I will experiment with other inputs in time.
So as I got further into testing I find that I was able to achieve 0mV offset and equal Vdrop across the resistors in the second channel. For the first one (the one I was concerned about), I ultimately set it so that the Vdrop was equal and found that the offset voltage was only 1mV. I don't expect that to be a huge issue.
I would much rather optimize the gain stage for best linearity and have a cap if needed. C1 is the lesser of the distortion evils. But lucky in that I was able to equalize and not have C1.
Final results:
Should never say Final......
Now onto the other M2x amp. These are part of a 3-way active system
So as I got further into testing I find that I was able to achieve 0mV offset and equal Vdrop across the resistors in the second channel. For the first one (the one I was concerned about), I ultimately set it so that the Vdrop was equal and found that the offset voltage was only 1mV. I don't expect that to be a huge issue.
I would much rather optimize the gain stage for best linearity and have a cap if needed. C1 is the lesser of the distortion evils. But lucky in that I was able to equalize and not have C1.
Final results:
Should never say Final......
Now onto the other M2x amp. These are part of a 3-way active system
I've planned wiring like this.
220VAC main -> 1.25A slow blow fuse -> inrush current limiter -> 400VA 21-0-0-21 toroidal transformer -> SLB power supply -> +/-24 VDC power chord beteween separate chassises -> M2X amp (or other first watt class A amps)
Is CL-60 proper for inrush current limiter or are there other recommendations?
220VAC main -> 1.25A slow blow fuse -> inrush current limiter -> 400VA 21-0-0-21 toroidal transformer -> SLB power supply -> +/-24 VDC power chord beteween separate chassises -> M2X amp (or other first watt class A amps)
Is CL-60 proper for inrush current limiter or are there other recommendations?
New build alert! I've been running an F5 for a couple of years but without warning one channel went pop and after replacing the obvious items I ran out spares, but had some M2x boards built up so here we are.
I've installed Ishikawas and onto Dim Bulb tests.
On both channels it does what I expect - i.e. bright then straight dims to nothing.
But then I spotted after about 30 seconds the bulb starts to come back on again - not fully but then I didn't wait long before I switched off again.
This happens on both channels - is this actually expected behaviour as the circuit "warms up"? - or have I got something in wrong?
I've installed Ishikawas and onto Dim Bulb tests.
On both channels it does what I expect - i.e. bright then straight dims to nothing.
But then I spotted after about 30 seconds the bulb starts to come back on again - not fully but then I didn't wait long before I switched off again.
This happens on both channels - is this actually expected behaviour as the circuit "warms up"? - or have I got something in wrong?
I've bought the jfets for Ishikawa daughter board.
Matched JFETs - Toshiba 2SK170/2SJ74 Quad 8-11mA
Are these right for Ishikawa?
Matched JFETs - Toshiba 2SK170/2SJ74 Quad 8-11mA
Are these right for Ishikawa?
@Mark Johnson
Ordering parts for the IPS7 input board and the D45H11G is a bit hard to find. Is there an easy substitute?
Ordering parts for the IPS7 input board and the D45H11G is a bit hard to find. Is there an easy substitute?
511-D45H11 should be good and there's 348 units available last time I looked at Mouser.
no joy on the mouser but I am not sure why we need 180v transistors. MJ should be able to explain.
https://www.digikey.com/en/products/detail/diodes-incorporated/ZTX696B/152467
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