Fuzz Face and Common Emitter Explorer board kits available now

[huntingtonaudio]

Hi.

This past week, I started selling (what I think are) some great little learning and prototyping tools.  I've written a bit more about them in the Market Place forum here:

https://www.diystompboxes.com/smfforum/index.php?topic=132061.0

They're available at huntingtonaudio.com

Thanks for your time!

[aron]

Looks high quality and cool!

[mozz]

Ordered one for the fuzz. I sort of have a homemade one with remote pots and transistor sockets but i have to unsolder to get a reading on the pots or pull a transistor. Actually have 3, one for npn, one for pnp and one for a rangemaster. I could go on about the ultimate designer board with room for axial caps and 10 turn full sized pots and switches for stock values but i will leave that go for now. I guess i can swap the trimmers with 3 pin headers so i can drop in 8.2k or 33k. Looks good, new toy, love to build stuff.

[huntingtonaudio]

Looks high quality and cool!

Thanks, aron! 

[huntingtonaudio]

Ordered one for the fuzz. I sort of have a homemade one with remote pots and transistor sockets but i have to unsolder to get a reading on the pots or pull a transistor. Actually have 3, one for npn, one for pnp and one for a rangemaster. I could go on about the ultimate designer board with room for axial caps and 10 turn full sized pots and switches for stock values but i will leave that go for now. I guess i can swap the trimmers with 3 pin headers so i can drop in 8.2k or 33k. Looks good, new toy, love to build stuff.

I'm glad you dig it!  The trimpots are socketed, so you can swap them out in some fashion for whatever other resistive element you want. And, I'm not sure if it was clear, this explorer board handles NPN or PNP witha quick flip of a switch and a couple rotated capacitors (they're all socketed). SO you could probably pop in some axial caps without much fuss.  As for those fancy full size 10 turn pots..... man that'd be nice!!

[mozz]

Probably mount this floating on top of a chassis of sorts.  I can always run some ribbon cable from the header pins to aux things.  I also like using pin jacks or banana leads to the meter.  Thanks for the discount coupon code on the CE board!

[mozz]

Got the board/boards today. Fuzz is built already as soon as i finished dinner! Thanks for the extras!
 
Now, don't take this as "mistakes". Consider it constructive criticism. I used to build and verify pcbs for a major audio company, 20 years ago though. I had engineers rush things though to get the prototypes done etc.etc.  I am good at finding mis-matches, reversed caps, shorted traces, bad footprints, the whole deal.
 I could be wrong on all of these too, so double check me.

Input cap, when set for NPN, you want the positive end of the cap towards the transistor base. If i follow the silk screening, it would be the other way around. I've checked it with a meter going from "input" directly to base on the zif socket. Pins 1 and 2 of the cap header go to the base, pins 3 and 4 go to the input header "input" pin. Please check me on this. Silk screening is swapped pnp/npn.

Rest is just me nit-picking.

330ohm has no mention anywhere for the 4 pieces. I know it is for the LED but no mention in the paperwork. I used 2.2k which is a bit dark, should have used 1k.

Schematic shows 2.2uf for the fuzz cap, should normally be 22uf.

Parts list doesn't show values for the trimmers, have to look at the pictures. Mine had 2 subs, a 5K for rv2/470 ohm, (instead of 1k) but i would not have used 1k anyway, maybe 2k or more so that's fine. And 100k subbed for the rv1/33k, (instead of 50k) but that's fine also.

More ramblings.
 I think the zif socket is more than enough options. You get lots of pinout combinations there, i don't think there is a need for the extra dual 3 pin headers on the sides. I would put dedicated Q1C, Q2C voltage measurement pins there instead, as most people are going to be tweaking for particular voltages.

The current measurement points are great, for me, but i see the paperwork says use "AC" current on your meter? It is a DC current in microamps.

LED's (dual color) and switches are nice, but after looking at the CEver2 board, i would like those push button momentary switches for taking resistance measurements!

Oh, this was my problem, battery was at 9.4 volts, since the 4 led's were on and i was swapping parts and transistors, i noticed my battery was down to 7.5v, it was probably mostly dead and the 4 leds helped to finish it off, something to look out for if using a old zinc carbon battery within reach that has been on your bench for years!

Stand off holes, are they GND? I know they are not bare but If i put metal stand offs on it and they get tightened a lot and contact the board? I would have then separate from the gnd plane. Or use plastic standoffs.



Other than all that, i am going to mount it above a chassis with outboard pots for the 33k at least and a few battery connections such as a 9v snap and a center neg Boss style jack.

[huntingtonaudio]

mozz!

I can't believe I missed the input cap footprint flip flop.  You are correct. And I really appreciate your feedback.

I take some solace in knowing that I can remedy this with the folks who have ordered one by sending everyone a decal for the board.  But I'm disheartened to realize now that you are correct. I'd have caught this if I used an electrolytic here myself. Damn it!

If I had your experience, I'm sure I would have caught this.

I appreciate your other suggestions as well. First, about the simpler switches and omission of the LEDs. I think these features are nice for folks who are just getting their foot in the door, as the indicators and toggles make it hard to mistake which trimpots are in or our of circuit. I had total beginners in mind when I designed this because I'm closer (at this point) on the spectrum of experience to the foot-in-the-door type than the seasoned engineer.

But that said, I'm discovering that there seem to be more people interested in this tool who already decades into this and are just looking to speed up parts of their process. So I may lean toward more barebones toggles going forward, catering to the audience who needs little more than to speed up some rote aspects of their design phase.

As for current metering - I welcome the opportunity to be corrected if I've got something confused.  I'm still digesting the basics as I've said before so any opportunity to learn from something beyond a text or an experiment in isolation is great! So, to your point, wouldn't the AC current of the signal be of interest at these junctions?

[mozz]

You would only have AC current if you had signal. Or if it was a oscillator. As it sits it is in static condition. Correct me if i am wrong, that's how i understand it.

 I too often use a non polarized input cap if i have them, or a 1uf film cap.

Yes maybe a simpler/faster board, toggles could be used for fixed/variable settings. Might make tweaking faster. I don't know if it's possible to make fixed/variable/measure switches.  I don't mean to say make another board cheaper because it might hurt the sales of this one!

Anyway, will be using it this weekend to quick swap out some different trannys, will post any tricks tips i can find.

I'll post pictures of what i "was" using and you'll see i am much happier using this board.

[dano12]

This is a great idea and really nicely done. A kit for experimenting rather than solder-then-seal-it-up is refreshing! Also extra points for the ZIF sockets, they are quite useful.

[huntingtonaudio]

Yes maybe a simpler/faster board, toggles could be used for fixed/variable settings. Might make tweaking faster. I don't know if it's possible to make fixed/variable/measure switches.  I don't mean to say make another board cheaper because it might hurt the sales of this one!

Anyway, will be using it this weekend to quick swap out some different trannys, will post any tricks tips i can find.

I'll post pictures of what i "was" using and you'll see i am much happier using this board.

For starters, thank you again for your detailed feedback. Supremely useful!  Second, it's not ONLY your suggestions that have me considering more streamlined boards for the future. There've been other comments and feedback that point to most users being beyond the learning phase already.  So streamlined might be a win for everyone.

Stand off holes, are they GND? I know they are not bare but If i put metal stand offs on it and they get tightened a lot and contact the board? I would have then separate from the gnd plane. Or use plastic standoffs.

Standoffs are actually bare, not plated, not connected to ground.

Other than all that, I am going to mount it above a chassis with outboard pots for the 33k at least and a few battery connections such as a 9v snap and a center neg Boss style jack.

This is another thing I'm realizing - most folks would like to see these boards with their own onboard I/O (signal and power).  Going forwards I'll accommodate this - at this point, I want that too.

330ohm has no mention anywhere for the 4 pieces. I know it is for the LED but no mention in the paperwork. I used 2.2k which is a bit dark, should have used 1k.

I've added some quick mention of these in the guidebook now. Thanks for noticing that. And I appreciate hearing your approach to dimming the LEDs. Your other comments about battery drain (I hadn't expected battery power but that makes sense now that you mention it) have me thinking that a single color red LED indicator for 'out of circuit' (the more momentary state) would alleviate battery drain concerns.  But as discussed earlier, might just make sense for us all if the next version of this has no indicators at all.

Schematic shows 2.2uf for the fuzz cap, should normally be 22uf.

Thank you again for your attention to detail. I've learned from this that I should temper my excitement about sharing these gadgets. I've got to slow down to ensure I hit the mark every time.

[huntingtonaudio]

This is a great idea and really nicely done. A kit for experimenting rather than solder-then-seal-it-up is refreshing! Also extra points for the ZIF sockets, they are quite useful.

Thank you for your kind feedback but more so for everything else. New as I am to being on the creator side of things in this space, your work has already been a significant influence and source of learning for me. I appreciate all that you've shared with this community.

[mozz]

Getting there, I have stock resistor values to plug in.  Certain part numbers need no changes to get 4.5v-5v.  Built a 9v regulated supply inside, input output jacks, q1c, q2c, supply test points. Tip of the day, when using npn silicon transistors, you can plug in pf caps across C-B junction in the extra socket points to see if your build needs them to tame treble.  Bi polar caps are also a plus when building different polarities. 

[mozz]

Now with meters for Q1C, Q2C.

[huntingtonaudio]

Hot damn, mozz.  Pretty soon that thing is going to grow legs and start giving orders.  Looks terrific. Really cool to see where you're taking it.

[mozz]

With stock resistor values plugged in, i can swap in a pair of transistors and instantly see if they will work as is or need a trimmer. Or i can see how they sound and note the voltages. I may trim the 1k pot or put that on a switch with 1k or 2k. Lots going on still.