this is one of the best treble boosters I've built and I've built alot of them being a Brian May fan.
this was traced from the circuit board and I have made 2 changes (that don't affect the sound)
1. in the original there are 2 power supply capacitors (47uf and 33uf) in parallel which was obviously used to keep production costs down - Greg will have initially put in the standard 100 uf capacitor but if his other pedals/products used 33uf and 47uf caps - it would have been cheaper to just parallel a couple of those up to get near enough.
2. the other change is that there are 2 10pf capacitors in series again this will be a production cost thing - it would be cheaper to use 2 10pf capacitors in series than adding 1 4.7pf cap to the build (if he used a lot of 10pf capacitors in other builds which he most probably will do.)
so with those changes noted: it sounds no different to the original unit but you can always swap them if you don't believe me.
Hi,
ReplyDeleteI was just wondering if you could clear something up for me as there are a lot of missing details.
1) The capacitors C4 and C6 don't have their rated voltage on the diagram, but I notice in the picture that one of them is rated to 35v. Is this really necessary as I have some 25v ones?
2) Is the pot connected to the input or output of the circuit and what value/taper are you using?
3) What type is capacitor is C7? Is it mylar?
Any help would be much appreciated. Cheers
1. as long as it's 16v or over it's fine. for future reference if voltages are not mentioned you always assume it's whatever is higher than the supply voltage by 5 or more volts (for safety)
ReplyDeleteanytime when this is not the case will always be mentioned separately (this is common in power amplifier circuits for example)
2. the taper is linear and the value doesn't matter and there's not a pot on the original but I used 100k
3. it's a polyester film cap but it's not essential I just thought it looked nicer - the original uses ceramics and electrolytics only.
Thank you for your reply and answers
ReplyDeleteThe only thing you didn't answer was whether the pot is connected to the input or output?
Cheers
sorry yeah - it's the output
DeleteThanks a lot. I've finished building this over the last few days and it sounds AMAZING! Thanks for sharing
DeleteI know, it's the best T booster I've ever built and I've done quite a few.
Deletedon't forget to send me a picture for the pictures section (also put your name with it!)
The clear coat on the enclosure is still curing, but after that I'll be assembling it properly and will be sure to email you a picture when it's complete!
DeleteThis looks like a great project and I've collected everything I need. One last question about the level pot, though. From the picture, it looks like the center lug connects to the output of the board, one side lug to the tip of the output plug, but the third lug is hidden. Does it go to ground? Apologies if this is an obvious question.
ReplyDeleteyes that's correct - 1-board output 2.output socket 3. ground
DeleteThanks! I'll get building.
DeleteIf you do this pot wiring, you will take the stomp switch out from the circuit. So, I think 1: Board output, 2: Stomp switch (below where pole goes to the output socket) 3: ground
DeleteJust put it together and it sounds very cool. Thanks so much for putting this design together and sharing!
ReplyDeletemake sure you send a picture for the pictures section!
DeleteHi
ReplyDeleteHow many hFE have the bc239 on the Fryer's booster?
it doesn't matter - HFE is really not important.
Deletewhat is important is that you use a BC239 Transistor and it will sound right.
you can also experiment with other transistors if you want - I've had good results using old
germaniums but the BC239 is the one to use to get the correct sound
Changing the hfe value will change the gain, or not?
DeleteI've tried this one and I seem to have trouble with the making. The pedal works but when I turn it on, the signal is very weak. It has the smooth overdrive but it's very weak. I've used the same components as listed. Where did I go wrong? Any idea?
ReplyDeleteI really can't answer that without the board in front of me.
DeleteI am having the same problem, i tried changing the transistor and the 100uf capacitor. Are those related to the power of the output, or should i try something else?
DeleteHello! Thank you for your circuits, first of all.
ReplyDeleteI am a little puzzled comparing the schematics and the board layout. In the layout, the output is connected to the transistor collector, while in the schematics, there is a capacitor and a resistor between them. What should I follow? The jumper in column 6 is also connecting the collector to another point of the circuit that is not described in the schematics.
I managed to make some deviations and built my prototype based on the schematics and also sounded weaker than I expected, like the comment above, maybe because of the 560R resistor?
Cheers, Alexandre
you should read the tips and troubleshooting page http://www.paulinthelab.com/p/tips-and-troubleshooting.html
Deletein case there are any other parts of the stripboard diagram you don't understand.
but yes - as you discovered in your second comment, the red squares denote cut tracks
I got it. I haven't considered the breaks on the tracks. (actually I did't understand what the red squares meant, in the first place!)
ReplyDeleteWill focus now on the weak output. When I have anything new, I will post to you.
Do you have any additional images/drawings of the wiring?
ReplyDeleteI'd like to build this booster, but without the level pot, or the power switch. My soldering and direction following skills are good but my electronics knowledge is very weak. So if I'm looking at this correctly
ReplyDelete1) 9v + goes to "9v"... does 9v- go to GND?
2) Input socket tip goes to "IN", sleeve must go to GND?
3) Output socket tip goes to "OUT", sleeve goes to GND?
4) To omit switch and pot, do I need to omit any resistors on the stripboard layout, or change anything?
1) yes
Delete2) that is correct
3) again, correct!
4) the switch and pot are just things I added because there were holes in the box for them
they aren't in the original so no, you don't need to change anything.
your electronics knowledge isn't as weak as you thought :)
Groan. Well, I just built it and it isn't working. :/ Now comes the unenviable task of trouble shooting. It passes signal but seems to reduce the gain a little (perhaps it's just reducing the bass) without actually adding any boost.
DeleteMy solution was just to rebuild it. This time it does work, but it doesn't seem to have the massive gain boost that my "range maistro brian may boost" had. It definitely boosts the mid/treble but much more contolled and not noisy at all. I wonder if I'm not getting the right voltage or if this booster is supposed to sound more controlled?
Deletewell - it is a low gain pedal that is designed to go into flat out AC30s but unless I hear yours I won't really be able to tell if it sounds right
DeleteI won't be able to really test it out but I don't *think* there's anything wrong with it. Again, though, my old booster would add a ton of volume (if the master wasn't dimed) in addition to cleaning up the bottom end. THis one just really cleans it up and makes the overdrive sing.
DeleteIs there any way to test the output to see if it's correct?
DeleteHey Paul
ReplyDeleteI have built a few various treble boosters and as a fellow Dr May nut, I am interested in doing this one but I have a couple of questions...
I really am a novice to building pedals and have learnt a lot from you and other sites so forgive my naivety but here goes...
The units I have built so far have included a bc109c transistor (by personal choice). How would this work in this unit? Would it give a bit more gain compared to the bc239?
Have you tried the Plus version? I believe that has a bit more oomph to it and as I loved BM's sound during the late 70's era, I wonder what the difference are in the schematics of the deluxe and the plus.
Finally, if I built it as per your layout but used a plastic enclosure, would I have to ground the pot??
Thanks a million mate and keep educating us :)
I'm not sure how the 109 would perform but I imagine it would give a bit more gain because it is a higher gain transistor (as I'm sure you know)
DeleteI'd say try it out - it'll certainly do something. (just check the pinout)
I've tried all the GF pedals - I just can't find schematics for them - I had to trace the schematic from the PCB in my deluxe and risk wrecking it just to do this one!
you would still have to ground the pot yes. it is better to use metal cases where possible because they keep the hum/noise out - I use sweet/mint tins for testing to see if I want to spend the money on a proper enclosure
Thanks for that. I have the parts and done some research on the sound the original makes and I can't wait to build it. One more thing, I've built other TB's where you can add a toggle switch so you can change the type of boost. This has been via the instructions and it is a nice option. So, if I wanted to do this with this unit, could I piggy back the switch off of the C1 cap??
ReplyDeleteOk, I built it last night with the bc109c and it sounds..... WOW!! and that is just through a crappy little 5w transistor amp that I use for testing. I'm gonna run it through my main rig today and I can't wait :).
ReplyDeleteIt really is the best sounding booster that I have tried/built so thanks again for sharing!!
I might try that myself - in fact I might just have a big transistor session - I've got boxes of the things. I'll have to try a germanium too. though I'm not too keen on using them because they aren't consistent. they sound amazing at the right temperature but go abit hot or cold and bleh!
DeleteDid you try various transistors? I need something with a touch more oomph than a bc109 as my Marshall dsl's crunch channel is a touch lighter then I want. The OD channel is too distorted. This booster has got me an inch away from having a glorious sound but its still a tad weak with my set up. A bit more gain will do it for me. Other than that, it sounds amazing and my live sound (I play theatres) has benefited from your work :) Cheers.
DeleteHi,
ReplyDeleteLooks nice, but could you draw the wiring of the input, output, switch and so on ? as all wires are black, it's not so easy... I'd like to it, but don't see how to connect exactly the battery switch if any, or the switch.....
if fact in general shame that the vero board is displayed, but not the wiring... ok it't not always needed especially for the battery.... ;o)
Many thanks for your site by the way.... looks pretty good and helpfull to go back to electronic DIY as a long time ago....
http://www.paulinthelab.com/2014/10/guitar-fx-switching-diagrams.html
DeleteI would second the above, it would be useful to us beginners to have a sketch showing the wired connections to the switch battery led and sockets. Just discovered your site and its great thanks for sharing your expertise.
ReplyDeletehttp://www.paulinthelab.com/2014/10/guitar-fx-switching-diagrams.html
Deleteyep just found it, but can you draw it with the 3pdt please ? I suppose this is the switching in the above link and also the battery switch to power on the treble booster when activated. Am I right ? By the way, no way to find a 3pdt footswitch in france... had to order in from UK. Strange world...
DeleteHi again, which box size did you use approx ? thanks !
ReplyDeleteit was just a junk one I had lying around - it's a 125B Enclosure
Deletebut I imagine you could get it into a smaller one
Hi Paul
ReplyDeleteThanks so much for this. I built one a few months ago and it has replaced my TS-9 on my board. Awesome booster!!! Ok, I decided to make another one but with a switchable type of boost (I did this on another TB and it worked fine). I fitted a on-on switch in place of C1 and put the 6.8nf cap onto one side of the switch and a 0.01uf cap on the other side. Is this the filter cap cos sod all happens! In fact, the whole thing seems a tad weak and there is no associated TB hiss (there is plenty on the other one I built :) ). Am I doing something wrong?
Thanks mate
Thanks for the info regarding the off board connections. I built this as a first project and its probably too scruffy to post pictures of but I was amazed - it worked first time - I never really fancied a treble booster but having read that Brian May uses one constantly I was curious and when I stumbled across your site I decided to make it and I am not disappointed it really enhances the sound as well as boosting it. I will be using this latest addition a lot! Everybody should have one.
ReplyDeleteThanks again for taking the time to post your projects, having built one I can certainly attest to their accuracy.
Peter T.
Hi Paul
ReplyDeleteThe pedal is excellent. I realized that consumes the battery all the time. is this normal? even when the guitar is not connected. thanks
if you haven't wired it up using a switching jack then it will use the battery all of the time - I don't really bother with batteries, I just use a power supply
DeleteHi Paul
ReplyDeleteGreat stuff - nice clean layout. I'm not a fan of vero as it all becomes a bit squashed but I really enjoyed this build. I didn't have an R2 (120k) so I used a 150k. As an amateur and build these like jigsaws with no understanding of what's going on, do you think this will make much tonal difference?
Kind Regards
thanks - I spend a lot of time trying to get the presentation of the layout nice as well as just making it work. I too hate messy circuits!
Deletethere might be a little difference because that part of the circuit shapes the sound so to speak. I would have put a 100K and a 22K in series but ultimately - if you like how it sounds now then that's all that matters
Right, well I'm pretty sure I have these values so I'll do a before and after video and post to YouTube. I've just checked and unfortunately, I don't have a spare AC30 in my toy room but I do have a Line 6 solid state Crapulator and a Marshall MA100C tube thing (which is amazing ONCE you learn how to dial it in).
ReplyDeleteSo, what I'm trying to say is, do I need to be putting it through a tube amp turned up to 11 to get the best out of it?
Deletenot really no. I use a behringer V-amp pro for all of my recording (and it sounds like this https://soundcloud.com/pstevenson/double-negative-lhit-life-lyndrome )
DeleteI am very much of the opinion that valve amps give instant gratification but are a pain in the arse to record and DSP stuff is the other way around.
this pedal sounds good no matter what you plug it into
Hi Paul, I am the one that used a bc109c transistor. I decided to get the original transistor and build a new one. I tested it out at a show in Birmingham on Saturday and I was completely blown away. Due to size of the venue, I had to forgo my board and just had guitar, booster and Marshall stack and it still sounded enormous! Thanks again for mate!!
ReplyDeletethey do sound absolutely amazing when you're playing loud - I'm glad you're having a good time with it!
DeleteDear Paul.
ReplyDeleteThanks for sharing the circuit layout with all of us. I love it. People like you make the difference!
I would like to share some modifications that change the sound.
The peak of the treble boost can be altered C1 = 4n7 (shift to higher frequencies), 6n8 (actual value), 9n1 (shift to lower frequencies) and in combination with the transistor type. This result is most probably known to all of you. Another mechanism works as follows:
The top end of the boosted curve on the output side is additionally shaped via the low-pass filter R7, R8 and C7. Many treble boosters do not have this low-pass filter and may sound a little too harsh on the top end. By cutting off high frequencies, the boosted curve is rounded and the output becomes smoother to listen to. However, if the cutoff frequency is too low, brilliance gets lost.
In order to see what I mean, compare the sound of the actual values of R7, R8 and C7 with the values from below. You will notice that the brilliance is increased and the sound becomes brighter. Personally, I like a) very much.
a) R7 and R8 unchanged, set C7 = 1n0 (higher cut-off frequency, more brilliancy because the middle frequencies are preserved)
b) Set R7 = 0 Ohm and remove R8 and C7 (low-pass deactivated, even more brilliant)
Another easy trick to prevent the loss of high frequencies and to preserve brilliance is of course the setup: Guitar -> Treble Booster -> Cable -> Effects -> Amplifier.
When I experimented with values, I used IC sockets (3 pin) that I cut in half. This way I was able to easily change the transistors, capacitators and resistors.
Cheers,
Torben
Hi Paul, I'm not sure if my previous comment got through via the google approach. Many thanks for this, and all you do. Your sight is excellent and informative. I built the booster and it works, I really like the tone, I'm a big fan of boosters in general. I decided to add the volume on the output and get an interesting effect as the volume to maximum, suddenly a hash of hf hiss and noise jumps in. Is it possible that this is some sort of parasitic effect as the output reaches a certain level capable of causing coupling elsewhere in the circuit? Its quite odd. I really enjoy it when something throws out an odd, or interesting unexpected to behaviour its usually the source of much learning. Cheers from North Wales! p.s. Loving your music on soundcloud!
ReplyDeleteno, it's because with a level control; you're putting a resistor in parallel with the 180K resistor and effectively changing the way the filter in the circuit works when you turn it - on mine I put the level control on the input rather than the output to "simulate" how Brian would use it on his guitar (controlling the gain with his guitars volume control)
DeleteI was in North Wales last month as it happens!
Ah right thanks for the reply appreciate it! Well, to try and avoid changing the voltage at the collector I subbed the pot for that resistor, piggy backing it with a resistor to get the value right. I wanted to try and preserve the sound of the guitar clipping even with the output reduced, somewhat like the supposed Richie Blackmore Hornby Skewes mod, so that when playing with different bands and venues at different volumes I can balance it with my non master valve amp. I agree with one of your comments above though, a valve amp is immediately gratifying but a total burden if you cant get it in the 'sweet spot' from a gain staging point of view. Ive been using a tech21 trademark 60, d.i'd for smaller gigs where I need more control and it reacts surprisingly well to boosters. I'm very mpressed with the sounds you're getting from the Behringer. Thanks again!
DeleteHello,
ReplyDeleteThanks for a very nice and informative web page!
Transistor BC239 with the addition C, will it make the job too? I have searched the net for info,and probably it works, but do you know?
Thanks for your help!
yes it will work - just check the pinout
DeleteThis comment has been removed by the author.
ReplyDeleteHello, I am from Argentina, I want to know the difference between the greg fryer treble booster and the brian may treble booster that you have in your site, because I was able to build the latter, although I know absolutely nothing about electronics, and I wanted to know if its worth to build this one.
ReplyDeletethe "brian may treble booster" is the one his father made for him when his original rangemaster got stolen.
Deletethe fryer one is Brians current treble booster and was designed to achieve the sound heard on the albums from late 70s through the 80s
basically it sounds fatter and has a bit more gain.
I am a massive Brian May fan so to me - it's worth building!
Thank you so much for your answer!! And it was real fast!! As you are obviously a BM fan, if you are interested, take a look at my guitar at http://www.fotolog.com/put_out_the_fire/53834590/
DeleteBye!
This comment has been removed by the author.
ReplyDeleteJust dropping by to say that this booster is awesome. Finished my build today, had to use different tranny since the shop was out of stock on BC239 (I used BC183), still sounds very decent. I recorded a small demo with my strat and a battery operated Vox Amplug AC30. Not quite Brian May, but I love the sound anyway. http://roihaj.mbnet.fi/troublebooster.mp3
ReplyDeletethat's cool dude, I recently got an AC30 and the first thing I did was plug this pedal into it and it just blew me away
DeleteHi and thanks for your info here. I really want to build this pedal and have read a lot to increase my ability to try and do this. I am a beginner though so please forgive my ignorance but except for the c4 and c6 caps, does it matter what direction I put the others in? From what I read only the electrolytic caps are polarized? But i have read so much lately Im having a hard time getting things to stick. Thank you!
ReplyDeleteyes - there's a little line of shading that denotes the negative side of the capacitor.
Deletethere's a little stripboard diagram on this page that might help http://www.paulinthelab.com/p/tips-and-troubleshooting.html
Thank you, Paul. I noticed that, and also the + symbol on your schematic. That part I understand :) I also understand that resistors you can place either way.
DeleteI mean the other parts, like the 6.8nf 4.7pf (c1 and c2), the 1nF and the others. The lettering on the caps in your pic face different
ways so it has me wondering.
Do *they* have to face a certain way? Again, sorry for the noob questions, I just want to try and do it right and am kinda nervous, hehe.
Thanks again, man!
I read that resistors can face either way.
aye that's right - the green oval ones can go either way - it's just the electrolytics that need to the right way.
Deleteit's better to ask and appear a noob than not ask and have an electrolytic blow up in your face
Hi Paul, and thanks for the replies. Indeed, very true.
ReplyDeleteAnother question: I noticed that R7 is a 560R ... I ended up getting a 560K, at least that's what my sticker says. Can I use this one without problem, or will I have to order a 560R again? Thank you!
I'm afraid you'll have to get the right resistor - if you have 2 spare 1K resistors you could put them in parallel and do it that way
DeleteThanks.
ReplyDeleteI do have two 1k resistors availible, but no idea how to put them in parallel on the board. Would I put them in 2 tracks next to eachother? :/
I've done a picture to show you (link below) - for future reference; there's a specific equation to get resistances from more than one resistor but basically if you have 2 resistors of the same value; when you put them in parallel it will halve the value IE 2 1K resistors will be 500R (ohms)
Deletepicture;
https://2.bp.blogspot.com/-fZFNNTCGadA/VtcSeK2WFlI/AAAAAAAABos/8Jtqv6-eqrc/s1600/P1060311.jpg
Ah, thanks Paul, for taking your time and effort into helping me (us all) out. This is great. This is sort of what I had come to the conclusion to, but wasn't sure if it was "legit". So basically, just solder two 1k resistors together (one clinging onto the others leg), then stick both of them in the R7 track?
Deleteaye that's it
DeletePaul, once again thank you for your help!
DeleteI completed it, and man....it's great! I am a big May fan also, and I absolutely love it. You rock!
I'm glad it worked for you!
DeleteI've done a few of Brians boosters including this one that his dad made for him when his rangemaster got stolen
http://www.paulinthelab.com/2014/04/brian-may-treble-booster-stripboard.html
Hi,
ReplyDeletethis boost is incredible ! I put 2N5088 and it is amazing, the amount of boost is crazy !
Many Thanks !
I'm glad you like it - I've tried a few trannys in it but not that one yet, I'll have to give it a go
DeleteCiao Paul! Congratulation for your website!! I would like to build a simple treble booster as the original Greg Fryer version, without volume knob, DC power supply, LED and footswitch. I have understood the layout remains the same but if it is so where should I connect the second GND exit?. The first GND goes to the IN Jack socket (sleeve pin), right? The second GND goes to the OUT Jack socket (sleeve pin)?
ReplyDeleteThanks in advance for your help!
Ciao from Italy!
Michele
both GNDs are the same - I just put the second one on there to go to the power jack/battery so the wiring is a bit tidier
DeleteHey Paul.
ReplyDeleteI build this as my first pedal project and had a good time with it, learned a lot from reading your stuff here.
Question though: I didn't install a volume knob on it (undecided if I want it) but this boost seems massively loud and my question is, is it supposed to be? I realize you can't check without seeing my circuit but is there any kind of wiring or soldering I could've done "wrong" to cause it to be louder than it should? Or, maybe it's just the way the boost is? However, with the volume at 2-3 on my solid state Laney it really rattles the house. Granted, in a good way. But still, thought I'd ask.
it's meant to be loud, you have to remember that this circuit is from the days before overdrive was really used so it went in front of a clean amp.
Deleteas for the volume control, the only reason I added one was because the enclosure was from something else and it had a hole in it for a control.
Brian Mays doesn't have a volume, he just uses his guitars volume control
Thanks, Paul. Just checking, since it was my first proper circuit.
DeleteYeah, the volume control. I haven't decided on it. I did want to try and keep it without at first just like Brian. I do love the sound from it though and I thank you once again for your time and answers here. :)
Hi Paul.
ReplyDeletefirst of all: thank you so much for this incredible unit: it's really easy to build and sounds amazing. I built two already, one as a pedal and I put the other one into a plastic cigarette box velcroed to my guitar strap (pretty close to the thing brian uses).
One question, though: with the BMG-Red Special guitar it sounds really amazing, but with a Strat the sound can get really harsh.
How can I modify the booster to keep the top end just like it is but allow a little more bass/mids to get through so that the overall sound becomes more even?
That would really great to know.
Again, thank you so much for the layout
Cheers from Germany
Although you mentioned that you have not seen the diagram for the treble booster plus version, could you speculate what changes could have been done in the circuit if they retained the same BC239 transistor? Following Greg Fryer description this version it has more vowel sound, more midrange, more gain
ReplyDeleteI imagine the only difference would be the 4.7pf capacitor
DeleteGreat sounding booster. Is it possible to change this circuit to allow it to run on 3V - 5V instead of 9V? What value components would I need to change?
ReplyDeleteBest regards,
Paul
Hi Paul. I've built a couple of these and they sound amazing. Thanks for sharing. I have a problem with my new one though and maybe its a basic answer but I hope you can help. I plugged the new one in and it works perfectly, the led lights and the snowstorm sound was there. After a minute or so, I picked the pedal up and it was very warm so I took the battery out only to find it was very hot. What can be causing this as the circuit is very simple that it shouldn't draw that much power from the battery as my others have been fine. I'm scratching my head as it shouldn't work at all if there is a short in the circuit. Cheers mate
ReplyDeleteG'day Paul and viewers of this site. I'm not sure if these comments are still be monitored, but on the off chance they are I just wanted to thank you for all the work you've put in over the years on your projects and sharing them with everyone ! I tried this board this week and the first board failed. I noticed I'd put in a 4.7pF in C7 instead of 4.7nF for some reason. I started a completely new board and this one doesn't work either. I cut the tracks first and checked with a multimeter to see if there was a join still and they are cut correctly. I don't have and dry joins. I've run a scalpel along the track gaps as recommended in the Tip's section. I've changed the input jack, output jack, batteries and I am still not getting anything coming through the project. This is my first time trying a Stripboard project so I'm lost as to what I've done wrong. I've checked all solder points for correct placement and the orientation of C6 and C4. I soldered one component at a time while building up the board so I wouldn't get lost in each position. I hope I can work this out because I want to continue on to make other projects you've been so kind to share. This one in particular will be great as I've just made my second "Deacy" amp out of vintage PA speaker enclosures using a 0.5watt amp kit. Anyway, things are great when they work but frustrating when you don't know why they don't.
ReplyDeleteHi Paul, and thanks for all your projects.
ReplyDeleteI have a couple of question (consider that I have completely no knowledge of electronics, so sorry if those questions are stupids):
1 - Can I use a 5nf capacitor instead of 4,7nf?
2 - The only bc239 transistor I've found is a bc239b, could it be right?
Thank you, and thanks again!
Hi Paul
ReplyDeleteIt's possible to have the complete schematic including wiring to the Jack IN, OUT and DC?
I'm sorry but I'm not very practical in these stuff :-)I would be very grateful.
Thank you so much.
Gianvito
Hi Paul,
ReplyDeleteGreat music, I listen to through the strip all the time and 'Ben's song' always brings a tear!
I am building this version of the Fryer TB and was wondering what the collector bias voltage is for this silicon transistor? All the info on the net only says half Vcc/Battery voltage but I know from research that biasses the transistor to the middle of it's linear swing to avoid distortion. Do I want this tranny biased more toward 'cut off' like the OC44? at 7volts please?
I received a Brian May Red Special guitar for Xmas (yeah, I'm a lucky guy) and wanted a more authentic-sounding TB to go with the new guitar. I just finished a breadboard prototype of this circuit. I put a 700k resistor in parallel with an a250k pot in place of the 180k output resistor to act as a volume control.
ReplyDeleteI'm also using +17V instead of +9V, yielding just under 36db of relatively clean boost, at full volume. Pumping that into my AC30 modeling amp and this sounds incredible. Thanks, very much, for sharing this schematic! Easily the best TB I've ever used!
Cool proyect. i put together the circuit and sounds very cool. Thanks
ReplyDeleteThe actual correct transistor is the BC 149! It's the only one Brian used in all of his Queen years with Freddie!!!
ReplyDelete