Mad Professor - Royal Blue Overdrive

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
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pamaz
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Post by pamaz »

hello all.
Somebody out there has any info that is willing to share?
Thanks

Paolo

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miter53
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Post by miter53 »

bump

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Dingleberry
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Post by Dingleberry »

Found a gut shot from a Japanese site. Not much but at least something.
Attachments
royal blue.jpg
Simplify before you amplify.

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BJF
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Post by BJF »

Hi there,
Right, well what do you want to know?

At your sincere service
BJ

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jamesdlow
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Post by jamesdlow »

BJF wrote:Hi there,
Right, well what do you want to know?

At your sincere service
BJ
Not the original poster but I have a few questions.

1) Looks like a bufferless TS style circuit with passive tone right?

2) I know you often use extended feedback loops around the opamps. Any of these at work here?

3) What frequency ranges are your tone and bass pots working at?

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BJF
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Post by BJF »

Hi There James,
1) if you wish- actually using limiting diodes in the feedback loop is much older than that ;)
2) yes and that one is to limit the HiFi treble-sadly at my age or from rocking too hard in my leathers as it says on the internetz I no longer hear these super sonic frequencies but I know they are there and I can count on them from memory of better hearing days. The way the filter works here is that it feeds back a portion of the highest frequencies and nulls them at the inverting input. The whole point being to have some of the treble present but restricting treble a little.

3) Treble makes boost and cut at about 2KHz but boost is made milder by allowing some upper mids by the aid of the 3-dB filter; Bass makes near symmetrical boost cut at about 100Hz while high pass occours in the circuit at about 70Hz bending the boost downwards at lowest frequencies. The notch created at full boost is centered at about 750Hz and that also makes the peak when in full cut.

At your service
BJ

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Skreddy
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Post by Skreddy »

Blah blah blah Where's the perfboard layout, Bjorn!?! :lol:

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BJF
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Post by BJF »

Hi there,

Actually I was wondering about the correct spelling of blah for the press release of my latest Fuzz:
It sounds like blah and behaves like blah, when you blah it. :hmmm:

Oh I'd be sure someone will do the honours with perfboard :thumbsup

Have fun
BJ
BJFElectronics
Sweden

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HamishR
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Post by HamishR »

I have one of these and would be interested in the circuit so I can build an "inspired by the Royal Blue overdrive" pedal. I'm not very good at drawing schematics but I can list all of the components and give and indication where they join if that helps? I tend not to like LEDs as clipping diodes, so they would be the first thing I would change. I think it's actually a very cool pedal. I like having bass and treble controls much better than nature knobs. :-)

Is anyone else interested in how this thing ticks?

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HamishR
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Post by HamishR »

Today I swapped the LEDs out for 1N4148 diodes and I like it a lot better. I'm also sure that a lot of guys would prefer the LEDs! I like the 4148s because they make the sound a bit crisper. They seem to have made the pedal a bit more "rock" to me. Really good overdrive.

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modman
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Post by modman »

HamishR wrote:Today I swapped the LEDs out for 1N4148 diodes and I like it a lot better. I'm also sure that a lot of guys would prefer the LEDs! I like the 4148s because they make the sound a bit crisper. They seem to have made the pedal a bit more "rock" to me. Really good overdrive.
Thanks so much for those pictures!
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lovetone
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Post by lovetone »

Just wondering if anyone has the schematic to the Royal Blue overdrive?

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cbriere
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Post by cbriere »

Any progress to get the schematics or pcb photos of this pedal? thanks.

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