Bill;
Check out the Nov.'98, Dec.'98 and Feb.'99 issues of Vintage Guitar magazine for a series of articles on Sunn by John Teagle. The "Smiley Face" Sunn amps had top-mounted controls and actually consisted of a Dynaco Mark III power amp and a modified Dynaco PAS tube pre-amp circuit in a separate aluminum chassis. Both chassis were mounted inside the wood/tolex cabinet. There were reportedly only about 200 of these amps made! (I'm the proud owner of one) Then around 1967 they switched to the bottom-mounted, one-piece chassis we are all familiar with. The "Smiley Face" amp evolved into the 200S. They changed the pre-amp, but the power amp circuit is essentially the same as the Dynaco Mark III. Additionally, if you check some of these 2nd generation amps you will see "Dynaco" stamped on the transformers and the multi-section filter caps since Sunn continued to source parts directly from Dynaco (later they purchased them directly from Dynaco's supplier).Check the home page for this website and click on the "catalogs" and you will see scans of the catalog from 1966 showing the early amp with the top-mounted controls. The speaker cab had 2-15" D-140 JBL's. Sunn's use of Dynaco hi-fi amps in the early days was symptomatic of a "hi-fi" mentality towards amp design. This produced very clean and powerful amps which allowed them to dominate the bass amp market in the mid-to-late sixties.
Ryan
