On 8/11/2012 1:13 PM, Todd, KA1KAQ wrote: > The best audio improvement for the SP-600 is called the SP-100 or > -200. (o: > There's some real truth here. The audio stages in these set use triode-connected 6F6's. Stay tuned for a rant and a website update. Al -- Al Klase - N3FRQ Jersey City, NJ http://www.skywaves.ar88.net/