"A box later" Dumble
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"A box later" Dumble
Anyone know anything about this little box? I'm guessing it's a Dumbleator with a fixed gain? It looks cheesy however it is a real Dumble item
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Ryan
https://www.thetonegeek.com/
https://www.thetonegeek.com/
Re: "A box later" Dumble
This picture has been floating around for years..I got it about 10 years ago and it came with a "Do not post on the Amp Garage"
At the time I got it I was told what it was but cannot remember, Possibly a transistor version of a Dumbleator IIRC
Tony
At the time I got it I was told what it was but cannot remember, Possibly a transistor version of a Dumbleator IIRCTony
" The psychics on my bench is the same as Dumble'"
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professormudd
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Re: "A box later" Dumble
Looks like it was posted to tumblr by John Mayer. The original post is gone, but here is a reblog: https://jenmayerbabe-blog.tumblr.com/po ... -box-later
-Matt
It may very well be that the sole purpose of your life is only to serve as a warning to others.
It may very well be that the sole purpose of your life is only to serve as a warning to others.
Re: "A box later" Dumble
Interesting!! That's my understanding as well. Curious if any new info came out since then.
Ryan
https://www.thetonegeek.com/
https://www.thetonegeek.com/
Re: "A box later" Dumble
Thank you for the link!!! This is super helpful actually because there is a mystery pedal by JHS on John's board and I had a hunch it was a Dumbleator of sorts since the name of it "box a lator" or something very similarly named that appears to have a loop incorporated.professormudd wrote: ↑Wed Sep 08, 2021 3:19 pm Looks like it was posted to tumblr by John Mayer. The original post is gone, but here is a reblog: https://jenmayerbabe-blog.tumblr.com/po ... -box-later
Ryan
https://www.thetonegeek.com/
https://www.thetonegeek.com/
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norburybrook
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Re: "A box later" Dumble
lol I was thinking the same thing. I think it's a J201 adaptation which I don't think Dumble would have really used but it's not off the table I suppose. I'm guessing it's his typical 18v FET inside. Maybe two of them....norburybrook wrote: ↑Thu Sep 09, 2021 1:36 pm Kleinulator
https://www.andertons.co.uk/guitar-dept ... ffer-pedal
M
Ryan
https://www.thetonegeek.com/
https://www.thetonegeek.com/
Re: "A box later" Dumble
Happy New Year everyone!!
I am revisiting this after some thoughts on and off over the last year or so getting to know more about the circuits made available by the community. I don't think the electronic circuit books that Dumble referenced back when the "a box later" was built (guessing circa 70's?) had simple tube-to-jfet adaptations like the Kleinulator. So either the enclosure itself has a standard tube Dlator inside (looking at the screws and spacing could accommodate a transformer assuming the brown cable is a 117vac outlet?)
OR
Perhaps he is using 2x Dumble FET circuits? One for send, the other for return. I know Keeley's Katana (pedalPCB schematic) has two JFETs back to back where the send/return could be in the middle, along with a 3m3 resistor on the return. Sticking with the Dumble FET approach for a minute, would the Dumble NTE452 JFET be suitable for such application in an enclosure like this? Assuming the step-down transformer kicks around 18vdc.... I am also attaching a JFET Loop design that follows my logic, I think...
I'll draw up a schematic during my lunch break today of the double Dumble FET thing if that helps with the conversation too... I have a few NTE452 on the way
-Ryan
I am revisiting this after some thoughts on and off over the last year or so getting to know more about the circuits made available by the community. I don't think the electronic circuit books that Dumble referenced back when the "a box later" was built (guessing circa 70's?) had simple tube-to-jfet adaptations like the Kleinulator. So either the enclosure itself has a standard tube Dlator inside (looking at the screws and spacing could accommodate a transformer assuming the brown cable is a 117vac outlet?)
OR
Perhaps he is using 2x Dumble FET circuits? One for send, the other for return. I know Keeley's Katana (pedalPCB schematic) has two JFETs back to back where the send/return could be in the middle, along with a 3m3 resistor on the return. Sticking with the Dumble FET approach for a minute, would the Dumble NTE452 JFET be suitable for such application in an enclosure like this? Assuming the step-down transformer kicks around 18vdc.... I am also attaching a JFET Loop design that follows my logic, I think...
I'll draw up a schematic during my lunch break today of the double Dumble FET thing if that helps with the conversation too... I have a few NTE452 on the way
-Ryan
You do not have the required permissions to view the files attached to this post.
Ryan
https://www.thetonegeek.com/
https://www.thetonegeek.com/
Re: "A box later" Dumble
Hey Ryan,
I think you are on the right track. It's going to be all speculation unless someone decides to share more info or pictures. Personally, I am pretty well convinced it is solid state rather than tube based.
Attached is my marked up picture. I have always thought the screws in the red were the transformer. Yellow was the power supply circuit board and green the signal circuit board. But who knows....
With max voltage for the NTE452 from Drain to Source of something like 30v, you could operate this at a higher voltage for better headroom. Probably worth breaking out the breadboard and playing around a bit.
-Dan
I think you are on the right track. It's going to be all speculation unless someone decides to share more info or pictures. Personally, I am pretty well convinced it is solid state rather than tube based.
Attached is my marked up picture. I have always thought the screws in the red were the transformer. Yellow was the power supply circuit board and green the signal circuit board. But who knows....
With max voltage for the NTE452 from Drain to Source of something like 30v, you could operate this at a higher voltage for better headroom. Probably worth breaking out the breadboard and playing around a bit.
-Dan
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Re: "A box later" Dumble
Thanks, Dan! Just the extra confidence I need to keep this thing going! I was thinking the exact same with your potential board and transformer layout! This could be a fun one! Standby for more...dbharris wrote: ↑Tue Jan 02, 2024 4:23 pm Hey Ryan,
I think you are on the right track. It's going to be all speculation unless someone decides to share more info or pictures. Personally, I am pretty well convinced it is solid state rather than tube based.
Attached is my marked up picture. I have always thought the screws in the red were the transformer. Yellow was the power supply circuit board and green the signal circuit board. But who knows....
With max voltage for the NTE452 from Drain to Source of something like 30v, you could operate this at a higher voltage for better headroom. Probably worth breaking out the breadboard and playing around a bit.
-Dan
Ryan
https://www.thetonegeek.com/
https://www.thetonegeek.com/
Re: "A box later" Dumble
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Re: "A box later" Dumble
This is great Ayan. Thanks so much.
Quick guess: regulated symmetrical power supply (two standing boards), opamp based loop.
Or am I being captain obvious now?
Quick guess: regulated symmetrical power supply (two standing boards), opamp based loop.
Or am I being captain obvious now?
Re: "A box later" Dumble
Certainly looks that way. Maybe TL072 would be a good candidate? I think you could run that with a bipolar supply of +/-15V or maybe keep it to +/-12V to be safe.
-Dan
-Dan
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Bombacaototal
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Re: "A box later" Dumble
Ayan, cannot thank you enough!!! This is absolutely out of this world! Appreciate the contribution