About when did Ampeg STOP using the "four-pin" connection on the 810 cab? Also, were the "speaker-out connections" on the SVT HEADS ever "four-pin"? After doing a search, I've read posts stating that "four-pin" cabs should be immediately converted to 1/4". But what if the HEAD has "four-pin" (and I have never seen one that was), should it be converted? Bassically, should the whole rig be made 1/4"? Lastly, is there a possibilty of having a head with 1/4" and a cab with the "four-pin"? Is this a bad idea? Help.