Canuck Audio Mart Hifi and Audio ForumCanuck Audio Mart Hifi and Audio Forum
It is currently Sun Oct 22, 2017 12:02 am

All times are UTC - 8 hours




Post new topic Reply to topic  [ 50 posts ]  Go to page 1, 2, 3, 4  Next
Author Message
PostPosted: Sun Dec 18, 2016 1:30 pm 
Offline
User avatar

Joined: Thu Mar 06, 2008 8:10 am
Posts: 1511
Location: Ottawa, ON, CA
Strangest thing happened. I'm sitting here in my dining room listening to my upstairs system, which has worked flawlessly for many years. All of a sudden I noticed the volume was progressively getting louder. By the time I could reach the volume, the system was playing at a deafening level.

The receiver is a Cambridge Audio 640R, about 8 years old now.

Anyone ever experience this? Hopefully I don't have to make anymore sprints to living room to save my speakers.


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 1:46 pm 
Offline

Joined: Thu Jan 10, 2008 10:03 am
Posts: 401
Location: cambridge, ON, CA
I experienced the same thing once previously and it was repaired without difficulty. I'll send you a pm.


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 2:19 pm 
Offline

Joined: Mon Dec 27, 2004 11:04 am
Posts: 24
Location: Whitby, ON, CA
I had the same thing happen with an Adcom preamp that had a motorized volume control. It was caused by a worn down battery in the remote control. Very scary experience. I have high powered amps and sprung from my listening position just in time to catch the rotating knob before it hit centre position.


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 2:21 pm 
Offline
User avatar

Joined: Thu Mar 06, 2008 8:10 am
Posts: 1511
Location: Ottawa, ON, CA
I just put fresh batteries in the remote. Hopefully that fixes it.

I'm getting too old for that kind of that action.


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 2:52 pm 
Offline

Joined: Tue Sep 03, 2013 5:13 am
Posts: 9
Location: Hamilton, ON, CA
Ramped-up the volume on it's own?! :o

Oh no!!....it has begun....the rise of The Machines and the end of our dominance of Plant Earth!!
:o

:mrgreen:


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 2:55 pm 
Offline
User avatar

Joined: Sat Feb 23, 2013 10:41 am
Posts: 7609
Location: Burlington, ON, CA
I had it happen with my Modwright pre but the knob didn't rotate, it just instantly jumped to full volume. Pushing an X-250 full blast into Forests. Boy, did I jump. I think Dan said it was a short or such

_________________
"I'm not Inspector Gadget!"


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 2:56 pm 
Offline
User avatar

Joined: Thu Mar 06, 2008 8:10 am
Posts: 1511
Location: Ottawa, ON, CA
Che Cavolo wrote:
I had it happen with my Modwright pre but the knob didn't rotate, it just instantly jumped to full volume. Pushing an X-250 full blast into Forests. Boy, did I jump. I think Dan said it was a short or such


Yikes. Did you blow up your Forests?


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 2:59 pm 
Offline
User avatar

Joined: Sat Feb 23, 2013 10:41 am
Posts: 7609
Location: Burlington, ON, CA
Nope. Zero collateral damage. Phew....

_________________
"I'm not Inspector Gadget!"


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 3:01 pm 
Offline
User avatar

Joined: Thu Mar 06, 2008 8:10 am
Posts: 1511
Location: Ottawa, ON, CA
Very lucky. I've blown up a pair of Sttafs, just doing stupid stuff.


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 4:02 pm 
Offline

Joined: Wed Jan 04, 2006 9:25 pm
Posts: 599
Location: toronto, ON, CA
Yes I can relate.
It happened to me as well with an older Harman Kardon AVR-7000 receiver. Known issue with my particular component.
George


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 4:35 pm 
Offline
User avatar

Joined: Thu Nov 25, 2004 4:52 pm
Posts: 993
Location: Montreal, QC, CA
Thats just the thing you want happening when your not home with some background music playing.. I`ve read about some SF preamps doing the same thing which gives me a reason to mute my TLP-1 when away.
Or, you may be in need of this gentleman's services: :mrgreen:


Attachments:
Father Lankester Merrin.jpg
Father Lankester Merrin.jpg [ 95.65 KiB | Viewed 2297 times ]
Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 4:45 pm 
Offline
Dealer/Sponsor

Joined: Tue Jun 14, 2016 8:33 am
Posts: 1045
Location: Kingston, ON, CA
The kind of device that does such things, tends to be the analog alps digital stepper control.

It has a track divided into two, an inner and outer..and each track is offset from the other. it looks like a dart board with the two checkerboard rings slightly offset.

Image

Depending on which way you turn it, it will receive an inner track pulse first, or an outer track pulse. ie, voltage into the unit, on pin one... and then a voltage pulse on pin two first or a voltage pulsed on pin 3..all depending on which way you turn the dial.

Alternately, a single track, with offset signal pins. (see the videos)

Thus an analog controller of 'voltage pulsing' for switching the volume up, or down, when those pulse voltages are sent to a chip which decodes the signal and signal order...it does the actual changing of the volume level.

Since it is actually almost the same design as a standard analog volume pot, they wear out.

Or go intermittent. Or read poorly. Sometimes they wear and the volume will only go in one direction and then, not at all.

It is approx a $10-15 part (Max), and about 30-40 minutes to install. Generally.

a video to show exactly what is going on:

https://www.youtube.com/watch?v=6r-t4G1mo5Q

https://www.youtube.com/watch?v=y4XF9PoidJQ

The very vast majority of them are made by ALPS, the potentiometer company.

_________________
(Ken Hotte, of) Teo Audio


Last edited by Teo Audio on Sun Dec 18, 2016 6:18 pm, edited 5 times in total.

Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 4:47 pm 
Offline
User avatar

Joined: Thu Mar 06, 2008 8:10 am
Posts: 1511
Location: Ottawa, ON, CA
Michael F wrote:
Thats just the thing you want happening when your not home with some background music playing.. I`ve read about some SF preamps doing the same thing which gives me a reason to mute my TLP-1 when away.
Or, you may be in need of this gentleman's services: :mrgreen:


I leave background music on for the dog when no one is home. I guess I may be coming to some blown up speakers and a terrified and deaf dog one day.


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 5:54 pm 
Offline

Joined: Sun Apr 05, 2009 7:06 pm
Posts: 944
Location: hawkesbury, ON, CA
it is not first time. back in the days first dts processor came out. it was a signature 2.0 Harman kardan it was a bad chip.
when I was playing dts 5.1 and was lowering volume control that goes from 60 down to 0 when turning down the volume and you get to 4,3, 2, 1 the subwoofer output only was going full volume all the suden. and when at 0 it stoped. if going back up 1,2,3,4 again volume of sub out, full volume, then 5 and up come back normal. was still on warranty, it took 4 visit to the repair shop at the 4 th visite, I personnaly demoed the problem to the tech. only then he could acknowledge the problem. then the next day I receive a phone call from the engeneer in California in a phone conference with the tech from montreal. and engeneer ask me to explain again what it was doing, and also ask me if there was other trouble beside that.they did a new update and burn a new version of that chip. and a week later everything was great. they even payed to recone my jbl 2245 sub. that was blown in the process. I told the tech that it blew with all those test I was doing for them. (4 trip to there repair shop before it was fixed) in maybe a 3 month back and forth.
this was my first volume problem. I also find many processor that have a dirty digital volume control. when it is dirty , you just touch volume with your finger and bang it goes bizzark. well that is what a dirty digital volume control does . most people use the volume on remote control only. I always tell people , use that volume control (directly on the unit, not remote) ounce in a whyle. the more often as possible it clean it up as you turn it, (just like analogue volume control) if you don't use it , it will get dirty. me everytime I replace a disc in the player, I ALWAYS turn volume down manualy on the unit. that way I always use it every time I play music.
I also saw other volume control problem on a anthem processor and integrated amp.it just went up on it s own. the integrated amp was eventually fixed, but the processor was never fixed properly. it sat in the store shelf for at less 7 year.


Top
 Profile  
Reply with quote  
PostPosted: Sun Dec 18, 2016 5:57 pm 
Offline

Joined: Thu Jan 10, 2008 10:03 am
Posts: 401
Location: cambridge, ON, CA
Thanks Teo for the links. This has happened to me and when it did, I had never heard of it before. From the posts here and the various brands reported, it is more widespread than I thought. As Teo mentioned, Alps potentiometers seem to be the common part and that is the brand in my Xindak xa6950 that the tech cleaned and restored to working order. It's since been trouble free in it's operation.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 50 posts ]  Go to page 1, 2, 3, 4  Next

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group