Enclosure not stated · 1 knob
Telefunken Echomixer "Kanal A" Pre AmpVerified
Based on the Telefunken Echomixer "Kanal A" Pre Amp
- Category
- Preamp / Amp-in-a-box
- Controls
- Input Gain
- Build
- Vero· 18×10· 8 cuts, 1 links
- Layout
- Verified · Dirtbox Layouts marks it as built and working
- Tags
- Pre Amp, Telefunken
From the post
A cool little pre amp circuit from an old german reverb unit. It is fairly clean on its own, it adds some volume, lows and sparkles to your sound. When being puched hard, it clips in a very pleasant way. It also works great for pushing a tube amp. And of course it can be used as a studio tool for drums and keys.
The stock transistors were TFK OC603s. After some experimitation I found out that low leakage transistors wih Hfe between 70 and 120 sounded best (....at least to my damaged eardrums) so transistors spec'd for Rangemasters or USSR germaniums works really good.
Layout with onboard voltage inverter. (Still unverified)
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 22 rows
Report a wrong parseGot parts in a drawer? See what you can build with them.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 11 | ||||
| ×1 | 820Ω | 820 | read from the layout by eye | |
| ×1 | 1.5K | 1.5k | read from the layout by eye | |
| ×2 | 5.6K | 5.6k | read from the layout by eye | |
| ×1 | 6.8K | 6.8k | read from the layout by eye | |
| ×2 | 15K | 15k | read from the layout by eye | |
| ×1 | 18K | 18k | read from the layout by eye | |
| ×1 | 47K | 47k | 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 | 150K | 150k | read from the layout by eye | |
| ×1 | 1M | 1M | read from the layout by eye | |
| Capacitors 7 | ||||
| ×1 | 15nF | 15n | read from the layout by eye | |
| ×1 | 68nF | 68n | read from the layout by eye | |
| ×1 | 100nF | 100n | read from the layout by eye | |
| ×1 | 220nF | 220n | read from the layout by eye | |
| ×2 | 10uF | 10u | electrolytic; read from the layout by eye | |
| ×1 | 100uF | 100u | electrolytic; read from the layout by eye | |
| ×2 | 220uF | 220u | electrolytic; read from the layout by eye | |
| Diodes 1 | ||||
| D1 | 1N5817 | 1N5817 | read from the layout by eye | |
| Transistors 2 | ||||
| Q1 | OC603 | OC603 | germanium; read from the layout by eye | |
| Q2 | OC603 | OC603 | germanium; read from the layout by eye | |
| Potentiometers 1 | ||||
| Input Gain | C10K | C10k | Potentiometer | read from the layout by eye |