Electronics Projects For Hobbyists Makers And Hackers With Stripboard Layouts
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Thursday, 3 April 2014
Brian May Treble Booster Stripboard Veroboard Layout
This is one I built years ago - lost - then decided to build again cause I loved it.
this is supposedly the treble booster Brian Mays dad built for Brian when his original Rangemaster got stolen.
I built this recently, substituting a 10kA pot for the fixed 10k resistor, similar to the GGG Brian May Boost or a Rangemaster. I used a NOS BC182L as in the original Brian May schematics. It worked OK but distorted a lot when the guitar volume was up all the way, and not in a good way. The hfe of the BC182L was around 160, which seemed reasonable, but I experimented with higher and lower gain parts. I finally settled on a 2N2369 with hfe around 55. Sounds great now, with a bit of grit when the guitar is up all the way. Good grit. The slope of the roll-off doesn't seem as steep as other treble boosters, so it doesn't sound as thin.
that 10K resistor is a bias resistor - you may damage the transistor putting a pot there. usually the pots would go after C7 shown in this diagram http://4.bp.blogspot.com/-lyoZcePjL4o/Uiz3hlZxwCI/AAAAAAAAAsw/x5fvC25Rt6A/s1600/Pot+Wiring.jpg but it's cool you're actually experimenting with things ! this particular project was one of the very first things I made for personal use back in the 90's because I was (and still am) a massive Queen fan as I'm sure you are if you're building Brian May pedals!
I'll be building this badlad tonight but I don't have any BC182's. I've ordered some but in the meantime, as I socket all my trannies (make your own jokes), could I use a BC239 as in the Greg Fryer TB?
hi everyone :D I've built my own pedal following the schematic by Paul (THANK YOU SO MUCH FOR SHARE THIS PEDAL :D), I have just a question, Can someone help me for the wiring??? Pics are welcome :D Thank you so much guys
Hi Paul, hope you are well? I am curious as to where you got the schematic for this build. Is it from something you've traced that sounds like it comes from the famous Pasty area of the UK circa '83?
You could try a 100K audio pot. However other, very similar, designs use a pot in place of the 10 K bias resistor (R7), wire it so that it is still acting as a bias resistor (using the outer pins) with the "volume" control tapped off the middle pin. The original diagram had a 6.8K resistor in this location, so you could approximate this using a 22K pot in parallel with a fixed 10K resistor (the combined resistance is 6.9K, close enough).
I built this recently, substituting a 10kA pot for the fixed 10k resistor, similar to the GGG Brian May Boost or a Rangemaster. I used a NOS BC182L as in the original Brian May schematics. It worked OK but distorted a lot when the guitar volume was up all the way, and not in a good way. The hfe of the BC182L was around 160, which seemed reasonable, but I experimented with higher and lower gain parts. I finally settled on a 2N2369 with hfe around 55. Sounds great now, with a bit of grit when the guitar is up all the way. Good grit. The slope of the roll-off doesn't seem as steep as other treble boosters, so it doesn't sound as thin.
ReplyDeletethat 10K resistor is a bias resistor - you may damage the transistor putting a pot there.
Deleteusually the pots would go after C7 shown in this diagram http://4.bp.blogspot.com/-lyoZcePjL4o/Uiz3hlZxwCI/AAAAAAAAAsw/x5fvC25Rt6A/s1600/Pot+Wiring.jpg
but it's cool you're actually experimenting with things !
this particular project was one of the very first things I made for personal use back in the 90's because I was (and still am) a massive Queen fan as I'm sure you are if you're building Brian May pedals!
I'll be building this badlad tonight but I don't have any BC182's. I've ordered some but in the meantime, as I socket all my trannies (make your own jokes), could I use a BC239 as in the Greg Fryer TB?
ReplyDeleteyeah it will work, just make sure you get the pinouts right - they are probably different.
Deletehi everyone :D
ReplyDeleteI've built my own pedal following the schematic by Paul (THANK YOU SO MUCH FOR SHARE THIS PEDAL :D), I have just a question, Can someone help me for the wiring??? Pics are welcome :D Thank you so much guys
Valentino
Hi Paul, hope you are well? I am curious as to where you got the schematic for this build. Is it from something you've traced that sounds like it comes from the famous Pasty area of the UK circa '83?
ReplyDeleteIf I wanted to add a pot on the output would anyone know what value log pot? 100k or 10k? Thanks!
ReplyDeleteYou could try a 100K audio pot. However other, very similar, designs use a pot in place of the 10 K bias resistor (R7), wire it so that it is still acting as a bias resistor (using the outer pins) with the "volume" control tapped off the middle pin. The original diagram had a 6.8K resistor in this location, so you could approximate this using a 22K pot in parallel with a fixed 10K resistor (the combined resistance is 6.9K, close enough).
Delete