I have a Chenin (2006 build) and I must say that it is an excellent platform for modifications. I have done several modifications to the unit and I believe it is now the best sounding preamp I have ever heard. Here is what I did to the linestage (no TT at the moment):
-Each 6SN7 replaced with one 2C22 single triode. This decreases the overall gain and requires re-wiring the socket and drilling four holes in the top plate for the anode and grid top cap wires to pass through. High-med-low selector switch removed and replaced with standoff to wire the CCS in place.
-Plate resistor for above tubes replaced with CCS made from cascoded IXYS 10M45S current regulator chips, running at 14.6mA current and 175V. This reduces distortion to extremely low levels and restores some of the gain lost in the 2C22 conversion.
-Cathode resistor and bypass cap for above tubes replaced with 4 stacked 1A, 600V Cree SiC Schottky diodes (3.4V bias).
- Power supply electrolytic caps (33uF and 100uF) replaced with Solen PP caps.
- Output transformers replaced with Lundahl LL1674 amorphous cobalt core units wired 4:1 stepdown, with snubber network of 2nF PPMFX Multicap and 520ohm TX2575 resistor on outputs. The transformer resistor loading selector switch is disconnected as it is no longer needed.
- Mute switch disconnected.
- Output Auricaps replaced with Duelund CAST PIO.
- Regulator tubes replaced with Sovtek KT-66
- Rectifier replaced with Mullard GZ-33
With these mods the Chenin is a worldbeater IMO. It is dead quiet at idle and very dynamic yet sweet in the midrange. If you are into DIY and want a great platform for modifications, pick up a used Chenin and have at it. I particularly like the copper chassis and separate power supply, and the point-to-point wiring makes mods much easier to do.
Anyone in the New Jersey area who wants to hear the effects of such mods is welcome to stop by for a visit, just PM me.
.
-Each 6SN7 replaced with one 2C22 single triode. This decreases the overall gain and requires re-wiring the socket and drilling four holes in the top plate for the anode and grid top cap wires to pass through. High-med-low selector switch removed and replaced with standoff to wire the CCS in place.
-Plate resistor for above tubes replaced with CCS made from cascoded IXYS 10M45S current regulator chips, running at 14.6mA current and 175V. This reduces distortion to extremely low levels and restores some of the gain lost in the 2C22 conversion.
-Cathode resistor and bypass cap for above tubes replaced with 4 stacked 1A, 600V Cree SiC Schottky diodes (3.4V bias).
- Power supply electrolytic caps (33uF and 100uF) replaced with Solen PP caps.
- Output transformers replaced with Lundahl LL1674 amorphous cobalt core units wired 4:1 stepdown, with snubber network of 2nF PPMFX Multicap and 520ohm TX2575 resistor on outputs. The transformer resistor loading selector switch is disconnected as it is no longer needed.
- Mute switch disconnected.
- Output Auricaps replaced with Duelund CAST PIO.
- Regulator tubes replaced with Sovtek KT-66
- Rectifier replaced with Mullard GZ-33
With these mods the Chenin is a worldbeater IMO. It is dead quiet at idle and very dynamic yet sweet in the midrange. If you are into DIY and want a great platform for modifications, pick up a used Chenin and have at it. I particularly like the copper chassis and separate power supply, and the point-to-point wiring makes mods much easier to do.
Anyone in the New Jersey area who wants to hear the effects of such mods is welcome to stop by for a visit, just PM me.
.