Connecting Speaker Cables to Dynaco ST-70

I wouldn't allow that to happen, George.  You would be putting a zero ohm load across a significant fraction of the output transformer's secondary (output side) winding.  I would certainly expect that to affect sonics, and I wouldn't be surprised if it also resulted in damage, eventually if not sooner.

Best regards,
-- Al
 

Thanks a million Al.  I will of course take your advice and ensure that only one tap is touching per side.  What a pain the large speaker connectors can be when working with older amps.  Live and learn. 
George

Search the following phrase on Ebay and you will find small spade to binding post/banana adaptors.

"Spade Banana Fork plug Mcintosh Amp Eico tube Adapters MC30 MC60 MC275"

DeKay

Nothing should touch or your system could be toast!!!

+1 dekay. I bought the adaptors for banana plugs. Work well on my ST-70.