New at runoffgroove.com: Thor

[mydementia]

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):

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

[B Tremblay]

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.

[tungngruv]

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!!

[phil]

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.

[Xavier]

I have just uploaded the layout with the GaussMarkov corrections to my gallery.

[phil]

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!

[karis12]

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.