Bass Dude

[Mike McLane]

Just downloaded the build docs for the Bass Dude. Curious about the tone stack design. Markedly different from the 5F6A design in the Fender schems. You like this one better?

 

[Anton K]

I wondered too. May be, vigilante dont like "mids".

 

[Mike McLane]

I'm not a EE, but the design looks "James-ian". That aside, a lot of stellar amps (blackface Fenders, DC30's, Dr. Z's) have no MID control. As I understand it these circuits carve out a space for the mids based on the crossover frequencies designed into the Treb & Bass filters and it obviously works just fine. I'm just interested in picking up some new knowledge.

 

[music6000]

I wondered too. May be, vigilante dont like "mids".

You got a bonus Gain control!

 

[vigilante398]

If I remember right the schematic I originally used was for the 5D6, which is a few years before the famous 5F6 of 1959, which is when the mids control was added. It should be noted that the Fender mids control is "cut-only", so the only option the TMB stack gives you is less mids than the TB stack.

 

[Anton K]

If I compare the schematic with the silkscreen, there are differences. f.i. R1 is 1k on the PCB, but 2k2 in the schematic. Seems, R1-8 is completely wrong, and there is no R7 and R8 in the schematic, but on the PCB. Which one to follow? @vigilante398

 

[vigilante398]

If I compare the schematic with the silkscreen, there are differences. f.i. R1 is 1k on the PCB, but 2k2 in the schematic. Seems, R1-8 is completely wrong, and there is no R7 and R8 in the schematic, but on the PCB. Which one to follow? @vigilante398

Definitely follow the silkscreen and not the schematic. I didn't even think about the designators, the power supply schematic was copy/pasted from whatever the first document I did was and those designators do not necessarily match the designators of the actual pedal. This is the actual schematic from the Bassdude power supply. I guess I should go through and fix everything.

 

[Anton K]

Thanks! Meanwhile i followed the traces on the PcB ... the values are right, but not the numbers.

 

[music6000]

If I compare the schematic with the silkscreen, there are differences. f.i. R1 is 1k on the PCB, but 2k2 in the schematic. Seems, R1-8 is completely wrong, and there is no R7 and R8 in the schematic, but on the PCB. Which one to follow? @vigilante398

Good observation!. vigilantes398 is always greatful if these things are bought to his attention & can be corrected.

 

[joelorigo]

If I remember right the schematic I originally used was for the 5D6, which is a few years before the famous 5F6 of 1959, which is when the mids control was added. It should be noted that the Fender mids control is "cut-only", so the only option the TMB stack gives you is less mids than the TB stack.

Does this mean that using the Bassdude as a preamp it has more of the "tweed" sound than the Black panel era?

 

[vigilante398]

Does this mean that using the Bassdude as a preamp it has more of the "tweed" sound than the Black panel era?

Yup, this is definitely more of a tweed Bassman than a blackface.

 

[Anton K]

Oh no! Finished the dude today, plugged in - and absolutely no noise. Ahhhhhh.
Bypass is fine, LEDs are on, NE555 and transistor are plugged in … sigh … now it's off to find the error

 

[Anton K]

... got it. The morning is wiser then the evening. Maybe, a wire-snippet was making a contact. Its working now. But not, what I expected. I expected some clean tone - but its distorting quite early. Is this right?

 

[vigilante398]

... got it. The morning is wiser then the evening. Maybe, a wire-snippet was making a contact. Its working now. But not, what I expected. I expected some clean tone - but its distorting quite early. Is this right?

It does have a fair amount of drive to it, but you should be able to keep it clean (depending on your pickups) with the gain low, like around 9-10 o'clock.

 

[Anton K]

thanks for the confirmation - so I did everything right. That's what I wanted to know.

 

[Anton K]

btw. does it doom? You bet it will! All knobs at 10 will do the job.

 

[Bricksnbeatles]

@vigilante398 do

If I remember right the schematic I originally used was for the 5D6, which is a few years before the famous 5F6 of 1959, which is when the mids control was added. It should be noted that the Fender mids control is "cut-only", so the only option the TMB stack gives you is less mids than the TB stack.

considering the fact that it’s also TB only, I’m guessing tge 6G6-B is probably similar to the 5D6. Looks similar based on the very pixelated schematics I’ve found, but I haven’t found anything remotely legible yet to see if any values are different.
Definitely interested in this more now though since the 6G6-B (Brownface/Blonde Bassman) was Macca’s guitar/bass amp of choice during the majority of the Beatles’ studio-only years, and I believe also what Alex Chilton used for much of the second Big Star record.

 

[bobbass4k]

Finished this last night and just had a good test this morning. Plugged into the power amp input of my old Peavey combo (2 x 6L6 and 2 x 12" drivers) it sounds incredible, plenty of clean/gritty space but with the gain maxed it definitely dooms on a C standard guitar with some old ECC83s (12AX7)

Tried the pair of ECC802s I got for the Nobel build (long plate 12AU7) and it sounds pretty good as a clean but rich preamp. Will be going with ECC83 for maximum doom though.

 

[Schisme]

Hey there,
Finished the Bassdude about 20mns ago. No sound, no light, I am reading voltages though. What should I check ? All solders seem fine and clean. I am obviously missing something.
Here is a picture if anyone has an idea, thank you !

 

[vigilante398]

Looks like your V+ and Ground wires from the DC jack are backwards.