How critical are the size/type of the caps?
For example, is there any problem if the 22uF to Gnd on the input IC (opa627) is actually 47uF or maybe a film capacitor? Same thing about the two 22uF caps on the 4N35?
On one circuit I see the 22uF/100 MKS4 caps specified for all 3 of these.
Also, i see the 0.1uF cap on the 4N35 opto specified as the 630v Zn 3% (the Phillips cap) - is there similar optional devices and for what advantages? Musicaps? Obbligato? Mundorf? Rifa Styrene? etc
For example, is there any problem if the 22uF to Gnd on the input IC (opa627) is actually 47uF or maybe a film capacitor? Same thing about the two 22uF caps on the 4N35?
On one circuit I see the 22uF/100 MKS4 caps specified for all 3 of these.
Also, i see the 0.1uF cap on the 4N35 opto specified as the 630v Zn 3% (the Phillips cap) - is there similar optional devices and for what advantages? Musicaps? Obbligato? Mundorf? Rifa Styrene? etc
You could reduce the center 10K divider resistors. What output transistors?
2sk2013 and 2sj313
In my (just completed) build, it was buzzing until I fully closed the box. I guess the buzz depends on the volume control, as the pot affects the impedance between the opamp noninverting input, the ground, and the signal source. In any case it went quiet with the box (a Hammond extrusion) closed and sealed.
I had a similar issue previously with my build of Pearl 2 (thank you Wayne ), and also could only solve it by fully closing the box. There I had to use lock washers under some of the flat head screws to get electrical contact between anodized panels of the enclosure.
I had a similar issue previously with my build of Pearl 2 (thank you Wayne ), and also could only solve it by fully closing the box. There I had to use lock washers under some of the flat head screws to get electrical contact between anodized panels of the enclosure.
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Fabulous. I'm really looking forward to building and hearing one.Once the final changes are made it will be available in the diyAudio store.
Once the final changes are made it will be available in the diyAudio store.
Will these be huge changes compared to the first boards Wayne sold. Will your build be based on the new board. Still populating mine one resistor at a time unless the wife says otherwise.
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