PR-101 Preamp Upgrades

The PR-101 preamp is no longer in production, but you can still apply upgrades.

You can install the PR-102 Tone Volume board into your PR-101. The PR-102 Tone Volume board adds these features:

F3 gets re-mapped into a MONO function. That's handy if you're listening to old mono records, as it drops the overall noise level.
F4 gets re-mapped into a HUSH function. Activating the HUSH button drops the signal level by 20 dB. It's perfect if you typically listen at background levels, as it lets you run the volume control in the central region. It's also great when someone enters the room for a discussion, but you want to leave the music playing.
The topology is a bit different than the PR-101...while both have vanishing distortion, the PR-102 has a slightly shorter signal path.
The PR102 Tone/Volume PCB has a pair of outputs, making it easier to hook in the headphone amp.