Hi All
Any of you guys that have read any of my posts know that I'm a big fan of the Brian May tone. So, I've built the ROG May Queen, various treble boosters, the fOXX phaser and loads more fun stuff.
One schematic that I've never seen is the Cornish TB-83 treble booster. There are plenty of Range Master schematics and Fryer TB layouts etc. floating around on that there internet but no Cornish.
Does anyone have a schematic or gut shots or any leads on this one?
(http://www.guitarexperience.co.uk/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/t/b/tb-83x_duplex_front_.jpg)
Well, of course it is a dual Treble Booster, but I can't say more than it. :(
I think there is a standard TB-83 and then the Extra is just two in one box. :icon_lol:
I think so.
And the TB-83's schematic? ??? This is the problem, it isn't?
QuoteAnd the TB-83's schematic? ??? This is the problem, it isn't?
Exactly. Or some gut shots would be nice!
Quote from: nickbungus on December 21, 2015, 07:35:54 AM
QuoteAnd the TB-83's schematic? ??? This is the problem, it isn't?
Exactly. Or some gut shots would be nice!
For the sweepstake, I'd like to put my money on "Something well known, slightly modified". He's generally a great horse, and usually a good runner in races like this.
Sorry not to be able to help more. Let me know when the results are in so I can cash the chitty.
Tom
Quote from: ElectricDruid on December 21, 2015, 08:25:45 AM
For the sweepstake, I'd like to put my money on "Something well known, slightly modified". He's generally a great horse, and usually a good runner in races like this.
Sorry not to be able to help more. Let me know when the results are in so I can cash the chitty.
Tom
Cheers Tom. I have no idea what you are talking about though. Cryptic ???
I always just assumed it was the Fryer May style treble booster. Not sure where I got that idea but I never questioned it until now.
This article seems to verify what Bill says:
http://www.petecornish.co.uk/queen.html (http://www.petecornish.co.uk/queen.html)
Edit- maybe not, it says that the CornishTB-83 is the same that Pete designed for Brian May
Quote from: Bill Mountain on December 21, 2015, 10:23:11 AM
I always just assumed it was the Fryer May style treble booster. Not sure where I got that idea but I never questioned it until now.
I once thought the same but having read a few bits here and there I don't think that's the case. It would be interesting to find out
QuoteI'd like to put my money on "Something well known, slightly modified".
QuoteCheers Tom. I have no idea what you are talking about though. Cryptic ???
i think he means it's probably say, a rangemaster for instance, with a tweak here or there.
Quote from: garcho on December 21, 2015, 12:16:39 PM
QuoteI'd like to put my money on "Something well known, slightly modified".
QuoteCheers Tom. I have no idea what you are talking about though. Cryptic ???
i think he means it's probably say, a rangemaster for instance, with a tweak here or there.
Thanks Garcho, that's exactly what I meant. But without at least a guts shot, we can't even start to guess what it might be related to.
Look for the Guild Brian May treble boost schematic there was a Guild one on the web in the past. Could this be the same circuit?
Found a site http://www.next.gr/circuits/guild-brian-may-box-l32329.html (http://www.next.gr/circuits/guild-brian-may-box-l32329.html)
Thanks Gus. I've considered this too, although without a gut shot or schematic we'll never know.
Best I build one just in case! ;D
This is just from a post on some forum (http://www.vintageamps.com/plexiboard/viewtopic.php?f=6&t=40999#p1032619), but if this guy has his facts right it is interesting stuff regarding the Guild Brian May box.
Quote
What you have here is a 1993 Guild Brian May treble booster, this was put on the market along with the Guild Brian May Red Special Pro guitar. The good dr. May has used a treblebooster of some sort during his whole career from the earliest known Queen recordings till today. Starting out with a modded Rangemaster, he later had Pete Cornish build him a unit which can be heard on most of the Queen and solo albums. In the mid-nineties he switched from Cornish to Fryer trebleboosters and more recent to KAT strapboosters specialy designed for the use with a wireless system.
There are many clones available that are mostly based on the Cornish TB-83 and you get the best result with the booster in a Vox AC30 using the 'normal' channel.
The Guild booster was claimed to be an exact clone of the TB-83 but turned out to be a bit of a dissapointment.
I've owned one since it first came out and have tested it against a Rangemaster clone, an Electrolead TB1 and a Covington Fireplace Classic. The Fireplace does sound the same as the TB-1, but it seems to be just a bit louder. The Rangemaster is a very nice pedal as well but does give a different tone, not as smooth as the trebleboosters.
...and the Guild booster, well, it does have a nice sound, but it's nowhere near the Electrolead or the Covington
Gus, I built the Guild one. I didn't have any MPS8098's so I tried a few different trannies. 2n5088s seemed the best although I was always trying them in pairs of the same sort. I could probably try different combos too but overall it isn't the best treble booster I've built.
This may sound sacrilegious to some but maybe removing the Cornish Buffer and just leaving the treble booster might help.
Anyway, I think I've built most treble boosters available online and I think the Covington one is the best even with its strange pot wiring and unnecessary resistors.
A confirmed schematic of the TB-83 still alludes me though.
I am not surprised at your post about the Guild build
A bootstrapped buffer can have a high input resistance.
A link http://www.diystompboxes.com/smfforum/index.php?topic=93834.msg808080#msg808080 (http://www.diystompboxes.com/smfforum/index.php?topic=93834.msg808080#msg808080)
Some screenshots of sims I posted before guitar volume at max(no series resistance) and tone at max treble Green is 10K Blue is 100k red is 470K etc.
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=47874&g2_serialNumber=1)
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=47877&g2_serialNumber=1)
Note with the bootstrapped buffer you would want to EQ out the upper resonance and then use a standard treble boost after
HOWEVER the upper resonance can disappear with series resistance (50K) as you turn down the volume the resistance part from input to wiper is in series with what follows so
as you turn down the volume control you will still not have the same interaction with a passive guitar to cable to a non buffered low input resistance treble boost
To wrap this thread up and to confirm what I had expected all along, a friend had just sent me a YouTube link. The clip is from Greg Covington of Covington pedals comparing his Treble Booster to the Cornish TB-83.
I believe the Covingon treble booster (http://www.diystompboxes.com/smfforum/index.php?topic=112665.0)is nearly a 100% clone of the Cornish. I think he's tried to add anti-pop resistors and also the gain pot (to the model I traced), but I'm pretty sure he's just taken the TB-83 apart and traced it.
It looks like I might be able to get a lend of one. As you can see below it looks like its going to be hard to get to. Has anyone got experience of opening something like this up? Will I be able to do it and then put it back together?
(https://docs.google.com/uc?id=1gsSx_49RTVLluFrp1Y8HNuInjzY302EJ)
Quote from: nickbungus on January 14, 2019, 04:15:16 AM
It looks like I might be able to get a lend of one. As you can see below it looks like its going to be hard to get to. Has anyone got experience of opening something like this up? Will I be able to do it and then put it back together?
(https://docs.google.com/uc?id=1gsSx_49RTVLluFrp1Y8HNuInjzY302EJ)
Back years ago I used to work in the repairs department of a company making dataloggers for the utility industries. Most of those were potted, so repair work meant digging out the potting to get to likely faults. It *can* be done using a scalpel to cut the potting and a sharpened flathead screwdriver to dig it out, but it's a risky process and it helps a lot if you already know what's underneath and where so that you can go gently in sensitive spots.
If the potting box itself is plastic, you might do best by cutting that off the outside so you can work in from all directions.
It's a risk though. If it was my unit, I'd try it, but I don't think I'd do it to anyone else's.
HTH,
Tom
Thanks Tom, I'm picking it up tomorrow. I'll reassess when I have it.
Ok - So I ended up buying it and I'm on a soak it overnight (acetone), scalpel, repeat system but its slow going. I am yet to excavate a component. I have however got a clean view of the copper/solder bottom.
(https://docs.google.com/uc?id=1yEBtr2QjZP5NYxHtSxGBulHIfMtZwYlR)
Now I know its a RangeMaster clone with an NPN tranny in it (probably silicon) and I also know that Greg Covington probably cloned it and in another post I traced that, so heres the schematic of the trace:
(https://docs.google.com/uc?id=1PlkEHMVLjgXbLNnuX67_tEjaDtCuOPq5)
So we determined there are some unnecessary components that seem to be antipop resistors and power filtering, so bearing that in mind I think the layout is something like this.
(https://docs.google.com/uc?id=1BbKtdDrf1UXqVgDAoxsZU2f08y7SsAGU)
There is that dirty big diode that I have left off that you can see on the previous images. I'm pretty sure I am wasting my time really as I doubt I will find anything I wasn't expecting but that need to know has consumed me!
Was wondering if anyone thinks I've got the layout right as Tom said, it helps to know where things are before I start mining?
Can someone please tell me the purpose of r10 is on the schematic above and tell me what difference a larger value would make and a lower one?
Thanks guys
its the same schematic that the greg fryer treble booster, in that its a silicon rangemaster slight modified with two rc filter at the output to smoothering a little, the 150k and 47 form a rc for 20 hz, and in the case of greg fryer there is another rc of 4,7n and 560r to filter very high freq its look like your schematic is lacking the resistor, witout it the 4,7 cap has no sens I think....
the 1m resistor its obviously a pull down, the same at the input, the two electros in parallel are to filter( its look like he dont have another cap ) :icon_lol:....c5 it will be the canonical 1n...
Good job on taking the time and effort to deggooping a tb83, I have looking since forever to build me one and I am just about to built a greg fryer on vero, but I suspect that the vero will serve me equally.... I will wait to know your findings... Which tranny it will use?? i bet the bc239...
Lookin forward to hear you Nick!!!
Thnks for your time
Quote from: nickbungus on January 27, 2019, 05:03:30 PM
Can someone please tell me the purpose of r10 is on the schematic above and tell me what difference a larger value would make and a lower one?
It doesn't make much sense, since it's in parallel with R9. The resulting value is what you get from the familiar "parallel resistors" calculation, and it might as well be a single resistor.
That assumes the diagram is correct. When I see things like that, I think "mistake!". In that case, I'd first assume that the lower end of R10 actually connects to the upper end of R9, in which case R10/C7 make a LPF to trim highs. But that gives 225Hz, which is a bit ridiculous. Back to square one.
So... perhaps it's the lower end C7 which goes to the upper end of R9, in which case it's a HPF at 225Hz. That'd trim some mains hums, and also tend to emphasise the "treble booster" sound by backing off the fundamental of the lower notes of the guitar.
That's my take on it. There are three possible situations there. You'll have to pick the one you like best!
HTH,
Tom
Sorry - just to clear something up, the Cornish TB-83 does NOT have the 1M(R9) in parallel. I think this was a Covington mod in an attempt to reduce switch popping (same as R4).
it would be great if we can get a grasp on how cornish does the wiring, how he does the wiring layout, he seem to use shielded cable in all the conections inside his pedals, I wonder too if he does the star ground thing.
Nick, the unit do you have is the one without pot isnt??
I understand that in the case of the cornish unit, r10 with c6 form a highpass at 23 hz....
What a BIG box for such a little circuit!
If you look at the schematic for the Covington and then look at TB-83 layout, the part numbers that I've labelled in overlay match. I did get R10 and C7 the wrong way round but that doesnt change anything.
The cabling isnt shielded and I dont understand star grounding but my overlay should tell you.
Quote from: Ben N on January 29, 2019, 01:02:54 PM
What a BIG box for such a little circuit!
Its because its battery only so most of the enclosure is jacks and battery space
Thanks Nick for all, so in the tb83 at the output we only have c6, c7 and r10 itsnt??.
Are you going to degoop the side of the component?? To check values and tranny id?? Are you going to post more pics of it??
Best regards
A good way to remove epoxy is by using the appropriate solvents, acetone is not very effective. You should give a try with DMSO (Dimethyl sulfoxide,use appropriate precautions, butyl gloves and avoiding inhaling it) and a heat gun.
The best way I know for effectively removing cured epoxy is using DMSO in a mix with pyridine, but it will also destroy plastic packages.
Quote from: Frabbio on February 10, 2019, 07:59:12 AM
A good way to remove epoxy is by using the appropriate solvents, acetone is not very effective. You should give a try with DMSO (Dimethyl sulfoxide,use appropriate precautions, butyl gloves and avoiding inhaling it) and a heat gun.
The best way I know for effectively removing cured epoxy is using DMSO in a mix with pyridine, but it will also destroy plastic packages.
Ah, interesting. Mrs Resynthesis uses DMSO at work, hmmm
Thanks Guys
I managed to scrape it all of going slowly using acetone and alcohol. I used acetone to soften it up and the alcohol on myself (mmm Heineken!)
I'm just testing a few things but I will be posting my findings very soon!
Quote from: Resynthesis on February 11, 2019, 05:13:59 AM
Mrs Resynthesis uses DMSO at work, hmmm
Well, whatever it takes to get you through till five o'clock, I suppose! I've never heard of it, but I'm sure it beats a couple of beers at lunchtime.
;)
Greg fryer in his blog, give us a clue about the cornish one in his "tri-trebleboost" proyect https://fryerguitars.wordpress.com/pedals-tech/
Check this!!
Seems similar to what I've got. I was questioning the 47k resistor from output to ground on my Cornish but that seems to confirm it.
I've got much bigger values for the electrolytic caps. I've no markings but the power filter one measures 137uf and the other one measures 87.
A bad 150uf and a bad 100uf?
A good 120uf and a very good 68uf?
An excessively "good" 100uf and a fair 82uf?
I've built a clone and used a 150uf and a 100uf. Sounded the same.
Oh. And the tranny is a bc549c but to be honest I was trying others and it didn't make much difference.
I keep meaning to draw it all up but I've been busy at work.
The power filter cap wont have any effect on the sound whatever value it have, and the cap on the emiter of the tranny its suspicious to be 100 u, i think its not the most critical...
Nick, the cornish booster do you have, it has pot? Where is attached??
no pot
Ok, thanks. I will do it with a pot. Time to figure if go by the route of a 10 k pot instead of rhe 6k8 or a 50k pot instead of the 47 k resistor..
What is the value of C5?
1n
I'm also happy that the electrolytics are 100uF and 47uF.
100 uf for the power caq filter and 47 for the emiter one?
Yes. I bought some axial ones and sizes seemed to match what I took off. Perhaps I'd damaged the originals slightly during the removal of the epoxy.
I've got some images that need a bit if tidying (a layout and the schematic)
ok, great¡¡ its look like you already have it almost nailed.
So in the end, the cap at the emitter it musnt be critical, because some post below you toll us that you try it with 100 instead of 47uf and sounded identical...
Hi Nick,
Sorry I was trying to understand this thread, (well done getting hold of the Cornish by the way) but, have you uncovered the components, or are these details being deduced from Covington's pedal you had before? Thanks!
Yeah I've got it. I'll post the schematic tomorrow as it's on my work pc
Ooh interesting! Excellent, looking forward to this! Time to get the soldering iron out...
Here you go!!! The most underwhelming experience after spending so much time scrapping off all the epoxy.
(https://docs.google.com/uc?id=1mzLn_MaEtaaTtrSJiNnwAfKuvv8hlCL_)
Thanks for this Nick, good work. Believe me, your efforts have not been wasted - finally, the actual Cornish circuit for all to see. It may not be surprising or unexpected, but we know for sure now!
Thanks!
The led clr resistor(r1) was obviously added by me and not present and the tranny was a BC549c. I've built a few replacing the R11 with a 10k pot, wiper to c6 and it worked
really well. I'll assume the Extra did this.
(https://images.reverb.com/image/upload/s--LtuzjXmH--/a_exif,c_limit,e_unsharp_mask:80,f_auto,fl_progressive,g_south,h_620,q_90,w_620/v1470844699/dk1z3jkeh9zv2oyuz3wx.jpg)
Excellent!
Do you have a pic of the components on the board?
No worries if not, just would be cool to have a look at Mr Cornish's work 8)
You'll need to mirror before etching. C7 and R10 were actually the other way round on the board
(https://docs.google.com/uc?id=1oUlhppgiBdER-4gH07fMb_xtvTxdJxC-)
Heres a rough translation of the board. It uses axial caps for the electrolytics.
(https://docs.google.com/uc?id=1BbKtdDrf1UXqVgDAoxsZU2f08y7SsAGU)
Great work Nick, thanks again for this!
Yes so it turns out that the link posted previously in this thread, pointing to Fryer's website, with a schematic for a "TB-83-ish" (part of the 3-in-1 booster), is in fact an actual TB-83
Yes it was correct but we didnt know for sure. Now we do!
I guess Fryer can't fool us :icon_lol:
I'm thinking...... FIGHT!!!
Greg Fryer vs Pete Cornish
Thank you very much Nick, a hell of a good work!!
I am gonna build it with a pot too, the 10k pot on r11 is a safe bet, but a 50 k pot instead of r10, I think is too a usual way to put a ot on a treble booster, at least its done this way by many makers...
So, in your opinion, Nick, how you compare the three principal "may" boosters, the fryer, covington, and cornish? If you d be hard pressed to choose one, which one would be??
I would discount the Covington as its just a TB-83 clone with some misguided antipop resistors.
I keep meaning to make a super boost that has a rotary switch that swaps between the Fryer and the Cornish. I'd probably add a switch to swap between the BC182 and BC549c too. I think I read somewhere the the Fryer Touring (or was it the Delux) was meant to be a TB-83 work alike.
I think for most of the 70s BM used a Rangemaster, so I would add that to the list. And the Rangemaster does sound noticeably different to my ears.
I think my favourite period of Brian Mays tone is the early 80s (albeit their music declined around that period) when he was using a TB83 and also a Boss CE-1 chorus. The CE-1 has this weird preamp/boost section and I've found his tone to be more saturated/distorted around this period.
(https://skypeguitarlessonsonline.com/wp-content/uploads/Brian-May-Stage-Rig-and-Pedal-setup-696x522.jpg)
Hello Nick, very interesting the switching between the two boosters...other thing that it would be great to swicht is the input cap, I dont know if the 10n cap its too much bass, the fryer have a 6n8..
Hi Nick,
I'd emailed Pete Cornish himself while on the hunt for details about the TB-83, and asked about the switch over between Rangemaster and TB-83, here are his words:
I still have my notebook with circuit designs from 1971 to 1975 and the Treble Boost I designed for Queen was done between 1972 and 1974 although the exact date was not recorded.
I did not make the TB-83 Extra until later in the '70s but BM was definitely using the Extra in 1981 but always in conjunction with a permanently in line TB-83, with the TB-83 Extra added for solos.
The TB-83 Extra has identical circuitry to the TB-83 but has the addition of an Output Volume Control and Bypass switch.
I would suggest that a TB-83 plus a TB-83 Extra will give you the result you are looking for.
So looks like the TB-83 was 72-74 sometime. By the way the result I was looking for was the Bohemian Rhapsody solo.
Hope this helps somewhat with dates...
I think you need to build a deacy amp (http://www.deacyamp.com/download/KAT_Projects/KAT%20Deacy-Style%20Amplifier%20Unit%20Project/KAT%20Project%201%20Watt%20Deacy-Style%20Amplifier%20Unit.pdf) then as well.
I know the deacy was often used in conjunction with a c-ocked wah.
Also, I own one of those Digitech Brian May things and the manual (https://3e7777c294b9bcaa5486-bc95634e606bab3d0a267a5a7901c44d.ssl.cf2.rackcdn.com/product_documents/documents/100_1289592854/RS_Manual_Final_original.pdf)says this about the BoRhap solo setting:
QuoteBased on the vocal-like and sustaining guitar tone from the first solo. The Red Special (with neck and middle pickups turned on and out of phase) is plugged into a treble booster and a VoxTM AC30.
But heres friend who said he recorded it using the Deacy Mode on the Digitech
https://www.facebook.com/josef.camilleri.54/videos/10156455137713520/?__tn__=%2CdC-R-R&eid=ARBMgfNM9ywWfdLEb4AMhlHpfXzMTzD56mu2xJ3gB-6qROoQQAjw0gfXkmsj5rfERn2WpA7FAsq6eiCs&hc_ref=ARR7uC_1AvTGvQ51X83gwEjJ6wGhfaNjWigWadlKOpxJgaTswWdnijC2gLoxmZV3emo&fref=nf (https://www.facebook.com/josef.camilleri.54/videos/10156455137713520/?__tn__=%2CdC-R-R&eid=ARBMgfNM9ywWfdLEb4AMhlHpfXzMTzD56mu2xJ3gB-6qROoQQAjw0gfXkmsj5rfERn2WpA7FAsq6eiCs&hc_ref=ARR7uC_1AvTGvQ51X83gwEjJ6wGhfaNjWigWadlKOpxJgaTswWdnijC2gLoxmZV3emo&fref=nf)
Deacy or AC30???
Aaarggh who knows?! So many builds so little time haha! Yes this certainly sounds pretty authentic and I have heard before someone else saying it was the Deacy. I obviously have no option but to build the ac30 and the Deacy to be sure haha
Deacy or AC30? FIGHT!!!!!! :icon_lol:
just throwing this out there:
how can you replicate his tone without considering the signal path on their recordings? think how much money people throw at a Neve channel strip, it ain't because it's perfectly transparent. calrec/sst/etc. channel compressors, eq etc., not to mention the mastering process. how do you listen to his music? the radio compresses the hell out of everything, CDs are obviously hi-fi (enough not to have to argue the point) but is your amp? your speakers? LPs have their own filtering, not mention cassettes. i don't see how you could ever get a clear picture of his "tone" without considering these elements. maybe i'm missing the point...
Hi Garcho,
Yep spot on, I agree 100%. If we're taking Bohemian Rhapsody solo as an example (and I was using this as an example to Mr Cornish to narrow down treble booster configurations), I've also heard the sound was partly achieved by multi-miking and deliberately inducing phase cancellations.
No, this actual tone is never going to be available to me. I'm not going to buy a Neve or record everything in the same way, in the same room, through the same mics and components (nice if I could...)
I don't think you're missing the point really, you're right, those things shape the sound we eventually hear at home enormously. I don't know about the others on here, but I'm just looking for a similar tone to come out of the amp speaker. So, using a BM guitar, sixpence and picking technique, Cornish treble booster and an AC30 it won't be far off.
The 'Brian May tone' to me is these elements alone, instantly recognisable. Any parts of the signal between my fingers and the speaker that I can get right, I'll try for that at least.
hope i didn't come off prickish and condescending, just an engineer so i guess i'm a little over eager to stand up for my compadres ;) also, i've read a lot of posts here that go like this "i built ____ because i really love _____'s tone but it doesn't sound right." Then by the end of the thread, it's usually something like "guess I'll give up".
i like your attitude, especially about the pick, such an overlooked part of the chain. and i meant to say before wow, congrats on communicating with Mr Cornish, what a brilliant and obscurely obvious thing to do, and he rewarded you with useful information even, bravo!
Not at all! No worries! :icon_biggrin:
Yes it's easy for people to get bogged down in trying too hard to do the impossible and not appreciating the bits they can do.
Nick has done well also getting the schematic down and he has built some of the phasers etc I believe to get the other missing bits of his tone.
I'm currently playing through a small Orange practice amp, and I'm happy with it for now. Even that sounds a bit Brian May-ish on the right settings.
But one day I shall build the normal channel of an AC30 because I think that's something I can realistically afford and be able to do.
Ps, Pete Cornish is surprisingly easy to get hold of! :icon_lol:
Saying this, I have found the schematic for the 1073 online...
Tempting...
QuoteSaying this, I have found the schematic for the 1073 online...
Tempting...
ha!
there's this:
http://www.gyraf.dk/gy_pd/ssl/ssl.htm (http://www.gyraf.dk/gy_pd/ssl/ssl.htm)
Ok looks like I'm going to be busy haha
Nick, you probably know this by now, but the super booster you were talking about that would switch between the Cornish and the Fryer, apparently is now available - they beat you to it I'm afraid! BM guitars now sells one that switches between 70s 80s and 90s sound, presumably translating as rangemaster, Cornish and Fryer!
Link:
http://shop.brianmayguitars.co.uk/bmg-accessories/bmg-tb-classic.html
Its not a problem, was never meant to be a commercial thing anyway. Thanks for the link though
No worries! Could still be fun to try and do your own custom one anyway :icon_biggrin:
Why dont you just get a TS?
(runs for cover)