Enclosure not stated · 6 knobs
Dr Boogie JFET preamp
- Category
- Preamp / Amp-in-a-box
- Price
- see vendorin stock
- Tags
- Dr boogie, mesa, boogie, rectifier
From the vendor
Dr Boogie JFET preamp emulator of the Mesa Boogie Dual Rectifier
Schematic
The schematic image is on the project page. Open it at PCBWay.
Parts list 33 rows
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Check before you build · 9 values the reader of this schematic was not sure of
- Source image is only 600x423 px, so nearly every value is a best reading from 4-pixel text; cross-checked against the higher-resolution Dr Boogie (guitarmania) sheet, which is a close but not identical circuit
- stage 3 coupling resistor to ground 220k vs 330k
- tone stack slope resistor 10k
- tone caps 220n vs 330n
- treble cap 6n8
- presence 2k2 / 33n
- Mid pot B1k and its parallel 1k
- stage 2 gate cap 22p vs 33p
- Bass A100k
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 13 | ||||
| ×3 | 470k | 470k | two series gate resistors plus one at the input; labels barely legible; read from the schematic by eye | |
| ×3 | 1k8 | 1.8k | source resistors of stages 1, 2 and 4; stage 4 label barely legible; read from the schematic by eye | |
| ×2 | 2M2 | 2.2M | input pulldown and the 2n2/680k network to ground; labels barely legible; read from the schematic by eye | |
| ×2 | 100 | 100 | supply filter; read from the schematic by eye | |
| ×1 | 68k | 68k | input series; label barely legible; read from the schematic by eye | |
| ×1 | 680k | 680k | read from the schematic by eye | |
| ×1 | 1M | 1M | stage 3 gate to ground; read from the schematic by eye | |
| ×1 | 3k9 | 3.9k | stage 3 source; read from the schematic by eye | |
| ×2 | 220k | 220k | series into stage 4; stage 3 coupling to ground; label 4 characters, read as 220k or 330k (the guitarmania version has 10k here); read from the schematic by eye | |
| ×2 | 10k | 10k | source follower; label barely legible; tone stack slope resistor; label barely legible (guitarmania version 47k); read from the schematic by eye | |
| ×1 | 1k | 1k | parallel to the Mid pot; label barely legible; read from the schematic by eye | |
| ×1 | 2k2 | 2.2k | presence network; label barely legible; read from the schematic by eye | |
| ×1 | 4k7 | 4.7k | LED resistor; read from the schematic by eye | |
| Capacitors 11 | ||||
| ×3 | 220p | 220p | gate-source caps; read from the schematic by eye | |
| ×3 | 1u | 1u | source bypass caps; read from the schematic by eye | |
| ×3 | 22n | 22n | stage couplers; stage 3 coupler may read 33n; read from the schematic by eye | |
| ×2 | 220n | 220n | tone stack; label read as 220n or 330n (guitarmania version 22n); read from the schematic by eye | |
| ×2 | 1n | 1n | one at the gain pot, one on stage 3 drain; read from the schematic by eye | |
| ×2 | 100n | 100n | input cap; supply bypass; read from the schematic by eye | |
| ×1 | 2n2 | 2.2n | read from the schematic by eye | |
| ×1 | 22p | 22p | stage 2 gate to ground; label may be 33p; read from the schematic by eye | |
| ×1 | 6n8 | 6.8n | treble cap; label barely legible (guitarmania version 680p); read from the schematic by eye | |
| ×1 | 33n | 33n | presence cap; label barely legible (guitarmania version 3n); read from the schematic by eye | |
| ×2 | 100u | 100u | electrolytic supply filters; read from the schematic by eye | |
| Diodes 1 | ||||
| ×1 | 1N4001 | 1N4001 | read from the schematic by eye | |
| Transistors 1 | ||||
| ×5 | J201 | J201 | four gain stages plus a source follower; read from the schematic by eye | |
| Potentiometers 6 | ||||
| Gain | A1M | A1M | Potentiometer | read from the schematic by eye |
| Treble | A25k | A25k | Potentiometer | read from the schematic by eye |
| Bass | A100k | A100k | Potentiometer | label barely legible; read from the schematic by eye |
| Mid | B1k | B1k | Potentiometer | label barely legible; read from the schematic by eye |
| Presence | B10k | B10k | Potentiometer | label barely legible; read from the schematic by eye |
| Volume | A100k | A100k | Potentiometer | read from the schematic by eye |
| Trimmers 1 | ||||
| ×4 | 100k | 100k | drain trimmers drawn as resistors with a wiper tied to the drain; read from the schematic by eye | |