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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
perose
40 posts
 
I know if I say mine is OK it will break. My Line3 did the ramp to max volume when I had my headphones on. OUCH! SF fixed it under warranty which involved a logic change. I don't know if the encoder was replace however.
ryder
1,687 posts
 
I have owned the Line 1. The unit went 'out'(cannot be switched on) in the 2nd year of use, and similiar problem arised just after one year. I've also encountered problems with the fancy volume control whereby the unit was not responsive in turning the volume up and down. This problem was somewhat more persistent and the amount of repairs I've done was disconcerting. I've sold the unit mainly due to reliability issues. I've moved on to solid state preamps ever since.
jea48
4,405 posts
 
Cicero42, What causes the problem? Did Sonic Frontiers ever give you any explanation? I checked the archives over on AA and only found posts that it was a problem, no causes why. Poor design???

If I could ask you a few questions;
*Do you use the volume knob alot instead of the remote control?
*What is the actual line voltage feeding the preamp. 115V, 120V, 123V, 126V, ?V, ?. Maybe over voltage?
*Did you leave the preamp/s powered up in standby mode 24/7 when not listening. Or did you power them down in the proper procedure completly off? Standby, then off.
*Do you have a problem with static electricity? Getting zapped when touching the preamp/s?

So far I have not had a problem with my Line one.
Here are the answers to my questions,
*I use a programmable Marantz remote control unit to control the volume on the Line One. Very seldom use the knob on the preamp.
*Line voltage 123V.
*I power the preamp down when not in use.
*I do not have a static electricity problem.

Hopefully others will chime in. Maybe there is a common thread for the volume control failure, and not just a design or component flaw.
Jim
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