Dynaco A-25 Version

[Hawkeye87]

Just bought these from a person who's father bought them in Holland in 1970, when he was in the Air Force (I have the original receipt). The tweeters are not working. I opened them up to see if anything was obviously wrong. The drivers do not look like any of the other Dynaco A-25 photos I have seen. However, it looks like I was the first person to ever open them up. There were no pry marks around the drivers and the black glue was very strong. The crossover has the 8u capacitor and the 5 position control on the back. Can anyone tell me what version these are from the pictures? 

[Diogenes]

13 hours ago, Hawkeye87 said:

Just bought these from a person who's father bought them in Holland in 1970, when he was in the Air Force (I have the original receipt). The tweeters are not working. I opened them up to see if anything was obviously wrong. The drivers do not look like any of the other Dynaco A-25 photos I have seen. However, it looks like I was the first person to ever open them up. There were no pry marks around the drivers and the black glue was very strong. The crossover has the 8u capacitor and the 5 position control on the back. Can anyone tell me what version these are from the pictures? 

Yours are stock production A-25s. It's just that they're from the couple of months in 1970 when SEAS was having severe production issues leading to supply shortages to those using their drivers and Scan-Dyna (the builder of the speakers for Dynaco) had strained relations with them due to their founding Scan-Speak with a couple of head hunted SEAS engineers and a bit of industrial espionage in driver design. (It was big news in the region at the time even receiving mention in some Danish newspapers.) Since Scan-Dyna couldn't get SEAS drivers and Scan-Speak hadn't geared up yet for driver production, they had to fall back on the Philips tweeter in lieu of the SEAS H087 and Peerless L100WG in place of the SEAS 25 TV-EW woofer. The crossover had to be tweaked with the addition of the inductor as the woofer didn't roll-off naturally the same as the SEAS and needed help to blend with the tweeter.

As for the tweeters not working, that's probably due to bad caps. That's a very common issue with these. Since you have them apart, it wouldn't hurt to take a multimeter and check the tweeters and resistors just in case something else has gone bad.