Computer device to pair with a Bitzie...

Nuance_Ember wrote: 1. The Bitzie tends to store quite a bit of charge on the analogue outputs. So I can leave the Bitzie unpowered for a few days, plug in my HD250II and then its diaphragm "pops". I can unplug it and plug it back in and it does the same thing repeatedly...  Is that normal???

This is not static. It is output capacitor charge. We have always used AC coupling capacitors and where there's room we use pull down resistors to maintain the charge. But on the Bitzie, and because we use full size metal film resistors (for a good reason), there is not the room. It does not cause any damage to headphones... you'd get more of a crack from quite a number of album tracks and definitely on some we test products with.

Nuance_Ember wrote: 2. When the dial of the Bitzie is furthest anticlockwise or just a little bit away from this point, I still hear a small amount of audio through the left channel of my HD250II whilst the right channel is completely off. As I turn up the dial, the balance soon establishes... Why is there this initial unbalance Graham?

One day I'll test a 'blue velvet' for this. Nobody ever comments about them doing the same and if they don't they're definitely defying physics...

...or perhaps it's because they cost so much nobody likes to admit they do it... we'll see.

Anyway, as it would be impossible to fit a 'blue velvet' in the Bitzie because of its size, I chose the high quality 9mm pot by the same manufacturer, Alps, and they're really well matched.

Matching is performed to be in the range of normal use, and as very few people insist on listening with the volume turned fully down, the manufacturer matches the two separate carbon (or polymer) resistance tracks to be a close match around the mid point of rotation. There will always be some residual resistance greater or lesser on one of the gangs compared with the other at either end of the travel. It is known in engineering as tolerance (something hi-fi users don't have much of).

You can get perfection however... Where it is essential such as in the recording studio, or in broadcasting, there is a perfect potentiometer which is made by Penny & Giles. Being a slider and having around 100mm of travel, it won't fit any of our existing products. They used to cost £60 each at trade prices 20 years ago...

Graham

You were referring to noise when connecting your headphones. With connected devices such as amps and speakers, the power up/power down of the Bitzie due to computer being switched on or off has never caused the same issue... otherwise we'd have done something about it.

I speak in a friendly but partially blunt 1970's 'north of the river Dearne tone' which is quite unique (and rare these days) in that it's not only a caring tone but a corrective one which only occurs in people whose eyes have been opened by a lifetime of experience in a particular subject.

Much of what you say is correct, especially in that improvements to your listening environment (equipment and other things) improves your perception so the equipment is responsible for part of the improvement and the listener for the remainder.