M-1 Golden Retriever Discrete OpAmp Dual Microphone Preamplifier





Built For Simon Berckelman and Golden Retriever Studios

The M-1 Dual Microphone Preamplifier is a discrete opamp based unit that provides lots of clean gain and a very broad frequency response.  Its design is essentially similar to that of the Duette unit I built some years ago.  Simon has borrowed this piece many times so we thought why not build one for his studio?  

One of the interesting features of this unit are the amazing ITT 30 position switches.  They feel very solid and it's great to make small changes of gain which are instantly repeatable.  As well, the top switches allow the output to be switched from transformer to unbalanced capacitor-coupled for a different sound.   Simon has some nice vintage Quad Eight transformers that are used here.  

Of course the case itself is unique.  It comes from military service and still has the U.S. Property badge to prove it!  Besides having a lid for easy transport servicing the unit is very easy as the entire chassis slides out of the enclosure by releasing the front bolts.