X-77

[John Bittner]

Getting back to your 77. You had it for years? your are a true warrior, how did you keep it running? No body I knew could, and every one I knew sold theirs not long after the problems would start. <post>621</post>


I purchased my X-77 in 1969 and kept it running for 25 years before selling it to make room for my Allen TO. I really liked this instrument, but it's clear that Hammond was struggling in very basic ways in making the transition to solid state electronics. The organ wasn't wired properly, the circuit boards weren't adequately shielded, and the switches and connectors were of low quality.

These factors led to a high level hum, susceptability to radio station pickup, pops and crackles from power line noise, and all sorts intermittancies. I was able to deal with these as they cropped up due to my electronics background, but a few years before I sold it, I finally had enough, ripped it apart and properly rewired the whole thing. The improvement in sound was amazing.

Compared to the B-3 the X-77 was more refined sounding. Less key click and less crosstalk. The low end went all the way down the manuals without note foldback as did the treble. This combined with the extra drawbars enabled alot more tonal variation than the B-3.

There were other differences that likely contributed to the fact the X-77 failed to surplant the B-3 as Hammond had hoped, but the reliability aspect was certainly a contributing factor.

[Norm]

I have had my X-77 for about three years now. Still learning about the quirks etc. I love the darned thing and would not trade it off. Would appreciate any tips that might help get ride of lighting etc. I'm not much of a technician but I try.

[John Bittner]

I was never able to reduce the noise from the fluorescent music light to what I considered acceptable levels. I did find that changing the lamp sometimes helped for a while.

If I still had the instrument, I'd probably replace the fluorescent tube with some rope lights and be done with it.

[Norm]

I simply did not repair the light inverter when it quit working. I have found a place in Tacoma Washington that can rebuild the main amplifier, power supply etc. . I find De-Oxit handy for use on the small pots on the circuit boards. I have had pretty good success in getting rid of a lot of the static crashes by using this stuff.

Has anyone tried to replace the light inverter with a common ballast found at the local hardware store? I still like the darned thing all the same.

[John Bittner]

Has anyone tried to replace the light inverter with a common ballast found at the local hardware store?

I suspect that the reason Hammond went to the trouble of the inverter in the first place was due to the fact that a fluorescent ballast simply radiates too much hum and it is picked up by the generator coils. I can't imagine any other reason. Unfortunately, the RF hash the inverter generates is just as annoying.

I can tell you that the pickups on the reverb spring located in the base are also very susceptable to hum pickup. I was able to help this by flipping the unit so the output pickup was as far away as possible from the power supply and inverter transformers. Today, I'd deal with problem by using a digital unit in its place.

Another hum source turned out to be the dressing of the wires to the power switch. They were in very close proximity to the drawbar matching transformer. Keeping these wires twisted tight and away from the transformer, helped alot.