Rocket Hiss and Pedal Popping

davidskywalker · Post by **davidskywalker** » Tue Jan 14, 2014 2:56 pm

I am wanting to purchase/build a TW Liverpool clone but am an avid pedal user. If the guitar volume is turned down low in order to create clean tones will this cause the gain signal from the pedals to suffer loss?

The reason I am asking is because my new Rocket has terrible hiss and pedals pop REALLY LOUD. Hiss also comes out when pedals are on and they don't do this with other amps.

redshark · Post by **redshark** » Tue Jan 14, 2014 5:18 pm

Express and Liverpools aren't pedal friendly. If you are a pedal player look somewhere else.

Tantalus · Post by **Tantalus** » Tue Jan 14, 2014 5:31 pm

Have you given the Rocket any thought? It's nicer to pedals than the other 'wrecks.

geetarpicker · Post by **geetarpicker** » Tue Jan 14, 2014 5:41 pm

With the high gain nature of these amps most pedals will become very noisy and/or washed out in front of a Liverpool or Express. You could tame the gain way down with different preamp tubes, but if you go to far you are missing the point of the amp in general IMHO. That said, you can run your ambient type effects (reverb, Delay, Chorus) post amplifier via wet/dry setup and they will sound killer. That said for this you will need pedals with a Kill Dry switching function such as the newer TC Electronics Toneprint pedals. Also you may need a smaller mixer to run them in parallel. These type pedals will sound stellar with a wreck in a wet/dry configuration and will give you near studio quality in your ambient effects.

Yes a Rocket has quite a bit less gain (but quite less clean to mean range from the guitar controls) which makes it much more pedal friendly.

Zippy · Post by **Zippy** » Tue Jan 14, 2014 5:54 pm

Welcome to TAG!

The Rocket is extremely pedal friendly. A bonus is that it is also more friendly to build - more tolerant of layout indiscretions, for instance.

See also the KT66 Rockster - a Rocket variant with big bottle output tubes.

davidskywalker · Post by **davidskywalker** » Tue Jan 14, 2014 6:32 pm

Ok. The reason I posted this for the Liverpool was because I bought a Rocket clone from Ceriatone. This is my first amp and have been successful in modding pedals and amps, but failed pretty badly and took it to an amp technician who brought it to life, but rerouted quite a few areas....overall the amp sounds amazing, but when used with pedals, although the tone is great, there is a ridiculous amount of hiss that is really not normal...especially for this amp which has no gain, and there is REALLY LOUD POP on almost any pedal I use...especially overdrives/distortions.

In all, I'm going to undo everything and go back to the original design that is in the ceriatone layout then come back and work from there....from the layouts and schematics I've seen the ceriatone looks pretty close to others.

Zippy · Post by **Zippy** » Tue Jan 14, 2014 6:41 pm

The Liverpool and Express share much of the same topography and character, the Rocket is much different.

From what you describe, you just need a GOOD Rocket. Since you've already got the Ceraitone clone, maybe the KT66 Rockster is just the ticket if you're jonesin' to do another build.

Contact RJGuitars on this forum for components. I don't know if he currently has any kits. He's been doing all the homework with the transformer companies to spec the best available iron.

RJ Guitars · Post by **RJ Guitars** » Wed Jan 15, 2014 6:12 am

A Rocket that hisses is a bit of a surprise... and not something I would expect from a Ceriatone. They are generally decent amps that you can tweak into excellent sounding amps with a reasonable effort. Hiss is generally associated with high gain tube circuits, so in this case it might imply that the hiss is in the early part of the circuit. I'd start by doing some tube rolling... maybe swap #1 with #3 if you haven't done that already. I have recently started supplying the Tungsol 12AX7's with build packages because they have strong gain characteristics along with a low noise floor. Let us know if the tube rolling does any good. If not then maybe the guru's here on TAG can teach us something about the source of amp hiss. I think it's worth getting the most out of that amp then look at the transformer tweaks... rj

davidskywalker · Post by **davidskywalker** » Wed Jan 15, 2014 2:29 pm

The hiss isn't so bad as much as the popping. The popping is super loud and I know it isn't the pedals because I've used them on other amps. The amp just seems highly sensitive. And from hearing other Rocket players they haven't had this trouble. I'll post some pics of the tech who bright it to life.

davidskywalker · Post by **davidskywalker** » Wed Jan 15, 2014 3:17 pm

Ok here are the pics. Remember, the tech that put this together rerouted some things. Didn't change the design, just rerouted.

1) Reconfigured the filter caps putting one on the board and one by the first
preamp tube. (He did change the value of the filter caps...don't have right
now but can get later).
2) Completely rerouted the grounding in the preamp area removing the
copper grounding on the pots.
3) On the power tubes he has used #1 on the tubes instead of connecting
them directly.

So far, I have tested the tubes and that isn't the problem.

Zippy · Post by **Zippy** » Wed Jan 15, 2014 4:17 pm

David,

From what you describe, it sounds like something has increased the gain - maybe early in the chain. Go over your layout (maybe compare values with the Rocket layout in the Trainwreck Documents) and check, especially, resistor values against what you have. I always verify values of resistors as I build to check for either mislabeled resistors or ones that are far out of spec.

In the future, please post pictures with the amp/board horizontal - that's how most of us are used to looking at them. Your pictures are like reading a book sideways to me.

Do you have any other tubes that you can substitute? Other than having a hardwired wrong gain, the culprit is usually tubes. Given that yours all came in a kit, it is possible that you're not hearing a change because all the like tubes came from the same batch - they may all be equally good (or bad).

FWIW - I suggest you edit your original post to request help in troubleshooting the hiss problem in your Rocket, or start a new thread. Many people, that could be quite helpful, may just go right past this thread under it's current title.

M Fowler · Post by **M Fowler** » Wed Jan 15, 2014 6:34 pm

Sounds like a microphonic preamp tube if your hearing popping or sensitivity.

davidskywalker · Post by **davidskywalker** » Wed Jan 15, 2014 6:52 pm

I've checked all tubes and switched them around for testing. They are also new in box Teslas sold as set for TW Rockets from tubes and more.

M Fowler · Post by **M Fowler** » Wed Jan 15, 2014 7:49 pm

In all, I'm going to undo everything and go back to the original design that is in the ceriatone layout then come back and work from there....from the layouts and schematics I've seen the ceriatone looks pretty close to others.

Looking at the photos I think what you said above is about the correct thing to do at this point.

Mark

Tillydog · Post by **Tillydog** » Wed Jan 15, 2014 8:24 pm

Also, regarding popping with pedals, see the highlighted part of this post:

https://tubeamparchive.com/viewtopic.ph ... ht=#266727

It may be the DC leakage which is causing problems with pedals popping. You could fit a DC blocking capacitor to the input.

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