Building a Rocket - Layout Check for group build

[Sven]

Greetigns,

Thanks for the layout, and updates. But, it is not yet clear whether Bass and Trebla pots are wired according to the schematics? Namely, I see that lug 3 on the Treble pot should be wired to lug 1 on the Bass pot. That is not so in the layout. Perhaps I am wrong? Or, is the lug 1 on the schematics the TOP connection and lug 3 the bottom connection, as seen on the schematics drawing ... both on Treble and Bass pots? If so, than are the lugs 1,2,3 on the layout actually lugs that are located on right, center and left, as we are looking at the layout drawing. I am looking at the latest (3rd) update of layout in Trainwreck Files section sticky.

Sven

[Fischerman]

That vinegar smell you detect when many of these silicon adhesives dry is just that...acetic acid vapors. Just let it fully cure before you button it up.

Sven,
It does look confusing the way the schematic is drawn (every one I've seen). The bass pot is 'backwards' on the schematic. When the wiper is at the 'top' in the schematic that's bass-on-0 and when the wiper is at the 'bottom' that's bass-on-10. You can clarify this in the schematic by putting a little 'up' arrow next to the Volume/Treble pots and a little 'down' arrow by the Bass pot. OR you can put a little '0' at the bottom and a little '10' at the top on the Volume/Treble pots and put the '0' at the top and '10' on the bottom of the Bass pot. The Cut pot is obvious by the way it's connected so you don't need to do anything there.

[dansamp]

on the original T/B add on for the AC30 the bass pot is wired backwards there is an article somewhere on the net indicating it was taken from a 50's Gibson amp (not sure which one now)
this article also discussed that there was actually an error in the design of the circuit (making the controls interactive)
I "reversed" the wiring of the bass pot on an AC30 clone I built (using hoffmans layout) and prefer the backwards wiring
FWIW

Dan...........

[Sven]

Greetings,

No matter what, now the schematics does not match the Treble and Bass pot connections in the layout. So, to make it simple, I have added numbers 1,2,3, to the schematics (here I cannot post the attachment) for Volume, Treble, Bass and Cut.

My assumption is that the "1" position on the pot in the schematics is when the knob of the amp face plate is on ¨0¨, meaning the least amount of resistance (CCW on pot, as per pot design); and when the knob is on max., that is ¨10¨ on the dial, the wiper (number 2, always, ofcourse) is closest to the lug 3 position. That means that in the schematics the lug 1 is at the top of the drawing of the pot symbol. If that is the case, than lug 3 of the Treble pot must be connected to lug 1 of the Bass pot, which is not the case in the layout.

So, having in mind that we have the least amount of resistance when the wiper (lug 2) is in its CCW position closest to lug 1, and the amount of resistance is the greatest when wiper (lug 2) is closest to the lug 3, one should correct the numbers and ckt. connections on this attached schematics. After that, one should also mark and draw the layout according to that logic.

I take it that on the layout drawing the lugs, from left to right as we look at the drawing, are 3,2,1. If that is the case, than, again, the current schematics and layout do not follow the proper logic.

I would appreciate final correction.

If the current layout is correct, than the schematics are not correct.

Here is the schematics with numbers drawn close to pot lugs, as assumed.

Sven

[Ron Worley]

Regardless of how you number them, the correct layout is posted in the files section under "Rocket Documents".

Ron

[Bear]

on the original T/B add on for the AC30 the bass pot is wired backwards there is an article somewhere on the net indicating it was taken from a 50's Gibson amp (not sure which one now)
this article also discussed that there was actually an error in the design of the circuit (making the controls interactive)
I "reversed" the wiring of the bass pot on an AC30 clone I built (using hoffmans layout) and prefer the backwards wiring
FWIW

The Tales From the Tone Lounge article? Good series of articles.

So did you prefer backwards of Vox or the Vox backwards-of-the-rest -- I'm not sure I can tell? I'm bad at sussing out tone stacks, but I think the Hiwatt CP-103 B-T stack (Townsend and Entwistle) might also do the interactive tone thing, and I've seen some limited verification for that idea.

Bear

[Sven]

Regardless of how you number them, the correct layout is posted in the files section under "Rocket Documents".

Ron

Thanks! That is a reassuring confirmation.

Sven

[dansamp]

on the original T/B add on for the AC30 the bass pot is wired backwards there is an article somewhere on the net indicating it was taken from a 50's Gibson amp (not sure which one now)
this article also discussed that there was actually an error in the design of the circuit (making the controls interactive)
I "reversed" the wiring of the bass pot on an AC30 clone I built (using hoffmans layout) and prefer the backwards wiring
FWIW

The Tales From the Tone Lounge article? Good series of articles.

So did you prefer backwards of Vox or the Vox backwards-of-the-rest -- I'm not sure I can tell? I'm bad at sussing out tone stacks, but I think the Hiwatt CP-103 B-T stack (Townsend and Entwistle) might also do the interactive tone thing, and I've seen some limited verification for that idea.

Bear

I prefered the Vox "backwards" wiring
but I'm am wondering if maybe using a reverse log pot wired "normal" would get you the same sweep and then be able to turn clock wise to increase bass ???

Dan......

[UR12]

Isn't the Matchless Lightning's Bass control also like that?

[Bear]

Isn't the Matchless Lightning's Bass control also like that?

I'm pretty sure it is. If an amp is going for the Vox Top-Boost vibe and has a Bass-Treble stack, I'd expect it to go this way. Heck, I think the Top Hat Club Deluxe does the same thing, but with a mid control in the mix. (The Club Deluxe is basically another TB derivative but with 6V6's.) I don't know whether the mid control adds flexibility or just chaos.

Bear

[RJ Guitars]

...(The Club Deluxe is basically another TB derivative but with 6V6's.)Bear

That sounds interesting, would you have a schematic for that or maybe lead me to one? I've got a Trainwreck style chassis that is punched out for Octal tubes and I was thinking about a an Express build... but maybe this is something else to consider?

rj

[Bear]

Schematic Heaven's got it, I think filed under post-70's amps.

One thought for your chasis-- as the Liverpool is essentially an Express with an AC-30 power section, maybe do yours as a Rocket/TB with an Express power section, switchable between 6V6 and EL-34. It might end up sort of like a TW version of an AC-50. That actually sounds pretty neat.

Bear

[RJ Guitars]

Hullo Forum,

I finally got back to amp building. Tonight I was trying to finish up the primary power wiring on my own Rocket build. I didn't quite get the heater wires done - does everybody else hate heater wiring as much as I do? I actually got a couple more tubes hooked up before I quit for the night. Looking forward to the fun part.

I didn't put the pilot light in yet cuz I will have to put the faceplate on first and I don't want to scratch up one of Eric's custom faceplates.

It's actually gone well and here is a look at things as they are now. If you see a wire hooked up to a wrong pin somewhere let me know.

rj

[angelodp]

hey rj, what is that white keeper you are using on the PT wires. Any thoughts about a bias circuit for this amp. Is the BOM and layout locked in.
What id that bare wire below the fuse?? Can you send another close-up please.



ange

[Allynmey]

RJ, connect the plates of V4 and V5 together and V6 and V7 together. You have them mis wired in that pic.