New ROCKET, from a newbie :)

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DocJames
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New ROCKET, from a newbie :)

Post by DocJames »

Good morning all,

Some may remember me, as I was one of the original rocket build group members. Life, unfortunately, didn't let me finish this build with everyone else. So after a few years, a couple children, and just a few more grey hairs, I finally got this amp built. It sounds amazing! It is clean on the bottom with gorgeous distortion when cranked. I love it!!

On startup, my B+ voltages looked good. They were 2-3 voltages higher then expected from the chart. My heater VAC however is reading at 3.0V instead of the 6.3V. Is this a concern?

Also, my treble pot doesn't seem to do much at all. Its got a lovely jingle at the top, and I can control it easily from the guitar. But as I sweep the pot left to right, I don't notice much discernable difference.

Anyway, any thoughts would be appreciated. I'm so stocked that I got this finally finished! I could include pictures if you like, but the build isn't anything special :oops: .
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NickC
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Re: New ROCKET, from a newbie :)

Post by NickC »

DocJames wrote: ........... My heater VAC however is reading at 3.0V instead of the 6.3V. Is this a concern?.................

How are you measuring that? From each of the two heater pins (pin 9, and pins 4 & 5 tied together) to ground?

With a PT heater supply of 6.3VAC, each leg should be carrying about 3.15VAC (1/2 x 6.3V) ...... 3.15V to pins 4 & 5 and 3.15V to pin 9. Measuring between pins 9 and 4 & 5 (tied together) should yield 6.3VAC.
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DocJames
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Re: New ROCKET, from a newbie :)

Post by DocJames »

And here's why I love this place. Simple answer to a simple mistake. I was reading 4/5 to ground and 9 to ground. Each at 3.0 V. So I guess I'm pretty close to the money :). Thanks a lot!
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NickC
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Re: New ROCKET, from a newbie :)

Post by NickC »

DocJames wrote:And here's why I love this place. Simple answer to a simple mistake. I was reading 4/5 to ground and 9 to ground. Each at 3.0 V. So I guess I'm pretty close to the money :). Thanks a lot!

Depending on the range selection of your meter, you are probably right on the money. Some meters, when set to higher ranges, will not be quite accurate when measuring a much lower voltage.
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Fischerman
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Re: New ROCKET, from a newbie :)

Post by Fischerman »

Don't feel bad, I was in that group build and STILL don't have a cabinet for that amp (I'm rectifying this asap!). Raven's faceplate is just too pretty to not have a cab around it.

The Treble knob should be quite noticeable, can you show a pic of the wiring?
Early brewers were primarily women, mostly because it was deemed a woman's job. Mesopotamian men, of some 3,800 years ago, were obviously complete assclowns and had yet to realize the pleasure of brewing beer.
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DocJames
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Re: New ROCKET, from a newbie :)

Post by DocJames »

Sure, I'll take pics as soon as I get home today.
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Lonely Raven
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Re: New ROCKET, from a newbie :)

Post by Lonely Raven »

Fischerman wrote:Don't feel bad, I was in that group build and STILL don't have a cabinet for that amp (I'm rectifying this asap!). Raven's faceplate is just too pretty to not have a cab around it.

The Treble knob should be quite noticeable, can you show a pic of the wiring?
I'm glad you guys still appreciate my work. I wish I could still make faceplates...Even though it was tedious work, I really enjoyed it.

Maybe someday when I have a spare $10k around I buy a *used* laser engraver! :roll:
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passfan
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Re: New ROCKET, from a newbie :)

Post by passfan »

A lot of times when the tone stack is not as responsive as it should be , check the ground and see that it hasn't been forgotten.
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redshark
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Re: New ROCKET, from a newbie :)

Post by redshark »

DocJames wrote:Also, my treble pot doesn't seem to do much at all. Its got a lovely jingle at the top, and I can control it easily from the guitar. But as I sweep the pot left to right, I don't notice much discernable difference.
The bass and treble controls in this amp are very responsive so check your wiring around the pots and grounds. I had trouble when I built mine with that resistor soldered to the grounding bus. Check allyour conections there.
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DocJames
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Re: New ROCKET, from a newbie :)

Post by DocJames »

Hi, just trying to quickly grab a few pics of of the specific area. I'll take a few more tomorrow.
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Fischerman
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Re: New ROCKET, from a newbie :)

Post by Fischerman »

I don't see anything wrong with the treble wiring but I've been out of this game for a while and my Rocket was done with a non-KF layout. So somebody else should verify. What is the value of the resistor to ground off of the bass pot? Doesn't look like 10K but I can't really tell what it is (looks like 9.1k which would be fine, but I can't really read it). Is the treble pot 1M?
Early brewers were primarily women, mostly because it was deemed a woman's job. Mesopotamian men, of some 3,800 years ago, were obviously complete assclowns and had yet to realize the pleasure of brewing beer.
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M Fowler
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Re: New ROCKET, from a newbie :)

Post by M Fowler »

I didn't see anything wrong with that wiring perhaps it could be a bad Alpha treble pot.
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DocJames
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Re: New ROCKET, from a newbie :)

Post by DocJames »

Yeah might be the pot. Was meaning to put PEC's into it, but I had these ones kicking around. Guess I should go ahead and order them :).

James

-edit- Yeah, Fischerman, it's a 9.1k resistor to ground. I didn't have any 10k's, and I figured that was close enough.
Last edited by DocJames on Thu Jun 09, 2011 3:04 pm, edited 1 time in total.
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surfsup
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Re: New ROCKET, from a newbie :)

Post by surfsup »

Fischerman, funny signature!
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Fischerman
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Re: New ROCKET, from a newbie :)

Post by Fischerman »

surfsup wrote:Fischerman, funny signature!
Thanks, that's been my latest obsession the last few years and why I haven't been building amps.
Early brewers were primarily women, mostly because it was deemed a woman's job. Mesopotamian men, of some 3,800 years ago, were obviously complete assclowns and had yet to realize the pleasure of brewing beer.
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