SOUND ELECTRONICS CORP X305R

[t7mackie]

Hi all,

Ampeg and Hiwatt had a baby and hatched a Vibroverb.

I saw an ad for this on Craigslist and I ended up grabbing it today. If I'm reading the date code on the speaker correctly this is a 1966 Sound Electronics Corp X305R. Info on SEC is extremely scarce but from what I can tell an Ampeg person went out on his own and started SEC in Long Island back in the mid 60's. Originally I was going to pass on this amp because, "Sound Electronics Corp" just doesn't have the same sex appeal as Fender or Marshall but I was eventually able to find a gut shot online. The lead dress and workmanship immediately reminded me of Hiwatt. The hook was set.

I checked it out, all the transformers had continuity & all the tubes were original RCA's - 4x 7025'S, 1X12ax7 & 7868 power tubes. It also has a Jensen C15N. That alone was well worth the price of admission. Buddy said it has been sitting in his basement for 30 years. Likely true.

The insides are completely untouched except for a res / filter cap change probably in the late 70's. It has 4 orange Spragues that all test good for ESR & 3 test good for Ohmage - the 4th is probably usable but is around 8M ohms. I'll be replacing these if anyone is interested in the spare parts.

Anywho, I was only able to find one sketchy illegible schematic online. If anyone has one please share. Depending on how much work needs to be done when I service it I may draw out a schematic & will share.

Sorry for the low quality photos. If anyone is interested I'll post more & better photos as the work progresses.

[FUCHSAUDIO]

Nice piece ! Cool amp line. Not around a long time. Run by a dude named John Dougherty who had connections to Ampeg, Oliver, Sound and eventually Marlboro on Long Island. I loved the zig zag chassis designs.....Ampeg-ish circuits. I asked Jess Oliver about him and he said "he wasn't a nice man"...not sure what that meant. He was a packaging engineer, not really a EE or circuit designer, so the stuff is common fare as circuits go, but the execution is pretty cool...and they sounded pretty decent.

[Stevem]

Some 8 years ago I worked on the single channel version of that, but the model number of it I can bring to mind right now.

The build of the amp with those blueish green caps is like a multivox premier B160 ( one again a NY base amp company ) amp I own, but it’s point to point.

[sluckey]

The build of the amp with those blueish green caps...

Magnatone was fond of those caps in the early '60s too.

[sll]

I've loved my X305-Rs. I've had 2, and still have one of them. The components and workmanship are top notch and they sound fantastic. Full, legible schematics appear to be nonexistent.