Bogner - La Grange  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
User avatar
Manfred
Tube Twister
Information
Posts: 1937
Joined: 04 Apr 2009, 23:42
Has thanked: 1671 times
Been thanked: 1344 times

Post by Manfred »

Why do you have an arrow going to the right of the switch? The cap is in series with pin 2 and not in parallel.
I omitted the capacitor in parallal to the clipping diodes.
The 100nF is the coupling capacitor.
The right switch goes to then next stage.

An asymmetrical instead of symmetrical clipping , it is a matter of taste.

There are better reads to find in the web regarding clipping circuits,
I read the most of it in the recent years.

User avatar
Lithium_Grim
Breadboard Brother
Information
Posts: 112
Joined: 21 Apr 2013, 08:45
Location: Holland
Has thanked: 39 times
Been thanked: 72 times
Contact:

Post by Lithium_Grim »

Manfred wrote: I omitted the capacitor in parallal to the clipping diodes.
There is no capacitor in parallel that's just it. Look at the cutout of the trace I posted a few posts back. It's in series.
I only give negativ feedback and y'all love it!
PCB shop

User avatar
Manfred
Tube Twister
Information
Posts: 1937
Joined: 04 Apr 2009, 23:42
Has thanked: 1671 times
Been thanked: 1344 times

Post by Manfred »

There is no capacitor in parallel that's just it. Look at the cutout of the trace I posted a few posts back. It's in series.
Thanks, for the hint.
So, I have to change the schematic once again.
The type 2 and type 3 switches cannot easily draw as schematic symbol,
I have to think about it.

User avatar
Manfred
Tube Twister
Information
Posts: 1937
Joined: 04 Apr 2009, 23:42
Has thanked: 1671 times
Been thanked: 1344 times

Post by Manfred »

Structer switch changed and 47nF capacitor omitted.
BognerLaGrange7.JPG

User avatar
bajaman
Old Solderhand
Information
Posts: 4549
Joined: 26 Jun 2007, 21:18
Location: New Brighton, Christchurch, NZ
Has thanked: 595 times
Been thanked: 2058 times

Post by bajaman »

ffs :roll: the 47n is in series!!!!!!
be kind to all animals - especially human beings

User avatar
Lithium_Grim
Breadboard Brother
Information
Posts: 112
Joined: 21 Apr 2013, 08:45
Location: Holland
Has thanked: 39 times
Been thanked: 72 times
Contact:

Post by Lithium_Grim »

Like this (I love paint :D )
BognerLaGrange7.JPG
I only give negativ feedback and y'all love it!
PCB shop

User avatar
Manfred
Tube Twister
Information
Posts: 1937
Joined: 04 Apr 2009, 23:42
Has thanked: 1671 times
Been thanked: 1344 times

Post by Manfred »

Lithium_Grim wrote:Like this (I love paint :D )
The attachment BognerLaGrange7.JPG is no longer available
Ok, I love painting too, further changes are always welcome. :D
BognerLaGrange8.JPG

User avatar
Thimotti
Information
Posts: 4
Joined: 10 Jul 2013, 18:26
Has thanked: 2 times
Been thanked: 1 time

Post by Thimotti »

Manfred wrote:There are three types of ON-ON-ON miniature switches, these differ in the switching scheme.
ON-ON-ON_switch types.jpg
I have examined which switching scheme could work and found that only the switch type 3 met the requirements.
BognerLaGrangeStructure1.JPG
BognerLaGrangeStructure2.JPG
BognerLaGrangeStructure3.JPG
Hi Manfred and Lithium_Grim,

Let's talk about the structure and voltage Threshold:

Vth of Red Led: 2.2v typ
Vth of Ger Diode: 1v max
Vth of Mosfet: 0.88v typ 1.5v max

Are you sure of:
Pos 1: Ger + Mosfet
Pos 2: Only Mosfet
Pos 3: Only Led
?

Makes more sense to me:
Pos 1: Ger + Mosfet
Pos 2: Red Led + Ger
Pos 3: Only Led

Could you explain me better? Thanks.

User avatar
Manfred
Tube Twister
Information
Posts: 1937
Joined: 04 Apr 2009, 23:42
Has thanked: 1671 times
Been thanked: 1344 times

Post by Manfred »

Vth of Ger Diode: 1v max
In general, the clipping start is deteremined by the lowest threshold voltage knee.
In the case of a Germanium diode the clipping starts at the minimum threshold voltages of 0.3 to 0.4 Volts.

If different types of diodes are connected in parallel the diode with the lowest threshold determines the clipping behaviour,
therefore, in my opinion, your suggestion makes no sense.

User avatar
Thimotti
Information
Posts: 4
Joined: 10 Jul 2013, 18:26
Has thanked: 2 times
Been thanked: 1 time

Post by Thimotti »

Manfred wrote:
Vth of Ger Diode: 1v max
In the case of a Germanium diode the clipping starts at the minimum threshold voltages of 0.3 to 0.4 Volts.
Oh, very thanks. This is the information that I was looking for.

User avatar
Lithium_Grim
Breadboard Brother
Information
Posts: 112
Joined: 21 Apr 2013, 08:45
Location: Holland
Has thanked: 39 times
Been thanked: 72 times
Contact:

Post by Lithium_Grim »

Looking at the clipping section again It seems that besides the wrong position of the 47nF capacitor (C1), there is nothing wrong with the SP3T configuration vs the DP3T. Let's throw some proof in:
LED.jpg
2N7000.jpg
1N34A.jpg
As you can see, Uf LEd = 1.9V, Uf 2N7000 is 0.72V, Uf Ge = 0,58V (Yes, it's a 1N34A and not a 1N270)
So in the DP3T of Manfred
1. GE+Fet = 0,58 vs 0,72 > Ge determines clipping
2. Fet > Fet determines clipping
3. LED > LED determines

Now in the before mentioned SP3T configuration:
1. GE+ LED = 0,58 vs 1,9V > Ge determines
2. LED > LED determines
3. Fet+LED = 0,72 vs 1,9V > Fet determines

So if Uf truly is the only factor determines clipping, I'd use the SP3T.
I only give negativ feedback and y'all love it!
PCB shop

User avatar
Saruman
Degoop Doctor
Information
Posts: 73
Joined: 19 Jun 2009, 17:41
Location: Russia
Been thanked: 145 times

Post by Saruman »

The best live sound with the LED. Other is not used.

User avatar
Manfred
Tube Twister
Information
Posts: 1937
Joined: 04 Apr 2009, 23:42
Has thanked: 1671 times
Been thanked: 1344 times

Post by Manfred »

So if Uf truly is the only factor determines clipping, I'd use the SP3T.
On the PCB image above is a DP3T switch applied, now you suggest a SP3T switch.
Please make a sketch how you wired it, than I going to change the schemativ drawing again.

User avatar
Lithium_Grim
Breadboard Brother
Information
Posts: 112
Joined: 21 Apr 2013, 08:45
Location: Holland
Has thanked: 39 times
Been thanked: 72 times
Contact:

Post by Lithium_Grim »

Yes, the PCB trace shows a DP3T so you need not change the schematic.
The only thing I try to point out is that the SP3T is also valid and gives the same options as the DP3T as long as Uf is the only determining factor for the clipping section.
I only give negativ feedback and y'all love it!
PCB shop

User avatar
Lithium_Grim
Breadboard Brother
Information
Posts: 112
Joined: 21 Apr 2013, 08:45
Location: Holland
Has thanked: 39 times
Been thanked: 72 times
Contact:

Post by Lithium_Grim »

I made some PCB's with all kinds of optional mods on board, based on the SP3T clipping section. Tested them and it truly sounds sweet. If anyone is interested you can PM me.
I only give negativ feedback and y'all love it!
PCB shop

User avatar
nycLPplayer
Information
Posts: 6
Joined: 19 Dec 2017, 14:58
Has thanked: 1 time
Been thanked: 1 time

Post by nycLPplayer »

Hope you guys dont mind the post but my LG appears to be dead on the OD side only (both sides light up). Boost still works and confirmed it is not power, cable, or amp.

Image

light blue squares i get not voltage

yellow stars I get voltage but 0 on the rest of that side of the chip
purple starts I get no voltage but readings on the rest of that side of the chip

Hoping it is just a bad part I can swap as I got this at a steal but then it died after 2 days.

User avatar
nycLPplayer
Information
Posts: 6
Joined: 19 Dec 2017, 14:58
Has thanked: 1 time
Been thanked: 1 time

Post by nycLPplayer »

nycLPplayer wrote:Hope you guys dont mind the post but my LG appears to be dead on the OD side only (both sides light up). Boost still works and confirmed it is not power, cable, or amp.

[ Image ]

light blue squares i get not voltage

yellow stars I get voltage but 0 on the rest of that side of the chip
purple starts I get no voltage but readings on the rest of that side of the chip

Hoping it is just a bad part I can swap as I got this at a steal but then it died after 2 days.

All the no voltage areas....maybe the big microcontroller

Image

User avatar
FeVeR2112
Breadboard Brother
Information
Posts: 142
Joined: 27 Dec 2013, 06:07
Has thanked: 47 times
Been thanked: 60 times

Post by FeVeR2112 »

If it is the PIC chip and it hasn't been put in protected mode, you will need to obtain the programming from either some one with the pedal who is willing to remove the chip/extract the Hex file .... or have Bogner supply a new chip or the program file.

You might obtain the programming from the existing PIC chip but it would be suspect for integrity.

At least the chip is socketed :D

While relays and programmed micro-controller chips are nice, they can be a repair stumbling block.

User avatar
nycLPplayer
Information
Posts: 6
Joined: 19 Dec 2017, 14:58
Has thanked: 1 time
Been thanked: 1 time

Post by nycLPplayer »

FeVeR2112 wrote:If it is the PIC chip and it hasn't been put in protected mode, you will need to obtain the programming from either some one with the pedal who is willing to remove the chip/extract the Hex file .... or have Bogner supply a new chip or the program file.

You might obtain the programming from the existing PIC chip but it would be suspect for integrity.

At least the chip is socketed :D

While relays and programmed micro-controller chips are nice, they can be a repair stumbling block.

Much appreciated....I thought I could part swap a new chip. Looks like this is going back.

User avatar
Lithium_Grim
Breadboard Brother
Information
Posts: 112
Joined: 21 Apr 2013, 08:45
Location: Holland
Has thanked: 39 times
Been thanked: 72 times
Contact:

Post by Lithium_Grim »

If (like me) you experience strange behavior when in boost only mode and turning the volume of your guitar down then consider putting a 10K between your guitar and the input of the Boost section. like this (Rx):
Bogner La Grange modified Boost.JPG
Bogner La Grange modified Boost.JPG (18.36 KiB) Viewed 4783 times
You could also consider to put Rx after C6 instead of before. Also you might consider a lower value then 10k (eg. 1k) if you think it is snooping off too much bass.

Personally I prefer this:
Bogner La Grange modified Boost pref.JPG
Bogner La Grange modified Boost pref.JPG (18.29 KiB) Viewed 4781 times
I only give negativ feedback and y'all love it!
PCB shop

Post Reply