OPA134

[pws10uk]

Hi All,

First time poster so be gentle 🙂

I have a 1984 FM tuner I want to replace the output amp based on the opa134.

I've attached the diagram taken from tuner info website (hope this is ok)
I can follow 95% of the diagram put sstruggling with the amp section.
i have orderd two opa134's for each of the left and right outputs so need to bulld two boards for this.

Can someone help with the audio ins and the outs...the diagram has some pins in brackets but no expaliantion.

Cheers

Paul
UK

 

[Mooly]

Those pin numbers refer to the two separate opamps within the one package. The OPA2604 is a dual opamp, your OPA134 is a single opamp, so make sure you get all the connections correct.

For the OPA134 pins 2,3 and 4 are the same. The output is on pin 6 and the positive supply is pin 7. Leave pins 1,5 and 8 unconnected.

 

[pws10uk]

Cheers Mooly.
Makes sense now 🙂

 

[Mooly]

Thats good 🙂

 

[pws10uk]

Hi Mooly

Sorry to nag again 🙂

The attachement in my first post has some of the values but not the voltage for the caps or wattage for the resistors.

As it going to be less than 15V will 1w resistors do the trick and 16v caps?

Cheers

Paul

 

[Mooly]

Resistors can be much smaller than 1 watt. Every resistor on there can be 1/4 watt. Caps are fine at 16 volt.

 

[pws10uk]

Cheers Mate 🙂
1/4w it will be then...its a mod to an 80's tuner..suposed to make it sing and be one of the better tuners around....Love radio and love to try new trhings so this little project fits the bill 🙂

 

[Mooly]

Good luck with it and let us know how you get on.

 

[pws10uk]

Will do Mate

My next challenge will be to find a feed for it all...12V....i have the circuit diagrame of the board but its a poor photocopy in PDF...may have to take it to a mate who's a tv repair man to find a source on the board....it maybe that its a 12v board so from the right side of the psu...but 230v hurts so will get my mate to find it 🙂

 

[Mooly]

It should be easy enough to find the supply with a circuit. If its not to big post the circuit here and we'll have a look (you can zip pdf's if they are to big)