The EH Dirt Road Special is Back for repairs

Well, quite a lot has happened since my last post on the great little amplifier, the Electro Harmonix Mike Matthews Dirt Road Special.  I replaced the original 70 VAC secondary transformer with a 12 VAC transformer.  My laborious temporary speaker repair did not hold.  I have replaced the original Celestion speaker with a vintage replacement speaker that I have had for quite a long time. 

Here is a photo of the 12 VAC transformer installed in the amplifier:

12 VAC Transformer in Dirt Road Special

I got the transformer at Radio Shack.  It has a three Ampere rating.   You can see that I have used heat-shrink tubing over the splices I made in the primary leads.  Here is a photo of the amp with the replacement speaker installed:


Electro Harmonix Mike Matthews Dirt Road Special Amp with GE speaker

This is an early 1950s speaker I inherited from a guy who used to hold "record hops" in his barn a few miles from here.  He had several of these speakers, each in a plywood open back box hanging from a barn beam.  He ran speaker wires to them from a record player on which he played mostly 45 rpm records of tunes that were popular at the time.  At any rate, I have been trying to find out more about the speaker for quite a long time.  It has an Alnico magnet and is similar in appearance to a GE model S-1201D speaker illustrated in the following scan of page 7 of the February 1952 issue of Audio Engineering magazine.

GE S-1201D Ad in Audio Engineering February 1952

 

The speaker still has its original felt dust cap.  The speaker is very efficient and sounds great in this amplifier.  It ought to.  If you apply the inflation calculator at http://www.westegg.com/inflation/ this speaker would have cost $1279.50 in 2012!