• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Audio Research

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kmtang

kmtang

Member
Joined 2004
Simplified AR SP-10

I first cloned the SP8 line stage but I didn't like it that much. After I studied the SP10, I found that it is rather for me to modified the SP8 to SP10.

The good thing about SP10 is that it get rid of the first input capacitor. However, the biasing for the first 6DJ8 will be depending on the 2nd and 3rd stage due to the direct feedback from back to front. By the way, I used 0.2uF and 0.47uF Jensen copper-in-oil as the coupling capacitors.

I just employ single 6DJ8 instead of parallel 6DJ8 for the last buffer stage. I removed the 24K cathode resistor because of such reason. I replaced the transistor HV regulator circuits with simple RC bypass filter for the first 2 stages. The line amp is powered by separated tube regulated power supply.

It took 2-3 weeks before the SP-10 breaks in. It sound very well with super clarity, and dynamic. I really enjoy the music from it.

Johnny
 
L

losin

Member
Joined 2007
Clone SP-10
IMGDEAD]
 
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