The STC4001B Acoustic Baffle for the STC4021 (Apple & Biscuit) circa 1935.

The very first post that I wrote for this blog back in 2012 was about the STC4021 (Apple & Biscuit). Still one of my favourite microphones.  I even made a YouTube video to go with it! In the course of the video I mentioned the STC4001B Acoustic Baffle. According to the STC brochure this could be purchased to modify the frequency response and directionality of the microphone. These days the 4001B Acoustic Baffle is very hard to find. So imagine my surprise when a brand new old stock 4001B (still in the box) appeared on eBay. 

So I thought I had better ‘Buy it now‘ and make another video to celebrate the occasion!


2 responses to “The STC4001B Acoustic Baffle for the STC4021 (Apple & Biscuit) circa 1935.

  1. Hello Martin, I love your site and am glad to see your most recent up dates are on one of your favourite mic’s and my most treasured mic/heirloom; that I was given by my mother who was a newsreader on the New Zealand equivalent of the BBC. The NZBC, once apon a time, still felt very connected to England and so in the 1930’s in the spirit of Empire, asked for and were sent a few experienced British architects and Audio boffins to design and supervise the construction a new building of studios and control rooms for the broadcast and recording of Drama, Music and Parliamentary Proceedings. There is a spurious story that does the rounds of it being the chaps who built one in Londen that would later be bought by EMI located on Abbey Road. Regardless, those studios (50 years later) were where I spent a great amount of time as a child exploring and irritating the venerable sound technicians who had likely been there since opening day. But, they indulged me and thats how I became a devotee of vintage recording equipment (or as it was known then, “the old Rubbish”. Eventually the day came when our government knocked those beautiful studios down and locked away, threw away and sold for scrap all the “old rubbish” equipment. My Mother (somehow?) found herself leaving work that last day with a pile of baffles/GoBos in her hatchback and the strangest mic she could find; a sphere of clack metal with a grill looking thing laying flat across it. I don’t need to tell you what it was and was for a long time a conversation peice in my studio that I assumed was a crystal mic of some sort.
    Now that the internet has allowed someone who lives as far away from possible from where ‘it all happens’ spend the last decade learning about the techniques used in the golden age of recording and the equipment used, I am extremely grateful for my mothers chutzpah that day in grabbing me a momento from the doomed building and equipment. And now finally there’s actually sites dedicated to my curious british microphone. I was unaware that coles sold a cable converter so I soldered an XLR to the terminating end and microphone is now back working. However when I read the technical specs of the Ball’n’Bikkie Mic in the manual you have so kindly made available it tells me that said microphone hopes to so around 20-30ohm at the pre amp in put stage and the options I have to ckoose from are multiples in the hundreds or thousands of that figure.
    Am I not able to make best use of my STC 4021 because my valve pre’s only offer to switch between 500ohm and 2.0kohm.
    I believe I heard on your clip that you use a focusrite pre/ADA? Thats a recently made bit of kit that would be offering similar impedance’s? Do you use some kind of DIY transformer or am I just in need of a refresher on the principles of Ohms Law?
    Advice would be greatly appreciated!!!
    p.s. I’ll try and email you some pictures if possibly but the body of mine is not finished in the same way as yours. Its still black however its matte black paint on gunmetal grey where the paint has chipped away and the STC legend surrounding the output jack is raised in relief to the body surface and it says “..and Cables Ld England” instead of “LTD” followed by the model number which Ive seen the ones here. Is mine a licence copy? A Fake? (seems unlikely..)
    Any ideas there either?
    Congrats on finding the 4001B Baffle by the way! I’m going to go off in search of one, and when I give up I may just have one fabricated if the correct materials are still available.
    Thanks again


    • Hi Marty, Many thanks for your fascinating message. It sounds like you had a great time as a youngster. Your Mum made a wise choice with the mic. Mine is marked the same as yours England followed by the model number. There are quite a few variations on this marking. At one point the company name just appeared as Standard Ltd. The original American Western Electric 618-A had several different markings and there was also a French version produced by STC which was labelled Material Telephonique 3630a. Anyhow, I would love to see some pictures of yours.
      As far as impedance goes, my Focusrite TwinTrak has a continuously variable impedance knob which runs from 60 Ohms to 3K. I think that there are quite a number of modern pre-amps which have this capability. The Focusrite also has a lot of gain available.
      Good luck with finding the 4001B baffle.
      All the Best


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s