Thor build - gaussmarkov layout!

[Pushtone]

I did a search and didn't see any reports on the Thor using Paul's (gaussmarkov) layout.
I was surprised since so many folks have built Paul's Dr Boogie layout.

Paul is a credit to his hobby. The layout and project file are fab and deserves a boost.
So I offer this build report.

The design is of course from www.runoffgroove.com
Paul's project file can be found on his website http://www.gaussmarkov.net/wordpress/circuits/thor/
For some reason the photo on that page is a different layout than whats in the project file.



I build it straight without any value subs.
The layout is very tight, er I mean compact and can fit in a "B" box either way, vertical or horizontal.
The boxed caps or Xicon sub-miniature caps are a must on this one.






Check out this tight little grouping of caps!
Note the nylon machine bolt - as - standoff.
Later I would remove the extra board material to change to a smaller box than I originally planned.






It was going to go into a "BB" but at the last minuet I went with a "B" box.
Even more last minuet I decided to etch the enclosure. Sure has been awhile since I etched a box.
The red in the photo is nail polish to reinforece the PnP mask.






I've been really into using drawer pulls as roll bars.
This box layout makes it mandatory to protect the toggles.







And finally the guts.
Thanks to Paul's layout skills the wiring for the pots and switches is extremely short and do not cross.
I went sideways but the layout would work the same in a vertical B box.
Just rotate the pots and PCB 90 degrees.






The sounds:

Like other ROG designs, the Thor sounds good (except through a Twin, all my pedals sound like S#$* through this Twin, a 2005 reissue, why I don't know?)
I set the trimmers to half way, then proceeded to plug it in for the first time.
I was happy it fired right up but I was expecting more gain.

Marshall super lead you say?
It took the setting the trimmers to max to make me think that. I tried a J201 in Q1 but it didn't make much difference.
I have a MPF102 in there now and with the trimmers at max this seems to reduce the hiss some what.

Over-all it is a relatively quiet pedal. If I could get rid of the hiss it would be a very quiet pedal.
I can back off the trimmers a little to reduce the hiss but its so minor I'd rather have the extra gain on tap.

I'm still playing around with the trimmers and transistors.

The bass toggle switch is very pronounced. Cleans up the humbuckers mud.
The bright toggle is harder to pin down. It depends what range I'm playing in and the amp.
Sometimes its effect can't be heard. Other times its a pronounced difference.

Big thanks to ROG and Paul for another great design and project.

[ambulancevoice]

how did you etch with the holes in the box???
did you paint the inside of them or something???

nope
well, how did it go???

[andrew_k]

Looks sweet 

Can you tell me where to get the bar over the controls from? As in, what it's made for so I can seek one out in this corner of the world? Thanks

[John Lyons]

Looking good!
Thanks for the build report. Gauss should like the build report as well. Nice to know how things work out in real life.
I assume you just dabbed on the Ferric chloride with a cotton swab to etch as the words are the only parts etched.

john

[Pushtone]

Yes I used a small paint brush to repeatedly apply the FeC.

I repeatedly rinsed in very hot tap water and worked inches under a 100W bulb to get the heat and reaction up to speed.
So I didn't heat the FeC, I heated the box!

Took about ten minuets of "painting".



The roll bar is a drawer pull from the hardware store.


Thanks for the comments.

Dave

[Pushtone]

I'd also like to point out that I used gaussmarkov's recommended method of star grounding.
At least I tried too.

In the photo you can see the output jack is the ground point and the purple heatshrink holds four ground leads that go to
the PCB, 3PDT, DC jack, and input jack.

Been doing it this way since gaussmarkov described it in another thread.


I start it off like this...

[soggybag]

That looks sharp, good job! I have been thinking about building one these for a while.

I like etching on the box. The paint brush idea is a good one. I usually just dunk the face of the box. What kind of brush did you use, I'd think the ferrell would get eaten by the acid?

[Pushtone]

What kind of brush did you use, I'd think the ferrell would get eaten by the acid?

So THATS what you call that little metal part on a paintbrush!?!

With an eight year old in the house there is no shortage of cheap all plastic brushes.
I though of that when selecting a brush. I think the bristles are nylon.



Hey soggy,

I etched this same layout but on your PCB design with the mounted jacks and 3PDT switch.
Plus I still have one of yours left. I should do one off your site with that pcb.

Thanks for the comments
Dave

[gaussmarkov]

geez dave, nice build report.  i would've missed it but stobiepole (chris) pointed it out to me.  thanks for the generous praise. 

i was confused by the difference between the photo (which is chris's build) and the layout on gaussmarkov.net and did some back checking.  as best i can make out, the pictured build is a later design that i did not post.  it uses the same layout ideas that i learned in the dr. boogey thread (linear signal path, grounded guard traces).  but someone told me that because the thor wasn't such a high gainer, it wouldn't make much difference so i set it aside.

you also see that there are no trimmers in that version.  that's because i decided to go with the advice that trimmers can be noisy.  instead socket some fixed resisters and try different values that way.  maybe that's good advice for the thor too?

that more recent layout is also one column narrower.  so it will fit even more easily into a B box the other way.  but in some ways, it's an even tighter layout.

cheers, paul

[Valoosj]

Nice work. Those knobs you are using, I have them too, but my pots are 0,3 mm wider. Do you have that same problem?
I'm thinking about drilling them with a 6,25mm drill

[Pushtone]

Great project file Paul! Thanks again for looking at my report.

Question, I'm I doing the star ground thing right?

Nice work. Those knobs you are using, I have them too, but my pots are 0,3 mm wider. Do you have that same problem?
I'm thinking about drilling them with a 6,25mm drill

Yes those knobs are for fluted shafts. I have to drill them out with a 1/4" bit (6.2mm)
Sometimes they mount crooked. Sometimes they are too loose after drilling and I use a little spot of masking tape on the shaft before pushing them on.

I got 100 of them off ebay for 20 bucks so I use them on most of my builds.
I like the fact that the knobs are the same diameter as the 16mm Alpha pots. You can really cram them in.

[azrael]

Wow, very nice!
Great looking build. I really like your idea to use a drawer handle to protect knobs...I may have to do that, now, for some builds...

Kudos to gaussmarkov for creating such a tight layout for the build.

[Pushtone]

I really like your idea to use a drawer handle to protect knobs.

Thanks but I got the idea from one of my favorite builders, Dano12. He's done it a bunch.

Check out his website...
http://www.beavisaudio.com/Projects/TrotskyDrive/
Lots of inspiration there.


Heres a pic of another use of a drawer pull.

[gaussmarkov]

Great project file Paul! Thanks again for looking at my report.

Question, I'm I doing the star ground thing right?

nice builds!  eye candy!!   hmmm hmmm.

re the grounding, that's what i do also.  for reasons that i cannot fathom (maybe because it's what boss does?), lots of folks prefer the input ground lug.  i sense that generally you can get away with pretty much any arrangement.     star grounding is something that is really important in amps but less so in stompboxes, excluding the pcb layout.  many ggg layouts have ground loops in them and have for years.  if there was a problem with that, the loops would have been removed long ago.

apparently, the arrangement of ground on the pcb can be critical.  some parts of a circuit (like the input buffer) may need their own direct path to solid ground on the pcb.  to the extent that routing the off-board grounds direct to ground for the entire box avoids polluting the pcb ground, the arrangement that you are using is better.  a leading example is anything involving an LED indicator for by-pass.  at least that's my understanding as of today. 

[Renegadrian]

Hey  this stompbox is a KILLER!!! 
Very very nice enclosure, and as I'm after high gainers,  I'll  build it sooner or later, now I'm just finishing  my BSIABII...

Congratulations, I believe we n00bs learn a lot from this forum members like you...Thank you 

[Pushtone]

Wow, I just realized I used a 2k trimmer for Q2 instead of the called for 20k.
Found it while comparing my voltages to ones posted by the designer.

No wonder I need to max out the trimmers to get it cooking!