Sunday, 18 June 2017

Tubeworks Real Tube 903 Modded Tone Stacks

So as most of you guys know when I'm studying for exams I tend to do a bunch of layouts when taking breaks to keep my sanity. So since I did a layout for the Tubeworks 903 I thought to myself if it's basically a tube pre-amp I thought why couldn't the tone stack be modded to that of some legendary amps. With that in mind, I modified the original layout I made with various tone stacks.

Original schematic can be found on Revolutiondeux.

Layout 1: Fender

 

Layout 2: Marshall


Layout 3: Vox


Layout 4: Hiawatt DR103



Layout 5: Sunn 1st Gen Model T



Layout 6: Orange OR120 MKII



Layout 7: Matamp GT120



Layout 8: 72 Ampeg SVT



Layout 9: Marshall Superbass



Layout 10: Dumble Overdrive Special 70's



Layout 11: Dumble Overdrive Special '97



79 comments:

  1. Replies
    1. no prob man. i also just added 2 more.

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    2. omg ...this is a gold mine of layouts. Building the Hiwatt as soon as I log off, will report back with results!

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    3. awesome. hopefully it fires right up. i went through the layouts a few times and didn't spot anything glaring, so i'm fairly confident. plus if you verify it then we hit 1000 verified layouts.

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  2. Hey Zach, any idea what A+ voltage is on these? I think I'd rather use a transformer if possible as opposed to the charge pump/daughterboard, thx.

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    1. it's written in the schematic in the link above. the pump is there to give you +12V DC and -12V DC it's not increasing the voltage, so need to use a +12V DC power adapter.

      if you want to go the route of making using a transformer than you'll need to make a separate board to match the power section in the schematic.

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    2. Ahh, I see so it's a 12v+/12v- dual supply. Any advice on the best method to get split rails out of a single trans using common parts? I noticed the original pedal uses a trans so I assume it can be done. Looked into a resistor divider but it appears this goes to heck once any load is connected so not sure how to properly go about this ...thanks!

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    3. Disregard my request, I found Bajaman's schematic on La Revolution and it spells out exactly how to build the supply using a 12v AC transformer.

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    4. again, if you look at the schematic in the link posted at the top you'll see how to setup a transformer and will have to make a layout for it. it's much easier to use a +12V DC power supply, and it will allow you to put the circuit in a 1590BB without the need for a bigger enclosure like the original one.

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    5. Ok, finally got the message, thanks for the heads up my friend.

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  3. It just amazes me how u can do so many layouts. I can't even layout a little vero lol. Thanks for all the work u do. Jack.

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    1. no prob man, and thanks. really it's not that big a deal for these since the front half is all the same, all i had to do was change values in the tonestack, or in the case of the ones that have bandaxall tone stack (orange, matamp, and ampeg) i just had to do some moving around components.

      i've got a few layouts i want to get done that are a much more complicated than these. those take a lot more time.

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  4. Hi, great work but AFAIK Marshall's tonestack is after a tube buffer while Fender(& Hiwatt) doesn't have a buffer before the tonestack, did you altered the circuit considering this?

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    1. There's no buffer in any of the layouts posted. In all the layouts the tonestack comes after the tube gain stage, particularly they all come off pin 1 of the tube.

      The original had a FET input and output buffer, but I have removed them.

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  5. Is there a way to make the charge pump run on 9VDC?

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    1. Yes, but the 12V isn't necessarily for the charge pump, it's actually for the 12AX7 heater. The reason the heater is wired directly to a 12V supply, and not to a 12V supply from a charge pump powered by 9V is that a charge pump would not have adequate current to run a 12AX7

      The heater wants to see that 12V to function properly.

      I have a Valvecaster (12AT7) build which I simply power with a 9V one spot (no charge pump) and it sounds great. You could always try powering it at 9V and see how that sounds, but it should work better at 12V

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    2. By the way, the bypass switching shown in these layouts is functionally identical to the normal switching shown in the offboard wiring, so no need to do anything differently with that

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  6. They could work as a preamp? Could be used with a power amp?

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  7. Slightly OT: how are you guys physically boxing up pedals with valves in? Any tips? Been getting some good sounds from a 12AU7 on the breadboard but no clue how to safely get it into an enclosure...

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    1. there's a bunch of different ways you can do it. take a look at the thread johnk started when he posted his layout for it.

      http://guitar-fx-layouts.42897.x6.nabble.com/BK-Butler-Bluetube-driver-td248.html#a1735

      you can also see how a zosotone, and Freppo did theirs. i'm planning on doing it similar to Freppo, but instead of just having the tube hanging out like that i ordered a few tube cages.

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    2. Thank you sir - very enlightening. I'm keen to have the tube inside the enclosure (I'm pretty clumsy) so I reckon I'll try zosotone's approach, that's darned clever.

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    3. Then pardon my ignorance, what happens if I power it up with a 9VDC to 12VDC charge pump? Or any charge pump for that matter.

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  8. I've done it like freppo but I used a socket with a removable shield (like on Fender amps).

    This is the easy way to do it, but if you were to step on the shield you'd probably destroy the socket and tube.

    For my next tube build, I am going to drill a slightly oversized hole that I will put a grommet on. Then I will mount the tube socket in the enclosure but recessed inside with standoffs. Then I will have about half of the tube sticking out of the big hole, held firmly by the grommet, with a little cage around the tube to make it road worthy

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  9. This is INSANELY COOL! Thanks Zach!

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  10. Very Awesome Zach.

    Thank you soooo much!!!

    Will

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  11. replacemente for LT1054? I can find it. i remember charge pump with 1044 i wasn't able to find it here :(

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    1. You can't use a 1044 with this. The maximum input voltage of the 1044 is 9.5V, this circuit needs a 12V supply.

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    2. Mouser has them (not cheap though).
      http://www.mouser.com/ProductDetail/Texas-Instruments/LT1054IP/
      http://www.ti.com/lit/ds/symlink/lt1054.pdf

      Although. You could simply go with ICL7660S, but then i'd strongly suggest taking a 100R resistor and 12V zener to ground from the pins 1&8. 7660S will burn instantly if it gets more than 12V to its input.

      http://www.intersil.com/content/dam/Intersil/documents/icl7/icl7660s-a.pdf

      Those are widely available and cheap. And yes, you'll need the "S" (super) version. One without the "S" won't do. (Due to lower internal oscillation frequency will lead to audible whine with 7660 - "S" version has higher, inaudible oscillation frequency.)
      +m

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    3. Oh. Those 1054s are available from china through ebay as well. One should, however, take note that chinese sell a lot of out-of-specs / counterfeit stuff through ebay. Not saying that this particular seller is doing it, but the possibility exists.
      http://www.ebay.com/itm/170955151686
      +m

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  12. no offense, but I hope you never graduate! ;) Love these study break layout avalanches.. keep up the fantastic work Zach!

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    1. Haha. Thanks man. Well trust me, I'll still be posting layouts when I'm done. The one thing that will change is I'll have more build time for myself. The only builds I've had time for is customer builds.

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  13. Awesome! Thank You Zach.
    Any chance of adding a dumble style tone stack?

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    1. shouldn't be an issue. i'll look to find a dumble amp schematic to lift the tonestack from.

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  14. 2 dumble tonestack layouts added. surprised it wasn't as easy as i had hoped, but should be good.

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  15. Hey, probably a stupid question but can I run this before other pedals or a solid state practice amp safely?

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    1. Why wouldn't? Theoretically it should give you a tubey overdrive. As far as how it will sound, won't know until you try it. Could sound great could sound terrible.

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    2. Thanks! I'm going to give one of these ago next week hopefully - I'll let you know how it sounds.

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  16. Wow! Thank you so much :)
    Going to be a while before I can build but will definitely do and report back when complete.

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  17. Great Layouts Zach! I was wondering how it sounds with a little solid state Poweramp and higher voltages at the plate of the 12ax7. Do you think there is a need for changing some values. I have some old transformers for dual powersupplys and that would be a nice oppertunity to do something with one of them.

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  18. Has anyone verified the "Dumble Overdrive Special 70's" version?

    Does the Treble 3 connect to both the switch and hi pot, lug 3?

    Same question with Bass 2...

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    1. yes they connect to both, which i why i showed the wiring on the switches.

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  19. Also...the layout says that mids 2 and 3 and volume 1 connect from the board...but below that it says that mid's 3 connects there as well...Is this correct?

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    1. ignore the note about low 1 connecting to mids 3, it's left over from a previous version.

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    2. Sorry, not following...

      One connection says "Mids 2 & 3, Volume 1" and the next one down says "Mids 3".

      Can you clarify when you get a chance?

      I built it, but when I connect the tube, the voltage drops from +12 / -12 down to around a volt (and my LED turns off), so I want to be sure I have the wiring correct to check that off my troubleshooting list.

      Thanks!

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    3. i'm not sure which layout you're talking about now. i took a look at both dumble layouts, and i think you're talking about the 70's dumble. if so there are is a typo that has been corrected. the wire that said "Mids 2 & 3, Volume 1" sound be "Mids 1 & 2, Volume 1."

      as for as the voltage dropping issue that mistake with the pot wiring shouldn't cause that. i believe there's build error or an issue with your power supply. post some pictures and a description of the issue in the debugging section of the forum.

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    4. Thanks zach. It is the 70's dumble. I found a backwards cap and missing resistor...still having issue though. Lesson learned...don't drink and solder.

      Should these questions be posted here or in the forum?

      I'll keep digging...thanks for your awesome work!

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  20. I'm building three of these (two Vox versions and one Sunn version, all for a ridiculous three-channel Leslie-emulator amp I'm building, but that's another story). The various schematics I've found all show one of the 10k resistors (in the Vox tagboard version, the one between the 100k and 68k resistors) going to A-. However, in the Vox mod on this page, that resistor goes to ground rather than A-. In the Sunn version, the 10k resistor goes to neither ground nor to A-. In each of these cases, is this correct? I ask because none of my three builds are working (they have below unity output and the drive pot is decidedly non-linear).

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    1. Oop. You're right. The 10k resistor should go to A- must have missed that when I was moving stuff around and changing the layouts for the different tonestacks. I'll make the change later today. Good catch. Try moving the resistor to A- and see if that fixes the issue.

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  21. went back over the schematic due to some errors brought up. made the corrections and updated all the layouts.

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    1. I rebuilt the Sunn version using the edited schematic. There are still some issues. It looks like "Mids 2" needs to be moved up one row. And there's some general weirdness with the cuts and jumpers to the south of the IC. The A- row should extend all the way across the board, I think, rather than getting interrupted by that cut below the IC. Those changes got me closer, but I'm still missing something.

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    2. you're right about the mids 2 wire, but A- does not go all the way across, the cut should be there. take the 47uF cap that has the negative side on pin6 and move that leg to pin 5. that's the issue along with the IC being a 7660s instead of LT1054 makes the power section correct. see if that brings it to life. if not there has to be an error in the main layout and i'll have to go through it all again checking to see what's off with the main board.

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    3. Thanks, Zach, for all your help with troubleshooting these boogers. Regarding that A- row, Shouldn't the 10K resistor, the one that's part of what appears to be a voltage divider coming off the 100k resistor, terminate at A-? It seems like the cut in question prevents that termination.

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    4. ah, i miss understood what cut you were talking about, thought you were talking about the cut under the IC that would conenct pin 4 & 5. yes that cut is a leftover and shouldn't be there. make a connection on the copper side of the board to jumper the cut and see if that fixes the issue.

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    7. Okay, yet another update on the Sunn iteration of this thing. Things are getting better. After consulting the Sunn schematic, I've changed the following in the tonestack:

      1,Volume 1 goes to ground, not to mids 1.
      2, The 22nf cap on the bottom row should go to Mids 2, not mids 1
      3, Mid 1 to ground
      4, The mid 2 link on board is erroneous
      5. Omit cut on A- row
      6. Move mids 2 one row north
      7. Add cut immediately to the west of the south leg of the 2.2uf cap that’s to the east of the IC

      The only thing that I'm still having problems with is the Gain pot, which has a tiny sweet spot and then goes silent to either side. I suppose this is a good time for me to learn what's going on in those opamps and then nail this sucker down.

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    8. Hey man a couple of quick comments after looking over the board again and what you've done so far.

      1. Mids 1 & Volume 1 both go to ground so you can link them together and connect them right below lows 2&3/ high 1
      2. That cut on the row with A- shouldn't be there
      3. Mid 2 goes to the bottom row that's marked mids 1
      4. The cut you made next to the 2.2uF are you talking about in between the 2.2k resistor & 2.2uF cap? Cause those need to be connected where they are and there's a cut to the right of the 2.2uF so adding another one isn't going to do anything.
      5. Did you try swapping out the gain pot? It's in the right location, so either it's bad or theres something else going on still.

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    9. In comparing the layout to the schematic (in this case, Rev B, 11/21/91), the gain pot weirdness was a consequence of the 22K resistor going to A- rather than ground.

      And so, now, with the changes outlined below, I'm pleased to verify the Sunn version of this circuit:

      1. Add a cut immediately to the west of the south lead of the 2.2uf cap that you’ll find to the east of the IC and to the west of the 1.5k resistor. Without this cut, the signal is erroneously diverged into the tone stack.

      [Since there doesn’t seem to be a common language for describing locations on the board, I shall henceforth use X,Y coordinates. I’ll call the southwest corner of the board (1,1), with horizontal columns represented by X and the vertical rows by Y. In that case, the cut goes at (12,4).]

      2. Mids 1 & Volume 1 both go to ground so you can link them together and connect them right below lows 2&3/ high 1 (20,6).

      [This’ll work, but, in hopes of reducing noise, I will not connect these to the board; instead I’ll solder them to the negative lead on the power jack]

      3. The cut on the row with A- (10,5) shouldn't be there

      4. Mid 2 goes to the bottom row that's marked "mids 1" (20,1)

      5. 22k to the west of IC should go to ground (7,6), not A- (7,5)

      6. And lugs 2&3 of the Drive pot should be connected, as opposed to 1&2.

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    10. Good catch on the misplaced resistor and catching the issues. The cut you're talking about I see now, typically we talk identIfy spots by what column and row, like you ended up doing. I'll update the layout tomorrow night. Btw, connecting mids 1 & volume 1 to the board won't increase noise, since all grounds are connected, so never be worried about connecting a ground to the board.

      Btw, how does it sound with the model t tonestack?

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    12. Okie dokie. The Sunn version (with the above tweaks) sounds great. There's some hiss, but it's well within tolerance. To my ears, the tonestack has very distinct bass, mids and treble ranges, with bass and treble skewing more toward the bass and treble ends of the spectrum, respectively, than your typical marshall/fender set up. The power supply using the 7660S chip is meeting all power needs.

      Zach: Thanks for your assistance. And now, onto the Vox version...

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    13. That's great news, most likely the other layouts with the FMV style tonestack are good to go too, so the big question is the dumble, and Bandax style tonestack circuits. Out of curiosity did you do a star ground? That might take away some of the little extra hiss.

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  22. Hey, I tried building the Fender version today, not realising the schematic had been updated. I haven't made the changes yet but I noticed I was having a similar issue to others on the 901 thread, and as the tube warms up the led gets dimmer and dimmer, before eventually just switching off. Is this likely to be an issue that would be fixed by the revisions? In the other thread I noticed you were suggesting 7660s', should I try that instead?

    Thanks again!

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    1. yes. i haven't changed that to the layouts because i have to do it to like 15 different ones. so before i do i want to make sure that's the culprit.

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    2. Thanks for the quick reply - I'll socket it this time and grab a 7660s. I'll let you know how it goes later this week

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    3. Hey - I tried rebuilding the fender version again today with the changed layout, the 7660s, the capacitor to IC 5 on the power board, and the above suggestion that it should be 2&3 joined rather than 1&2 for the drive (I tried it both ways, same result). While it does power on and hold power now, all I'm getting from it is a high pitched wine that fades in with the tube warming up. It seems to be connected to the drive as it disappears when the drive is below midway, but still no sound. I have gone over it a few times tonight and I'm sure there's no shorts or mistakes in the build, but I will double check in the morning when I have a clear head

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  24. I keep blowing the 47uf cap at the chargepump between A+ and the ground, its rated for 35v. Anyone has an idea why?

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    1. Is your cap reversed? Negative marked lead needs to go to ground - if not, then your symptom is expected.
      +m

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    2. Hey Mirosol, the polarity is the same as given on the the schematics of the Ampeg SVT

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    3. So the negative lead of that cap is to ground. Then check the voltages and the pump. Only way to blow a filter cap is to feed it voltage in reverse.
      +m

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  25. Hi, i've built dumble 70's and didnt work.
    I found that jazz 6 connect to nothing. Is that correct?
    Thanks

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    1. Jazz 6 is not connected to anything. This wil probably take the 330pf from treble 3 and leave it out of the circuit. That would be my guess.

      It shouldn't be the reason why you're 70's dumble doesn't work.

      In the meantime, is the pedal working now? Or are you still searching for an error in the circuit?

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  26. I've built the dumble 70's as well with the same result..did not work. I also built the standard 903 and can't get it to work. I have checked and double checked everything and I can't get any sound to pass through the tube. Any ideas anyone?

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