Happy Holidays from runoffgroove.com!
Thor is a redesigned and improved version of the Thunderchief circuit. It much more accurately resembles the character of the legendary Marshall Super Lead sound. Check it out: http://runoffgroove.com/thor.html
Also, we are holding a contest for the best Thor sound clip. Submissions must be an mp3, with a maximum file size of 1MB. Please e-mail your sound clips and all the recording setup information to the address at the bottom of the page linked above. Results will be announced by February 1, 2007. The winning sound clip will be posted as the official sound clip for Thor and the winner will also get a sneak peek at the next runoffgroove.com project.
Thank you for the christmas gift! great new ideas in your new creation. Thank you!
1) Awesome! :o
2) Dammit! I just etched and started building a Thunderchief 2 days ago. :icon_rolleyes:
:icon_twisted: YEAH!!! :icon_twisted:
Did your research happen to identify how the Super Bass differed from the Super Lead? Could a "Bass Thor" be just a matter of substituting components?
Yes, I am thinking of emulating a Chris Squire sound...
Thanks,
-- T. G. --
Hey B Tremblay, thanks yet again for another Amp sim. circuit! ;D
Did your research happen to identify how the Super Bass differed from the Super Lead? Could a "Bass Thor" be just a matter of substituting components?
I believe the Super Bass Schematic would be available, it is simply a matter of printing one or both, then noting...what is probably mostly value differences in components, most often larger cap values to let more bass through. Not that Chris hasn't had his SB modded, or that every SB has exactly the same values, this could probably be researched...
@@R@te, my estimation is that an emulation is a good bet at trying to gett a Bass Sounding a certain way..then just tune the circuit...like someone would an amp for certain bass guitar, I haven't read "Thor" text....next, there's probably a tweek or two in there you could pass over to the Jfet SB emu, for bass, possibly shooting for lower gain ... I dunno!...build some fairly easy to get to gain mods [like start with source resistors longlegged so you can piggyback parallel R for the smaller R value testing there] trimpot drains, try hi/lower gain Q's, make accomodations for voicing series SP Caps, LP filters which tap signal and shunt to ground are generally very easily accomodated as afterthoughts.
For a "Super Bass" change the 1n to 10n drop the 470p and decrease the 100n at the output to 220n or bigger, maybe a additional samll bypasscap on the 1st FET is needed (if the Thor sound somewhat like a SLP from the the first years, it's all you must do).
Stephan Möller has spent alot of time comparing the reaction and distortion of Fets and preamp tubes, he published the results somewhere on the www. Interesting article and he decided to use ICs and diodeclippers for the AC30 sim instead of Fets.
BTW:
Marshall changed the SLP and SB circuit in details quite often from '66 to '70, used different tubes and brands, trannies, changed the anode voltage .... All SLPs I've played sound quite different, so mod the Thor to your personal liking.
JHS
Looks great! Thanks guys! I think Ill givr a try this week end.
Bump for another great addition at ROG. Will try a perf layout as my own little present for Xmas.
Thanks guy's nice xmas pressie :D
MM.
Music to my ears... 'new at runoffgroove.com'... ;D
Can't wait to build this one!!
Thanks, as always, to ROG for their excellent contributions...
Mike
Nice work. :icon_wink:
The active filter idea is a good one- Coincidentally, I came up with a very similar idea for a design I've been working on for a few weeks.
Quote from: tommy.genes on December 21, 2006, 09:28:23 AM
Did your research happen to identify how the Super Bass differed from the Super Lead? Could a "Bass Thor" be just a matter of substituting components?
Yes to the first question. And yes to the second.
The Super Bass is essentially the same as the JTM45. The shared cathode design of the early leads also were very similar. You won't be able to work out the cathode resistor for the first stage without jumping through some hoops, but you can simply change the source bypass caps to a larger value like you'll see on the Super Bass schematic. You'll also need to increase the sizes of the coupling caps as seen on the Super Bass schematic.
If you aren't sure what to do, shoot an e-mail to the RoG contact address. I'll help you out.
Doug, I love your sig line! That's funny stuff!
Happy Holidays!
Great Stuff. :icon_cool:
It's great to see such enthusiasm from everyone. Thanks!
I should point out that for a sound clip to be eligible in the contest, it must be recorded using the circuit exactly as shown on the schematic. If you ABSOLUTELY must deviate, please explicitly indicate the changes that were made when you e-mail the clip.
We do not want to limit creativity by imposing audio samples using the exact version of the circuit, but it is quite obvious that a clip of a modded circuit will not be totally representative of the circuit itself. Nevertheless, we are open (and eager) to receive the suggestions/improvements/mods that you find when building your own THOR.
Also, it is very important to accurately indicate your recording setup for each audio clip, as different gear has different sonic characteristics. Please consider including information such as:
1) Type and location of the pickup(s) used
2) Knob and switch settings for THOR
3) If any other effect is active in the chain
4) Which amplifier & speaker type you are using, or if a cabsim was used
5) Postprocessing effects used (such as reverb)
6) Any other relevant information that might apply
Just to remember everybody that there is great variation in parameters when it comes to FETs in general (JFETs and MOSFETs).
As we wanted to make sure the circuit would be reproducible by other builders (one of the shortcomings that had the Thunderchief), we specifically chose "average" J201's and 2N5457's. The J201's had a Vp between -0.8 and -0.9V, while the 2N5457's had a Vp around -1.6V, both quite representative of the devices we've seen so far. It is not mandatory to measure your devices, but if in doubt or if you feel like it, the Fetzer Valve article provides additional information on how to do this.
Perhaps the main difficulty some builders will face is having a single type of JFET available. This will of course affect the sound of your build, not necessarily in a negative way, so just consider these guidelines:
1) When using a J201 in the first stage, use the drain and source components as indicated for the second stage. You will have more overall gain.
2) When using a 2N5457 in the second stage, use the drain and source components as indicated for the first stage. Install a 10u capacitor in parallel with the source resistor so as to compensate the lower gain of this stage.
3) When you replace the 2N5457's by J201's in the third stage the clipping will be somewhat harder.
4) Tune bias for the first and second stages as indicated in the schem first and then fine tune by ear as desired.
To MikeH: The light side of having a Thunderchief nearly done is that you can compare it side by side with Thor and see which you like best, and of course, tell us back!
Thanks for the Super Bass replies. It will surely be into next year before I get to play with this, but I will report what I find.
-- T. G. --
Nice job fellas!
I always look forward to new offerings from ROG with great interest.
Thanks for sharing! :icon_wink:
Being the sick gain pig that I am, I'm thinking you might as well use a dual op amp and add a Tube Reamer or Blue Clipper type circuit to the front end, the way you would a real amp. :icon_twisted:
Hey RoG, not only that i like the amps that inspire you but your cover text is great and informative, not to mention pleasant and civilized. Somehow i very much enjoy the fact that your share is so popular.
Doing up a 16 pin 'perma-tweek-perfboard' build...
Looking at Q1C w/the 5k trimpot...is that an error?
Also I couldn't remember cap conversions so I brought up this Nf/Pf/Mf chart:
http://www.radio-electronics.com/info/data/capacitor/capacitor_conversion_chart.php
and the cap on Q1 output is shown as 1n [1 nanofarad converts to .001uf...small...is that what is intended for SLP/THOR?
Pete, the trimpot values are optimised for the JFETs specified for each stage. A 2N5457 requires a drain resistor around 1.6k when fed from 9V, thus a 5k pot is a good choice of value, as oppossed to the overly large 100k trimpot traditonally employed. In a similar manner, the J201 requires a drain resistor around 10k, thus a 20k or 25k trimpot is perfect.
The 1n series capacitor just after the first stage is small on purpose, and it produces a low frequency rolloff that has its -3dB point at 160 Hz. There is nothing to be afraid of, since the original valve stage uses a 2k7 cathode resistor in parallel with 0.68uF, which also produces less amplification for the bass frequencies. All in all, the 1n cap value was chosen so as to match the original amp soundwise (based on listening tests), however you may experiment with its value if you like as this is certainly an important component for tweaking.
Cheers.
The 1n series capacitor just after the first stage is small on purpose, and it produces a low frequency rolloff that has its -3dB point at 160 Hz. There is nothing to be afraid of, since the original valve stage uses a 2k7 cathode resistor in parallel with 0.68uF, which also produces less amplification for the bass frequencies. All in all, the 1n cap value was chosen so as to match the original amp soundwise (based on listening tests), however you may experiment with its value if you like as this is certainly an important component for tweaking.
Cool thanks for the verification/explanation STM! That particular cap, being the first Seriesed in the SP, closest thing to an input cap on THOR, got 4 pins of a socket !
I got this mostly done on 2 x 16 pin IC sockets, The first socket is for Q1/Q2 and the coupling caps, second socket for the Mu and OA stages..I've tried this kind of layout a few times before, I like both sides of a full IC socket, the wiper lug type are accomodating of slightly larger leads/two small leads per lug...I prefer solidly mounting [two 'sides'] them, just use the whole thing...RS is dwindling down, no more 8pin IC sockets...
Thanks a lot guys
Cheers
Rafa
Exactly what i was looking for :icon_biggrin: :icon_biggrin: :icon_biggrin:
Many thanks...
Once again, my hat is off to 'The Groove. :icon_cool: :icon_cool: :icon_cool:
You guys are fantastic.
The writeup mentions the fixed bias mu amp stage as being suitable for emulating the breakup of the LTP moreso than a JFET stage. Is it a fact that the *JFET* SRPP/mu amp is so strong in the odd orders? I've messed around with both a minibooster and a tube SRPP on a similar layout, and to my ears the FET minibooster sounded substantially sweeter, although admittedly the two were in completely different places in the signal chain so that evaluation means very little.
Quote from: billings on December 22, 2006, 03:46:24 PM
The writeup mentions the fixed bias mu amp stage as being suitable for emulating the breakup of the LTP moreso than a JFET stage. Is it a fact that the *JFET* SRPP/mu amp is so strong in the odd orders? I've messed around with both a minibooster and a tube SRPP on a similar layout, and to my ears the FET minibooster sounded substantially sweeter, although admittedly the two were in completely different places in the signal chain so that evaluation means very little.
The main reason to use 2N5457's over the J201 for the last stage is softer clipping. In fact, as the Vp parameter of the JFET increases, the clipping is less hard and "rounder". The MPF102 / 2N5458 / 2N5459 should have even rounder clipping. In addition, the inclusion of the 390 resistors with the sources help tame the excess of gain and make clipping less harsh.
This isn't a Fuzz!
You've done a Fine Job, the Friends at ROG!!!
Thank You!
It's going pretty good and sounds Great!!
This pedal is making my amp emit smooth sweet sounds ! Quite responsive with amount of OD to attack/input amount, leads in particular are ringing with a Com-Plexi-Ness which reminds me of the plexi sound I could never get enough time on [loud enough to DO that] to get used to, very rarely would an opportunity come up to crank it to that level...I never really figured it out...lol...this Reminds me of it, but doesn't have the 'dont touch hard here' caveats which the amp I had exhibited..I had to be very careful with bass note loudness to avoid 'overwhomping'...
So the pedal has some of the characteristics, lacks some of the caveats...sounds about as real plexi as I've gotten close to with a real plexi, generally easier to play >IME. I have excellent feedback/sustain on lead notes, even at moderate volumes...haven't had the TS out lately, none of my other pedals really even try to do the smooth 'settling into a sustain pitch' like this...
I'm Happy !
The Thunderchief I built...well that's quite a different circuit, I think the Mu Amp in there is a great choice, I like Mu's anyway, this pedal has a very nicely voiced distortion tone IMO.
States "Dig In" !...push on it to get out the great stuff !
This put a new angle on picking and style after a while. At first I wasn't quite sure and didn't know what I have...
Being the 'sick gain pig' that I am, I'm thinking you might as well use a dual op amp and add a Tube Reamer or Blue Clipper type circuit to the front end, the way you would a real amp.
Yeap, it's tasty treat , gain ... and it's hard to tell it': "I've had enough"..'No More for Me'...'Very Good but if I add Anymore I may appear a bit shaggy from the side'...shaggy is cool, but I'm trying to cut back !
That OA could be a single, but why, dual is more space effecient..if I were to build this with the 'other OA used for something Distortey, I'd put it on a Bypass.
Getting used to the dynamics / response of the circuit...I began to re-develop a dig in style of picking..very fun sound to 'lean on hard/tread lightly/play medium, let the sustain work for me.
Reminded me of my 'amps of type' I had..at first plug in, quandried by the tone/unsatisfied preconcieved notions [I bought a Plex/4x12 thinking Bad Co. AC/DC..greeted by something very different [great, but 'dull' compared to expectations] upon first amp test. Thor is quite similar, took a minute or three of playing before I actually dialed in the dynamics/response thing, besides dialing in the gain/vol/amp vol.
It wasn't/isn't 'till I began digging in, acclimating myself to the response, altering picking style etc. before I understood what could be released by whomping on JB Good rythms, letting single/double note leads sustain etc. a 'workingmans' sound, it doesn't play itself like a Fuzztone...you have to lean on it!
Then I added somethings and had my longtime P.C.Expectations satisfied.
Very pleasing, usable high gain tones, dynamics, sustain.
After hours of adulated playing on this one, it's a great 'base tone' circuit. Stick a Fuzz or Dirtbox before it or my Starved MuBoost after it...WOW is that fun.
Preliminary summation:
Great sounding circuit !
Does the 6' amp in a 5'' box thing really well.
Responds to dynamics, very fun to play.
Responds to being Fuzzed or driving Dirt/boost boxes really really nicely.
A1 Jfet amp sound!...does the 'ampinbox' thing convincingly, in some ways better than the real thing! [doesn't require shaking the rafters in the house next door]...easier to work with than: a way too big tube amp trying to sound big when dialed to miniscule settings, requiring a dirtbox to come close to sounding anything like itself cranked. Surely this would make a plexi turned down sound more like a plexi turned up.
I can solidly recommend this distortion circuit to anyone trying to get a 'plexi sound' out of a plexi at low volume, actually any volume...unless you have a plexi and are already getting 'that'..I rarely to never did...I always had to put a dirtbox on it anyway.
Nicely voiced balance of great stuff: Sustain 'pitch finding', dynamics/compression/distortion...but it isn't, and doesn't do 'fuzzbox', without a fuzzbox.
Turn the gain knob down a bit for thick 'dirtboost' tones.
A highs adjust knob would be a useful addition, I have this two knobber in a 3knob Box!...maybe a few switchable mods, lifting a bit of the LP filtering near input...lotsa places you could mess with it.
Superb sounding circuit gets finishing touches and pedalboard status [right after the RM/Dist+ box, before everything else in chain.
I have added a perf layout for it. Hope it's correct, at least it looks so.
http://aronnelson.com/gallery/albums/Layouts/Thor.gif (http://aronnelson.com/gallery/albums/Layouts/Thor.gif)
sweet. thanks very much! :icon_biggrin:
Quote from: Doug_H on December 21, 2006, 12:12:28 PM
The active filter idea is a good one- Coincidentally, I came up with a very similar idea for a design I've been working on for a few weeks.
yeah, i've been interested in this, too. seems like the passive tone stack approach has been a default. :icon_wink:
Quote from: Xavier on December 27, 2006, 04:42:16 AM
I have added a perf layout for it. Hope it's correct, at least it looks so.
http://aronnelson.com/gallery/albums/Layouts/Thor.gif (http://aronnelson.com/gallery/albums/Layouts/Thor.gif)
Thanks for the Layout Xavier - This will be my first build for 2007!
Quote from: phil on January 02, 2007, 04:10:35 PM
Quote from: Xavier on December 27, 2006, 04:42:16 AM
I have added a perf layout for it. Hope it's correct, at least it looks so.
http://aronnelson.com/gallery/albums/Layouts/Thor.gif (http://aronnelson.com/gallery/albums/Layouts/Thor.gif)
Thanks for the Layout Xavier - This will be my first build for 2007!
Please let us know how it works for you. Also let us know if you find any error in the layout
Quote from: Xavier on January 02, 2007, 06:52:45 PM
Please let us know how it works for you. Also let us know if you find any error in the layout
Will do - I just ordered the parts so when I get them I'll start the build and update this thread with the results and any necessary modifications to your layout if any. Thanks again for the layout - even if it's not 100% it's a really big help as I just don't have the hang of creating decent layouts from schematics yet ...
Count the number of connections at each node of the schematic, count where the traces go on the layout, printed versions makes this easier I think.
Also at each node, note how many parts connected there have 'orientation, and what they are.
Does anyone have any soundclips of the thor yet? I want to hear it; I'm guessing it sounds like the Thunderchief only more badass...
thanks again to xavier for the layout.
i think i found one error. first, note that the labels on Q3 and Q4 have been switched relative to the rog schem. that's not an error, but you'll need to know this in order to check this error: i think that C9 is incorrectly wired to C6 at e16 and e17. instead connect e17 to e14 by running a trace or wire under C6.
if i'm confused, apologies in advance! :icon_biggrin:
all the best, gm
I think GM is right - but it still didn't help my build...
Here's a snapshot of my post over in MartyMart's thread (http://www.diystompboxes.com/smfforum/index.php?topic=52889.0):
Quote from: mydementia on January 04, 2007, 10:34:06 PM
Well... I just built another Thor (tired of debugging the first one) - this time using Xavier's perf layout (http://www.diystompboxes.com/smfforum/index.php?topic=52621.20). At first, I built it to 'print' - then I saw Gaussmarkov's comment (think he's right) so I cut the trace and added the jumper - didn't make much difference though... I still get strange behavior with the gain pot... clean(ish) from 7-8 - squeel like a pig from 8-4 - huge gain from 4-5 (7=min, 5=max). All my voltages look right and signal seems to flow... just not sure what's going on with the gain pot. Yes, I tried two different gain pots (1MA's) - same result. I also tried a few trannies in Q1. No change... interesting that I built the circuit from two layouts and have the same malfunction... grrr...
I haven't seen a bunch of positive build reports on this circuit yet... anyone else had success besides Marty and Pete?
To be continued...
I built my first Thor from the ROG PCB layout on perf - moved things around a bit to fit the perf I had...but stayed with the same basic flow. Only changes were a 50k trimmer in place of the 20k trimmer and some close value faked resistors (who has 56k resistors in their bin?). All else per the schem...
Any ideas?
Thanks for looking.
Mike
I'm sorry to hear that you are having difficulty with your Thor builds, Mike.
Why don't you post your voltages and list any changes/subs you've made. Then we can try to work together to find the source of the issues.
Just wanted to say that I finished it up tonight. Sounds really good, even just biasing the trimpots by ear. I'll get them exact tomorrow and try to post a clip, depending on what my chores are for the weekend. I perfed it along the lines of Gringo's PCB, did not socket the trannies and had to use two 25k trims (didn't want to wait for a 5k). I have no experience at all with the Thunder Chief but I will say this: the "Thor" I built sounds really good. It's not a super high gain sound (Boogie) but a pleasing cranked up Marshall tone. Great job ROG!!
Quote from: Xavier on January 02, 2007, 06:52:45 PM
Please let us know how it works for you. Also let us know if you find any error in the layout
Hi Xavier - just successfully finished the build of the Thor using your layout and the only change I made to it was to incorporate Gaussmarkov's changes - (instead of wiring C9 to C6 at e16 and e17, I connected e17 to e14 by running a wire under C6). Thanks again for the layout!
My Thor sounds very grainy right now - I think it's because of the parts I used - (I used Ceramic Caps for the 220pf and the 3 470pfs
, Boxed Metal Film Capacitors and Metallized Polyester film caps for the rest). I've ordered all poly film capacitors from Small Bear and I'll swap out the Ceramic capacitor for Poly film and see what change there is. If that doesn't do it, it may be the Metal film caps I used and I'll just do a new build with all Poly film.
Hopefully it's just the ceramic caps - the Thunderchief I just finished 2 weeks ago sounds incredible and I used a polystyrene capacitor for the 470pf instead of ceramic. I also used all Poly film (and electrolic) capacitors so there's a chance it's the new Metal film caps I used that are making the Thor sound very grainy. I'll post an update when I find out more.
I have just uploaded the layout with the GaussMarkov corrections to my gallery.
Quote from: phil on January 07, 2007, 08:56:16 PM
Hopefully it's just the ceramic caps
Well, I replaced the ceramic caps on my first build with film caps and that did not change the sound noticably, so I did a new build with all film caps except for the 2 100ufs (also a regular TL071 instead of an SMD TL071 which I mistakenly ordered for the first build) and finished it last night. It fired up first time and all I can say is that I was blown away with how great it sounds !!!
I really liked the Thunderchief that I had finished 3 weeks ago and was expecting the Thor to be just a more refined version of it, but they sound completely different to me... The Thunderchief has a lot more gain than the Thor, but the Thunderchief really only sounds good to me with my tube amps ( Epiphone Valve Junior, homebuilt Marshall 18 lite). The Thor on the other hand sounds great with with all my amps and sounds very very tube like even with my solid state marshall MG30DFX. I thought I was going to choose between boxing up the Thunderchief or the Thor, but to me they are different pedals so I'm boxing both of them up - they are both keepers!
I'm a newbie at building effects, but even so I have to say I was very impressed with the Thunderchief compared to the other commercial effects I have (Keely modded Blues Driver, Keely modded DS-1, Modded SD-1). The Thor takes it a whole other level higher - it is just awesome!
Thank you guys at ROG - not only do you perform feats of electronic magic, but you make it freely available to us DIY's - you really Rock!
Hello everyone, sorry for the thread bump, but I have a question regarding the Thor's overall treble response. I have built one, and I am enjoying the tones the circuit puts out through solid state amps, but struggling with tube amps, almost as though there is a blanket over the speaker kind of deal. I ran simulations via LTSpice and found that the 470p cap on the op amp is responsible for the high cut which makes it work for more brittle sounding amps. I am guessing omitting this component, making it switchable, or maybe even mounting it on a pot for additional control, would solve my problem? Or are there other places in the circuit I should pay attention to? Thanks in advance for replies.