ага как я понял это усилитель какой то ...вот пишут - Update on Pops, ticks, and blips on DX7II-FD:
I disconnected the YA3 amplifier board from the DAC, and the ticks, pops, and blips stopped. So now I'm thinking it's not the YA3 amplifier board. It may be something with the DAC circuitry or the DAC itself. Though when I look at the DAC output, I don't see any spikes or disturbances at all.
I already replaced the two filter electrolytics for the DAC power. There are three ceramic caps left in the power supply for the DAC. Could it be those? Somehow I doubt it. The DAC also has a 10k 1/8w resistor on the output, and I doubt that's the problem either. Though for lack of an alternative, I would replace all of those before replacing the DAC itself.
Does anyone know if the pops and ticks and blips are a sign of a DAC failure? What suggestions do you have at this point?