Conjoined Twin diyF6s

[Antoinel]

A schematic of the subject balanced amp is attached. The Left and Right channels were joined at the source ports of their lower JFETs [or MOSFETs] to make a differential amplifier [Jumper1 or bridge in place]. This schematic promises vanishing distortion through a loudspeaker. Let us play this game to understand why.

• Remove Jumper 1 to give separate diyF6s
• Ground the + and - inputs.
• Make believe that the Left channel has a persitent low frequency oscillation or is motorboating. By contrast, assume the Right channel is absolutely quiet.
• Follow the numbers [0 to 6] on the half shaded sine wave signals.
• Signal 1 starts at the - power output port of the Left amp.
• This Left amp tries to minimize the amplitude of Signal 1 via loop feedback.
• The key is that the simultaneously generated Signals 4 and 6 are out of phase with Signal 1 as the Left amp does its best to minimize the amplitude of Signal 1; which persists in the end.
• Connect a loudspeaker between the power output port of the Left amp and ground. It sings.
• Connect a loudspeaker between the power output ports of the Left and Right amps. It sings.
• Insert Jumper 3. The loudspeaker is quiet. Here's why.
• Signal 5 at the gate of the lower JFET [Left amp] induces Signal 7 at the source of this JFET. Or this JFET operates as a buffer.
• Signal 7 is Signal 8 at the source port of the lower JFET [Right amp]. This JFET operates in the common gate configuration.
• Its output signal is Signal 9 which is in phase with Signal 8.
• Connect a loudspeaker between the power output port of the Right channel and ground. It sings.
• Connect a loudspeaker between the power output ports of the Left and Right amps. In this instance it does not sing. Why?
• Signals 1 and 9 are in phase and most probably are of equal amplitude. The loudspeaker rejects their flow-through.
• The Right amp does its best to minimize Signal 9 via its feedback loop like the Left amp did. But; as long as their are Signals 7 or 8 at the joined source ports of the lower JFETs, there must be a Signal 9 in phase with them.

A blank schematic [unmarked for practice], and another operational example are forthcoming.


Best regards

[Nelson Pass]

You can use similar logic in examining patent #5375899.

[Zen Mod]

#5376899 ?

[Antoinel]

Originally Posted by Nelson Pass

You can use similar logic in examining patent #5375899.

Similar, and imo identical to the logic in US 5,376,899. Conjoined twin diyF5s and conjoined twin diyF6s are further applications of your patent.
Best regards

[Zen Mod]

however , as every LTP is good only as long Tail is , it needs to be examined how long Tail is in case of Conjoined Twin F6

logic - longer the Tail , greater SUSY is , meaning greater error correction is

complicate it - include looong tail , on expense of third PSU leg

[Antoinel]

Originally Posted by Zen Mod

however , as every LTP is good only as long Tail is , it needs to be examined how long Tail is in case of Conjoined Twin F6

logic - longer the Tail , greater SUSY is , meaning greater error correction is

complicate it - include looong tail , on expense of third PSU leg

Thanks Zen Mod for your analysis. Every extra helps.
Best regards

[buzzforb]

I look forward to your opinion on its sound. F6 is funny thing. Some folks love it, some folks like it, some folks dont care.

[Antoinel]

Originally Posted by buzzforb

I look forward to your opinion on its sound. F6 is funny thing. Some folks love it, some folks like it, some folks dont care.

The schematic suggests goodbye to the beloved harmonics DIYers love [and nurture] in Pass amps. It'll sound different from simpler non-conjoiined balanced amps; which are relatively richer in harmonics by comparison. It'll sound great.

[buzzforb]

DIYers are not the only ones who nurture those harmonics.

[Antoinel]

Originally Posted by buzzforb

DIYers are not the only ones who nurture those harmonics.

Why bother spend legal fees to patent US 5,376,899 if the perceived harmonics are all that matters to great sound? Mr. Pass taught in it vanishing harmonic distortion; meaning goodbye [or good riddance] to H2 and Hn... Its practical amps sound great without reliance on harmonics. These amps still create harmonics in their subunits like any other; except the harmonics do not pass through the loudspeaker; because of mutual replication of each other's harmonics in both amplitude and phase.