Vox AC30 1963 Tone Control working clockwise+ Vibrato/Tremolo noisy channel

[pielle]

Hi,
I had the chance to get an old JMI Vox AC30 from 1963 copper pannel esthetically in really good condition, but internally it needed a bit of maintenance.
I had the name of a guy here in Turin (Italy) and I decided to bring it to him to let him have a look - as yes I have knowledge in terms of electronics but not really great experience (and not so much time) with old amps and also I don't have all the tools and spare parts that I might need.

He changed few caps on the board and the 2 bigger one (grey and blu one in the pictures), he replaced the socket for the El84 as he showed me that they were really weak on clamping the valve and replaced all the tubes with Sovtek.
Also, he told me that some Bright and Normal input internal cables were replaced as they were not shielded originally.

Once I had it back home I just noticed that:

• The Tone control should work in the opposite way - clockwise add more treble and anticlockwise cutting the treble.
  I have a 78 vox and the Tone is working as I mentioned - clockwise add more treble and anticlockwise cutting the treble. Is that the correct way for the 63 models as well?
• All the 3 input channels are having, after servicing, surface (background) noise. The noise was present before servicing but it was much higher. For Brilliant and Normal the noise is more present when the volume is going after 3/4 o'clock, but for the Vibrato/Tremolo this noise is starting much more earlier - around 1 o'clock and once the Tremolo or the vibrato is in I really can hear the noise pumping true the channel - With the tremolo in pumping nouse is much more present. Also when I try to blend Vibrato with Brilliant, adding and taking off with the volume of the Vibrato, I noticed that the Vibrato channel is making the sounds a bit muddy cutting some high frequency. It seems that the tone is not really effective the Vibrato at all. Is this should be normal?

I tried to go back to the guy but he told me to take my time to try the amp, and in the meantime, he will try to find another model from the same era to do some comparison.
Can I have some second opinion? whats do you think? Do you think this Vibrato channel behave is normal?

PS
Attached some pictures after the servicing

[shooter]

•The Tone control

ALL amps I know of;
clockwise more treble, easy fix if this not the case, swap outside 2 wires on treble pot.

noise is a complicated "thing" that requires knowledge and time to isolate and fix

[Latole]

In my opinion your noise problem would come from the wires coming from the tubes socket. They have poor routing.
We can see it very well in your photos between the two circuit boards.

With this bad routing, these wires act as an antenna to pick up noise.
All these wires must run alongside the metal chassis.
Crossing wires must do so in 90 degrees.
Avoid parallel wires.

Look at my photos

The wires going to the tubes’s grids should be as short as possible. These are the most sensitive . Ideally they would be shielded with only one end of the shield to the ground.


To have more help, post in the right sub-forum ; Tube amps -Tweak-Repair

https://el34world.com/Forum/index.php?board=13.0