Description
Celebrated Elektor audio design specialist Ton Giesberts has once again released a phenomenal design for a high-end audio power amplifier, the Elektor Fortissimo-100. Once again, the results of the amplifier on the test bench challenged Elektor’s high-spec Audio Precision test gear close to its noise floor.
The specifications, ease of construction, and the overall stability of the Fortissimo-100 are deemed so good that Elektor are offering the project as a kit of parts for assembly at home, using plain tools. The kit contains each and every part to build one Fortissimo-100 mono block, including a set of high-quality PCBs, the heatsink, and other mechanical parts like standoffs and ceramic isolation washers for the power transistors. Again, all parts are through-hole.
A detailed, step-by-step assembly guide (downloadable PDF) should enable every audio lover with the ability to work accurately and sensibly, to assemble the mono block and ravish at the sound quality. Two mono blocks are required to build a Fortissimo-100 stereo amplifier, plus a symmetrical 40-V, stabilized power supply per amplifier. Don’t use a single power supply for two amplifiers! The supply is not included in the kit, but a suggested source is given in the description for the project, so readers can opt for their personal desires.
Specifications
| Input Sensitivity | 1.076 V (94 W/8 Ω, THD = 0.1%, B = 22 kHz) |
| Input Impedance | 10 kΩ |
| Sine-wave Power | 94 W (8 Ω, THD = 0.1%)
181 W (4 Ω, THD = 0.1%) |
| Bandwidth | 3.3 Hz – 237 kHz (–3 dB, 1 W/8 Ω) |
| Open-loop Bandwidth | ≈ 20 kHz |
| Open-loop Gain | ≈ 140000 (8 Ω load) |
| Slew Rate | 45 V/μs |
| Signal-to-Noise Ratio | 103 dB (B = 22 Hz – 22 kHz linear) |
| Harmonic Distortion Plus Noise | 0.0008% (1 kHz, 50 W, 8 Ω, B = 80 kHz)
0.002% (20 kHz, 50 W, 8 Ω, B = 80 kHz)
0.0042% (20 kHz, 100 W, 4 Ω, B = 80 kHz) |
Intermodulation Distortion
(50 Hz : 7 kHz = 4 : 1) | 0.0015% (50 W, 8 Ω)
0.0041% (100 W, 4 Ω) |
Included
- Two PCBs: amplifier PCB and protection PCB
- All parts, including heatsinks
- Construction Manual – Downloadable PDF
Elektor Jumpstarter
This product is the result of a successful campaign on our electronics project support platform Elektor Jumpstarter. Readers and interested parties can submit their product ideas and, together with the Elektor development team, a finished product can be brought to market after extensive consideration and many tests. Note that these are always small series production runs, so the products are considered 'Elektor Collector Items'.
