Executive headphone preamp and line stage by System Dump

Executive - Headphone Preamp - DIY

$29.99 $40.00

1 left

Executive is a simple headphone amp and line stage with a directly coupled design — a keep-it-simple-stupid headphone output stage, optimized for discrete op amps, with a robust power supply behind it.

It's a combination of state of the art and repairable. Any part can be replaced. Build yours today.

Specifications

Topology	Directly coupled, discrete op amp
Recommended op amp	Sonic Imagery Labs 994Enh-Ticha (dual, DIP8)
Power supply	Bipolar ±18 V
Rectification	SiC diodes — eliminates switching spikes
Function	Headphone amp + line stage
Gain stage board	42 × 35 mm
Power supply board	140 × 69 mm
Mounting holes	M3, both boards
Serviceability	Fully repairable — any part can be replaced

What's included

DIY Boards — 1 × gain stage board + 1 × power supply board (bare PCBs)

Not included: components (see BOM below), op amp, transformer, volume pot, standoffs.

Documentation & parts

Complete BOM (XLSX)Mouser shared project DigiKey bulk-add list Mouser BOM (CSV)

Easiest route: open the Mouser shared project and add all parts to your cart. Or paste the DigiKey list into your cart's Bulk Add box, or upload the CSV using the Mouser BOM Tool (account required). The list covers both boards plus the RCA jacks, IEC inlet, fuse holder and 0.5 A slow-blow fuses; the transformer is ordered separately (below).

Recommended op amp

We recommend the Sonic Imagery Labs 994Enh-Ticha — a dual discrete op amp in the standard 8-pin DIP footprint. It runs comfortably on the Executive's ±18 V rails, and its Class A output stage can source or sink 150 mA, so it's at home driving headphones directly. Ordered separately.

Sonic Imagery Labs 994Enh-Ticha

Build notes

The questions we get asked most. Short version: the values in these positions aren't critical — more than one answer is correct.

Decoupling / bypass caps — the silkscreen says 1 µF. Either 0.1 µF or 1.0 µF works in those positions. Use whichever you have on hand; nothing here is crucial to adhere to.

Feedback resistor — this is what sets your gain. 1k gives you 1 dB of gain, 10k gives you 10 dB. Pick the value that suits your headphones and source.

LED resistor — 470k. The LED goes between the power rails, so it sees the full 30 V. 470k keeps the current low: a nice dim glow, and a safe value for the LED not to go boom.