Sony TA-D705 Receiver not loud enough (Preamp gone?)

[Ronin53]

So I have this Receiver from the 90s its called Sony TA-D705 the problem is that the receiver when connected to my Speakers is not loud enough. I have to turn up the volume dial to the max, to barely hear something. When I put a CD in my Player and press CD Direct on my Amplifier it plays loud enough and normal. Also, when I connect my phone to the CD Input on the Receiver and press CD Direct Mode my music plays in a normal sound level, but when I connect my phone to the Inputs Video 1, Video 2 or Video 3 it plays again so quiet that I have to turn up the volume dial to the max to barely hear something. My assumption is that my preamp is not working or failing in the receiver. I have opened it, but I could see any things that would be conspicuos. In the Internet there is a guide for repairing this current amp/ receiver. Where should I look for the problem or what could be the problem ? Dad Capacitators ? Or something else

Thanks in advance for your help

 

[mbz]

Since both channels affected I'd be thinking either a failed opamp or power supply to the opamp. Give me a moment to try and locate service manual. What happens if you connect CDP to CD inputs but don't select CD Direct?

 

[Powertech]

I would suggest that there is a problem with the buffer amplifer(s) probably within the tone control section of the amplifier. If this is OPAmp based,, it could be a fault with the negative feedback loop which has reduced the section gain to 1.01 - unity gain (i.e. very low).

 

[Robisme]

Does that model require jumpers in the EQ I/O's? If so, are they present?

Rob

 

[Ronin53]

Since both channels affected I'd be thinking either a failed opamp or power supply to the opamp. Give me a moment to try and locate service manual. What happens if you connect CDP to CD inputs but don't select CD Direct?

Here is a repair guide for the Receiver which is free to download

Elektrotanya for electronics experts

Electronics forum for electronics experts to repair defective appliance.

elektrotanya.com

 

[Ronin53]

Does that model require jumpers in the EQ I/O's? If so, are they present?

Rob

I have a sepaerate eqalizer with the jumpers for it and have already plugged it in but I couldn't notice any differnet and I dont know if it requires them

 

[Dswankey]

So I have this Receiver from the 90s its called Sony TA-D705 the problem is that the receiver when connected to my Speakers is not loud enough. I have to turn up the volume dial to the max, to barely hear something.
When I put a CD in my Player and press CD Direct on my Amplifier it plays loud enough and normal. Also, when I connect my phone to the CD Input Receiver and press CD Direct Mode my music plays in a normal sound level,

A couple of things:

It's NOT a receiver it's an Integrated amplifier, a receiver denotes that it has a tuning section for AM/FM radio which yours do not have.

What were you trying to listen prior to your CDP & Phone that you had to turn the volume to the max? if it was a TT have you verified the TT is working correctly

 

[Robisme]

See the picture in the previous post? Do you have an EQ connected here? Is it connected properly? Set up properly?

Try disconnecting the EQ and use a patch cable to jumper the EQ out/in.

Rob

 

[Ronin53]

See the picture in the previous post? Do you have an EQ connected here? Is it connected properly? Set up properly?

Try disconnecting the EQ and use a patch cable to jumper the EQ out/in.

Rob

The Problem was indeed with the Equalizer when I reconnected my whole System again I say that I have connected the ports from the equalizer in the amplifier false there are 2 in and out's on the equalizer and 2 in and out's on the amp for the amp. Previously I have connected in with in and out with out. Then I changed it and my amplifier started working normal again. So I understand that when I want to use just the amplifier without the equalizer I have to the bridge the in and out's on the amp. I am right ?

 

[Ronin53]

A couple of things:

It's NOT a receiver it's an Integrated amplifier, a receiver denotes that it has a tuning section for AM/FM radio which yours do not have.

What were you trying to listen prior to your CDP & Phone that you had to turn the volume to the max? if it was a TT have you verified the TT is working correctly



View attachment 3200174

The Problem was indeed with the Equalizer when I reconnected my whole System again I say that I have connected the ports from the equalizer in the amplifier false there are 2 in and out's on the equalizer and 2 in and out's on the amp for the amp. Previously I have connected in with in and out with out. Then I changed it and my amplifier started working normal again. So I understand that when I want to use just the amplifier without the equalizer I have to the bridge the in and out's on the amp. I am right ?

 

[Dswankey]

... when I want to use just the amplifier without the equalizer I have to the bridge the in and out's on the amp. I am right ?

Congrats on figuring out the problem, glad to hear your back up and running.

So yes if your equalizer is not connected you want be sure that the supplied RCA "Jumpers" are connected