BeePre 2 Modification for Highly Sensitive Systems

[aroide]

PB,

Is there an equivalent change for the original BeePre (with BeeQuiet)?  I have to put a -12dB L-pad at my amp to drop the hum noise so it doesn't bug me.  I'd love to handle that at the preamp end.  Lower gain is not an issue.

And I've eliminated all the usual noise suspects.  And have a nice 120V of regenerated power.

[Paul Joppa]

The original BeePre solves that particular problem in a different way, so there is no equivalent.

[PT]

I recommend part number PR02000202709JR500.

Does it have to be specifically Vishay or any other metal film 27R 2W 5% should do?

[Paul Birkeland]

Any one will do.

[PT]

Any one will do.

Modification performed and tested. Solid -13.5 dB noise decrease for me based on attenuator settings, a great improvement when used with headphones, especially at low volume listening.

[Toobuzz]

I finally got around to installing these 4 resistors and it made an enormous difference. I don’t have sensitive speakers (87db) but it is an obvious improvement in lowering the noise floor.  In between tracks or in quiet passages one could easily detect a buzzing noise from the listening chair. Now, at loud listening volumes (without music playing) I can barely detect noise with my ear an inch away from the drivers.  My only regret is waiting so long to do this mod.  Great work, PB!

[ConradEdgewood]

I did the Modification for Highly Sensitive Systems, and it works great!  My question is, with each upgrade, does it ever get removed?  I did the stepped attenuator/Constant Current Source upgrade, and now will do the Output Hybrid Shunt Regulator and low impedance balanced output upgrade.  Do I just keep the resistors from the Highly Sensitive Systems in place?  Or should they be removed with one of these upgrades?  Thanks in advance.  Eric

[Paul Birkeland]

You can leave the resistors there.  When the second upgrade is added, they are not explicitly necessary anymore, but they also don't hurt anything.