Orange Bass Butler [schematic]
- bajaman
- Old Solderhand
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still very curious about R33 ?
R15 is awfully large value at 470n - are you sure it is this large ?, if so R33 could indeed be a lower resistance value, however this would load Q5 significantly if as low as 30k ? hmmmm
bajaman
R15 is awfully large value at 470n - are you sure it is this large ?, if so R33 could indeed be a lower resistance value, however this would load Q5 significantly if as low as 30k ? hmmmm
bajaman
be kind to all animals - especially human beings
- tuck
- Breadboard Brother
Thonk uses the dots as model marking
Two yellow dots = RoHS compliant VTL5C3
https://www.thonk.co.uk/wp-content/uplo ... 3-RoHs.pdf
I will desolder R33…
I wrote down the value that is printed on the sides. More pictures will follow.
Two yellow dots = RoHS compliant VTL5C3
https://www.thonk.co.uk/wp-content/uplo ... 3-RoHs.pdf
I will desolder R33…
I wrote down the value that is printed on the sides. More pictures will follow.
- tuck
- Breadboard Brother
R33 1,017M
But how are these bands brown?!? Totally greyish not like the other resistors.
The Mid value is 25 because as mentioned the picture was mirrored and it is up side down. The values are printed on the lower side of the pot symbol on the pcb. The top of the 5 is the bottom of the 2.
Mid pins are not shorted.
Be aware that the bottom side of the pins on the top side of the pcb is turned by 180° for the clean channel because the pots are facing another direction than on the dirt channel as you can see on the first page of this thread. I marked pin 1 and 3 for that.
C15 is 470nF
But how are these bands brown?!? Totally greyish not like the other resistors.
The Mid value is 25 because as mentioned the picture was mirrored and it is up side down. The values are printed on the lower side of the pot symbol on the pcb. The top of the 5 is the bottom of the 2.
Mid pins are not shorted.
Be aware that the bottom side of the pins on the top side of the pcb is turned by 180° for the clean channel because the pots are facing another direction than on the dirt channel as you can see on the first page of this thread. I marked pin 1 and 3 for that.
C15 is 470nF
- bajaman
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Excellent work Tuck
so it was 1M !
I wonder why they made C15 so large at 470n ?
47n would have been more than sufficient
SO - here is hopefully the final schematic
cheers
bajaman ps: i notice that all the resistors are mounted the same way around on the board - must be an ocd person that stuffed this board
so it was 1M !
I wonder why they made C15 so large at 470n ?
47n would have been more than sufficient
SO - here is hopefully the final schematic
cheers
bajaman ps: i notice that all the resistors are mounted the same way around on the board - must be an ocd person that stuffed this board
be kind to all animals - especially human beings
- tuck
- Breadboard Brother
Yes temol that's correct.
Unfortunately the pcb manufacturer I order at will send out his free shipping pcbs starting next year
Can't verify until next year... no parts for the breadboard... horrible
Thank you guys for figuring it all out!
This is just great!
PS: somewhere I read that you can see the work of Ade Emsley by looking at the resistor placement
But if there is some OCD going on then why is there no mid control to even out the number of pots?
If one can add one this would be a nice modification.
Unfortunately the pcb manufacturer I order at will send out his free shipping pcbs starting next year
Can't verify until next year... no parts for the breadboard... horrible
Thank you guys for figuring it all out!
This is just great!
PS: somewhere I read that you can see the work of Ade Emsley by looking at the resistor placement
But if there is some OCD going on then why is there no mid control to even out the number of pots?
If one can add one this would be a nice modification.
- bajaman
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ok - my mistake with the mid to bass connection
here is the final schematic
Tuck - the placement of the resistors is strange in many ways - I would keep the feedback resistors and HF compensation capacitors around the op amps MUCH closer to the pins than this
The fact that all the resistors perfectly align with the screen-printing is pure OCD - does Ade know something about 1% metal film resistors like Dumble knew about polyester coupling capacitors ?
Makes it VERY easy to read the colour code on them correctly as they are all the same way round
Adding a mid control to the clean channel can be done by adding another variable filter section around IC2b, but perhaps Ade deemed this unnecessary - or you could always add another dual opamp and build a high mid and low mid section around each like Bob Gallien does in his GK amplifiers - perhaps Ade ran out of board space !
Anyway - thanks for all the work and help in bringing this trace to a final schematic - an interesting concept that could be implemented quite differently by another designer - i am already looking at running the whole circuit from a bipolar 15v power supply using a dc/dc convertor powered by a standard 9v dc dc input, and this may be a good project to occupy my mind over the impending Christmas break
cheers bajaman
here is the final schematic
Tuck - the placement of the resistors is strange in many ways - I would keep the feedback resistors and HF compensation capacitors around the op amps MUCH closer to the pins than this
The fact that all the resistors perfectly align with the screen-printing is pure OCD - does Ade know something about 1% metal film resistors like Dumble knew about polyester coupling capacitors ?
Makes it VERY easy to read the colour code on them correctly as they are all the same way round
Adding a mid control to the clean channel can be done by adding another variable filter section around IC2b, but perhaps Ade deemed this unnecessary - or you could always add another dual opamp and build a high mid and low mid section around each like Bob Gallien does in his GK amplifiers - perhaps Ade ran out of board space !
Anyway - thanks for all the work and help in bringing this trace to a final schematic - an interesting concept that could be implemented quite differently by another designer - i am already looking at running the whole circuit from a bipolar 15v power supply using a dc/dc convertor powered by a standard 9v dc dc input, and this may be a good project to occupy my mind over the impending Christmas break
cheers bajaman
be kind to all animals - especially human beings
- bajaman
- Old Solderhand
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Thank you too Tuck
I have my own very simple and low cost dc/dc convertor circuit using the XL6007 chip - I have already simulated the drive section running on +15v and -15v (had to increase drains to 75k and modify the potential dividers between stages to maintain same gain structure) and the frequency response is identical with approximately 3dB greater headroom - same current draw through the jfets (approximately 120uA)
cheers
bajaman
I have my own very simple and low cost dc/dc convertor circuit using the XL6007 chip - I have already simulated the drive section running on +15v and -15v (had to increase drains to 75k and modify the potential dividers between stages to maintain same gain structure) and the frequency response is identical with approximately 3dB greater headroom - same current draw through the jfets (approximately 120uA)
cheers
bajaman
be kind to all animals - especially human beings
- bajaman
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(PR1 is the first jfet gain stage) - ignore PR6 !
cheers
bajaman
be kind to all animals - especially human beings
- bajaman
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Hi Tuck
How about the gerber and drill files I could not upload in personal message section
Let me know if you need anything more cheers
bajaman
How about the gerber and drill files I could not upload in personal message section
Let me know if you need anything more cheers
bajaman
be kind to all animals - especially human beings
- bajaman
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I just discovered a missing trace on my pcb layout between R80 and R81 !
be kind to all animals - especially human beings
- bajaman
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On the subject of enclosures - the pcb will fit inside a Hammond 1590DD box BUT even using the low profile mini pots , there is still not enough space to fit the two XLR sockets - if you were to use balanced stereo jack sockets there will be enough room but the beauty of using XLR sockets is the ready availability of balanced microphone cables - still you could always build some short adaptor cables using stereo 6mm jacks to male XLRs I suppose
Another problem is the footswitch - it will not fit inside the enclosure unless the pcb is modified and the status leds moved
bajaman
Another problem is the footswitch - it will not fit inside the enclosure unless the pcb is modified and the status leds moved
bajaman
be kind to all animals - especially human beings
- temol
- Solder Soldier
There's something not right around Q1. R4 connected between Gate and Source? Also, the pinout seems to be reversed. Top-right pin of the Q1 it's a Drain and should not be connected with R5.
I haven't checked other transistors yet.
I haven't checked other transistors yet.
- tuck
- Breadboard Brother
That's how it is on the original but i found this on the datasheet:
https://experimentalistsanonymous.com/d ... s/J201.pdf
In another data sheet the drain is on Pin 3
https://www.mouser.de/datasheet/2/308/1 ... 811729.pdf
In another data sheet the drain is on Pin 3
https://www.mouser.de/datasheet/2/308/1 ... 811729.pdf
- tuck
- Breadboard Brother
My mistake, I drew a line to R4 in the early picture but it should connect to R3.
The latest schematic is correct but the PCB not. It was also corect in my first schematic but not in my drawing bajaman made the first layout from.
The latest schematic is correct but the PCB not. It was also corect in my first schematic but not in my drawing bajaman made the first layout from.