Thoughts on Pass B1 buffer "preamp"?

Hi everyone,


My system is a fully horn loaded 104dB multi-amped system with an analogue active crossover. Main source is digital, DAC outputs a high 3v. For years and years I've been using the same vintage preamp, that I love, an almost unknown Korn&Macway SP100 that sounds fantastic.

Lately tho I've been wondering about trying out a simple buffer volume control such as the Pass B1, as with the preamp most of my listening happens with the volume pot well under the 09:00 position. The preamp has a great potentiometer (ALPS Black Velvet) and sounds great even at these low positions, no channels unbalance or such, but still it seems stupid to throw away so much volume to amplify it again farther down the chain.

I'd also love to have something that I can thinker with easily (swapping coupling caps, trying a stepped attenuator, that sort of things, without demolishing my beloved preamplifier.

So I'm looking for people who are using or have been using a B1, for reference. Basically, does it sounds as good as the hype says?


Well, I took the plunge and bought one, built by someone else with quality parts.

I must say, it sounds fantastic, very transparent but not thin nor sterile. A wonderful preamp.

@pindac the Korg version is a very different beast, I'm talking about the basic B1 JFet buffer.

@vinylvalet yup I've seen it, actually that's why got me interested and I don't regret it! There's my thread too now (Nickname is Kanedak)

@rolox I know the B1 Buffer, I have heard it used not too many years past, on a few different systems. I have also heard it in different build guises, even one that was referred to as the Hot Rodded version. It was one on my list to get to receive a Demo' from when I commenced with the idea of having a New Pre-Amp' or Not. 

At this time, I was receiving demo's of a variety of simplistic design Pre's, Buffers, Stepped Attenuators and TVC's in my own system as well as other systems. 

My Travels have introduced me to a few different versions of Pre-Amp, where the designs are able to create a quite different Sonic between the models.

I have recollections of demo's that were perceived as being quite Clinical, through to a design that can be perceived as having a perception of being Ethereal.

Across the demonstrations I have found that I am with a predilection for a Pre-Amp' that creates a perception of Transparency. To date I certainly have not encountered any Branded Products that are able to create this bias I have toward the Sonic Trait of being 'Transparent'.

The impression made on myself that got my attention was a Slagle AVC. I bought the AVC, as a Stop Gap, I classed it as the best of a Group, better than what I was using, but not quite what I was hoping to discover. It has been a decent device to be in use, whilst I have been working my way towards a Keeper Pre-Amp or Not.

I settled for the AVC as the stop gap Pre-Amp'. Other Pre-Amps' when in use in my system, had left an impression they were not as attractive as the Slagle, each was adding their own Sonic Traits to various levels of being perceived.

The Slagle has a Sonic Trait, that I am able to live with, even though it is one that is not attractive to me. The Sonic Trait which I am detecting is present, and is not comfortable for my sensitivities, is present with a very small perception, which for myself is relatively easy to be overlooked.

My pursuit evolved into seeking out a Pre-Amp that is able to be perceived as getting completely out of the way of the Signal being received.

At present, after a Long-Term Loan of a very much liked DIY Built Pre-Amp', that can really create the perception of being 'Transparent' and out of the way not impacting on the Signal received.

I have decided to continue with a method to acquire a Pre-Amp', that I have had in use for the building of my system, a method that I have been sold on for too many years. 

I have now embarked on the tried and trusted methods for building the system. I am to have a Bespoke Design and Built Pre-Amp produced for myself.

The Pre- Amp' Circuit is designed. It is based on a 'Balanced Model'. I have had the Topology laid out for me, and Bespoke PCB's are now produced and in my Possession.

I have had two Volume Controls Bespoke Produced, that are extremely quiet and very precise in their measurements to each other. 

Power Supplies are in the design stages at present, which will be a refined version of a Power Supply that has made a big impression on an upgraded version of the long-term loaned Pre-Amp'. The Upgrade version of the Pre-Amp has been the most impressive Pre-Amp I have received as Demo' in my own system and been demo'd in other systems.  

I believe the Pass B1 Buffer was the first Pre' I went out of my way to receive a demo' of when I commenced with my investigations, it certainly was the Buzz Amp at the time of the DIY Section of forum users from this period. Indirectly it is responsible for how I have evolved during my search for an end game Pre-Amp'.  

There are numerous converts to the Korg B1 from the B1, it will be interesting to see how your inquisitive evolves, as a result of the Honeymoon Period with the B1 coming to an end.