Hi,
Surely this is governed by the number of gain stages in the amp, each one providing a nominal 180 Deg. shift or 'reversal'.
If so, Aleph 30 with 2 stages is non-inverting, but some of the earlier Alephs (IIRC, but I cannot access the schematics now to check) had 3 stages, in which case they would be inverting.
Surely this is governed by the number of gain stages in the amp, each one providing a nominal 180 Deg. shift or 'reversal'.
If so, Aleph 30 with 2 stages is non-inverting, but some of the earlier Alephs (IIRC, but I cannot access the schematics now to check) had 3 stages, in which case they would be inverting.
The amp, taken as a whole, is non-inverting.
The output stage is inverting. The front end, being a differential, can be hooked up to be either inverting or non-inverting. In this case Nelson chose the inverting hookup.
The signal comes in, inverts going through the front end. Now it's "upside-down." Then it goes through the output stage and gets flipped once more, making it "rightside-up."
Grey
The output stage is inverting. The front end, being a differential, can be hooked up to be either inverting or non-inverting. In this case Nelson chose the inverting hookup.
The signal comes in, inverts going through the front end. Now it's "upside-down." Then it goes through the output stage and gets flipped once more, making it "rightside-up."
Grey
Grey's the man who will know!
Hi Grey,
Is my above recollection right that one (some?) of the earliest Alephs had 3 amplifying stages, and were accordingly inverting?
I had only downloaded the A30 details, and, of course, Nelson has needed to remove the other circuits from prying eyes.
Regards,
Hi Grey,
Is my above recollection right that one (some?) of the earliest Alephs had 3 amplifying stages, and were accordingly inverting?
I had only downloaded the A30 details, and, of course, Nelson has needed to remove the other circuits from prying eyes.
Regards,
Re: Grey's the man who will know!
Bob,
His 1st gen Alephs like the 0 and 1, although having three gain stages is also non-inverting as the 3rd stage is a bunch of paralleled followers and does not invert the output of the 2nd stage. The input is a diff pair with output taken from the drain inverts then the 2nd is a voltage gain stage will revert back to the same phase as the input signal.
Allan
Bobken said:Hi Grey,
Is my above recollection right that one (some?) of the earliest Alephs had 3 amplifying stages, and were accordingly inverting?
Regards,
Bob,
His 1st gen Alephs like the 0 and 1, although having three gain stages is also non-inverting as the 3rd stage is a bunch of paralleled followers and does not invert the output of the 2nd stage. The input is a diff pair with output taken from the drain inverts then the 2nd is a voltage gain stage will revert back to the same phase as the input signal.
Allan
Hi Allan,
Thanks a lot for this clarification. I was right about the 3 stages then, but my memory let me down on the topology details.
Tries hard, could do better, only 5/10!
Nelson spoilt us all, maybe for too long, and I guess I took it for granted that these details would always be available on his site.
It was a really sad day when I saw that Nelson was forced to remove his schematics, but I fully understand why he did this.
I just wish I had downloaded them all ages ago, when they were available.
Regards,
Thanks a lot for this clarification. I was right about the 3 stages then, but my memory let me down on the topology details.
Tries hard, could do better, only 5/10!
Nelson spoilt us all, maybe for too long, and I guess I took it for granted that these details would always be available on his site.
It was a really sad day when I saw that Nelson was forced to remove his schematics, but I fully understand why he did this.
I just wish I had downloaded them all ages ago, when they were available.
Regards,
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