Enclosure not stated · 3 knobs
Electro Harmonix Clone TheoryVerified
Based on the Electro-Harmonix Clone Theory· 2 other boards clone it
- Category
- Vibrato / Chorus
- Build
- Vero· 33×31· 69 cuts, 39 links
- Layout
- Verified · Dirtbox Layouts marks it as built and working
- Tags
- Chorus, Electro Harmonix, Modulation, Vibrato
From the post
This is it for, now. Covid restrictions were lifted here today so I'm going to take a break and try to live a normal life for a while ;-). But here is a project of the 70s version of EHX Clone Theory which should keep you occupied for a while. An onboard voltage doubler is included followed by a 15v voltage regulator for the required power supply. The only addon in the audio path compared to the vintage units is a booster stage and volume trim before the output to cure the slight volume drop when the circuit is engaged. Schematic is avaiable HERE.
Schematic
This is a board layout, a drawing of where each part goes, and the post may link the schematic it was drawn from. Open the layout at Dirtbox Layouts. No KiCad fragment has been drawn for this circuit yet.
Parts list 57 rows
Report a wrong parseGot parts in a drawer? See what you can build with them.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 25 | ||||
| ×3 | 22Ω | 22 | read from the layout by eye | |
| ×3 | 100K | 100k | read from the layout by eye | |
| ×2 | 1K | 1k | read from the layout by eye | |
| ×2 | 12K | 12k | read from the layout by eye | |
| ×2 | 51K | 51k | read from the layout by eye | |
| ×2 | 150K | 150k | read from the layout by eye | |
| ×2 | 200K | 200k | read from the layout by eye | |
| ×2 | 220K | 220k | read from the layout by eye | |
| ×2 | 300K | 300k | read from the layout by eye | |
| ×1 | 3.3K | 3.3k | read from the layout by eye | |
| ×1 | 6.8K | 6.8k | read from the layout by eye | |
| ×1 | 10K | 10k | read from the layout by eye | |
| ×1 | 22K | 22k | read from the layout by eye | |
| ×1 | 33K | 33k | read from the layout by eye | |
| ×1 | 47K | 47k | read from the layout by eye | |
| ×1 | 62K | 62k | read from the layout by eye | |
| ×1 | 68K | 68k | read from the layout by eye | |
| ×1 | 120K | 120k | read from the layout by eye | |
| ×1 | 160K | 160k | read from the layout by eye | |
| ×1 | 330K | 330k | read from the layout by eye | |
| ×1 | 390K | 390k | read from the layout by eye | |
| ×1 | 470K | 470k | read from the layout by eye | |
| ×1 | 1M | 1M | read from the layout by eye | |
| ×1 | 2.2M | 2.2M | read from the layout by eye | |
| ×1 | ? | ? | LED resistor, value not given; read from the layout by eye | |
| Capacitors 12 | ||||
| ×3 | 22pF | 22p | read from the layout by eye | |
| ×1 | 27pF | 27p | read from the layout by eye | |
| ×2 | 390pF | 390p | read from the layout by eye | |
| ×1 | 560pF | 560p | read from the layout by eye | |
| ×2 | 22nF | 22n | read from the layout by eye | |
| ×7 | 100nF | 100n | read from the layout by eye | |
| ×1 | 220nF | 220n | read from the layout by eye | |
| ×4 | 1uF | 1u | electrolytic; read from the layout by eye | |
| ×1 | 4.7uF | 4.7u | electrolytic; read from the layout by eye | |
| ×3 | 10uF | 10u | electrolytic; read from the layout by eye | |
| ×3 | 22uF | 22u | electrolytic; read from the layout by eye | |
| ×3 | 100uF | 100u | electrolytic; read from the layout by eye | |
| Diodes 4 | ||||
| D1 | 1N5817 | 1N5817 | read from the layout by eye | |
| D2 | 1N5817 | 1N5817 | read from the layout by eye | |
| D3 | 1N5817 | 1N5817 | read from the layout by eye | |
| D4 | 1N5817 | 1N5817 | read from the layout by eye | |
| Transistors 2 | ||||
| Q1 | 2N5457 | 2N5457 | JFET; read from the layout by eye | |
| Q2 | 2N5088 | 2N5088 | read from the layout by eye | |
| ICs 6 | ||||
| REG | 78L15 | 78L15 | regulator; read from the layout by eye | |
| IC1 | JRC4558 | JRC4558 | read from the layout by eye | |
| IC2 | MN3007 | MN3007 | read from the layout by eye | |
| IC3 | CD4047N | CD4047N | read from the layout by eye | |
| IC4 | 1458 | 1458 | 1458, TL062, LM358 etc.; read from the layout by eye | |
| IC5 | LT1054 | LT1054 | read from the layout by eye | |
| Potentiometers 3 | ||||
| Ch/Vib | B10K | B10k | Potentiometer | read from the layout by eye |
| Depth | B100K | B100k | Potentiometer | read from the layout by eye |
| Rate | C1M | C1M | Potentiometer | read from the layout by eye |
| Trimmers 4 | ||||
| Bias | 100K | 100k | read from the layout by eye | |
| Cancel | 5K | 5k | read from the layout by eye | |
| Gain | 100K | 100k | read from the layout by eye | |
| Volume | 100K | 100k | read from the layout by eye | |
| Switches 1 | ||||
| Vibrato/Flange Sw | DPDT on/on | DPDT ON/ON | toggle; read from the layout by eye | |
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