Hi,
I've recently started getting an intermittent scratchy sound (like static) through my left speaker. I've isolated the problem to my Audio Research Reference 3 preamp. I swicthed the 6H30P tubes (left with right) and the noise is still from the left channel only.
Any help would be appreciated.
Thanks.
I've recently started getting an intermittent scratchy sound (like static) through my left speaker. I've isolated the problem to my Audio Research Reference 3 preamp. I swicthed the 6H30P tubes (left with right) and the noise is still from the left channel only.
Any help would be appreciated.
Thanks.
The SE test won't tell much. Unless you are lucky.
Start with the Deoxit and inspect all solder joints on the tube board. Seems there are always a couple of relays along the signal path, no matter what input is in use and relays are, annoyingly, also suspects.
If these casual measures don't help you would probably need to get your hands dirty, disconnect the amplifier board from the volume control section and test it using an external volume control, like a variable output cd player. This is not so straightforward as it sounds and probably involves lifting one side of the grid stoppers and providing grid leak resistors.
Start with the Deoxit and inspect all solder joints on the tube board. Seems there are always a couple of relays along the signal path, no matter what input is in use and relays are, annoyingly, also suspects.
If these casual measures don't help you would probably need to get your hands dirty, disconnect the amplifier board from the volume control section and test it using an external volume control, like a variable output cd player. This is not so straightforward as it sounds and probably involves lifting one side of the grid stoppers and providing grid leak resistors.
Hi Maxzimum
I am a repairman and i have repaired a Ref 3 some time ago.
First: do not put deoxit on tube socket!
At first, it will wok but after a while, it will isolate the contacts because of the heat.
The heat make a sort of gum...
This preamp is too young to clean the tubes sockets.
The problem sems likely to be the plates resistors: they have pretty high voltage on them and sometime they make noise. Look for red resistors.
It may be also a fet or a cap but it is unlikely and you will need to order the originals parts if it is the problem.
You will need a scope to fix this unit.
Be carafull: high voltage.
Good luck
I am a repairman and i have repaired a Ref 3 some time ago.
First: do not put deoxit on tube socket!
At first, it will wok but after a while, it will isolate the contacts because of the heat.
The heat make a sort of gum...
This preamp is too young to clean the tubes sockets.
The problem sems likely to be the plates resistors: they have pretty high voltage on them and sometime they make noise. Look for red resistors.
It may be also a fet or a cap but it is unlikely and you will need to order the originals parts if it is the problem.
You will need a scope to fix this unit.
Be carafull: high voltage.
Good luck
Dragon2 said:
Hmmm. Deoxit is rated for 200C. Not good enough? I also thought the preamp was too new but if it worked under high humidity conditions oxidation is not too strange. Or at least not stranger than expensive overrated resistors going noisy
Why would he need a scope? Scopes are quite useless with intermittent phenomena.
Already sprayed deoxit before I read the posts above.
It seems to have made a difference. The noise still does come but not as frequently as before.
"The problem sems likely to be the plates resistors: they have pretty high voltage on them and sometime they make noise. Look for red resistors."
There are plenty of red resistors. About 20 per channel.
It seems to have made a difference. The noise still does come but not as frequently as before.
"The problem sems likely to be the plates resistors: they have pretty high voltage on them and sometime they make noise. Look for red resistors."
There are plenty of red resistors. About 20 per channel.
Something you could try carefully is to wriggle around the tube in the sockets when the unit is powered and see if this is audible. Also knock on various components, pull wires etc. I always try this with intermittent faults but you obviously have to be careful and use a low power power amp which won't blow your speakers or ears. And try not to get electrocuted.
analog_sa said:
analog_sa said:
The problem has since re-occured and hence seems to be something else. I have wriggled the tubes, tapped on parts and cables, but no luck. I have asked the dealer (in another country) to now check with ARC and let me know how to sort this.
Will post some photos soon.
scratchy noise
Hi Maxzimum -
14 years later, and I have the same issue with a unit I'm trying to repair for a friend - left channel as well. not the tubes or cabling or sockets, etc. I suspected the FET, but I just read your post and it seems it was the resistors. This unit does not have any of the PRP red resistors - they are all conventional - look like Vishay resistors. I'm curious - which did you replace? All of the ones all around the 4 tubes and 2 FETs? or any ones in particular I should focus on?
thanks!
Hi Maxzimum -
14 years later, and I have the same issue with a unit I'm trying to repair for a friend - left channel as well. not the tubes or cabling or sockets, etc. I suspected the FET, but I just read your post and it seems it was the resistors. This unit does not have any of the PRP red resistors - they are all conventional - look like Vishay resistors. I'm curious - which did you replace? All of the ones all around the 4 tubes and 2 FETs? or any ones in particular I should focus on?
thanks!