Sunn Beta Bass preamp schematic
Hi everyone!
Hope the topic is in the right area.
I'm updating the ugly jpg schematic of this amp, now I've made only a "single channel" version, removing the electronic switch. Here's an eagle version with really dummy libraries (sorry, first works with this software!), but more readable than the old one,and (I hope) useful!
I'd like to put this preamp in a box, and if someone wants to help with the layout will be great!
Single Channel Schematic
http://s3.postimg.org/ada3tjr0h/Sunn_Be ... hannel.png
Double Channel A/B Schematic
http://s4.postimg.org/rw46zwogr/Sunn_Be ... hannel.png
Hope the topic is in the right area.
I'm updating the ugly jpg schematic of this amp, now I've made only a "single channel" version, removing the electronic switch. Here's an eagle version with really dummy libraries (sorry, first works with this software!), but more readable than the old one,and (I hope) useful!
I'd like to put this preamp in a box, and if someone wants to help with the layout will be great!
Single Channel Schematic
http://s3.postimg.org/ada3tjr0h/Sunn_Be ... hannel.png
Double Channel A/B Schematic
http://s4.postimg.org/rw46zwogr/Sunn_Be ... hannel.png
Hi jbgron,
I've seen only the service manual of these amp, found online, and the schematic should be correct. What I'd like to do is a sort of ABY switch (true bypass) instead the electronic switch of the amp, and put all in a stompbox or similar.
The IC of the amp are CD4069 and 4558, right?
I'm trying put all in a veroboard layout, but I'm slow and lazy, so I started with sharing the "simplified and readable" schem!!
Cheers!
I've seen only the service manual of these amp, found online, and the schematic should be correct. What I'd like to do is a sort of ABY switch (true bypass) instead the electronic switch of the amp, and put all in a stompbox or similar.
The IC of the amp are CD4069 and 4558, right?
I'm trying put all in a veroboard layout, but I'm slow and lazy, so I started with sharing the "simplified and readable" schem!!
Cheers!
- grrrunge
- Diode Debunker
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If you're handy with Eagle or similar pcb-cad software: Not that difficult.ZombiCrow wrote:How difficult will this be to distill into a distortion pedal, would you say? Thank you!
If you're badass around vero or perfboard: Not that difficult.
Otherwise: Pretty hard.
A true believer in the magic of Sherwood Forest Pedal Pirates
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New base of operations: http://www.knucklehead.dk
- grrrunge
- Diode Debunker
Information
Looks like a fun project! Here's the service manual schematic:
A true believer in the magic of Sherwood Forest Pedal Pirates
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New base of operations: http://www.knucklehead.dk
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New base of operations: http://www.knucklehead.dk
Hi ! Please excuse my bad English because I'm French.
It seems like two resistors have been forgotten on the first post schematics.
R123 100k on channel 1, should be placed between lug 2-1 of Drive pot (R5/2 1M lin), and lug 1 of IC2A 4069N
= R152 100k on channel 2, should be placed between lug 2-1 of Drive pot (R40/2 1M lin), and lug 1 of IC7A 4069N
R186 1,5k on channel 1, should be placed between lug 7 of IC4B LM4558N and between the ends of R26 and C20
= R170 1,5k on channel 2, should be placed between lug 7 of IC9B LM4558N and between the ends of R61 and C42
There is a mistake on the Single Channel Schematic: it is mentioned that IC2 pin 8 is joined to +15V and IC2 pin 4 is joined to -15V. But it should be IC3 pin 8 and 4.
This mistake is not repeated on Double Channel A/B Schematic.
And lastly, C20, C21, C42 and C43 should have been reported as Non-Polarized: NP
I hope my post is understandable
It seems like two resistors have been forgotten on the first post schematics.
R123 100k on channel 1, should be placed between lug 2-1 of Drive pot (R5/2 1M lin), and lug 1 of IC2A 4069N
= R152 100k on channel 2, should be placed between lug 2-1 of Drive pot (R40/2 1M lin), and lug 1 of IC7A 4069N
R186 1,5k on channel 1, should be placed between lug 7 of IC4B LM4558N and between the ends of R26 and C20
= R170 1,5k on channel 2, should be placed between lug 7 of IC9B LM4558N and between the ends of R61 and C42
There is a mistake on the Single Channel Schematic: it is mentioned that IC2 pin 8 is joined to +15V and IC2 pin 4 is joined to -15V. But it should be IC3 pin 8 and 4.
This mistake is not repeated on Double Channel A/B Schematic.
And lastly, C20, C21, C42 and C43 should have been reported as Non-Polarized: NP
I hope my post is understandable
- grrrunge
- Diode Debunker
Information
Mind giving this a lookover, before i begin layouting?
A true believer in the magic of Sherwood Forest Pedal Pirates
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New base of operations: http://www.knucklehead.dk
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New base of operations: http://www.knucklehead.dk
I think this one is correct,
I don't know how CD4049UBE should be powered, but on the original schematic 74C04 is powered with +8V
Why don't you use 4069 instead ?
Maybe you should indicate +V is +15V and -V is -15V
The volume pot is not wired as the Sunn schematic, but I don't know if it's important.
I don't know how CD4049UBE should be powered, but on the original schematic 74C04 is powered with +8V
Why don't you use 4069 instead ?
Maybe you should indicate +V is +15V and -V is -15V
The volume pot is not wired as the Sunn schematic, but I don't know if it's important.
- deltafred
- Opamp Operator
4000 Series CMOS is limited to a supply voltage of 15v, how you are proposing connecting it would supply it with 30V.morain51 wrote:I think this one is correct,
I don't know how CD4049UBE should be powered, but on the original schematic 74C04 is powered with +8V
Why don't you use 4069 instead ?
Maybe you should indicate +V is +15V and -V is -15V
The volume pot is not wired as the Sunn schematic, but I don't know if it's important.
It is usual, but not mandatory, to connected it between 0V and +15V supplies on a -15/0/+15 supply.
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Jeez, she's an ugly bastard, she makes my socks hurt. I hope it's no ones missus here. - Ice-9 2012
Jeez, she's an ugly bastard, she makes my socks hurt. I hope it's no ones missus here. - Ice-9 2012
Sorry, I meant just specify that the circuit is powered with -15/0/+15 on your schematic (not especially the CMOS),
on the top left with the connecting points or in the indications at the bottom right.
If the CMOS can be powered with 0/+15V so you're right, let's skip the +8V
on the top left with the connecting points or in the indications at the bottom right.
If the CMOS can be powered with 0/+15V so you're right, let's skip the +8V
- grrrunge
- Diode Debunker
Information
That's a typo. The schematic should say CD4069UBE. My badmorain51 wrote:Why don't you use 4069 instead ?
The service manual is a little blurry, but the way i see it, the VCC-pin is connected to +15V through a 470R, and then there's a test point that should read +8V directly at the VCC-pin.morain51 wrote:on the original schematic 74C04 is powered with +8V
Connecting it to both a 15V and an 8V supply makes absolutely no sense, whereas a 7V voltage drop across 470R implies a current draw from the 4069 of roughly 15mA. That seems plausible.
The plan is that this thing is going in a pedal. The most obvious solution would be to supply the circuit +/-9V from a 9V charge pump.morain51 wrote:Maybe you should indicate +V is +15V and -V is -15V
I think you're right. It's wired backwards in my schematic. Considering this is an inverting amplifier, the gain should rise as more resistance is introduced in the feedback path.morain51 wrote:The volume pot is not wired as the Sunn schematic, but I don't know if it's important.
A true believer in the magic of Sherwood Forest Pedal Pirates
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New base of operations: http://www.knucklehead.dk
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New base of operations: http://www.knucklehead.dk
You are certainly right, on Sunn manual the +8V is drawn with a circle instead of an arrow like the -15/+15V, it may be a test point.grrrunge wrote: The service manual is a little blurry, but the way i see it, the VCC-pin is connected to +15V through a 470R, and then there's a test point that should read +8V directly at the VCC-pin.
Connecting it to both a 15V and an 8V supply makes absolutely no sense, whereas a 7V voltage drop across 470R implies a current draw from the 4069 of roughly 15mA. That seems plausible.
So, this schematic is ready to being layout
Are you planning to edit a pcb board, or a veroboard ?
- grrrunge
- Diode Debunker
Information
Just to correct myself: It looks like my drawing is correct. Look at the pot numbering and the direction indicating arrowgrrrunge wrote:I think you're right. It's wired backwards in my schematic. Considering this is an inverting amplifier, the gain should rise as more resistance is introduced in the feedback path.morain51 wrote:The volume pot is not wired as the Sunn schematic, but I don't know if it's important.
A true believer in the magic of Sherwood Forest Pedal Pirates
---
New base of operations: http://www.knucklehead.dk
---
New base of operations: http://www.knucklehead.dk
I admit I'm a bit lost with pot numbering. Fortunately, it is very easy to verify when plugging a pedal for the first time (and to correct mistakes )
Just in case, if you want to build a Beta Lead version, you will have to swap the following values in your schematic :
C15 : replace 56n by 22n
C17 : replace 8n2 by 5n
C18 : replace 15n by 8n2
C21 : replace 47n by 27n
I think these are the only differences between the two preamps.
Just in case, if you want to build a Beta Lead version, you will have to swap the following values in your schematic :
C15 : replace 56n by 22n
C17 : replace 8n2 by 5n
C18 : replace 15n by 8n2
C21 : replace 47n by 27n
I think these are the only differences between the two preamps.
Hi guys,
thanks all for the job on this thread
i have the "service manual" and want to make a "lead" version of the grrrunge schem'
so, i'm a bit lost ....
not on the rez/caps values difference but on the IC's
why replace the rc4558 to 4opa ?
is the sound already "legit" with these replacements ?
if anybody have succesfully built one, can you please tell me what IC's u utilised (ref.) and if the grrrunge schem is working?
thanks all for the job on this thread
i have the "service manual" and want to make a "lead" version of the grrrunge schem'
so, i'm a bit lost ....
not on the rez/caps values difference but on the IC's
why replace the rc4558 to 4opa ?
is the sound already "legit" with these replacements ?
if anybody have succesfully built one, can you please tell me what IC's u utilised (ref.) and if the grrrunge schem is working?
- grrrunge
- Diode Debunker
Information
The 4OPA designation is for my own reference only, as the board layout I'm working on uses quad op-amps. 4558 will work fine in this circuit, as will any other general purpose op-amp
A true believer in the magic of Sherwood Forest Pedal Pirates
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New base of operations: http://www.knucklehead.dk
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New base of operations: http://www.knucklehead.dk
- grrrunge
- Diode Debunker
Information
Nope. I haven't had the time recently. Exam preparations and studio-building is what i do most these days.
I'll get around to it eventually
I'll get around to it eventually
A true believer in the magic of Sherwood Forest Pedal Pirates
---
New base of operations: http://www.knucklehead.dk
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New base of operations: http://www.knucklehead.dk