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Sonic Frontiers Line - 1 Volume Control

Has any owner of either a SF Line-1, 2 or 3 preamp experienced problems with the volume control? You may know that the control is in fact an optical shaft encoder.
I have had 3 failures of these units.
First pre-amp just "froze" after a few month's use, and was replaced with a brand new model (as opposed to being repaired).
The second unit also developed similar problems after 2.5 years use, though this time the fault was more severe in that the volume control would inexplicably "ramp-up" to maximum (95.5db) unassisted in any way. Took out a few KT88 tubes on one of my power amps before I get to it - and turn off. The preamp was fitted with a new shaft encoder and "logic" box (behind the fascia) under warrantee in 2000, and was fine until last month when the shaft encoder froze (yet again) after turning on from Standby. The unit will still funtion of course via the remote control, so its NOT the end of the world!Have sourced a replacement encoder and awaiting fitting by local techo.
Purpose of this question is to ask if any other owner of these series of otherwise very fine pre-amps have experienced similar problems?
(RH)
cicero42
semi
646 posts
 
The volumne problem is very common on all SF Line series which use an optical encoder. Sonic Frontiers does not make that encoder, so blame it on the manufacture that makes it.

It's relatively easy to replace, I did mine in less than 2 hours and that was my first job. You can order parts from Frank in SFI or from outside source, but price is very close and Frank is a super nice guy that will guide you thru any problem you might encounter.
jea48
2,944 posts
 
Semi
The volumne problem is very common on all SF Line series which use an optical encoder. Sonic Frontiers does not make that encoder, so blame it on the manufacture that makes it.
Semi
Have you ever heard a reason why it fails?
Is the new one you installed the same as the old, or a new design?
How did you know where to start in the replacing process?
Do you remember how much it cost?
madore8595
6 posts
 
my line 3se have the same trouble,mute the volume and make a "click click click..." mute on mute off sequence.first i think about tubes...but after a short time i realise that the trouble may come from the headphone input.cause when you put the jack on it,the preamp click to mute!!! it may come from the haedphone circuit board!!!.since this time,when i listen music for a long period and want to listen trouble free,.....i put a cotton swab on it!!!!
jimdur
3 posts
 
I have a Line one that just stuck on mute after using headphones.
When you listen to headphone you can hit the mute button and it goes into mute and hit it again and it works but only on headphone,
The mute light stays on and it wont switch on and off.
Worked fine before using the headphones.
Do not have the remote but I am told that the Logitech harmony 650 works all the functions, Maybe I should get one and try it
Any sugestions  
jimdur
3 posts
 
I don't know if this will help but a common problem with the Sonic Frontiers Line series is the 3rd pin on the headphone jack sticks and causes the pre to stick in mute mode or flicker on and off
If you change the headphone connector it fixes the problem
Part # is Neutrik NJ6FD-V, It is a easy job as long as you can solder
You have to remove the faceplate to do it.
The total job should only take 1/2 hour to 45 min at most
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