2db maybe more lower channel?

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This is my second post. The previous situation is all cleared up, thanks guys. But I'm still not out of the woods.:confused:

Again, I have a set of Bose 901, Crest AMP 900V, Gemini PA-7000, Sony CD/DVD deck. The problem is that when I play music one channel is a lot lower then the other one. When I use the balance, the right is loud and clear, the left one is very low, you almost can't hear it. But when I use the headphones, both channels run fine. Tomorrow I'm installing new RCA wires. Can anyone help, once again, thanks.
 
Well, this morning I changed all the RCA wires, still the "B" channel is down. Headphones are good though, both channels working. Question, Is their a video in You Tube or in this forum with this procedure? Even though I've been working with music and equipment. This is my first time I'm going into an electrical equipment like this to give service. I do have pictures, or I can even post pictures of the inside of my Preamp.
 
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You've told us that this preamplifier will drive headphones but somehow the signal from the preamplifier to the amplifier and speakers is down - almost dead in one channel, right?

It seems obvious but this does indicate that the problem is in the amplifier/speakers so why are you focused on the preamplifier? Is it because you swapped inputs to the amp. and both amplifier channels worked the same?

As Max Headroom pointed out, if there is a fault in the preamplifier, it will likely be in the internal connections to the connecting sockets. As it drives phones, there isn't much that could be wrong there that isn't loose connecting wires, broken soldering etc.

Tracing circuit problems though, does require the schematic which is not free on the net so few will be able to help you, unfortunately.
 
The reason why I state that its a PreAMP, I've already taken the AMP to a Certified technician and he told me the AMP was fine.

The reason why I think its the PreAMP, I try it on mono and it works fine. In Stereo where the problem is.

Here is the AMPs pdf Crest V900 AMP

Here is the PreAMP pdf Gemini PA-7000

I use the Bose 901 Factory active EQ.
 
I think I found the culprit. what can you tell me?
 

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The connection faults are not likely the cables almc, because you can swap them to prove they are good or not in seconds.
The problem you have to deal with is most likely INSIDE the preamp. and the INTERNAL wiring and connections. This is not a simple, user maintenance matter of plugging things in and out of sockets.

You will require phono inputs for turntables and they must have impedance correctly matched to the type of cartridge fitted to the player arm.
 
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OK, guys, I'm back. This time I just waited for a set of 1/4 to RCA wires. I plugged them in the Crest AMP from the RCA jacks and now it works in Stereo, sort of. :confused::rolleyes: Which means, as you can see in the above picture. The 1/4 wires plugs outlet were waisted. But the Gemini also has a set of RCA jacks that can be used as outlets also to work with the 1/4 CREST V900 AMP plugs. Done :cool:

This time, when I use both channels. It sounds like crap, It sounds better with the balance to one side or the other. Let me explain.

I place the balance in the middle. Both channels sound...horrible. High sounds and voice, but no bass!

Then I turn the Balance nob toward the left side, or the right side completely. Then it sounds great, like it should sound. With bass, voices, and music.

What's next?:scratch1::confused:
 
Make sure + and - connected the same on the amp and speakers, that's in phase. If you have one channel reversed + on amp to - on speaker that channel will be out of phase with the other channel, no bass and weird sounding. But normal when only one speaker is playing.

Craig
 
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