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Perhaps somebody remembers who did the supply circuitry, not Joachim ?
Perhaps somebody remembers who did the supply circuitry, not Joachim ?
In a german version of a Paradise R3 assembly guide V5
I see a brute force method to tame supply oscillations :
https://www.dropbox.com/s/8ayxldua68hphsy/Paradise R3 assembly guide V5 deutsch.pdf?e=1&dl=0
at about 40% down the pages. This is only a hint, I do not
necessarily agree.
I see a brute force method to tame supply oscillations :
https://www.dropbox.com/s/8ayxldua68hphsy/Paradise R3 assembly guide V5 deutsch.pdf?e=1&dl=0
at about 40% down the pages. This is only a hint, I do not
necessarily agree.
"Sziklai compounds rather?" : in my textbook, available in at least
14 editions since 1969 these are called complementary darlington.
14 editions since 1969 these are called complementary darlington.
I looked it up just now and I see they are the same thing.
From Wikipedia, the free encyclopedia
Figure 1. Sziklai pair that acts like a single NPN transistor with collector C, emitter E, and base B.In electronics, the Sziklai pair, also known as a complementary feedback pair, is a configuration of two bipolar transistors, similar to a Darlington pair.[1] In contrast to the Darlington arrangement, the Sziklai pair has one NPN and one PNP transistor, and so it is sometimes also called the "complementary Darlington". The configuration is named for George C. Sziklai, thought to be its inventor.
I had to take the brute force route with both the shunt PSUs in my Paradise build. They did stop oscillating though.
I did have one board that would not work correctly, the Servo Op amp output was nailed to the rail. I found is was the tiniest solder bridge between a pair of transistor legs. Took me a while to spot and fix.
Hi salas, while you're here. What values did you come up with for the flat riia parts, Vs Joachim's funky curve?
Slugging the shunt with 2.2n and 470pf across the 327/337 under the heatsink did work, there's an additional pair of 0.47uf caps to ground that Werner added that really hammers it, but at a cost.
Picture in post 4529
Picture in post 4529
Found my alt RIAA notes from back in the day. Here's the text:
"Miib tuning has a bit more treble and bass. +0.4db HF +0.2dB LF in my build by measurement. Add 1nF to the treble caps C2a, C2b and parallel 820k-1Meg to R9a R9b. Matter of tolerances. You are looking for 67.8k net. That way it goes near neutral so you can have an alternative listening session. Its a matter of taste and system integration mainly. That makes for 33n3 12n 9k1 67k8.
I had also used half the total mF at the emitters and deleted their bypasses. For earlier subsonic roll-off"
"Miib tuning has a bit more treble and bass. +0.4db HF +0.2dB LF in my build by measurement. Add 1nF to the treble caps C2a, C2b and parallel 820k-1Meg to R9a R9b. Matter of tolerances. You are looking for 67.8k net. That way it goes near neutral so you can have an alternative listening session. Its a matter of taste and system integration mainly. That makes for 33n3 12n 9k1 67k8.
I had also used half the total mF at the emitters and deleted their bypasses. For earlier subsonic roll-off"
Half skipped emitter AC bypass caps can also be seen missing in my picture (#4,584). So the notes I found look true to my final tweaks.
I am sure I had also lessened the value of the DC servo output drive resistors to the R5 nodes. Probably down an order of magnitude. To make the DC offset correcting action much more aggressive. But I don't seem to have kept a note on them.