C2CE Nobelium Bass Preamp & DI

[fmcc]

Build Rating

4.00 star(s)

I've finished this build today, a little bit ahead of schedule. I've only spent a while today playing with it and monitoring through headphones, but I'm very pleased with it so far, and looking forward to trying it at volume through a power amp. Particularly enjoying the boost from the bass control, and I'm looking forward to experimenting with this in conjunction with the HPF.

I've had the boards for this for a couple of months, and have slowly been gathering the parts from various UK suppliers. I did use the Lightning Boy MC15 transformer, since it ended up as being about the same as sourcing something in Europe. Valves are JJ Electronic ECC802s. Onboard DI volume trimmer has been moved to a panel mounted pot - at present this is a 500k linear pot, but I'll replace it with a log pot once it arrives. This is the only thing justifying my overzealous "/apr" dating in my labelling of the enclosure.

I _think_ my labelling of the HPF is correct, but it's my first time attempting to calculate the slope of a filter.

Biggest issue was sourcing 100uH 2.1A inductor, so I've ended up with one that's fairly massive that overlaps other components. Having read some other sushibox threads today, I think I could have used one with a lower amperage, but

The enclosure was hand drilled, largely following the positions from the tayda drill templates. The DI volume was squeezed into the only place I could find to fit it around the other controls, but this necessitated moving the 3/4" jacks along a bit. I had been considering mounting the ground lift switch on the top, mostly to avoid cutting the switch slot, but think I managed a pretty clean result with a 4mm drill bit and a file. I had some leftover 3mm hole/4mm pitch steel grill that I used as a template when drilling out the valve vents. I don't normally sand down my enclosures at all, but I ended up taking some to it to deal with the burr left from all the small holes - I don't think I did a great job of it, and I hope the aluminium oxidising eventually makes it less apparent, though the bright light doesn't help.

 

[darwin999]

Looks great!
And apparently sounds great, which is the most important thing!!!
Hey, the pedal will be at least 5-6 feet away from you anyway - at least that's what I tell myself about any flaws on my pedals.
One thought for next time: get an inexpensive countersink drill for dealing w/ those burrs, easier than sanding the front panel.
Enjoy it!

 

[chris.knudson]

Looks great. I think you did a fantastic job. I have to say, this pedal (although the most expensive I've built) is also the most rewarding pedal I've built. I seriously believe this pedal leveled up my playing. I get so much more tone and punch from my playing with this pedal -- and the dynamics make a huge difference.

 

[Mentaltossflycoon]

Nice work! I've been leaving mine with the bass knob at noon, hpf engaged and then hitting it with a drebbel pre with the bass boosted to get some lows back. Pretty happy with the results.

 

[fmcc]

One thought for next time: get an inexpensive countersink drill for dealing w/ those burrs, easier than sanding the front panel.

I normally get this effect when using the stepped cone bits to drill out larger holes, but I think I'd probably manage it with the tip of a broader drill bit for these 3mm holes. Main difficulty is keeping it consistent when drilling, so it might be better twirling the bit by hand to deburr. I've got a particle accelerator to build as well, so I'll try this when doing the grill for it, though it remains to be seen whether I've got the patience for it for so many wee holes.

I've been leaving mine with the bass knob at noon, hpf engaged and then hitting it with a drebbel pre

I'd only come across the drebbel pre for the first time last night, and I'm quite tempted after reading through your build thread. I've got a schalltechnik pumpernickel that I normally use that I need to experiment with using with the Nobelium before I start adding any further EQ'ing.

 

[darwin999]

Countersink bits with tips like these will work much better than a larger drill bit.
And they're not expensive, and last a long time if you're using them on soft metals like aluminum/brass/copper.
My set are 35 years old, and still work like new.
If you have a drill press, you can also set the depth limit so that all the holes end up with the exact same countersink appearance.
(I just grabbed this picture from Google/Harbor Tools, who I avoid, but there are lots of better vendors who make these.)

 

[fmcc]

Countersink bits with tips like these will work much better than a larger drill bit.

I've not come across them before - I've got countersink bits with the fluted tips that have never really worked well, but these look like they'd be way better. I'm stuck with a hand drill until I've got space for a drill press.

 

[jwin615]

Awesome build! A cheap t handle hand reamer works well clearing out burrs and can be had for a couple bucks.

I have a cheapo like this one. Coated the removable handle in liquid electrical tape to keep it in place. Also useful for cleaning powder coat. On mine at least, the tip is just large enough to clear 3mm led holes.

 

[Band of Dans]

Missed this when you originally posted, but I think that enclosure looks really nice! Your stamp lettering is impressively even and I like the little details like the knob indicators. Any tips on getting even spacing and keeping letters level? Also curious what you're using to fill them in. I've been using a fine-tip paint pen, but it's not quite fine enough and I find it hard to keep paint from escaping the letters.

Either way, looks great to me and glad to hear it sounds great too. There's just something about a pedal that looks DIY at first glance, but is clearly made by a skilled craftsperson when you look closer and see all the great details. Sort of the opposite of my UV printed pedals with sloppy drilling and flux all over the board

 

[fmcc]

Missed this when you originally posted, but I think that enclosure looks really nice! Your stamp lettering is impressively even and I like the little details like the knob indicators. Any tips on getting even spacing and keeping letters level? Also curious what you're using to fill them in. I've been using a fine-tip paint pen, but it's not quite fine enough and I find it hard to keep paint from escaping the letters.

Yeah, I've really struggled to get the stamp lettering even over the years. What I do now is produce a layout template for the lettering stamps as part of the drill template - I tend to redo any drill templates in CAD as part of my process of working out the build.

I'm using 1.5mm letter stamps for these, the circles are all 3mm which is about the size of the head of the stamps so it's easier to line them up. 2.5mm centre to centre horizontally and 4mm vertically. The indicators are all the letter "I" and I tend to put a radial line in to get them at the right angle - I'll have set their position by the size of the knob I'm using.

I'm also using a fine tipped posca paint pen to fill them in - I just tend to let it overfill and escape a bit and then come back with something lightly abrasive when it's dry. I think most recently it's been a slightly damp melamine sponge that's been most effective. I do often have to come back and scratch out the centre of letters with a point though.

Either way, looks great to me and glad to hear it sounds great too. There's just something about a pedal that looks DIY at first glance, but is clearly made by a skilled craftsperson when you look closer and see all the great details. Sort of the opposite of my UV printed pedals with sloppy drilling and flux all over the board

Thanks, I really appreciate this - not least because it really reflects the aesthetic I'm going for with the things I make.

 

[Band of Dans]

Generating a stamp template is a great idea that I’ll have to steal!

 

[Erik S]

That’s a hot tip on the lettering template!

I really like the pattern you used for the vent holes, and I’m impressed with your drilling job. Any hole that was off there would have been super obvious, and it came out great.