Rocket Hiss and Pedal Popping

[Mark]

I could be wrong, but I really don't like the white axial cap on the cathode follower. How is the cathode follower biased if the grid is decoupled via a capacitor?

What are the resistor values in power supply, they seemed different from the typical 9.1K resistors I'd expect to see.

Why is one of the power supply caps mounted away from the other caps?

[RJ Guitars]

Forgive me for suggesting the overly simple test methods but what happens to the hiss when you pull out tube #1?

[davidskywalker]

Mark...I'm not equipped as I'm a beginner in amp technology. I can say that the tech who cleaned up the mess I made and brought it to life...told me he needed to reroute some areas because he felt the values were off, particularly with the filter caps.

I'm slowly trying suggestions that fit my ability...one was to put a 100K resistor tacked onto the plate resistor (220K) to help reduce the gain. Also to add a master volume.

I'm not so much worried about losing the original Rocket tone as much as I'm trying to solve a problem with the hiss and popping with pedals. AT this point I just don't want to lose my initial investment and get a pretty good sounding amp without having to spend a load of money.

This problem does not happen when guitar is direct into the amp, only with pedals. But from hearing other players with rockets, they've used pedals without any problems.

[davidskywalker]

For RJ:

Forgive me for suggesting the overly simple test methods but what happens to the hiss when you pull out tube #1?

I did the test on this and hiss and all tubes would cut the noise out.

[JazzGuitarGimp]

Perhaps the issue is gain-staging. The noise is only present when pedals are introduced into the signal chain. I believe the fist post said that the guitars' volume control is being used to control clean to mean gain settings. This means the amp's volume control is set fairly high, and with the volume control that high, the noise generated by the pedals is going to be amplified considerably more than when the guitars' volume control is left wide open and the amps' volume control is used to set the playing volume.

I'd suggest the following tests:

- Insert a volume pedal between the last pedal and the amp. Leave the guitars' volume wide open, and use the volume pedal for clean to mean settings. This will reduce the noise generated by the effects when the volume pedal is in the clean position.

- if the amp has an effects loop, put all the pedals in the effects loop, and connect the guitar directly to the input of the amp.

Cheers,
Lou

[Tillydog]

... I really don't like the white axial cap on the cathode follower....

^^This in giant neon lights (well spotted!).

That cap will cause all manner of problems, and needs to go (not from any tonal considerations, just to make the circuit functional).

If that's an example of your tech's work, then I think returning it to stock layout (I guess the Ceriatone one is as good as any) would be a good thing to do. (We can then start trouble-shooting from a 'known good' base.)

As I said in the PM, the 'popping' sound might be a symptom of a problem, or it could be due to DC on the grid (for the reasons in the post I linked to before), and need a cap on the input to block this from your pedals. The hissing / gain will likely be something else.

Stick with it!