Hotcake - Flapjack with mojo!

[timbo_93631]

Finished up my Hotcake/Flapjack last night.  I love it, turned out so clean thanks to the awesome PCB from Jeff (jtn191) and 3PDT board from Josh (gtr2).  I was able to sneak some mojo parts in there too, standup resistor is a 1/2 watt 1M carbon comp, I can't believe I burned through 200 1M metal films in the past year.  That spurred me on to throw as many other 1/4 watt CC's in there as I had in my parts bin.  Again thanks to Jeff, Josh, and Forrest.  You guys are pretty dang great in my book.

[timbo_93631]

And gutshot!  In the picture there is a Burr Brown OPA2134 in there, didn't work, I must've been sleeping last night not thinking about the LM741 being a single op amp, not a dual, duh!.  Works great with the LM741 it was designed for.  I think it would work with a BB OPA134 (single op amp), pins 5 and 8 are swapped but on the pcb it looks like they are both NC.

[pryde]

Very clean build ya got there friend. Looks like plenty of room left for a battery as well. How would you descibe the sound of this little beast? Hoping to get one next round.

[timbo_93631]

Yup, I don't usually do batteries, but I though I'd better leave room in case I didn't dig it and was going to sell it.  It is a really interesting dirt box, without trying to get "all TGP" I'll try to describe it.  The signal sounds mixed between clean and distorted, like simultaneously.  It preserves the clean signal at the same volume as the distorted signal until near max gain I'd say.  Similar to running a stereo rig with one amp set clean and the other distorted both playing at the same time.  That is the most unique thing about it.  I think that is what makes it so good, your signal is colored, but you also hear your guitar's primary tone coming through.  I'd even call it "expansive".  I know alot of people are chasing that transparent tube breakup sound in an OD, but my amp does that at a manageable volume so I am always looking for dirt that is going to play nice with an already pushed amp.  This works well in that application.  At max gain it is fuzzy too, not pure OD or distortion, like distortion/fuzz mixed.  Sort of like a Cosmopolitan.  I really really like it.  I think I might have gone "all TGP".

[pryde]

Ya sold me  I gotta build one.

Anyway, nice job on the build.

[jtn191]

Nice build! Where did you get the LM741? I have a TL071 in mine right now and would like to try the stock opamp for comparison

And nice description! Nels Cline called his a "cream-ier, beefier" overdrive, but it's definitely transparent

[gtr2]

Cool build.  Love the orange cap.

Josh

[timbo_93631]

LM741 came from Mammoth, lighter orange cap is an EROMAK-1 polycarbonate film and foil cap.  It just fit right in there so nice next to the opamp.  If I had a 0.1uf one I'd have put it in right next door instead of the greenie.  I am so happy with how this thing turned out, got a good chance to play with it for the past hour or so.

[pickdropper]

Yup, I don't usually do batteries, but I though I'd better leave room in case I didn't dig it and was going to sell it.  It is a really interesting dirt box, without trying to get "all TGP" I'll try to describe it.  The signal sounds mixed between clean and distorted, like simultaneously.  It preserves the clean signal at the same volume as the distorted signal until near max gain I'd say.  Similar to running a stereo rig with one amp set clean and the other distorted both playing at the same time.  That is the most unique thing about it.  I think that is what makes it so good, your signal is colored, but you also hear your guitar's primary tone coming through.  I'd even call it "expansive".  I know alot of people are chasing that transparent tube breakup sound in an OD, but my amp does that at a manageable volume so I am always looking for dirt that is going to play nice with an already pushed amp.  This works well in that application.  At max gain it is fuzzy too, not pure OD or distortion, like distortion/fuzz mixed.  Sort of like a Cosmopolitan.  I really really like it.  I think I might have gone "all TGP".

You won't have gone "all TGP" until you write 5 more gushing posts and then put it in the for sale section.

[chromesphere]

Nice build, the caps look cool!!
A few hotcakes going around at the moment!  I'm suprised it hasnt recieved much attention early to be honest, its a cool sounding effect, hugely versatile.  I ordered an LM741 from futurlec and recieved a UA741.  A freestompboxes forum member (where i got the PCB layout) suggested that it "was the same thing".  Not sure about that, but next time i order with mammoth i might try a comparison between the UA and LM.
Paul

[timbo_93631]

I ordered an LM741 from futurlec and recieved a UA741.  A freestompboxes forum member (where i got the PCB layout) suggested that it "was the same thing".

Thanks for the nice comments, I just peeked at the datasheets and they look nearly identical.  The preceding letters usually indicate the manufacturer/designer, so I would say LM's are Fairchild, and UA's are Texas Instruments based off of the datasheets and info I dug up with a quick google.  If anyone can explain this better, please educate us.

[timbo_93631]

You won't have gone "all TGP" until you write 5 more gushing posts and then put it in the for sale section.

I may have gone "all TGP" because I did end up selling the first one, and then the second one I built, but the third is a keeper.  #2 and #3 have the "Bluesberry" mod which puts a 1N914 from pin 2 (cathode) to pin 3 of the IC, and from pin 2(cathode) to ground (pin 4).  On #2 on I soldered the 1n914's to the IC legs so you could revert to the unmodded circuit buy swapping IC's, but #3 I put one 1N914 under the IC on the socket, and another under the board on the IC socket pins.  I called #2 and #3 "50/50 Drive" because of the kind of "clean signal with dirt signal running parallel" sound this pedal has.

#2

[timbo_93631]

#3

[timbo_93631]

More #3, I think the CLR is gonna hold up on this one.

[jtn191]

Cool! thanks for sharing. I'll try this out and add it to the doc if I remember to