Tube preamp (do I dare bring up modelers!?!?!?)

1. What type of pots do you use? I would guess standard 12mm would take up quite a bit of depth and hamper placement of the Sig board relative to the PS to some degree.
2. Any rec's on tube socket brand/type? How do you physically secure it? Kingsley appears to just use brass standoffs bolted to the wall of the enclosure.
3. How do you physically secure the circuit boards. Particularly given that you want the voltage regulator to be affixed to the enclosure for heat dissipation. I don't notice any protruding screw heads on the exterior surface of your units that would indicate "bolted in" standoffs so I'm guessing its magic?????
 
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Mike McLane said:
1. What type of pots do you use? I would guess standard 12mm would take up quite a bit of depth and hamper placement of the Sig board relative to the PS to some degree.
2. Any rec's on tube socket brand/type? How do you physically secure it? Kingsley appears to just use brass standoffs bolted to the wall of the enclosure.
3. How do you physically secure the circuit boards. Particularly given that you want the voltage regulator to be affixed to the enclosure for heat dissipation. I don't notice any protruding screw heads on the exterior surface of your units that would indicate "bolted in" standoffs so I'm guessing its magic?????
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Well I have to separate what I usually do from what I'm looking at for your build here, but this is what I do:
  1. I use 9mm PCB mount pots (Alpha or Cusack, I use them interchangeably), those are also what I use to mount the PCB to the enclosure. I like the size and the number I can fit in a small box and also the mechanical tabs for securing it.
  2. I like Belton, but the PCB mount sockets I use on my builds are just no-name ones I get in bulk from a Chinese supplier. For builds like what you're describing I would recommend something like these: https://www.tubesandmore.com/products/socket-belton-9-pin-miniature-top-mount
  3. I can show you how I envisioned the mounting of the power supply board when the boards show up, but my intention was that it mounts against the wall with brass standoffs but snugged all the way to the top of the enclosure so the heatsink of the 6V regulator is flush against the enclosure, then you can just drop a machine screw through the top and bolt the heatsink to the enclosure. That being said I don't use regulators on my builds and I just run the tube heaters in series (instead of parallel) straight off the input at 9-12V.
 
So you would design the pots into the signal board PCB similar to the way PPCB does? So as with your PS board, a properly designed PCB could handle the current required for the signal board? That said I did some toying with how one would route the traces accommodate PCB mounted pots and have attached my humble offering. Also did a rough layout for a single foot switch 1590BB and I still don't know how you could slide a tube in there. But most important, we have yet to deal with the LED indicator o_O. As long as you feel that a PCB signal board is good-to-go then it seems there's not much more head scratching to do until you get a look at the power supply daughter board (i.e. - I can leave you alone for a week or so). Thx tons for your help on this!
 

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Hello... is this a tube preamp like "Space heater" on Sushiboxfx?

I got a preamp pedal from THCustom, Valvetizer, very nice in the clean version, maybe the limit of that pedal is that if you use the clean-version, even if you turn up Gain pot, it still remains clean (with 12au7...) I will maybe try to mod it with a switch and a cathode capacitor to have some overdrive. Anyway, I've listened to Space heater audio and it's very nice sounding!
 
Kreisky said:
Hello... is this a tube preamp like "Space heater" on Sushiboxfx?

I got a preamp pedal from THCustom, Valvetizer, very nice in the clean version, maybe the limit of that pedal is that if you use the clean-version, even if you turn up Gain pot, it still remains clean (with 12au7...) I will maybe try to mod it with a switch and a cathode capacitor to have some overdrive. Anyway, I've listened to Space heater audio and it's very nice sounding!
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Hi there, I'm Nathan from Sushi Box FX :p The high voltage daughter board I posted pictures of earlier are the same circuit I use in all my tube pedals. If you want to see how Space Heater was designed you can read more on theory here: https://forum.pedalpcb.com/threads/tubes-101-intro-to-tube-preamp-design.10625/

Trying to remember what the voltage is that they get out of that CD40106 circuit in the Valvetizer. 60V, somewhere around there? Anyway. I've never built it myself, but I know people that have built it and liked it.
 
Mike McLane said:
So you would design the pots into the signal board PCB similar to the way PPCB does? So as with your PS board, a properly designed PCB could handle the current required for the signal board? That said I did some toying with how one would route the traces accommodate PCB mounted pots and have attached my humble offering. Also did a rough layout for a single foot switch 1590BB and I still don't know how you could slide a tube in there. But most important, we have yet to deal with the LED indicator o_O. As long as you feel that a PCB signal board is good-to-go then it seems there's not much more head scratching to do until you get a look at the power supply daughter board (i.e. - I can leave you alone for a week or so). Thx tons for your help on this!
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I'll take a look at how to fit pots in there, but 1590BB doesn't have enough vertical clearance for the jacks to go over the PCB, so you can't stretch it very far vertically. I'll see how much guidance I can give without just designing the board for you :p
 
A 1590C will give 2.2 height. That should provide enough height wouldn't it? I've ordered signal board parts. Let me do a physical mock up while your waiting on the PD board.
 
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Mike McLane said:
A 1590C will give 2.2 height. That should provide enough height wouldn't it? I've ordered signal board parts. Let me do a physical mock up while your waiting on the PD board.
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I threw together a quick design on the signal board to see how small I could get it with board-mounted 16mm pots. I kept the 2.25" width but had to grow the height a little to fit two rows of pots. I'll plug it into my 3D model and see what it looks like.

top.JPG bottom.JPG
 
I know you said you're losing the EQ Shift footswitch, but even with it this looks like it could fit. you have to squeeze pots together a little, but they'll fit.
 

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Mike McLane said:
What would it cost to have your vendor build one of these for testing?
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I mean bare PCBs are like $5 for 5, shipping is where they get you. I could throw these on with my next order (which will literally be tomorrow because I have a PCB addiction) if you want to try one out. Save a couple bucks on shipping.

Oh and I forgot to mention the footprints were sized for 1/2W carbon comp resistors, Mallory 150 film caps, and 25V electrolytics. That's what I use so that's what I had in my library :p
 
When you say "bare" do you mean the design you showed above except absent the electrical components? I ordered 1/2W resistors and 50V electrolytics, but that shouldn't be a big issue. Just tell me what the number is. I should be around first thing in the morning so I can respond quickly.
 
Re pot sizes... I thought the standard size of pots was 16mm. I use 16mm and 9mm, the only thing I've ever seen with 12mm is BYOC stuff.
I've never seen them in my Internet travels or I would've picked some up, but I've not sought them out specifically so maybe they're more available than I think. It's a good size, not sure why there seems to be a dearth of 12mm.

PS: increase your space for jacks, from
1590BB (34mm) vertIcal space to
1590BB2 (38mm) and even more vertical, the
1590BBS.(42mm)
 
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vigilante398 said:
Hi there, I'm Nathan from Sushi Box FX :p The high voltage daughter board I posted pictures of earlier are the same circuit I use in all my tube pedals. If you want to see how Space Heater was designed you can read more on theory here: https://forum.pedalpcb.com/threads/tubes-101-intro-to-tube-preamp-design.10625/

Trying to remember what the voltage is that they get out of that CD40106 circuit in the Valvetizer. 60V, somewhere around there? Anyway. I've never built it myself, but I know people that have built it and liked it.
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Hi Nathan, thanks for the link to your tube preamp design! That's different from Valvetizer, as you say it works about at 60-70V with 9-12vdc input. On my version it's a cathode foller, that's why there's no overdrive at all.
Anyway your Space Heather is very nice but to high voltage to try from scratch myself!
 
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I can give a quick update to this for anyone that's interested. I got the boards in a few weeks ago and have tested the SMD high voltage boards, they work great. I don't regularly stock a lot of through-hole parts but I ordered parts to put together a through-hole high voltage board for verification. Once those are verified I'll solder up one of the preamp boards and see how that sounds, though we've already determined there are some changes to be made to it for ease of building so there will likely be another revision.
 
Mike McLane said:
I wonder about a tube driven preamp as a front end to a modeler setup to impart some "tubiness".
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This is what the Vox VT series amps are. IIRC it goes:

Single Tube Preamp -> Digital MultiFX 1 (Noise Gate, Tuner, Compressor, RangeMaster, Tubescreamer, OD3, etc) -> Digital EQ / Amp Modeler -> Digital MultiFX 2 (Harmonic Tremolo, Chorus, Delay, etc) -> Digital MultiFX 3 (Reverb) -> Class D Power Amp -> Neutral-ish Speaker

The Tube definitely adds some warmth and the modeled sounds are about 2/3ds of the way there, but overall it isn't a joy to play like the any of the real amps it tires to model. That said I keep mine as a backup since it's small, lightweight, reliable and loud.
 
Mike McLane said:
The whole Ukraine thing has brought up the tube sourcing saga and suggests the eventual death of tube amps as the predominant force in the guitardom.
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Some companies out there have tried making solid-state, drop-in replacements for tubes. Has anyone tried any of them out?

I have yet to go down that rabbit-hole, but it would be a dream to be able to replace a 12AX7 or EL84 with something that is more consistent, not NOS and is going to have 10x the lifespan.
 
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