While everyone is entitled to their own opinion, I find the above post at the asylum entirely off mark. I've owned the TF10, and own the TF12 (about six years and counting), and find the TF12 to be a considerably better preamp than the TF10 (though the TF10 is no slouch, particularly with the "A" modification). The TF12 has a considerably lower noise floor; has a much, much wider dynamic range; throws a huge soundstage on the X,Y and Z axis, and is anything but thin or silvery sounding, nor is it polite and soft. The preamp (like all of Berning's equipment) is an accurate conduit through which music flows - it is neither euphonic in the typically tubey way, nor is it sterile and thin (in fact, being a pure tube design it is much less euphonic than the hybridized TF-10). If you are looking for a preamp that is more forgiving, then the TF10 is the right choice for you. However, as one's associated equipment continually improves, it becomes more and more obvious that the TF12 simply lets one see into the musical picture with greater resolution and understanding - something that the TF10 eventually hits a brick wall with. As far as reliability issues are concerned, Berning used sockets for some of the ICs in the unit, and these are best removed and the ICs directly soldered to the board to avoid some of these issues (particularly the +/- 12V regulators for the volume circuitry). The TF10 has much greater switching flexibility for tape paths and the such, and it also has 3(!) phono inputs should one have multiple RIAA sources, and one may be configured as a MC input. The TF12 avoids most of the clutter in the signal path (at the expense of all that switching) to focus more on fidelity. The TF12 also dispenses with normal potentiometers, and instead employs an optical encoder to step the volume/balance in 1 dB increments for greater accuracy and repeatability - and all this accomplished via a remote which is nice. The tube complement of the two units is totally different - the TF10 utilizes 12AT7 throughout (except for the phono stage which uses 12AX7). The TF12 is based on the 6DJ8 for line-level amplification (and uses the same ECC81/83 complement in the phono stage). Tube life is superlative (as it is in all Berning products). The TF10 is built using conventional phenolic circuit boards; the TF12 utilizes Teflon ciruit boards. There are several worthwhile upgrades to the TF12 which David Berning mentions on his website which I have deployed to great effect. In conclusion, both preamps are unflagging in their dedication to making music. Both are competent high-fidelity devices, but the TF12 takes everything the TF10 does right several levels higher, and omits the things the TF10 does wrong entirely. Easy choice. Good listening,
-Richard