Enclosure not stated · 3 knobs
Boss FA-1 FET PreampVerified
Based on the Boss FA-1 FET Amplifier· 5 other boards clone it
From the post
Well it's the 21st here so I'm getting this one in early in case the world ends soon so we can get it verified first. :o)
Another must try for fans of U2 and The Edge and another one of the boost pedals in his arsenal. Info from Boss about the long discontinued original:
The FA-1 is an incredibly small Field Effect Tramsistor (FET) based pre-amp. The controls are real easy. There's controls for volume, bass, treble and a low cut filter switch. The amplification is as much as 20 times (26dB) and it has an input impedance higher than any other device.
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 Tagboard Effects. No KiCad fragment has been drawn for this circuit yet.
Parts list 24 rows
Report a wrong parseGot parts in a drawer? See what you can build with them.
| Ref | Value | Normalized | Type | Notes |
|---|---|---|---|---|
| Resistors 11 | ||||
| ×3 | 10K | 10k | read from the layout by eye | |
| ×2 | 15K | 15k | read from the layout by eye | |
| ×2 | 470K | 470k | read from the layout by eye | |
| ×2 | 8K2 | 8.2k | read from the layout by eye | |
| ×1 | 1M | 1M | read from the layout by eye | |
| ×1 | 100K | 100k | read from the layout by eye | |
| ×1 | 33K | 33k | read from the layout by eye | |
| ×1 | 22K | 22k | read from the layout by eye | |
| ×1 | 3M3 | 3.3M | read from the layout by eye | |
| ×1 | 6K8 | 6.8k | read from the layout by eye | |
| ×1 | 470R | 470 | read from the layout by eye | |
| Capacitors 7 | ||||
| ×2 | 5n6 | 5.6n | read from the layout by eye | |
| ×1 | 10n | 10n | read from the layout by eye | |
| ×2 | 33n | 33n | read from the layout by eye | |
| ×1 | 47n | 47n | read from the layout by eye | |
| ×1 | 470n | 470n | read from the layout by eye | |
| ×4 | 10u | 10u | electrolytic; read from the layout by eye | |
| ×1 | 100u | 100u | electrolytic; read from the layout by eye | |
| Transistors 1 | ||||
| Q1 | 2SK246 | 2SK246 | JFET; Q1 is 2SK246 or similar; read from the layout by eye | |
| ICs 1 | ||||
| IC | LM1458 | LM1458 | IC is LM1458 or similar; read from the layout by eye | |
| Potentiometers 3 | ||||
| Treble | B50K | B50k | Potentiometer | read from the layout by eye |
| Bass | B50K | B50k | Potentiometer | read from the layout by eye |
| Volume | A1M | A1M | Potentiometer | read from the layout by eye |
| Switches 1 | ||||
| Low Cut / Flat | SPST | SPST | toggle; 2 position SPST or SPDT (only lugs 1 & 2 used); read from the layout by eye | |
Other boards based on the Boss FA-1 FET Amplifier
- Prism Aion FX · 125B · $12.50
- Prism (Legacy) Aion FX · 1590B
- Boss FA-1 FET Amplifier Dirtbox Layouts
- Boss FA-1 FET Amplifier Effects Layouts (blog) · 1590B
- Amp-fet-amine One Five Cats Pedals · 1590B · £4.50