DIY KIT: will need yourself to solder all parts
Assembled board: we will soder and tested it well.
PCB Size: 160mm*110mmX1.6mm
Works Voltage: recommend AC15V-0-AC15V
HV-1 Highlights:
1. The power triodes are connected in parallel to improve the driving force and control force, and the sound field is wider; it effectively solves the problem that the original A1 circuit promotes the weak intermediate frequency and poor control force of the AKG and Senhai series headphones, and the effect is very obvious!
2. 300MV earphone special protection circuit,
3. Omron power relays have larger contacts and copper sheets than small signal relays, and the signal loss is lower.
4. Separate power supply for the op amp in the AMP to improve the separation degree
5. Optimized ground processing, higher signal-to-noise ratio
HV-1 Hearing Summary
Three-stage balance, neutral and mellow, suitable for various types of headphones, "All-match King" headphone amplifier
Basic parameters:
• effective Vp-p 23.47
Frequency response, 20 HZ-20 KHZ (+ 0.01, 0.09),
signal-to-noise ratio:-90 DB or below,
the dynamic response, more than 91 DB
• total harmonic distortion (THD) : < 0.007%
• intermodulation distortion: < 0.007%
• stereo separating degree: > 88 DB (1 KHZ)
• suitable 32-600ohm load.
Main materials:
Original ST33078N dual op amp, STDB139-140 power transistor
Japan ALPS 27 type Potentiometer.
1/4W 1% precision metal film resistor
Omron G2R - 2 12V Relay 700MV Protection circuit,7 seconds delay connect function.
Package include: HV1 Headphone amplifier kit ( board ) X 1 (inlcude the ALPS Potentiometer)
The suitable power transformer link :
https://www.ebay.com/itm/325306923969