Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Reduction => Topic started by: 2SunSounds on April 29, 2023, 02:52:43 PM

Title: Reduction modifications
Post by: 2SunSounds on April 29, 2023, 02:52:43 PM

Now that Bottlehead has "retired" the Reduction, with a new Eros 2 Phono preamp, I am embolden to ask the following. I find the Reduction lacking detail and slam. Is there an "easy" change to Reduction to use 12ax7 tubes (with the hope of improved sound)?

Title: Re: Reduction modifications
Post by: Paul Joppa on April 29, 2023, 03:45:58 PM

In a word, no. The tubes are as different as it is possible to be.

The C4S plate loads and shunt voltage regulator upgrades are the only improvements we've found, other than the usual tube rolling.

Title: Re: Reduction modifications
Post by: Paul Birkeland on April 30, 2023, 05:11:12 AM

I would add that with the 12AX7, you would have to compromise and either use feedback equalization or a third tube stage in order to deal with output impedance issues.  We typically find that feedback equalized RIAA preamps don't sound all that great, and the kit isn't set up in such a way that you could add a third tube, so those changes are tough to make. 

Tube rolling can have a big impact here though!