If you check out This Thread
, you'll notice that the Bozak uses 3 different types of circuitry...
Taken from Vinyl Junkie's thread
There are 3 (not including the original D, which is different, but so rare it doesn’t bear discussion) types of Bozak circuitry – and you can interchange between transistors and various other options such as caps and I/O features freely. This means that the mixer can be customised exactly to a configuration that suits your ears – some people prefer the ‘hairier’ sound of the early Bozak, and some prefer the ‘sweeter’ sound of the later models – you can even have an interim version which isn’t as quiet as the last DLA-onwards version, but is just as smooth – for example.
What's amazing is that people talk about the Bozak having a 'particular sound', yet the 3 versions all sound very different (this is also complicated by the fact that each version is sensitive to setup, which – again - affects sound).
Due to its design, the Bozak is particularly sensitive to transistor beta. The 3 grades of circuitry used each have very different transistors, each with completely different noise specs / Hfe.
Anyway - as I said response to your PM, MC, because Bozaks were hand-built, they often substituted parts - you find many inconsistencies and anomalies. I regard finding out which quirks apply to your mixer as one of the joys of owning a Bozak - each one has a different story to tell.
BTW - In the 2nd post in this thread, the poster is talking about the DLA-onwards type of circuitry, which would explain the confusion!
I find it absolutely amazing that, in all the 5 years I’ve been visiting this group, this and VJ’s thread from last December are the first times I’ve seen it mentioned that the Bozak uses 3 different kinds of circuitry!