Bass with Onboard Nobellium

[Alex Xander]

Hi Folks,

First post here.
I recently bought an assembled Nobelium from @SamuelG and am in love with it. I have found the secret sauce for “my” tone.

I build my own basses (Booka Bass on the socials) and am now dead set determined to build a basses with a onboard Nobelium (and maybe a JTEX one knob compressor). I gig with in ears, so the intention would be to run with an XLR from the bass, straight to the desk.


I do not posses the electronic mastery of people on this board, and would this be most likely to buy an assembled Nobelium and dissect it.

My thoughts thus far are as follows

1. It’s a big pedal, and the likely best place for all the electronics is under the strings. Any issues with this placement?
2. I can run wires from the PCB to pots in the normal location
3. I would power it with 9.4v NiMH battery packs
4. I will need some kind of low voltage cutout to prevent over-discharging batteries
5. High voltage is not to be messed with (it needs to be as isolated as it would be in a pedal box)
6. The DI trim pot would need to be replaced with a proper pot, or maybe an on/off switch (which is basically what I use a volume knob as anyway).

Questions for the braisntrust

1. What’s have I forgotten?
2. Would having magnetic pickups either side of the Nobelium circuit cause any issues? I am currently think two jazz style pickups in more extreme locations to accommodate the Nobelium in between them.
3. If space becomes an issue, I can run a piezo bridge (I have several high quality ones in inventory). Is the input impedance of the Nobelium suitable for piezos, or would I need a buffer?

In short, I have no doubt I can build a bass that fits a Nobelium and a battery big enough to last a gig. Can anyone tell me what is wrong with my plan? Is anyone interested is helping me on a slightly wild ride?

Comments, suggestions etc etc are most welcome.

 

[vigilante398]

Nothing wrong with your plan. This is my bass with an onboard Underground Accelerator (similar to the C2C Particle Accelerator) preamp. Built with a Warmoth body that I routed out to accommodate the custom PCB I designed for it. I use a large 9.6V RC car battery pack (I have three I can swap and recharge) and it lasts about 4 hours or so on a charge.

1. Doesn't look like you've forgotten anything, looks good to me.
2. Having pickups close to the preamp shouldn't really affect anything, but as long as you can keep the PCB properly isolated from the walls, it's not a bad idea to use shielding paint or copper tape around the cavity of the PCB.
3. Nobelium is designed with a 10MΩ input impedance, should be fine with a piezo pickup.

You mention that you don't have electronic mastery, but obviously the ideal solution would be to design a custom PCB with all SMD components for size and with pots connected offboard (I designed a separate PCB for the pots and switches for my build, connected via ribbon cable).

I hope this helps, and I would love to follow along on your journey and answer any questions I can.

 

[Tassieviking]

If you don't intend on having a 1/4" output then half of the nobelium circuit is not needed and you only need one tube as well as far as I know, I say as far as I know in case I say the wrong thing but I feel 99.99% sure I am correct there. Nathan please jump on me in case I screwed up again.
One tube and the transformer should fit nicely in the body of a bass I think, especially if a custom PCB is made up for it ( hint hint SamuelG ).
I love throwing people under busses.
is that a volt meter display on that bass Nathan to monitor the battery voltage ?
Cheers
Mick

 

[vigilante398]

If you don't intend on having a 1/4" output then half of the nobelium circuit is not needed and you only need one tube as well as far as I know

That is correct.

is that a volt meter display on that bass Nathan to monitor the battery voltage ?

It is indeed. I intended to have the voltmeter always active so I could monitor the battery voltage constantly, but I was getting some noise in the preamp when the voltmeter was active, so I added the red momentary pushbutton there to check the voltage so I can mute the preamp when I need to check the battery.

 

[Tassieviking]

I remember that a local magazine in Australia once ran a project for a swich/pot panel on a guitar that was an actual PCB and all the tone caps etc were SMD mounted on the inside of the PCB, I think it was a bit over the top but the pickguard is certainly large enough to build a complete SMD pedal on on the inside.
I can't see myself ever doing it but the article was a fun read.
https://www.siliconchip.com.au/Shop/8/6970

 

[Alex Xander]

Hi Folks,

Thank you so far for the replies and feedback. @vigilante398 i think I followed your build on Talkbass, maybe it was a build off entry.

A custom board for a SMD setup is very much in the too hard box, but an excellent idea.

Thinking bad ideas out loud... if I only need half the Nobelium to drive the XLR out, is there an easy way to use both tubes, feeding one into the other? Could this be an onboard tube drive?

Alternatively, is there another option I should look at that is already a single tube peda thag has a Noble characterl? Note that the XLR out is really mandatory for this build. I run the PA for our band, so bringing less stuff has a lot of appeal.

 

[Tassieviking]

Thinking bad ideas out loud... if I only need half the Nobelium to drive the XLR out, is there an easy way to use both tubes, feeding one into the other? Could this be an onboard tube drive?

I am not sure what you mean by this, in the Nobelium the first tube is used up to where the XLR is tapped off, the second tube is only used to feed the 1/4" output.
If you don't need the 1/4" output in a Nobelium pedal you could remove the tube on the right hand side when looking from the back of the pedal.
I don't think it would be a good idea to try to keep 2 tubes if you are installing it in a Bass body, 2 tubes would cut your battery time in half.

EDIT: I looked at your bass builds and noticed you are into long scale builds, what is the lowest frequencies you would go down to ?

 

[vigilante398]

Hi Folks,

Thank you so far for the replies and feedback. @vigilante398 i think I followed your build on Talkbass, maybe it was a build off entry.

A custom board for a SMD setup is very much in the too hard box, but an excellent idea.

Thinking bad ideas out loud... if I only need half the Nobelium to drive the XLR out, is there an easy way to use both tubes, feeding one into the other? Could this be an onboard tube drive?

Alternatively, is there another option I should look at that is already a single tube peda thag has a Noble characterl? Note that the XLR out is really mandatory for this build. I run the PA for our band, so bringing less stuff has a lot of appeal.

I agree with Tassie here, if you don't need the 1/4" output I would recommend leaving out the second tube. Is it possible to turn Nobelium into a tube overdrive? Sure, but that isn't what Nobelium was designed for and it doesn't lend itself particularly well to overdrive.

I consider Nobelium to be more or less a one-trick pony, it's just that the trick it does is useful for 98% of bassists.

If you're looking for a single-tube preamp that captures the Noble sound, find one of the skilled members on this forum and ask them to design a custom board for you without the second tube on there. Steddi Go is a single tube clean preamp that covers the same general territory, but it isn't based on Noble by any stretch of the imagination.