this project is Working and you need absolutley
because it's able to rebuild the acoustic scene
just as you like 🙂
because it's able to rebuild the acoustic scene
just as you like 🙂
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Hmm.....
Whats 'Halfer-Variation'.....?? Google refers to some kind of genetic research...
Guess all chip amps and nearly all discrete silicon amps these days are OTL....
Prefer 'Proper' Tube OTL myself....
Whats 'Halfer-Variation'.....?? Google refers to some kind of genetic research...
Guess all chip amps and nearly all discrete silicon amps these days are OTL....
Prefer 'Proper' Tube OTL myself....
Single ended push-pull, (SEPP)
ok the correct name is this in Title
important have same gain in each rail
Hafler It features Jim Strickland’s
trans•nova circuitry and his brilliant discovery,
Dynamically Invariant AMplification Optimized
---> suorces are on GND
ok the correct name is this in Title
important have same gain in each rail
Hafler It features Jim Strickland’s
trans•nova circuitry and his brilliant discovery,
Dynamically Invariant AMplification Optimized
---> suorces are on GND
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Err....
But, The Gain Isnt equal, Is It!
Thats why Julias Futterman had the bottom end of phase-splitter sitting on the O/P to accomodate for the difference in Drive Needed between the Top tube, and the Bottom tube, as their gains are different, but the tubes were not both acting as 'Cathode-followers' so 'Technics' (I think....) inverted the drive as well, so that both tubes act as followers and lower the O/P impedance.....!
--This was always the issue with the SRPP/SEPP type out-put stage...
To achieve symetrical wave form output, you would need unequal resistors in the concertina phase-splitter, to accomodate for the difference in drive requirements--Or do the 'Futterman' thing....
Top tube is acting like cathode-follower (little less than unity gain) while bottom tube acts as common-cathode (That has gain more than 1) in the SRPP
In your Transistorised schematic, You have Complementary Transistors (MOSFETS) a P channel and N channel....
Sadly a Positron Valve/Tube does NOT exist, so any Tube circuit is 'Quasi Complementary' and not a true complementary o/p stage....
In your First Schematic, You have Unequal Phase-Splitter resistors, compensating for the difference in gain between top and bottom....
But, The Gain Isnt equal, Is It!
Thats why Julias Futterman had the bottom end of phase-splitter sitting on the O/P to accomodate for the difference in Drive Needed between the Top tube, and the Bottom tube, as their gains are different, but the tubes were not both acting as 'Cathode-followers' so 'Technics' (I think....) inverted the drive as well, so that both tubes act as followers and lower the O/P impedance.....!
--This was always the issue with the SRPP/SEPP type out-put stage...
To achieve symetrical wave form output, you would need unequal resistors in the concertina phase-splitter, to accomodate for the difference in drive requirements--Or do the 'Futterman' thing....
Top tube is acting like cathode-follower (little less than unity gain) while bottom tube acts as common-cathode (That has gain more than 1) in the SRPP
In your Transistorised schematic, You have Complementary Transistors (MOSFETS) a P channel and N channel....
Sadly a Positron Valve/Tube does NOT exist, so any Tube circuit is 'Quasi Complementary' and not a true complementary o/p stage....
In your First Schematic, You have Unequal Phase-Splitter resistors, compensating for the difference in gain between top and bottom....
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Yes, a silly design. It will only balance at one particular load impedance. At other impedances the two output valves could assist or work against each other. A genuine SRPP might be better, although that is load dependent too.
Nah, I wouldnt go quite that far!😉
With a few tweaks, it can easily be turned into an 'Inverted Futterman' and give prob. extremely good results as a low O/P imp pre-amp or headphone-amp...
As it is however, I think the very load-dependant O/P will make for pretty high 2nd and 3rd harmonic--which could be exactly what the O/P wants--if he wants a guitar pre-amp or effects device....😀
I have NO idea where all the strange references like 'Halfer-Variation' come from though....
Just because a scheme has a wicked name, dont mean its gonna work well!😱
Oh dear, You Really ARE missing the point, I'm afraid.....🙄
You claim that in your Tube scheme that the gain must be equal on both top/bottom rails, and it clearly Isnt!
Cannot apply 'Hafler' to it
'Hafler thing' will apply ONLY to a Fully COMPLEMENTARY (P channel, + N channel) O/P stage, and whether it requires feedback in this discussion is irrelevent, as we are NOT talking Hafler stage with your TUBE pre-amp....
Tube scheme is NOT Fully Complementary, Gains are Different top/bottom UNLIKE Hafler thing you are trying to make, where the gains are the same approximately....
Who cares, If you Like its sound, then you have achieved what you're after
Personally, IMHO I would Not consider your Tube pre-amp a 'HiFi' device, but more like, an Effects device, for 'stage' use.....
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With a few tweaks, it can easily be turned into an 'Inverted Futterman' and give prob. extremely good results as a low O/P imp pre-amp or headphone-amp...
And indeed, that's where this design appears to have originated:
The Bijou Headphone Amplifier
Stee, you probably should have given some credit to Alex in your post for the original design...
And indeed, that's where this design appears to have originated:
The Bijou Headphone Amplifier
Stee, you probably should have given some credit to Alex in your post for the original design...
Ah,--
Now isnt That interesting!....
Scheme looks virtually the same --apart from the O/P version has been 'De-Futtermanned'
Poor Alex, He should have been given a reference--But maybe its best he hasn't--Doubt he wants to be associated with this bastardised inferior version!
Now isnt That interesting!....
Scheme looks virtually the same --apart from the O/P version has been 'De-Futtermanned'
Poor Alex, He should have been given a reference--But maybe its best he hasn't--Doubt he wants to be associated with this bastardised inferior version!
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