I'm thinking you have an open shield ground on the RCA input side. Connecting speaker inputs possibly restores the ground. Try connecting the high level inputs then disconnect the remote end of the cables (floating the grounds).
Then get out an ohmmeter and find that open circuitor or bad solder joint between RCA ground and real ground in the speaker's amplifier. Or.... if speaker ground kills the hum and you want to use RCA Line Level input to the sub, just connect one minus speaker output on your source amp to one minus on the sub's amp.
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You are the Man (or Guru or whatever you prefer). Cool idea. Excellect troubleshooting logic that I would have never thought to try.
Here's what I did and the results.
Connected left line level RCA input to the Yamaha subwoofer #1 output and the Yamaha surround back left speaker ground (not used - 5.1 system for now) to the subwoofer's left speaker level input - did not work.
Switched the line level input to the subwoofer's right RCA jack and bingo - subwoofer works.
I can also switch the speaker level ground from left to right and the sub still works.
So before I pull out my multi-metter yank the guts out of the sub, what do you think I should look for? Faulty ground on the left line level input or both line level inputs?
I have my moments of clarity.
All the grounds (or minus') in the receiver or sub amp are theortically the same, so choosing one or another speaker 'minuses' should make no difference. If I understand what you observed, any speaker ground works with the Right sub RCA input. I'd be looking for a faulty RCA ground that affects BOTH RCA connectors in the sub.
I can't find any details on your sub, not even a picture of the back. Even BA's website has no record of a VR500. Some subs can live with just one side of the two RCA inputs connected. Perhaps yours prefers the 'right' one. If it works, do you really need to go inside?
I only need to go inside so I can get rid of the speaker level ground/minus wire that I will need one day soon for surround back speakers. Plus, it just aggravates me to know that I'm using a work-around vs. fixing the real problem (I have obsessive-complusive moments). I can email you a scanned copy of the VR2000 back panel. It is the big brother (300w) of the VR500 (100w) and the back panel inputs/switches/controls are identical except for one additional "fixed" line level input on the VR2000 (added in 1990's for the "newer" receivers that actualy had a dedicated subwoofer-out jack and for the THX certification of the VR2000).
By the way, the VR2000 is crapped out too. Wanna take a shot at that one as well :-)
Ground is ground is ground. The minus can remain where it is when you get other speakers as long as you never connect a plus to the other side of the sub. In fact, one could conceivably run a single ground to one speaker and hop that from speaker to speaker as long as the plusses never meet each other.
You never mentioned if you have the manual.
VR2000 ??? That one has no hits at BA either. Wassup with it?
I do not have the manual for the VR500. I bought it used. I am going to have to call BA support and request one. The VR2000 has a higher pitched buzz as soon as you power it on regardless of whether anything is connected or not. Sounds more like it is coming from inside the box vs. the speaker. Someone once told me I needed to replace the amplifier but I think that was more of a guess than a diagnosis...
That one sounds like a broken ground somewhere, too. Wild guess - do you have track lights with a dimmer? Mine causes a higher-than-line-frequency buzz on analog sources in my rig.
I also had a sub's internal amp die on two copies of the same model so I converted it to unpowered and drive it with my own external amp.
No. No track lights. This was a one day it worked and the next day it didn't thing. The sub produces nothing when connected to the audio source that it has been connected to for years.
Well, a buzz means the driver is probably ok. That leaves the amp.
Well, I opened up the VR-500 and found a cracked solder connection between the line level inputs and the ground circuit on the board. Drop of solder and done. Thanks again for all of your help. Since I am feeling all cocky now, I'll probably open up the VR-2000 tomorrow. I'll let you know what I find.
Unless it's broke, I wouldn't try to fix the VR-2000. Do you still have a buzz?
I had a self-powered sub that blew its amp, got a whole new replacement sub and IT blew its amp, too, so I just disconnected the amp and wired the driver directly to the outside so I can drive it with a Carver. Not a total waste.
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Well, I opened up the VR-500 and poked around for an hour before I found the problem - cracked solder connection between the grounds on the line level inputs and the rest of the ground circuit on the board. Probably from overly-agressive or repeated RCA cable connections. Drop of solder and done. Thanks again for all of your help. I will probaby open up the VR-2000 tomorrow since I'm now feeling cocky. I'll let you know what I find there.
The VR-2000 is definitely broken. All it does is buzz.
it's broke. Nothing but the buzz regardles of the input.
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