Germanium Pre-amp

Hey man,
hope all is well with you and your family.  Have you checked out my website videos yet?

Well the mixer is on hold indefinitely
Picked up a Soundcraft Folio for now

Germanium Preamp

Germanium Preamp

The studio is but a few weeks away from semi completion. Just painting(not sure what color)and sound proofing I’ve added a pic of a Chandler Germanium Pre amp Wondered if you could theorize what’s going on inside

Thanks Paul

1 Comment

  1. Strangely( author ) :

    Feb 26, 2009 8:01 am |

    Paul.
    Well it’s the best part of 1000 quid, I can tell you that. You can probably sense an impending torrent from myself; so I won’t disappoint!

    For ALL this sort of thing, whenever I see the word “classic” I immediately replace it with the word “Old” – it helps keep things in context!

    So to the front panel, and ignoring sockets, we have a gain control (works in combo with the feedback control); some “Pad” and “Thick” preset equalisation switches; and a feedback control.

    The whole thing is Class A germanium, they say. A big selling point is that all the old “great” preamps and consoles used Germanium…. This is a pure statement of fact brought about by necessity. Germanium transistors pre-dated silicon by several years hence they were the only ones about! After the initial point-contact types, the junction type was developed which was more robust. However, you have to ask yourself WHY the manufacturers moved to junction silicon SO rapidly when that technology was invented? Even the top-end hi-fi makers did!!!

    The answer is that silicon is better on many fronts.

    Germanium has an advantage when used in Class B because it’s B-E voltage drop is only 0.1V c.f. 0.6V for silicon. However this amp uses Class A! It’s (hopefully) striving to get a linear response across the whole range of its Vce max. It says the PSU is 40V…this is the top-end Vce for most small signal germanium stuff. So this preamp is probably using the full voltage swing and striving to be linear throughout. This of course is impossible and is what gives the “sound” to the product.

    My definition of a preamp is that it should amplify without making it’s presence known. Anything else, in technical terms is called distortion! So if you hear the effect an amp is making, it’s not an amp any more – it’s a sound spectrum modifier.

    If you want to pay £1000 for that then I can make you one and you can give the money to me instead! I know how to wire up a few OC71s and OC72s with a bit of surrounding circuitry, ha ha! It was my very first construction project, after all.

    The FEEDBACK is positive and the “sound” is that of a Class A transistor driven into clipping. In old radio parlance this was called “regeneration”! To reduce the harshness of the sound, they’ve tandemed the control (probably ganged) to a standard simple tone control so that as gain(+ve feedback) increases, THD goes up, treble is cut and bass is boosted. Apart from my guessing the actual operation, the words are all theirs. A thousand quid for that? Not ‘arf!

    Your new mixer.

    Isn’t this the company that Douglas Self used to work and design for? You could be using one of his creations! I hope you have some success with it.

    I’ve checked out some of your video links. Personally, it’s sort of interesting but a bit negative-conspiracy-thing and at this point in my existence I’m striving to be positive and see the bright things. I know I report the dark things on this website a lot, but it’s only because I can see the bright sunrise of a gleaming future, and I don’t want it dimmed.

    BTW. Did you know Johnny has decided to get back on the road in a BIG way? Fair play.

    Rees