on this forum. I need help troubleshooting an issue with my Premier 140 amp. I am getting an intermittent crackling sound coming from my right speaker only. I hear it during silence between tracks or when no track is playing and it is very noticeable from my listening chair. However, I don't notice it while music is playing (although it is probably still occurring). I am sure it is the amp because it happens even when the amp is the only component powered on. It doesn't happen when a different amp is connected, so it isn't the speaker. I have checked all cable connections and they are clean and tight. I thought perhaps it was a tube going bad, but I just re-tubed and cleaned the connectors with de-oxit and the problem still persists. I am stumped.

The amp is about fourteen or so years old. It has never been serviced and has not had the capacitor upgrade. It has seen only moderate use and was actually in storage for seven years, but if memory serves me correctly this problem predates the amp going into storage. The crackling is intermittent, and is more prevalent in the beginning after turning the amp on. After an hour or so of use it diminishes in frequency of occurrence, but still comes back occasionally. Can anyone give me any ideas on what may be causing this issue? Thanks in advance for any help you can provide.

[admin]

First, welcome to CJO. It's great to have you with us.

So this sounds like it may be a contact issue. The fact that it happens more earlier on with power up means that as the components are heating up there is some expansion and a bad solder joint or other contact issue may be occurring. One thing I would try is to take the cover off and turn the unit on. Then with the eraser side of a pencil slowly and gently start pushing on the circuit path and components for the right channel. If you are able to reproduce the crackling with physical pressure to the board or components that may help you narrow down the problem and identify where the issue is happening.

Of course it could be a specific internal component failure but that would be more difficult to diagnose as you would actually need to test the components themselves.

[Big Dog RJ]

g'day greetings from melbourne!

ah! The premier 140, another "awesome" amplifier by cj.
never owned one myself but similar crackling problem, yes have experienced this once my manley monoblocks. I initially thought it was a bad driver tube because whenever pressure was applied to it pressing down, the crackling would subside. replaced the, same problem occurred. At the end of a long investigation, it actually turned out to be the actual tube sockets, they were old plastic types and had actually cracked under ware & tare.

eventually manley labs replaced all sockets with ceramic types and resoldered all connections on the sockets. The crackling stopped and infact the sound slightly improved as well. ceramic tube sockets are probably the best, however they are fairly fragile.

I wouldn't think most tube amp brands would use ceramic due to their fragile nature. I do a handful of brands that use ceramic and they stand by this material stating that it's superior to the plastic sockets the majority of brands used.

As admi suggested, have a poke around and you will be able to identify ftom where this crackling sound originates from. Also, whiles the amp is one and connected you can actually touch and press down the smaller tubes to see if they are loose in the sockets or if a socket has a hairline crack in it. If you are not comfortable doing this then don't, just leave it to s tech.
My tech was so bold and used to tube amps he used to even touch output tubes with his bare hands. something I would never do even if I was drunk!
hopes that helps, this crackling can be sorted, it's not a major issue. just check all the tube sockets as well.
Cheers,RJ

[Avadia]

Thanks for the replies, guys. I turned it on and pressed around on the tubes today. Couldn't cause it to happen. So I'm guessing it is a bad solder joint or some component inside going bad. I guess when I get some time I will take the cover off and look around / poke around and see if I can figure anything out. After that, I'll call CJ and see if they have any ideas. If I have to send it in for repair, I guess I should probably go ahead and do the capacitor upgrade, though I hate to spend that kind of money on it. I do absolutely love the sound of this amp/preamp combo driving my Martin Logan Summits. CJ tube amps and electrostatic speakers are a match made in heaven!

[Big Dog RJ]

Hey mate, nice to know that you've got stats. totally agree on the cj+stat combination, the musicality factor is highly addictive and unmatched, especially in the midrange.
Was just wondering, if you're completely satisfied with the overall sound and what the premier140 delivers in your present system, might as well just get that crackling noise attended to and perhaps later on attend to the cap upgrade. Although the 140 may be one of their previous designs, it is a superb power amp and one that I truly missed since I didn't have the means at the time.
improving with tubes may not generate the best results, afterall that is a personal preference. cap upgrades would be something to consider if you intend on keeping the 140 for the long haul.
I am sure any experienced good techie with experience on tube amps / electronics would be able to fix small issues, may also save you a bit more. cj would be the best bet but at the end of the day I am sure their tech team is just about as good as the well experienced tech that you may find out there.
Cheers,RJ

[Joe Appierto]

I owned the Premier 140 for a number of years and as RJ states, I also thought it was an excellent amp. Not as musical or euphonic as the 11A but more in the modern school. I did send mine in for the C1 Teflon Caps upgrade and it made the 140 sound more of what I thought it was good at. Better frequency extremes, more detail, a wider and deeper soundstage (an improvement IMO over the 11A to begin with), and just about anything you can think of. On the other hand, it did cost USD2,300 back in 2012 and I have no idea what they're charging for that nowadays.

Should you decide to go the C1 route, they'll fix the crackling issue as they go along. This isn't an insignificant amount of money but the improvements were quite significant.

Just my 2¢ naturally.

[Avadia]

Thanks for that information, Joe. Nice to hear the experience of someone who has done it before. It is tempting as I love the amp and plan to keep it long term, but it is a lot of money, especially considering I only spent $3500 on the amp when I bought it brand new from the dealer. That was a heck of a deal, though. And the Cap upgrade will surely be even more expensive in five or ten years.