Found the same thing, side adjust that fit are only single turn.
Also discovered that the trimmers vary based on wattage - so 1/4watt have W and Y versions and exactly opposite as the 1/2 watt version.
The 1/2 watt trimmer for Ishikawa board is 64W and it is correct inline pins, even verified the two data sheets side by side. Really means you have to check each item and it’s data sheet before placing order.
After cooking for about two hours, one channel has stalled at about +12mv DC on the output. When still warming up it could be adjusted to zero. Offset also does not respond much to the RV1 trimmer, whereas previously it was reasonably sensitive. I don’t see anything obviously wrong. Heatsink is about 55C. I have the standard R6/R7 of 47K on both boards. I think I’ve seen suggestions of changing R6 in this situation. I am running one channel only with input shorted and IPS daughter card removed and IPS Post2 directly wired to Post4 per Mark’s direction. Any thoughts are appreciated. Thanks.
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For some reason I can now zero it out. But I now have unmatched power readings on the left and right channels. I get 19v from each secondary pair going into the PS, but 21.9 and 23.4 coming out. I’m going to let the whole thing simmer overnight and if all is well, attach the Ishikawa IPS.
I had a fight getting exactly symmetrical plus/minus voltages that does not change over time (after warmup period). I solved it and I have <5 mV DC-offset on both channels.
One of the tricks was to get rectifiers with very low feedforward voltage that does not change much with the peak current going through the devices. Rectifiers with low feedforward voltage will also run cooler so temperature will not effect the feedforward voltage. I also learned that if voltage is not exactly the same over the two diode pairs handling each halfwave of the sinus it creates uneven harmonic distortion of the 50/60 Hz fundamental.
The problem with different plus/minus voltage can also be a bad connection (the one with the lowest voltage) or uneven load of the two. But an uneven load that creates that amount of difference in voltage should only occur if amp has an fault.
One of the tricks was to get rectifiers with very low feedforward voltage that does not change much with the peak current going through the devices. Rectifiers with low feedforward voltage will also run cooler so temperature will not effect the feedforward voltage. I also learned that if voltage is not exactly the same over the two diode pairs handling each halfwave of the sinus it creates uneven harmonic distortion of the 50/60 Hz fundamental.
The problem with different plus/minus voltage can also be a bad connection (the one with the lowest voltage) or uneven load of the two. But an uneven load that creates that amount of difference in voltage should only occur if amp has an fault.
The Cedarburg design includes circuitry to control and manage its internal power supply rails.
The IPS7 design also includes circuitry to control and manage its internal power supply rails -- but quite different circuitry than Cedarburg.
Maybe it might be fun to consider marrying these two designs. Call them Mom and Dad, and then imagine what kind of children they might produce. What do you get when you cross Cedarburg with IPS7?
You might imagine that their offspring would "interpolate" between the two parents? Or, maybe the offspring "extrapolates" beyond both parents?
Exercising your imagination furiously, you might very well discover some intriguing ideas and tantalizing possibilities.
The IPS7 design also includes circuitry to control and manage its internal power supply rails -- but quite different circuitry than Cedarburg.
Maybe it might be fun to consider marrying these two designs. Call them Mom and Dad, and then imagine what kind of children they might produce. What do you get when you cross Cedarburg with IPS7?
You might imagine that their offspring would "interpolate" between the two parents? Or, maybe the offspring "extrapolates" beyond both parents?
Exercising your imagination furiously, you might very well discover some intriguing ideas and tantalizing possibilities.
I'm not sure if you can use the 330uF, but these are the ones I ordered, Nichicon 220uF 25V NP - 647-UVP1E221MPD1TD
They could also be changed out later for UES if I don't like them. Didn't want to wait 3+ months to get the caps.
