Nobelium - tube bass preamp project

Thank you both. These kits come at a price. But they look pretty neat. More than the KLD one.
I'll dig into the description of both before letting my GAS act. 👍
For my wants and needs for bass a 100 watt DIY build runs about the same and actually has enough headroom to keep me reasonably happy, but of course the B-15 is iconic for a reason. My recent build as seen in the amps section here wasn’t from a kit though, and you will pretty much always pay a premium for that convenience. Welcome to the PPCB forum, BTW.
 
Your amp is really inspiring. Even if I don't have the chance to source parts from an old amp factory, your solutions will help me figure out how to get a little bit more power from a 15W kit that I could use as a base (like this one : 15W tube amp portaflex style ). 30 tube Watts would be great. 50W would be holy grail.
 
Your amp is really inspiring. Even if I don't have the chance to source parts from an old amp factory, your solutions will help me figure out how to get a little bit more power from a 15W kit that I could use as a base (like this one : 15W tube amp portaflex style ). 30 tube Watts would be great. 50W would be holy grail.
So you live in Europe then? I still have some cool leftover parts from my buy out but shipping outside the US might be prohibitive.
 
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Any chance you have an ETA on when faceplates are coming in? They seem to be OOS. I don't need to replace my (MBP SludgeHammer) Sansamp BDDI but I don't have any projects going on now and was considering a nobelium
🤷‍♂️

If I don't really NEED another DI, is it a fun build without the DI, just as the preamp?
Took a little longer than I hoped, but Nobelium faceplates are back in stock.
 
First gig with the Nobelium.
It was a big room, on a stage. Very loud.

The good:
- Worked reliably.
- Great studio/bedroom sound. Lots of youtube clips showcasing the lovely low-medium volume B15 tone.
- I find on a lot of DIY pedals/pre-amps the control ranges are not optimal. They are very good on the Nobelium, the bass treble and volume pots are all in (roughly) the sweet spot. On a power amp set to 0.775 v sensitivity the volume control worked perfectly from 0 to f*&$$%ng loud.
- Great headroom, very clean. With a passive bass I couldn't get it to clip.
- Sound guy (a bassist) praised the balanced output sound.
- The valves Klaus supplies are relatively inexpensive but very high quality. Used to be JJ, now Psvane. I find that the meaty JJ valve is warm and lovely in the first position, the hi-fi clean Psvane good in the second.
The less good:
- Used by itself into a power amp at very loud volume I find it doesn't have enough tonal control for me, particularly the mids. At high volume it tends to be boomy (but never farty nor distorted).
I found loud and live setting it flat was optimal (bass and treble at 0) at high volume. But then you don't have a lot of further tonal control.
Chaining into another preamp is probably a more common use case, so none of this is a problem, just not the way I was using it.
- Gets quite warm. Klaus uses 105 C rated electrolytic caps in his kits, but I don't know the rated hours. Vig suggested drilling ventilation holes in the enclosure to improve air circulation, I'll probably do that.

I'll keep at it.
I think it has a beautiful recording/bedroom tone.
Very useable, tons of clean headroom and warmth.
For me, the live usecase would be for low-medium volume gigs. Loud, difficult rooms might require further tone shaping.

What do you peeps reckon?
Anyone else using a Nobelium in anger?
 
What do you peeps reckon?
Anyone else using a Nobelium in anger?
First use in a rehearsal situation yesterday, with a quite heavy drummer, guitar and two singers.

Until yesterday, I used it for bedroom practice at low volume and I was utterly pleased by it. But yesterday, with Gain and Volume cranked up in my Ampeg Micro VR, I had to much noise (like the "ffffffff" of an overplayed 80's walkman tape). Very too much and ended by unplugging it saddly (and the noise disappeared). Even with bass and treble knob at zero, and volume on the Nobelium at 30%.
Maybe it's not normal. What shall I look at first ? Swap the position of the tubes ?
I'm not using the XLR out for the moment. Only the 1/4" output.
 
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First use in a rehearsal situation yesterday, with a quite heavy drummer, guitar and two singers.

Until yesterday, I used it for bedroom practice at low volume and I was utterly pleased by it. But yesterday, with Gain and Volume cranked up in my Ampeg Micro VR, I had to much noise (like the "ffffffff" of an overplayed 80's walkman tape). Very too much and ended by unplugging it saddly (and the noise disappeared). Even with bass and treble knob at zero, and volume on the Nobelium at 30%.
Maybe it's not normal. What shall I look at first ? Swap the position of the tubes ?
I'm not using the XLR out for the moment. Only the 1/4" output.
What power supply are you using with the pedal? Also, any particular reason you went into the front of the amp? Most people I've talked to run into the FX return to bypass the amp's preamp and go straight to power amp so you aren't stacking a preamp into another preamp.
 
What power supply are you using with the pedal? Also, any particular reason you went into the front of the amp? Most people I've talked to run into the FX return to bypass the amp's preamp and go straight to power amp so you aren't stacking a preamp into another preamp.
My power supply can't be blame, it's a Cioks Sol delivering 660mA at 9VDC per output.
But you're right about my "preamp stack situation". I didn't think about that. I'll try with pluging my pedalboard in the return input. That will surely make things better. I'll tell you.
Thank you !
 
So I underwent some testings.
If I plug my nobelium in the return loop input, I have the same problem (big noise even when the bass isn't plugged in the input, even with volume knob at zero). So I swapped the position of the tubes, that was far better : noise started to appear higher in the course of the volume knob, but still not OK for rehearsal as I will have to crank volume on the Nobelium and the amp.
I tried the "pencil test" which is tapping the tip of a pencil on the tube as far as I understand it. One of the tube (the one closest to the side of the enclosure) generates big "blop" into the amp, the other tube generates barely no "blop". Should I consider it microphonics ?
 
So I underwent some testings.
If I plug my nobelium in the return loop input, I have the same problem (big noise even when the bass isn't plugged in the input, even with volume knob at zero). So I swapped the position of the tubes, that was far better : noise started to appear higher in the course of the volume knob, but still not OK for rehearsal as I will have to crank volume on the Nobelium and the amp.
I tried the "pencil test" which is tapping the tip of a pencil on the tube as far as I understand it. One of the tube (the one closest to the side of the enclosure) generates big "blop" into the amp, the other tube generates barely no "blop". Should I consider it microphonics ?
If tapping the tube creates noise through the amp, that is definitely microphonics. If you're only using the XLR output then you only need one tube, but if you're using the 1/4" output you'll need both, so you will likely want to try swapping in a different tube for lower noise.
 
So I will say this, you used to be able to order just the standard tubes from amplified parts and be okay. Now you are much better paying the extra couple of bucks to get tubes that have been tested for low noise and performance. Take that for what it’s worth but that’s just my 2 cents. I won’t order the untested ones anymore.
 
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So will say this, you used to be able to order just the standard tubes from amplified parts and be okay but now you are much better paying the extra couple of bucks to get tubes that have been tested for low noise and performance. Take that for what it’s worth but that’s just my 2 cents. I won’t order the untested ones anymore.
I don't know if it was just because of me or if there were others, but I like to think I was a contributing factor in that. Story time!

When I first started building my pedals at a relatively large scale, I was ordering most of my stuff from CE Distribution, which is the wholesale arm of Amplified Parts. This included tubes, and I would place large and frequent orders for preamp tubes. I would get a bad tube every now and then from an order of 100, which wasn't great but wasn't a huge deal. You can theoretically reach out to their customer service and they'll refund or replace new tubes. But eventually I started testing every tube myself to make sure I was only putting good tubes in my builds.

Well on one order I had like 20 tubes test bad from an order of 50. I reached out to their customer service and let them know, and they took the tubes back and refunded me for them (they offered replacements, but I said I would just get some on my next order), but it was an inconvenience because it left some of my builds without tubes for a while. Shortly after that I talked to someone about TubeDepot, where I was told they actually test every tube before shipping them. I placed an order with them to try them out, and sure enough every tube tested good. Their bulk discounts weren't as steep as I was getting from CE Distribution, but I decided it was worth it to get pre-tested tubes.

Fast forward 6 months or so, and I get a phone call from a sales rep at CE Distribution. They said they just wanted to reach out and find out why I stopped placing my big orders with them, particularly for tubes. I told them the truth, I was paying more to get pre-tested tubes from somewhere else, and I said that if CE/Amplified Parts were to offer pre-tested tubes I would be likely to switch back to them as a supplier, because I honestly didn't have anything else against them. He thanked me for letting him know and said he would pass the message along to his manager.

Fast-forward a couple months and I was re-tubing one of my amplifiers. I've always bought power tubes from them because I like the options for Apex matching, and I figured I would take a peek at their preamp tubes while I was there, lo and behold, they now offer Apex tested preamp tubes!

Again there may have been other factors leading to them offering that, but it made me smile because I felt like I was actually listened to. I still order from TubeDepot every now and then because they're geographically closer to me so I can get things faster when I need them, but the performance tested option at CE/Amplified Parts now is great and I get them most often.
 
Let's replace both !

I red somewhere that it becomes more and more difficult to source tubes (at least here in Europe), maybe because some of them are made in Russia (just wondering, I'm not geopolitician) ?
Maybe that's why Musikding provides Standard Psvane tubes which are Chinese as far as I know.. And obviously not tested, the package was still sealed.
 
Let's replace both !

I red somewhere that it becomes more and more difficult to source tubes (at least here in Europe), maybe because some of them are made in Russia (just wondering, I'm not geopolitician) ?
Maybe that's why Musikding provides Standard Psvane tubes which are Chinese as far as I know.. And obviously not tested, the package was still sealed.
Psvane are Chinese. I recognize that they are one of the better Chinese tubes out there, but I personally don't like them. JJ are made in Slovakia so they should be easier to source than Russian tubes in Europe. JJ are my favorite because they're reasonably priced and kind of "middle of the road" tonally; I don't find them to be "too much" of anything.

TAD in Germany is also a reasonable option, though I recognize they aren't a manufacturer, they just test and relabel tubes from other manufacturers. I assume Musikding uses Psvane instead of TAD because Psvane are less expensive even when TAD is in the same country as Musikding. I don't think Musikding offered tube projects before he started carrying my boards, so I don't know if he does enough volume to warrant working out a bulk deal with a local source like TAD.
 
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