Monday, 11 March 2013

Greg Fryer Treble Booster Deluxe

Well built simple Brian May signature booster. And the original unit is reasonably priced, goopless box - so you should concider getting one. Basic info from manufacturer's site:
" Powerful, rich, good treble detail"

• 35 dB gain 
• Punchy rich sound 
• Balance between fatness and treble definition
• Evokes the BM sound of mid 1970s Queen albums "Sheer Heart Attack", "A Day At The Races" and the Brian May 1980s live concert sound.

Adding volume control to the output may be worth a try... (that's 100K log pot, board output to lug 3, lug 2 is your new output and lug 1 to ground...)




28 comments:

  1. Would anyone have a guess how this would go with a BC249?

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  2. Well, tag it :P Works fine. Not really fond of treble boosters, but I liked the "original" concept of this one: no switch, no control pot, always on between your guitar and amp.

    Nice ffect to emaulate Brian May... if you have a VoxAC30 too, of course :P

    BR

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    1. Excellent, nice one mate

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    2. You're welcome!

      Just a question, any special reason to use 2x 10pF instead of just 1x20pF?

      BR

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    3. No idea :) That's just how the original has it.
      +m

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  3. JaviCAP- sometimes it is easier to ask than to waste time and resources building :p

    After comparing datasheets and getting no useful reply here, I built it using the lowest rated 249 I had, and it needs a 239.

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    1. Dennis,

      If I'm not wrong, the BC249 does not exist, or l least, I can't find not the slightest reference anywhere.

      The only one I've foound info is the BD249, and this one is a power transistor. If so, it hardly can work on this circuit.

      Are you sure that you hace a BC249?

      BR

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    2. I don't know what resources you're using, but I've got a bag of them, they're used in a lot of projects, and the first three results in Google are datasheets. Thanks anyway.

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    3. You only get a useful reply Al / Dennis if one of us knows the answer. When it comes to suitability, as long as the transistor you're using are the correct polarity then give it a go. But like Javi I've never heard of it either, and the first 3 results on google aren't datasheets, the first two "imply" there is a datasheet but there isn't one when you go to the page linked. Alldatasheets shows a number that contain the characters "BC249" but one is a burst fire controller and the other three are solid state relays, and datasheetarchive are just material lists which contains reference to the BC249 but no information about them.

      This site encourages DIY absolutely, and that will often include trying things to see if they work and certainly finding your own datasheets if you need to refer to them.

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  4. Are their alternative transistor options for this? I haven't any BC239...but some 2N5088/89 and some other general purpose...are they interchangeable? I'm still gathering my knowledge on transistors :)

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    1. 2N5088 or 2N3904 will be fine. You could try any NPN Si transistor in there. Just mind the pinout. 2N transistors are more commonly EBC, while BC ones are CBE.
      +m

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    2. Thanks Miro,

      So I'm trouble shooting this thing with a probe...and it's blowing my mind that I'm having issues with what should be pretty straight forward. I get audio signal from the both ends of the 6.8nf and the 1K but only from the top of the 100K and 1nf. The 2.2k, the 22k, and the 47uf all have signal at the top but none at the bottom and there's no signal getting to the right side of the board...my traces and cuts appear to be fine, ran a razor between the lines and reflowed...any idea what might be causing my signal to die off?

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    3. My bad - the 2.2, 22, and 47 DON'T have signal at all, top or otherwise.

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    4. So you don't have a signal on the base of the transistor? Usual suspects would be wrong value or one component place to wrong holes. You should be getting the signal to the base via that 1K resistor. Then it should come out amplified at the collector...
      +m

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    5. Man! I've been all up and down this thing and it's killing me...resistor values check out, caps checkout, placement checks out...the signal gets to the Base, but doesn't go from the Emitter or Collector...I'm just going to build a second one from scratch and see if that works then go back and follow that signal path.

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    6. Are you sure about the transistor pinout? What voltages are you reading on base, emitter and collector?
      +m

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    7. I checked the datasheet for direction...I switched direction just to be sure. The datasheet showed CBE would be the flat of the 2N3409 facing right according to the layout. I made a second and it's doing the exact same thing...I must be making one incredibly obvious error or something, but appear to be powerfully oblivious to it. The voltages all read in the same area but I'm not sure if I'm doing it right. I socketed the transistor...that wouldn't matter right?

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    8. No. It should work as intended with a socket.. You should not have the same voltage on all the transistor pins...
      +m

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  5. Done qnd working, I used a BC550C. It works and boosts well, although I find it's non properly a treble booster, high frequencies are not so clear as expected. Maybe a capacitor, I used a 47uF in place of 33uF:-(

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  6. I've just built this and it sounds fantastic! Many thanks!

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  7. I built a version of this recently, but using the layout of the Brian May Boost from Paul in the Lab. I substituted a 10kA pot for the 6.8k resistor, similar to the GGG Brian May Boost or a Rangemaster. I also 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.

    I added a switch so I could disconnect the 180k and 4n7 from the output, to be more like the original Brian May boost. These parts filter out some of the fizz when the circuit is driven hard, but disconnecting them adds a bit of sparkle when the signal is clean. This switch would go in place of the far right jumper on this layout.

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  8. Do the value of the electrolytics really matter? Or are they just filter caps?

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    1. No. Those are just ripple filters. 1x 100µ should be just fine. Circuits like these are usually prone to supply ripple noise..
      +m

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    2. Okay cool. Two things, the 10pf caps, can those be omitted? I can't find any laying around and this is the only layout I've seen with those included! Also, would a 2n2222 be the best option for the transistor? Works well in the naga viper... I do also have BC108's, 2n3904, 2n5088, and a few others...

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    3. They're included to filter some noise out of your input. You can change the top left cap to a link and just use a small value cap for the right one. 33pf e.g.. OR leave them out altogether and see how it sounds but being a treble boost it's probably worth putting something in there.

      As for your transistors...use a socket, mind the pinout and go to town. Thats the joy of DIY.

      Good luck

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    4. So to omit them would I just leave them off? Or jumper the top left one?

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    5. Yes you can just omit them and it'll work fine. But if you want to add a single cap instead of 2....replace one of them with a link/jumper and the other with your desired cap value. Doesn't matter which.

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