Hi,
Recently I acquire a beautiful pair of unfinished Ecio HF-60 project from a forum member, I want to share the information with my success to build this project, any opinion are welcome.
I had completed build one unit. I do some changed on the circuit as below
1. Add CCS on the long tail pair instead of the 18K resistor.
2. Add voltage regulator for driver stage instead of the 15K.
3. Removed the EF86 cathode 50 uf cap to reduced some gain.
4. Used solid state rectifier for B+ instead of GZ34 tube. B+ was 40 volt
higher, the output was increased to around 70 watt at clip point.
5. Add dynamic bias control and set idle current at 40ma from 65ma.
6. Add a 0.5A fuse at B+ to output transformer.
7. Add a thermistor on the power transform primary side.
Recently I acquire a beautiful pair of unfinished Ecio HF-60 project from a forum member, I want to share the information with my success to build this project, any opinion are welcome.
I had completed build one unit. I do some changed on the circuit as below
1. Add CCS on the long tail pair instead of the 18K resistor.
2. Add voltage regulator for driver stage instead of the 15K.
3. Removed the EF86 cathode 50 uf cap to reduced some gain.
4. Used solid state rectifier for B+ instead of GZ34 tube. B+ was 40 volt
higher, the output was increased to around 70 watt at clip point.
5. Add dynamic bias control and set idle current at 40ma from 65ma.
6. Add a 0.5A fuse at B+ to output transformer.
7. Add a thermistor on the power transform primary side.
