I just finished a PassDIY Pearl and need just a little more gain. Maybe 20dB or so. I am using an AN UK transformer to get it up to about the same level as the disc player and tuner. But would love to do it with active amplification. Do any posters have a simple circuit suitable as a moving coil amplifier.
I have single rail supplies, very quiet and around 20v available to power either a transistor or opamp. Looking for warm, full bodied, fast, dynamic, and quiet. Not asking for much.
The MM input is close to the jacks, the leads could be pretty short on both ends. Currently the unit is very quiet even with the transformer.
George
I have single rail supplies, very quiet and around 20v available to power either a transistor or opamp. Looking for warm, full bodied, fast, dynamic, and quiet. Not asking for much.
The MM input is close to the jacks, the leads could be pretty short on both ends. Currently the unit is very quiet even with the transformer.
George
Thanks, I will breadboard one up and give it a try. What voltage battery do you use? The input stage in my phono has a well filtered supply putting out 11 volts. Can this be used instead of the battery?analog_sa said:Try 2 parallel 2sk170; drain - 1.2k, source - each 33R, whatever loading resistor suits you at the gate, 2.2uF output cap. Plays fine with 300uV carts and with NiMH batteries, tantalum resistors and MIT RTX output caps better to my ears than any transformer i've tried
George
I am about to put this together. It is very close to the input stage of the Pearl. I have purchased 2SK170 transistors from MCM several times. They are not listed as GR, BL, or V. But looking at the transistors they are the GR and BL classification.analog_sa said:Try 2 parallel 2sk170; drain - 1.2k, source - each 33R, whatever loading resistor suits you at the gate, 2.2uF output cap. Plays fine with 300uV carts and with NiMH batteries, tantalum resistors and MIT RTX output caps better to my ears than any transformer i've tried
The Pearl uses the BL type and the IDSS runs 2 - 3 ma with 11 volts Drain to Source. Is there an advantage to using the GR at the low current levels?
George
I am about to put this together. It is very close to the input stage of the Pearl. I have purchased 2SK170 transistors from MCM several times. They are not listed as GR, BL, or V. But looking at the transistors they are the GR and BL classification.analog_sa said:Try 2 parallel 2sk170; drain - 1.2k, source - each 33R, whatever loading resistor suits you at the gate, 2.2uF output cap. Plays fine with 300uV carts and with NiMH batteries, tantalum resistors and MIT RTX output caps better to my ears than any transformer i've tried
The Pearl uses the BL type and the IDSS runs 2 - 3 ma with 11 volts Drain to Source. Is there an advantage to using the GR at the low current levels?
George
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