1967 Electro-Voice EV-1180 Stereo System

Every once in a while you'll stumble on a sentimental relic. I found this Electro-Voice EV-1180 stereo at an antique mall for $25. It came with its original two-way speakers, which was a bonus. I worked for a company years ago that sent me to an exclusive seminar at Electro-Voice in Minneapolis, MN,  and I've been a big fan ever since. So, when I saw the stereo at the antique mall, considering I've never seen an Electro-Voice stereo before, I was ecstatic. 

Antique malls usually over-price things, especially any thing retro or swank looking. The immediate fact that the stereo was only $25 led me to suspect that something was wrong with it. I tested the stereo in the store and despite some fuzz it was able receive FM stations. But when I got home I noticed that it wasn't typical tuner fuzz but a wicked 60 Hz buzz. Given how rare the stereo was and how much I like it I had to fix it. 

I cleaned the pots, RCAs, and exposed speaker fuse terminals, the latter which seemed to improve some static through the speakers. The 60 Hz buzz continued. 

I noticed that the buzz was present through all three channels (phono, tuner, aux). The FM tuner signal could also be hear loudly through all three channels. I figured that this condition would be unique enough to find a clear solution. So I started looking at forums. The forum that helped me out most was Audiokarma.org. There is a wealth of knowledge there. The first person to reply to my thread suggested that the selector switch was faulty. But a continuity test by a multimeter proved the selector switch functional. The next suggestion was replacing capacitors. This lead me to a thread explaining the problematic sounds of defective power-conditioning electrolytic capacitors, that is, an highly audible 60 Hz ground hum with distortion. This sounded more like my problem.

I removed the existing capacitors for testing. They were two large 25v 2500uf and one 15v 1000uf, all marked "Whale" (See picture). They had no continuity, would not dissipate a DC charge, and I found no resistance on the multimeter. Further, none of these latter findings affirmed that the capacitors were defective as much as the fact they were leaking oil. They were oil-filled electrolytic capacitors. Which I'm not sure if that is a vintage thing? It's the first that I've seen or heard of such a component. However, it explained why the received stunk five feet away and that the bottom of the wood cabinet was oil-soaked, which I had trouble removing.

I then replaced the capacitors with newer, smaller ones. Their values are: 25v 3300uf replaced the two 25v 2500uf and I was able to find a match for the 15v 1000uf. It is acceptable to increase the values when substituting capacitors so long as they are not drastic. Here I was very satisfied with matching voltage and increasing only the capacitance. 

Recapping the power-conditioning section of the receiver removed the 60 Hz buzz entirely and quieted---but not eliminating---the passing of the FM tuner signal, the latter of which can still be heard faintly on aux, tuner or phono modes. This I'm addressing as we speak.

But none-the-less I am greatly satisfied with being able to repair and reinstate life to the EV-1180. It is known for its output power (30 watts) for its size which I can attest to. Its accompanying speakers, EV 7B, which are two-ways so far as I can tell, sound very clear on the FM tuner. However, they sound a little muddy from the aux mode---this is probably another old faulty component in the receiver which I'll have to address also.

For modern convenience, I added an 1/8" jack to the faceplate just under the aux light and tapped it into the RCA jacks in the back. I can now easily plug in my phone or laptop. This really isn't necessary but I thought it fun to do.