tardishead
Well-known member
I've got a Vermona ET6-2 transistor dual manual combo organ made in DDR circa 1970
It really is quite amazing. I'm a bit of a combo organ fetishist but the designers of this thing must have found a time machine because its very unique and spacey sounding.
However its got quite an annoying "beehiving"drone (when you can hear the whine of all the oscillators at once)especially prevalent when the balance of both manuals are turned up. All frequency divider organs that I have come across have got this to some extent but this is the worse than usual.
As usual I replaced the caps in the power supply and some other large ones dotted around but that did not attenuate the noise at all really. Normally this fixes it straight away. I'm scratching my head.
I have checked the ground wires which seem to be solid and intact
Wondered if anyone out there has any experience with these organs or whether someone can point to some other culprits.
Its pretty good inside - very well laid out and has not been tampered with much over the years. Its very nice build quality which makes me think that this level of background noise would not have been a design issue.
Is it possible the ground wires need replacing because they have oxidised? I have only really thought about this today but these organs rely on good grounding. Does oxidisation cause grounding issues over time? Anyone noticed this in any other equipment?
Maybe there are contacts on the keybed which should normally be shorted to ground when key is not pressed - maybe dirty and causing problems?
Power supply need more capacitance?
Grateful for any assistance
It really is quite amazing. I'm a bit of a combo organ fetishist but the designers of this thing must have found a time machine because its very unique and spacey sounding.
However its got quite an annoying "beehiving"drone (when you can hear the whine of all the oscillators at once)especially prevalent when the balance of both manuals are turned up. All frequency divider organs that I have come across have got this to some extent but this is the worse than usual.
As usual I replaced the caps in the power supply and some other large ones dotted around but that did not attenuate the noise at all really. Normally this fixes it straight away. I'm scratching my head.
I have checked the ground wires which seem to be solid and intact
Wondered if anyone out there has any experience with these organs or whether someone can point to some other culprits.
Its pretty good inside - very well laid out and has not been tampered with much over the years. Its very nice build quality which makes me think that this level of background noise would not have been a design issue.
Is it possible the ground wires need replacing because they have oxidised? I have only really thought about this today but these organs rely on good grounding. Does oxidisation cause grounding issues over time? Anyone noticed this in any other equipment?
Maybe there are contacts on the keybed which should normally be shorted to ground when key is not pressed - maybe dirty and causing problems?
Power supply need more capacitance?
Grateful for any assistance
