Well into building a klon clone

Sadie-f

Senior Member
Messages
427
A few things got me moving on this: first, I've super enjoyed the overdrive / distortion pedals I've got, second, the guitar shop I go to put a new in box ~1998 klon up for sale at $7500. Maybe most of all, record high COVID rates here and the need for good winter-friendly projects.

I enjoy building circuits, I know I could buy any of a number of exact, or souped up clones off the shelf &, however that doesn't allow for the fun of the build process.

The enhancement from a true clone I have in mind will be a small external breadboard where I can trial a variety of clipping circuits, I plan on 3 selectable circuits, initial thought is germanium, silicon & breadboard.

About half the components are installed, with a bit more than 2/3 the board space remaining. Hopefully it runs smooth and performs well.

I've got no expectation I'll like this better than my Open Window, still vive la difference!

 

Attachments

  • 16408780078491.jpg
    16408780078491.jpg
    316.6 KB · Views: 95
  • 16408779946950.jpg
    16408779946950.jpg
    552.7 KB · Views: 88
I nominally finished this this afternoon, added the pots, jacks, 9v battery for testing (haven't received the max 1044 charge pumps yet, so for now, I'm just wiring it up with the 2nd pair of op amps running at 9v instead of +/- 12 V).

Not surprisingly, I got no output, so when I have time, I'll take an afternoon and hookup proper voltage using an external power supply, supply a straight up sine wave for input and trace through the entire circuit to see where in the path the signal is being lost.

I hope i'm close to done, will see :).
 
vetteman said:
I believe the proper voltage would be 121 gigawatts!  :laughing7:

Hmm, holding the voltage at 24, I could do that. Do you know where I can find a 0.476 micro-Ohm resistor? At that rate, we only need  to source ~50.4 MAmps. If I can find a charge pump good for maybe a picosecond pulse? I'll look into resonant tunneling diodes for a time-reversing clipping circuit.

;-)



 
Mayfly said:
Hey, how's it going on that thing?  get a spark out of it?

Haven't had spark or smoke yet, also no signal at the distal end. With ~57 individual components, more than double that many connections, I'm not shocked, so it's oscilloscope and signal tracing time.

I did receive my max1044 devices and they're making the expected voltages, and those are correctly present at the 3&4 stages op amp. so that much is ok for now; I've read that 1044s are easy to smoke, so while knocking wood, I'm glad of this.

In the meantime, I've also received 2 flavors of very low forward voltage LEDs, 1.07, 1.18 Vf respectively, both are IR spectrum and so nearly invisible to the eye, and quite visible to a digital camera :), see below ..

I also found, but can't obtain 1V zener diodes that might make for a soft shoulder / asymmetric distortion, trouble there, the minimum order was 600 units, a lot more $$ than I want to spend on a flyer :).



 

Attachments

  • 16412491102621.jpg
    16412491102621.jpg
    482.5 KB · Views: 82
  • 16412490935120.jpg
    16412490935120.jpg
    586 KB · Views: 74
  • 16409820173441.jpg
    16409820173441.jpg
    622.6 KB · Views: 77
  • 16409813208240.jpg
    16409813208240.jpg
    624.2 KB · Views: 76
Mayfly said:
Hey, how's it going on that thing?  get a spark out of it?

Ok, yes! Got spark through the second/gain amp stage, I may have wired the 2-gang gain pot in opposite correct direction, the useful band of the pot is about 10%. Something is off in the summing & tone sections, that may take some time to diagnose, the layout is very dense. But I'm sure I'll find it :).

Whole circuit draws 25 mA, seems about right. The sound of just the gain stage is pretty nice. Right now it's 1n4001s because that's handy, I'm waiting on the 1N34As, and looking forward to trying lots of options :).
 

Attachments

  • 16412640519123.jpg
    16412640519123.jpg
    914 KB · Views: 88
  • 16412639451072.jpg
    16412639451072.jpg
    900 KB · Views: 86
And it works. My GF called the 'layout' "Coruscant like", referring to the components stacked vertically in the amplification sections. I counted, there are a dozen places with vertically stacked passive components, 5 with 3 stacked. Unfortunately, between that and the (11) components soldered into the back side, it's too tall to fit in the standard box. So I'll be adding a spacer to the box, not the end of the world :).

The main error I'd made was connecting the distortion stages directly into the input of the summing op amp without an AC coupling capacitor, with that fixed, the latter stages look to be working great.

Hard to judge much on the sound now, with no shielding and the in/out jacks being hooked in with jumpers, the 60 Hz noise level is huge. Fundamentally working is a great start! I look forward to tweaking different diode networks, and as I've worked on it, I've thought of some other possible interesting tweaks. The waveform I saw when feeding it a pure sine input wasn't what I was expecting, however, allowing for the big hum, the sound is fine.

Time to work on the box mechanics, and I'm still waiting on 10k pots for treble and output control.


 

Attachments

  • 16415089757230.jpg
    16415089757230.jpg
    1.1 MB · Views: 77
Played with it some more!

From reading other people's notes, I guess it's easy to draw more current than the max1044 can source, I've apparently overloaded one. Of course the second tlo82, operating on the 1044 supply rails is drawing most of the current, which, in turn as I read it is close to the limit of the 1044 device .. or, I shorted something as I was tweaking.

Anyway, after soldering the jack connections, I replaced the charge pump and played thru it for about an hour & left it hooked to power most of the day, no more failures :). Even without a case and with lots of external noise, I'm super happy with the sound!

I've commissioned a woman woman whose art I like to make an Harley Quinn inspired archer for a decal, should be quite striking when done :).

p.s. that local $7500 NIB klon sold last week, I think they had it on the shelf for 3 weeks before it went.
 
I got a the first pass on the artwork, just the line drawing as a start. It's gonna look great!
 

Attachments

  • RDT_20220110_1848585492564953185689850.gif
    RDT_20220110_1848585492564953185689850.gif
    211 KB · Views: 86
Two comments:

1 - I would never get away with artwork like that on my pedals!
2 - May I suggest that the person on the right be holding an apple?  It's a more typical arrow target than a rose.
 
Mayfly said:
Two comments:

1 - I would never get away with artwork like that on my pedals!
2 - May I suggest that the person on the right be holding an apple?  It's a more typical arrow target than a rose.

1. lesbian household, lesbian artwork
2. I left design to the woman who did the art, and loved what she came up with.  :)
 
So many fun supply chain problems with trying to move this ahead.

The pots and foot switch I'd ordered late December, will finally arrive today, it seems Omicron hit Memphis hard and the USPS hub there held on to the pkg for 4 weeks.

I just ordered tl072 op amps and only smd mount are available. So I'll bridge to my circuit with an smd-DIP adapter.

Not directly related, but an acoustic from SCGC that was slated to arrive to a local shop in early December, just showed up here last Thursday. It's not for me, but I got a chance to play it the day before our blizzard hit. It's a cocobolo dreadnought, gorgeous in looks and a stunning voice.


 
Sadie-f said:
I've got no expectation I'll like this better than my Open Window, still vive la difference!

My mini pedal board has a ryra klone and an open window, they stack together great and I'm sure you're gonna love them both. I keep the open window just on the edge of breakup and the klone with a bit more drive.
 
Back
Top