Questions about 6V6 Rocket

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sliberty
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Joined: Fri May 26, 2006 5:03 pm

Questions about 6V6 Rocket

Post by sliberty »

I built a 6V6 Rocket varient, and have a few questions.

1. The cleans are really nice. Chimey, and shimmery. But the overdrive is not as smooth as the std Rocket. It is more raw, and as it is turned up, more aggressive. Is this normal on a 6V6 Rocket?

2. I built using solid state rectification due to space limitations (I am planning some additional mods later, leaving no room for the additional tube socket). As a result, my preamp voltages are a little higher than a std Rocket. Maybe 10-25V higher depending upon the stage. If I wanted to drop these voltages down a bit without affecting the B+1 and B+2. would it be reasonable to remove the series 9.1K resistors (total of 18K), and replace with something larger, say 24K-33K? I haven't done any math, so I am just guestimating the values - I would experiment to get it where I want it.

3. This one is more a problem rather than a question. When I flip the standby switch to play position, there is a crackling sound for a few seconds, and then it is gone. It doesn't come back until the amp has been on standby for a while. I have changed my filters and dropping resistors, the diodes and all tubes without resolving the problem. Any thoughts on what might be causing this?

Thanks,
Steve
PCollen
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Re: Questions about 6V6 Rocket

Post by PCollen »

Could be under-rated pre-amp tube plate resistors..what type (CC,CF, MF ?) and wattage rating did you use ? I've often heard complaints of "frying bacon" sounds from amps, but have never experienced it myself or read of a definitive solution being found.
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sliberty
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Re: Questions about 6V6 Rocket

Post by sliberty »

I used 1 watt (over rated) CF's. I could change them on the chance that one is bad, but wouldn't that sound last beyond a few seconds if that was what it was?
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sliberty
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Re: Questions about 6V6 Rocket

Post by sliberty »

Bump!
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Darkbluemurder
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Re: Questions about 6V6 Rocket

Post by Darkbluemurder »

sliberty wrote:I built a 6V6 Rocket varient, and have a few questions.

1. The cleans are really nice. Chimey, and shimmery. But the overdrive is not as smooth as the std Rocket. It is more raw, and as it is turned up, more aggressive. Is this normal on a 6V6 Rocket?
My first homebrew was based on the Tophat Club Deluxe which is very close to a 6V6 Rocket. I did not find this amp aggressive compared to the EL84 amps that I built later. What transformers did you use?
sliberty wrote: 2. I built using solid state rectification due to space limitations (I am planning some additional mods later, leaving no room for the additional tube socket). As a result, my preamp voltages are a little higher than a std Rocket. Maybe 10-25V higher depending upon the stage. If I wanted to drop these voltages down a bit without affecting the B+1 and B+2. would it be reasonable to remove the series 9.1K resistors (total of 18K), and replace with something larger, say 24K-33K? I haven't done any math, so I am just guestimating the values - I would experiment to get it where I want it.
This should work just fine. Maybe you will get a bit more sag.
sliberty wrote: 3. This one is more a problem rather than a question. When I flip the standby switch to play position, there is a crackling sound for a few seconds, and then it is gone. It doesn't come back until the amp has been on standby for a while. I have changed my filters and dropping resistors, the diodes and all tubes without resolving the problem. Any thoughts on what might be causing this?
Never seen this happen but if you changed everything else without success then the culprit could be the standby switch itself or the wiring. Does the switch switch DC? If so you should convert it to switch AC, i.e. the HV secondary wires from the PT should go to the switch and from there to the rectifier.

Cheers Stephan
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Structo
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Re: Questions about 6V6 Rocket

Post by Structo »

I built a 6V6 Rocket, but I haven't played it in so long I can't describe the distortion very well.

Mine was made from a Hammond organ convert so I used a 5U4GB rectifier that came with it.

I think you may need to play with the resistors on the PI to maybe lower the gain a bit.

As far as crackling noises go, just about every time I have experienced that it was a bad preamp tube.

I suppose it could be a bad solder joint as well.
Tom

Don't let that smoke out!
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