1973 fender twin reverb volume

[gla1013]

Why would turning the reverb level down on the vibrato channel turn the volume level down. Turning the reverb all the way down turns the volume off on the vibrato channel. All resistors and caps have been changed as well as the tubes, tube sockets and transformers. I changed the circuit to AB 763 and removed the master volume. Any advise would be appreciated.

[m-fine]

After the second stage of valve 2, the signal splits, and goes to the reverb and on to the second half of valve 4. My guess is there is a break in the second path, and the signal is only going through the reverb. Check your connections on the 3.3m resistor between valve 2b and 4b.

[gla1013]

fender twin reverb

Found I put two 470 ohm resistors with 3.3M changed one 470 where it should have been a 220 ohm . Now problem is turning reverb knob down has no effect on reverb amount only changes volume and reverb sounds maxed out no matter how much I try to adjust it. Any suggestions to fix this problem?

[m-fine]

Print out a schematic and fender layout. Get a highlighter out and trace every connection and check ever component, highlighting the ones you have verified as you go. At any connection point verify you have the right number of connections and that the solder joints look good and test good with a multimeter. Double check your ground connections.

[gla1013]

fender twin reverb schematic AB763

The schematic shows at v6 12AT7 a dotted line showing 98 volts at the triangle where the two 1M ohm resistors and 470 ohm resistor meet. Does this mean there should be a wire connecting at that point? Pin three on v6 preamp tube feeding this stage show a 100 volt dotted line also I'm not sure if this means pin 3 should feed the junction point of the two 1M and 470 ohm resistors. Any help deeply appreciated.

[Jazz P Bass]

Fender PI

The dotted lines on Fender Layout Diagrams typically mean that the connection runs "under" the board.
The phase inverter pin 3 & pin 8 are tied together.
Off of this point is attached a 470 ohm resistor.
The other end of the 470 meets the two 1 meg resistors.
The 1 megs go to the grid pins.
1 to pin 2.
1 to pin 7.

[m-fine]

The schematic shows at v6 12AT7 a dotted line showing 98 volts at the triangle where the two 1M ohm resistors and 470 ohm resistor meet.

I think you are looking at the layout. That is why I said print both a schematic (logical drawing) and layout (physical) and trace through the circuit on both. If you do this you should get a better understanding of how things flow.

[gla1013]

twin reverb

Thanks for the advise I see on the schematic v6 preamp 12AT7 there is a 100 ohm resistor to ground then there is a .1 capacitor connected to the 1M resistor it looks like a number 200 between them anyone know what that means.

[JoeM]

Thanks for the advise I see on the schematic v6 preamp 12AT7 there is a 100 ohm resistor to ground then there is a .1 capacitor connected to the 1M resistor it looks like a number 200 between them anyone know what that means.

The number 200 is just the voltage rating of the .1 cap. Most of the other caps have a higher voltage rating.