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Old 16th March 2013, 03:42 PM   #3901
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I forgot the question
The dog that I am though...
Unnecesary, i believe.
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Old 16th March 2013, 04:01 PM   #3902
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the two little helpers of Zen Mod.....very skilled electronic men....

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Old 16th March 2013, 04:55 PM   #3903
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Originally Posted by Antoinel View Post
Thanks flg for the schematic. I'll print a paper copy and insert half shaded sine waves to understand its operation. Note that buzzforb and Zen Mod are using only one instead of two Jensens as the principal challenge.
Note in my conceptual schemo there are ports labeled "A" and "B" which should be connected together(A to A and B to B). Also that the secondary phase of the xfrmrs is swapped from N.P.s original design. I have not really given this idea any sim testing or even enough thought.
Regarding 1 xfrmr, ideally susy depends on cross coupled MATCHED circuits. Using 2 xfrmrs will likely not be as good as typical fully direct coupled designs (without xfrmrs) or even as good as a design with 1 transfomer. I suppose a xfrmr(1) with the correct winding configuration could be used in the scemo I presented. I was after a simple balanced/bridged configuration of the F6 with Susy.
I may be OT or something But let's just say we use a(1) 1+1:1+1+1+1 transformer instead of the 2 from the original design you are imagining in my picture.
Will it work? Is it susy?
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Old 16th March 2013, 05:37 PM   #3904
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Originally Posted by Antoinel View Post
Thanks flg for the schematic. I'll print a paper copy and insert half shaded sine waves to understand its operation. Note that buzzforb and Zen Mod are using only one instead of two Jensens as the principal challenge.



Hurray flg. You have a successful schematic. I used a technique practiced by Mr. Pass to follow a signal bearing a distortion marker[ e.g. an arrow]. Here is how it worked out.
  • The Right side amp has a Positive Output; meaning the half-shaded portion of its output sine wave is arbitrarily chosen positive .
  • The Left side amp has a Negative Output; meaning the half shaded portion of its output sine wave aims down by comparison.
  • Both amps are connected to each other by feedback bridges per flg's schematic; namely via Points A and B. The objective by flg is to allow the Right and Left amps to talk freely to each other.
  • Assume that the Right amp develops a sustained distortion. I show this as an arrow aiming downward and emanating from the unshaded negative portion of the output sine wave. The choice of the amp and location of distortion is totally arbitrary technique by Mr. Pass].This is also reflected in Point B which goes to its corresponding Point B destination on the Left amp.
  • The arrow pointing down [distortion] in the left amp circuit is applied [fed back from Right amp] to the primary windings of the Jensen exactly like in diyF6.
  • Transformer action shows this distortion arrow pointing down at the gate of the upper R100A. It follows that the distortion arrow also points down at the source of R100A.
  • Transformer action also shows this distortion arrow pointing up at the gate of the bottom R100A. Since the lower R100A inverts signal phase, then the distortion arrow at its drain also points down like at the source of the upper R100A. .
  • The magic of flg's design is at hand. The distortion arrows at the Power Outputs of both amps point down at the same time. The distortion signals are in phase and of equal amplitude. So, this is what happens when a loudspeaker bridges the power outputs. The sine wave signals pass right through; because they are 180 degrees out of phase. By contrast, the distortion signals [current] do not pass through because they are in perfect phase.
Conclusion : A balanced diy F6 amp per the schematic of flg will work. It has this uniqque characteristic of cancelling distortion emanating from the Right and/or the Left amps. The amps did talk to each other in a constructive manner!

Best regards
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Old 16th March 2013, 05:50 PM   #3905
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Quote:
Originally Posted by flg View Post
Note in my conceptual schemo there are ports labeled "A" and "B" which should be connected together(A to A and B to B). Also that the secondary phase of the xfrmrs is swapped from N.P.s original design. I have not really given this idea any sim testing or even enough thought.
Regarding 1 xfrmr, ideally susy depends on cross coupled MATCHED circuits. Using 2 xfrmrs will likely not be as good as typical fully direct coupled designs (without xfrmrs) or even as good as a design with 1 transfomer. I suppose a xfrmr(1) with the correct winding configuration could be used in the scemo I presented. I was after a simple balanced/bridged configuration of the F6 with Susy.
I may be OT or something But let's just say we use a(1) 1+1:1+1+1+1 transformer instead of the 2 from the original design you are imagining in my picture.
Will it work? Is it susy?
flg I fully understand your schematic and its potential. I noticed that you suggested a hexfiliar transformer; availability and price may need investigation. Mr. Pass wrote in an early post of this thread that one can also use two independent transformers instead of the Jensen. Your concern may be a mismatched drive [from 2 transformers] to the JFETs. But; it came to light later on that the R100A in diy F6 need not be tightly matched either!. There is leeway.
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Old 16th March 2013, 08:08 PM   #3906
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Default Operation of Babelfish F6x [BFF6x for short]

Two unsolicited posts. This one discusses the inner workings of one of two matched amps in BFF6x. A hand-drawn skeletal schematic of this half amp or solo amp [implicit permission from Zen Mod] is attached. Note the following.
  • It is totally different in topology from that of diy F6.
  • Note the phase of the signals in the circuit.
  • The Summing Junction is one very important innovation. The output impedance of the buffer [Zo] has a finite value, and is not zero Ohms. A possible example of this buffer maybe one cell of Mr. Pass's "Beast of a Thousand Jfets".
  • Two out of phase signals add up at the Summing Junction and generate an error or difference signal. One signal is from the buffer's internal generator [Gen], and the other out of phase or feedback signal emanates from the power output port. This is a different approach from that used in diyF6.
  • This difference signal is presented to the gate of the lower R100A via a high quality coupling capacitor. It is amplified and appears phase inverted at the the drain of this R100A or the output port.
  • The above difference signal is also presented to the coil of the transformer. Transformer action thereafter presents it to the coil attached to the gate of the upper R100A. Note its phase. This signal is then processed by the upper R100A, and appears at its source in phase with that generated by the lower R100A.
Suppose a DIYer loves this solo amp design, and wants to build it; like assembling its cousin a diy F6. Here is the second important feature of this solo amp. The DIYer may use a 1:1 transformer instead of the the quadrifilar Jensen. This former transformer is expected to be readily available and may be cheaper than the Jensen. Clearly, the Jensen is also useable in this approach.

I have another post which will show the potential of BFF6x to cancel distortion at its power output ports. It'll be a treatment like I did for flg's schematic in an earlier post. I'll have to hand-draw its skeletal schematic first.

Best regards.
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File Type: jpg HalfBabelfishF6x.jpg (269.6 KB, 192 views)
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File Type: pdf HalfBabelfishF6x.pdf (24.6 KB, 11 views)
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Old 16th March 2013, 08:51 PM   #3907
Zen Mod is offline Zen Mod  Serbia
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read this :

http://www.ti.com/lit/an/sloa054d/sloa054d.pdf
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Old 16th March 2013, 09:28 PM   #3908
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Thanks Zen Mod. It is a valuable reference. I was interested in DIDO [Diff In Diff Out] in the mid 1970s. The attached shows an example; the author of the book [taught at the University of Illinois] is Fitchen/1970.
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Old 16th March 2013, 10:18 PM   #3909
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this is ( at least - something as it was ) all in what I was interested in mid 1970s ..........
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Old 16th March 2013, 10:30 PM   #3910
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