Extremely low volume on old receiver

23.120.117.77

Posted on April 4, 2015 at 17:33:14

K-Bob
Audiophile

Posts: 614
Location: Missouri
Joined: December 21, 2000

I have a Pioneer SX-580 receiver with extremely low output level. Have to peg the volume knob to barely get background level. Even with headphones have to turn it up all the way to barely hear it. Quality of Tthe sound seems ok, if weak in the bass. here is equal output on both channels. All controls and functions operate normally. Problem occurs on aux input as well as built-in tuner. It's just as if the amp section stopped working.

Problem began suddenly and the first few times only occurred when I first turned it on and then after 5-10 minutes normal volume would kick in and sound just fine. But is all the time now.

What would go bad and take out both amp channels without affecting anything else?

--

Mucking around the low-end since 1986.

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RE: Extremely low volume on old receiver

rickl

13:23:54 04/06/15

Thanks to all.

K-Bob

20:51:03 04/05/15

10

Great job

airtime

06:51:26 04/07/15

...

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RE: Extremely low volume on old receiver

rickl

13:23:54 04/06/15

Thanks to all.

K-Bob

20:51:03 04/05/15

10

Great job

airtime

06:51:26 04/07/15

RE: Great job

K-Bob

09:10:20 04/07/15

RE: Thanks to all.

Crazy Dave

09:19:53 04/06/15

brute force -- but effective

mhardy6647

06:36:48 04/06/15

6

sealed enough

K-Bob

10:26:33 04/06/15

5

I have read that you can low speed drill them. ...

Crazy Dave

07:24:36 04/08/15

4

RE: I have read that you can low speed drill them. ...

K-Bob

08:01:58 04/08/15

3

RE: I have read that you can low speed drill them. ...

Crazy Dave

08:35:59 04/09/15

2

Think I know why it worked

K-Bob

12:10:46 04/09/15

RE: Think I know why it worked

Crazy Dave

09:42:14 04/10/15

if you haven't -- clean all pots, switches, and controls

mhardy6647

08:08:23 04/05/15

RE: Extremely low volume on old receiver

Garth1

05:50:44 04/05/15

RE: Extremely low volume on old receiver

Eli Duttman

18:23:07 04/04/15

2

Fixed, thanks.

K-Bob

12:15:15 04/09/15

RE: Extremely low volume on old receiver

K-Bob

22:23:02 04/04/15

RE: Extremely low volume on old receiver, posted on April 4, 2015 at 18:23:07
Eli Duttman Audiophile Posts: 10455 Location: Monroe Township, NJ Joined: March 31, 2000	"What would go bad and take out both amp channels without affecting anything else?" Possibly a messed up or mis-set tape monitor loop switch. Eli D.

RE: Extremely low volume on old receiver, posted on April 4, 2015 at 22:23:02
K-Bob Audiophile Posts: 614 Location: Missouri Joined: December 21, 2000	Cool, thanks. It does seem to be the tape monitor switch. Didn't think to check that. Normal volume when connect to tape in (after fiddling with switch). The switch is sealed but I'll see what I can do about hitting it with cleaner. -- Mucking around the low-end since 1986.

RE: Extremely low volume on old receiver, posted on April 5, 2015 at 05:50:44
Garth1 Audiophile Posts: 12 Location: southern Ontario Joined: June 15, 2014	I would leave it alone and give it to your kids. Make your lfe a lot better

if you haven't -- clean all pots, switches, and controls, posted on April 5, 2015 at 08:08:23

mhardy6647
Audiophile

Posts: 16018
Location: New England
Joined: October 12, 1999
Contributor
Since: October 23, 2016

... and don't skimp; CAIG's DeOxit is the best readily available contact cleaner (although not compatible with absolutely every possible device, and also bereft of lubricant).

If this is unfamiliar territory to you, see the guide at the link below.

If it's not a noisy (intermittent) control -- it could be serious. Does it do it on all inputs?

(oh, and my apologies if all of the above is old news)

all the best,
mrh

Thanks to all., posted on April 5, 2015 at 20:51:03

K-Bob
Audiophile

Posts: 614
Location: Missouri
Joined: December 21, 2000

It turned out to indeed be the tape monitor switch. It went bad somehow.
It is completely sealed so I was unable to get cleaner into it.
I got the schematic and looked at the switch layout with plans to jump the switch to force it into the "source" position. In experimenting with it I found two pins to jump that made the switch operate normally.

I am the first to admit that this kind of work is not my forte and I have trouble reading schematics, so I cannot explain how soldering a jumper between those two adjacent pins made the switch work again. By all rights it shouldn't have. Anyway, it is working normally again. Hurray!

I did no other work besides blowing the dust out of it and looking for swollen caps. I did not clean any other switches or the tuner since everything is working fine. Btw, I just use Radio Shack contact and control cleaner, which I used to clear up a problem with the selector switch on my Rotel pre just before I started on the Pioneer.

Thanks again guys, I'm glad to heave the old Pioneer back in the bedroom.

--

Mucking around the low-end since 1986.

brute force -- but effective, posted on April 6, 2015 at 06:36:48
mhardy6647 Audiophile Posts: 16018 Location: New England Joined: October 12, 1999 Contributor Since: October 23, 2016	"completely sealed", eh? all the best, mrh

RE: Thanks to all., posted on April 6, 2015 at 09:19:53
Crazy Dave Audiophile Posts: 14371 Location: East Coast Joined: October 4, 2001	On some of these switches, you can drill into them and spray with Deoxit. I still have tape decks, so I want the loops. Dave

sealed enough, posted on April 6, 2015 at 10:26:33
K-Bob Audiophile Posts: 614 Location: Missouri Joined: December 21, 2000	Completely enclosed. No gaps or anything. Only two TINY holes on top.... not enough for cleaner to get in to the contacts. Unlike the Rotel which was easy to clean with the cleaner. But the jumper worked. -- Mucking around the low-end since 1986.

RE: Extremely low volume on old receiver, posted on April 6, 2015 at 13:23:54
rickl Audiophile Posts: 583 Location: Twin Cities Joined: February 7, 2002	I just put an old Sony receiver in the brewery. One of the ex-brewers wanted his equipment which included a Marantz. I had similar problems but was able to clean the AUX/FM/Phono switch and get it working great. I cleaned the volume pot and other switches since I was in there. looking for some jazz and a little libations - js

Great job, posted on April 7, 2015 at 06:51:26
airtime Audiophile Posts: 11287 Location: Arizona Joined: February 4, 2003	Had a speaker switch do the same exact thing. Just stopped working one day for NO reason? Excellent job

RE: Great job, posted on April 7, 2015 at 09:10:20
K-Bob Audiophile Posts: 614 Location: Missouri Joined: December 21, 2000	Selector switch on my Rotel started getting fuzzy, but only in one position. Thought for months my tuner (or the interconnect) was dying. Once I assumed it was the tuner or the wire, it took a little while to shift gears and realize it was the switch. Stupid dirt/corrosion. -- Mucking around the low-end since 1986.

I have read that you can low speed drill them. ..., posted on April 8, 2015 at 07:24:36
Crazy Dave Audiophile Posts: 14371 Location: East Coast Joined: October 4, 2001	It will take courage, but if the only other option is to replace, you not really risking anything. I plan to give it a try on my Adcom GFP-1a preamp. There are too many switches to replace them all. Dave

RE: I have read that you can low speed drill them. ..., posted on April 8, 2015 at 08:01:58
K-Bob Audiophile Posts: 614 Location: Missouri Joined: December 21, 2000	I thought about drilling it, but not knowling the interior design of it I'd prob drill in the wrong place. Since I only needed one position to work I elected to just jump the switch. Pure luck that what I did made the switch work normally... go figure. -- Mucking around the low-end since 1986.

RE: I have read that you can low speed drill them. ..., posted on April 9, 2015 at 08:35:59
Crazy Dave Audiophile Posts: 14371 Location: East Coast Joined: October 4, 2001	Interesting! I wonder what happened there. Dave

Think I know why it worked, posted on April 9, 2015 at 12:10:46
K-Bob Audiophile Posts: 614 Location: Missouri Joined: December 21, 2000	Talked to a friend about it and he's like, "You just re-established a bad ground." Duh! Somewhere along the path the ground to the switch went bad, and my jumper re-established it. That's the only thing that makes any sense. -- Mucking around the low-end since 1986.

Fixed, thanks., posted on April 9, 2015 at 12:15:15
K-Bob Audiophile Posts: 614 Location: Missouri Joined: December 21, 2000	Jumped a couple of pins on the switch and it works normally now. My theory is that somewhere along the path the ground to the switch went bad, and my jumper re-established it. Thanks for putting me on the right track. -- Mucking around the low-end since 1986.

RE: Think I know why it worked, posted on April 10, 2015 at 09:42:14
Crazy Dave Audiophile Posts: 14371 Location: East Coast Joined: October 4, 2001	That sounds very plausible. Dave

Vintage Asylum

Extremely low volume on old receiver

23.120.117.77