Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

JVC RX-315 amp high pitched whine
JVC RX-315 amp high pitched whine
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 17th May 2007, 03:43 AM   #1
miekedmr is offline miekedmr  United States
diyAudio Member
Join Date: Jun 2005
Location: ny, usa
Default JVC RX-315 amp high pitched whine

I recently got a cheapie 2nd hand JVC amp. There was a fairly quiet but totally annoying treble hum coming through the speakers at all times. It didn't matter which input the amp was set to or whether there was anything besides an output connected toit. The hum was especially apparent when using headphones and would make my head ache after a while.

I searched online to see if anyone had the same problem, and only saw one post on another forum with no replies. I decided to fool around with the amp a bit and see if I could make the hum go away.

Open the case and there is a secondary circuit board mounted above the main one in the back right corner. That's the AM/FM tuner. I found that by disconnecting the two black ribbon-like cables from the board, the intereference disappeared.

So! It would seem you either have to live with the hum or give up the radio tuner. I do not listen to the radio with this, so it was a perfect solution for me.

Now the signal to noise ratio seems very reasonable. There is only a faint hiss when the amp is turned up all the way, beyond where it would ever be during use.

This is just here as a reference, for anyone else with this otherwise decent amp. (I would have replied to the one post I found on the other forum, but I couldn't register with any of my email addresses )
  Reply With Quote
Old 14th July 2010, 05:17 AM   #2
kd7kdo is offline kd7kdo
diyAudio Member
Join Date: Jul 2010
Default RX-315 Whine

I have that amp and took it out of service when it developed a whine. On the o-scope it appears as a square wave with small duty cycle ... low level and around 1.2 KHZ as I recall ...

I will check and see if it is coming from the FM receiver as you found... strangely however, it seemed to go away after cycling the speaker outputs on and off while running a test square wave into the unit....

I thought it might be due to leaking electrolytic capacitors that bypass the DC supply ... the old 6800 uF caps look like they leaked out onto the circuit board. will measure and replace them when I get a chance....
  Reply With Quote
Old 14th July 2010, 12:00 PM   #3
east electronics is offline east electronics  Greece
diyAudio Member
east electronics's Avatar
Join Date: Jan 2006
Location: Athens GREECE
often in machines like that can have leacky electrolytics in the tuner area that might drive the tuner in oscilation and for a couple of times this oscilation was effecting either pre or main resulting a tone or a hiss in the output no matter what input selected ...

Last edited by east electronics; 14th July 2010 at 12:18 PM.
  Reply With Quote
Old 4th April 2017, 11:28 PM   #4
axiozen is offline axiozen
diyAudio Member
Join Date: Apr 2017
Yes! Thank you. This fixed the annoying whine going on with my unit.
How did you pull the black cables out though? I just removed the white tabs holding them in, but couldn't get the cables out.
Thanks again!
  Reply With Quote
Old 4th May 2017, 07:25 PM   #5
zeebee78 is offline zeebee78
diyAudio Member
Join Date: May 2017
Default in lieu of having your baby.....

I picked up a used RX-315 a couple of years back for $20 to replace an old head unit in my office. I tried every thing I could think of to get rid of that whine aside from taking the unit apart(That was probably why they got rid of it) and then finally decided to live with it. Today I had enough and finally decided to google it AGAIN and whadyano?

BIG THANKS MIEKEDMR!!!!!!! I was about to wear out the speaker selector from turning it off so much.

BTW, same leaky 6800uF caps here too. And,(axiozen) the white plastic tabs act to decompress the spring contacts on the receptacle. When you push them down, they should disengage the metal contacts that hold the tinned ends of the wire. You could also remove them and use a small flat screw driver to disengage the contacts manually and wiggle the wire from side to side and they will work loose.
  Reply With Quote
Old 28th July 2017, 05:44 PM   #6
swib is offline swib
diyAudio Member
Join Date: Jul 2017
Yes! Thanks, miekedmr. Finally got rid of that annoying hum. Removing the ribbon cables is how, though I applied more of a brutal tearing rending technique to get them loose. Probably should have read more carefully. The internet, she is a beautiful thing.
  Reply With Quote


JVC RX-315 amp high pitched whineHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
High pitched whine when using laptop input ormo Chip Amps 33 15th December 2009 07:34 AM
High pitched whine when using active guitar preamp with phantom power HankMcSpank Instruments and Amps 2 25th July 2008 11:39 AM
Need HELP with alt whine pityocamptes Car Audio 105 3rd December 2007 11:12 PM
Please,a) cause of high pitched hum, b)DC wires twisted or not frank2395 Tubes / Valves 3 1st May 2005 07:18 PM
Can someone help me with alternator whine? Timbers Car Audio 14 23rd February 2004 04:14 PM

New To Site? Need Help?

All times are GMT. The time now is 10:46 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio