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Friday, 11 November 2016

Bogner La Grange

Original Info:
The La Grange pedal is designed to emulate the famous British "Plexi" amplifiers from the mid 60's. The wide variety of controls and switches, give you decades of legendary plexi tones, all the way up to the era of the modded amps from the late 80's and throughout the 90's.
An independent boost function, with a level control, can be activated via it's own foot-switch to be either used as a stand alone boost, or together with the La Grange's main circuitry. Essentially two independent pedals, with the boost being in series after the La Grange!
Reinhold designed the La Grange pedal with an op-amp input, followed by five discrete Class A gain stages and incorporated Germanium diode clipping. This approach minimizes the input noise floor while retaining touch sensitivity and clarity throughout the entire gain range.
Original FSB thread and schematic available here.
You can find the original manual PDF here.
I've used Mark's Dual Effect Offboard wiring.
21/11/2017 Layout Updated! Fixed Boost section based on updated schematic.


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55 comments:

  1. Anonymous11 November 2016 at 13:34

    omg, this goes onto the build list for sure! :)

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    1. Anonymous11 November 2016 at 13:53

      oh lookin at this, to me this is very similar to the Zvex box of rock / distortron, and as I see the boost is pretty much an SHO - just with more controls

      Delete
  2. Unknown11 November 2016 at 15:46

    Can I use 2, 12v diodes? I have a bunch but no 10's.

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  3. Unknown11 November 2016 at 15:46

    Hi, 2 question:

    - is the 7660s a voltage converter?

    - can i use this opa132ua?

    http://www.ebay.com/itm/BB-TI-OPA132UA-SOP-8-High-Speed-FET-INPUT-OPERATIONAL-/221575682186?hash=item3396f0988a:g:NfcAAOSwAHZUPQs1

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  4. Iago11 November 2016 at 18:48

    Holy crap, great job, Alex!

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  5. Alltrax7412 November 2016 at 17:41

    Shouldn't the boost be at the end of the chain ? According to your layout the in is connected to the boost and the main circuit to the out

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    1. Alex13 November 2016 at 13:41

      Probably but not according to the schematic.
      If it doesn't sound right it's just a question of swapping some wires.
      The Boost part would go to SW6-5 and Sw6-7.
      The main circuit would go to SW5-5 and Sw5-7.

      Delete
    2. Alltrax7414 November 2016 at 08:59

      Ok thanks it's a mistake in the layout then, but some might prefer it that way so...

      Delete
    3. Alex14 November 2016 at 09:42

      Layout should be correct cause it matches the schematic (or at least I hope so).
      Either the guy has drawn the schematic wrong or the boost goes in front but (as we've said before) it's very simple to swap. You could even add a DPDT toggle switch to swap the boost position in front or at the end whenever you want. Should test it first.

      Delete
    4. Alltrax7414 November 2016 at 11:31

      Oups sorry I meant the schematic not the layout. It's said in the video that the boost comes after. I was also thinking of a toggle, both options are interesting whether you need more gain or more volume ;-)

      Delete
    5. Alex14 November 2016 at 16:55

      If you build it (and it works) let me know if the boost sounds good in front (sometimes they don't). I'll add a toggle switch!

      Delete
  6. Willy13 November 2016 at 05:47

    Looking at the layout, the footswitch LEDs only get power if the variac switch is flicked a certain way. Wouldn't you run them (or the clrs at least) straight off the 9v rail? Or am I missing something?

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    1. Alex13 November 2016 at 10:25

      The LEDs are wired correctly.
      The 9V is always there.
      The Variac switch just changes the voltage that goes to the BS170s. The rest works at 9V.
      If you check the schematic it will be clearer.

      Delete
    2. Alltrax7414 November 2016 at 08:58

      Speaking of voltages Alex, which electro capacitors should be rated 25v+ ?
      Thanks

      Delete
    3. Alex14 November 2016 at 09:46

      I would use 25V everywhere, just to be safe.

      Delete
  7. Unknown14 November 2016 at 07:41

    Thank you! I have been waiting for that one :)

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  8. Unknown14 November 2016 at 22:37

    Ohhhhhhh hell yeah

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  9. Unknown16 November 2016 at 03:05

    hi
    great post alex.
    thanks for this one.
    built it but lacking of this OPA132
    i can tell the tone wires are reversed.
    i put opa275GP so all i got is a a big hiss (like distortion on with vol off on the guitar) and a reaction of the treble and the vol pots.
    is there any sub for this opa132 ?
    thanks

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  10. Markus26 November 2016 at 08:32

    Hi Alex,
    maybe it is a dumb question. What do you mean with that you used Marks Dual Effect Offboard wiring? I checked Marks Post where he explained it. I understaood that you are going to use it when you have 2 veros, aren't you?

    Many thanks in advance!!
    Markus

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    1. Alex26 November 2016 at 12:17

      Hi Markus.
      You use it when you have two independent separate circuits. Like in this case.
      The Boost in this pedal can be switched on on its own.

      Delete
    2. Markus26 November 2016 at 21:31

      Hi Alex,

      thank you very much! I see, it is too difficult for me now :-) I am going to try a few easier one.

      Thanks

      Delete
  11. Arngus29 November 2016 at 05:35

    Hello,

    Interested for build it, but is there any opa132 replacement ?

    thanks ....

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  12. Unknown10 December 2016 at 23:14

    You can tag this one as verified. Thank you for this great layout once again. A few problem with pots : blend, boost and tone work reversed. Just a few wire to swap, nothing hard. My build has whistle when I push gain or when I go to trebby setting but I test it with OPA134 and AD820 (less whistle) as I don't have yet OPA132. This problem is not from the layout I'm sure. Except this whisle the sound is awesome an it seems to be very versatile.
    I add a toggle to reverse boost position, but I didn't play enough to know my favorite order.

    Pics of the build :

    http://dl.dropboxusercontent.com/u/9520625/20161210_235751.jpg

    http://dl.dropboxusercontent.com/u/9520625/20161210_235812.jpg

    Thanks again for this layout

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    1. Anonymous13 December 2016 at 07:54

      have you tried some more common IC in it, like TL071 for example?

      Delete
  13. Unknown10 December 2016 at 23:18

    Think too late, in waiting to find an OPA132, do you think that tweaking the 22P cap close to the IC will be able to reduce the whistle?

    Thank you

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  14. Unknown11 December 2016 at 23:15

    I revert wire 1 & 3 on tone and blend and attach lug 2 & 3 on boost pot to make them work in the good way. Just now wait for a good OPA132.

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  15. Unknown13 December 2016 at 10:53

    Finally, the whistle was because of my 7660S. I change them and it stop the whistle. There is 2 kinds of 7660S there is CPAZ and IPAZ, in that case the IPAZ work better in my build. I will play with it and keep you update for the boost position.

    Thanks again for the layout

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    1. Unknown27 December 2016 at 11:53

      The 7660S tend to add high frequency whine when they are used as +/- voltage supply or voltage doublers. Sometimes the problem can be solved by putting them on a daughter board and placing this away from the main board or shield it with some foil. But I have found that the LT1054 works much better and rarely produces any noise. You can use the same socket, just make sure you don't connect PIN 1 (clip or bend out of the way).

      Delete
  16. glasspak7314 December 2016 at 09:58

    Can i use 9.1volt zener diodes for D3-D5? I also have 12volt zeners but no 10volt.Has anyone tried alternate diodes for D3-D5? If so do they make a big differance in the sound?

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  17. Unknown15 December 2016 at 22:37

    So after test, I really think that the boost has to be in second position. It works very well as a volume boost and not very well at gain one. And the pedal has a lot of gain so boost the gain is not realyy usefull.
    In first place it works only well when the gain is low on the main board. That's why I think it has to be second. A toggle to change the position can be a good idea for some setting. Only needed if you want a 2 stage gain.
    In my case, I had to change the 5K1 resistor to correctly bias the BS170 of the boost. I use a 15K resistor to bias it to 6V.

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    1. Alex16 December 2016 at 10:24

      Thanks Thomas! Made those changes.

      Delete
    2. Unknown25 January 2017 at 20:48

      I have built it and most of the circuit works fine. But the booster does not really seem to work. With 5k1 to ground and 5k1 to +18V it does not provide much boost. It is basically an SHO on the lowest Boost setting.
      Does the Boost pot really go from Source back to the Gate. Shouldn't it go to ground?

      Delete
    3. MAO29 January 2017 at 19:31

      Thomas, did you bias the Boost BS170 at 6V by ear, or is that documented somewhere?

      Delete
    4. MAO29 January 2017 at 21:40

      I finished mine up this afternoon and was not crazy about the Gain and Boost pots.

      They were acting more like switches than adjustable controls. Either nothing, or full on. Nothing in between.

      I replaced the Gain pot with a 50k log, much improved response and available gain.

      I also re-biased the boost BS170 as Thomas mentioned, but IMO it is still not functioning correctly.

      I think there may be a schematic error with the boost.

      Delete
    5. MAO29 January 2017 at 23:40

      The re-wiring of the boost control per the manfred schematic update here seems to be an improvement.

      http://www.freestompboxes.org/viewtopic.php?f=7&t=27693&p=262312#p262312

      I just noticed I'm getting a loud squeal with the gain switch in either outer position, in the center off position sounds fine. Squeal changes tone when in 18v mode, but gain, quiet in the center off position.

      Would someone mind posting the voltages you have on the the gain switch's BS170 DGS pins?

      In 9v mode, gain switch in center position, I have:
      D 7.63v
      G 3.70v
      S 1.65v

      Gain switch in high gain mode (1k resistor shunted to ground)
      D 5,69v
      G 2.82v
      S 0.59v

      Gain switch in max gain mode (100R shunted to ground)
      D 4.74v
      G 2.27v
      S 0.08v

      Delete
    6. Arnold Dikstaal20 November 2017 at 22:05

      This comment has been removed by the author.

      Delete
  18. Unknown30 January 2017 at 20:11

    I have completed mien and I am finally satisfied. The following changes worked for me:
    Boost behind the main circuit
    Boost pot goes to ground, not back to the Gate
    Gain Pot should be 50K log (100K log with 40-60 K works too - experiment)
    Dispensed with 2M2 parallel to Gain pot
    Blend Pot is C1K instead of B1K
    LT1054 to make 18V
    100uF instead of 47uF to ground on the 18V side
    -9V and 18V circuits on separate daughter boards - as far as possible away from the main board
    Shielded wires for everything longer than an inch (there is a truckload of gain when you max everything)

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  19. MAO30 January 2017 at 21:24

    Excellent Han Solo,

    I'm also close...

    What did removing the 2M2 improve?

    Would you mind posting your voltages on the gain switch's BS170 so I can compare?

    Will try shieleded wires tonight to see if that tames the squeal I'm getting with the boost switch.

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    1. MAO31 January 2017 at 05:59

      No improvement with the shielded wires, still squeals like crazy with the gain switch.

      I did note that with the gain pot turned down to around 1k, the high gain switch setting stops squealing, the highest gain switch still squeals though.

      Maybe there is to much gain further upstream, due to a component error or something, not sure.

      Hopefully someone can post their voltage readings so I can compare. Maybe for the 2n5088 too?

      Delete
    2. MAO31 January 2017 at 07:20

      Here's a sound sample of the squealing:

      https://soundcloud.com/maopedals/la-grange-clone-squealing

      Delete
    3. Unknown31 January 2017 at 21:55

      This comment has been removed by the author.

      Delete
  20. Unknown31 January 2017 at 22:00

    Sorry I can't give you the voltage readings, I built the pedal for someone else and he has already picked it up.
    The squeal is not the typical whine you get from the 18V supply.
    Are you sure the Gain switch is wired correctly?
    I did not use Alex' Vero layout but build my own because I wanted the voltage converters off the board and also run a few components off board to make pot wiring easier and get a smaller Vero footprint. One of the things I changed is to run a wire from the source of the first BS170 to the center lug of the SPDT Gain Switch and then ran the 100R and the 1 K from the other two lugs directly, off board, to a ground rail. I did the same with the 470n and the 47u on the Blend knob and initially the 47R and the 2M2 from the gain knob, but I took these out again later as they do not serve much of a purpose.
    As a test: set the gain switch to the center position and then hook a croc clip to the S leg of the first BS170 (or the respective end of the 5K1), clip a 1K or 100R to the other end of the croc wire and touch the enclosure/ground. See if it is still squealing.
    In 9V Mode, my build was actually pretty quiet, even with gain switched to high gain.

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    1. MAO1 February 2017 at 21:08

      No luck as of yet, also tried the 22uf coupling cap as suggested by Manfred over at FSB.


      I know my layout matches the latest achematic, going to work through it with a meter and audio probe tonight to be sure my board matches my layout, and see exactly where the squealing enters the circuit.

      Delete
  21. richard8 March 2017 at 16:01

    Hey Alex,
    Thank you so much for all your work on this. I'm going to get started on this build soon. Do you have any more information on how one would hook up an expression pedal for the gain. I see where the connection works go on the board, but would it just go to a jack? How would it be switched if so?
    Much thanks!!
    Rick

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  22. Arnold Dikstaal20 November 2017 at 21:20

    This comment has been removed by the author.

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  23. Arnold Dikstaal21 November 2017 at 13:26

    Ok, stupid me... I checked the trace at freestompbox and the boost in this vero does not compare to the trace... Considering the trace is correct, then you will need an extra 1M to ground after the 100n that is connected to SW6-5. The boost pot should be connected pin 3 to ground and pin 1&2 to the negative side of the 4u7 and the positive side of the capacitor to the zener, source of BS170 and the 5k1.

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  24. Arnold Dikstaal21 November 2017 at 13:26

    updated boostschematic : http://www.freestompboxes.org/viewtopic.php?f=7&t=27693&p=267135#p267135

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    1. Alex21 November 2017 at 15:17

      The layout was based on the original schematic.
      I've updated the boost section.

      Delete
    2. Arnold Dikstaal29 November 2017 at 11:07

      I think I spotted another mistake in the schematic vs trace. The structure switch should be DP3T on-on-on and not SP3T. the first position should switch the LED's only, center should be LED's and 1n270's and the last position switches the 1N270's and 2N7000's.
      Also I think the 47n that now goes from pin 2 on the structure to ground should be in series with pin 2 and the 100n and 22n.
      See my remarks here: http://www.freestompboxes.org/viewtopic.php?f=7&t=27693&p=267282#p267282

      Delete
  25. Jason S6 February 2019 at 12:56

    This comment has been removed by the author.

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  26. tk29 December 2021 at 10:34

    I made mine today for my holiday gear.
    I noticed that the drain voltages on the lower three BS170's were not equal.
    I had to change the 5.1k resistor going to the right and left BS170s to a variable resistor (20K) and bias them.
    As for clipping, this SPDT (ON-OFF-ON) switch allows to switch between the three clippers, and looking at the FSB thread, that seems to be about right (the actual wiring looks different, but the result should be the same because of Uf values).

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  27. Arnold Dikstaal25 April 2024 at 16:52

    I revisited the trace on FSB and bought a la grange to check the trace. I found multiple differences and if you want to know more, go to FSB.
    https://www.freestompboxes.org/viewtopic.php?p=299010#p299010

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  28. Silva1 November 2024 at 00:42

    Here is a summary of Arnold's changes:

    Change the 100n just below D6 to 10n

    Change the 100n to the left of OPA132 pins 3 and 4 to 10n 

    Change the 68k resistor just under D8 to 6k8 

    470n connected to the base of 2N5088 is POSSIBLY a 47n (I A/Bed them both and I think the 47n has a tiny bit more more upper mids and highs an the 470 has a tiny bit more lows but it's negligible and I just might be hearing what I want to hear

    The Structure switch should be a DPDT On-On-On. Check the link for the wiring diagram.

    https://www.freestompboxes.org/viewtopic.php?p=299010#p299010

    1-1 is Mosfets, 1-2 is LEDs, and 1-3 is 1N270s

    I had to nudge the top leg of the 3k3 resistor over a little to make room for a wire to go through the hole just to the right of the 22n top connection. Also check to see which type of switch you have; mine was different from the wiring diagram so I had to make a few wire swaps.

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  29. Arnold Dikstaal1 November 2024 at 09:29

    Tanks for updating Silva!

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