Ironamp Video Posted

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Official Court Jester
Joined 2003
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just finished watching ( after playing Tom Sawyer with brush episode in front of our house ) .....

tnx for tnx ! , I really like xformers , when used with cause ...
(don't tell anyone that my love for xformers is primary because - when you don't know nuttin' , they are easiest to use ...... :devilr: )

btw. - who are these two other guys - Pass and Didden ?

I hope you enjoy it. :)

Yes very much !
Instant classic.
Happily for Diyers the Big Boys
never stop share his fascinating projects:D
This is interpretation of Western Electric 25B triode amplifier ?
L'Amp versus Ironamp sound witch one is more transparent ?
Could be possible please discribe this subjective sound presentation ?
Very friendly video excellent work:bulb:
thanks Mr Michael Rothacher

Best regards
Joined 2000
Paid Member
This is why I'll never understand electronics. This is a perfect example, even though it's such an easy schematic.

There's 100v going across the OPT into the drain, but "a signal is developed by the SIT at the drain".

Do people just accept this and don't ask why this works? :confused: Is it because electrons really flow from negative to positive? Is because there is an AC signal and the 100v is DC? I'll never get this stuff!
It becomes easier to understand when you have separate abstract ideas of DC resistance and AC impedance. OPT=low resistance, high impedance. SIT=(virtually) high resistance, low impedance.

You actually don't have 100V across the OPT. You are connected to the 100V rail through the OPT but since the OPT has a small DC resistance it will only have a few DC volts developed across itself during idle. The SIT presents a larger effective DC resistance at idle so it develops the lions share of supply voltage across itself.

AC-wise, the OPT has (due to its inductance) a significantly larger impedance than the SIT so the OPT develops the lions share of AC voltage across its winding during operation.
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As 12B4 said, the DC "Iq" "Bias Current" is only seen by the DC resistance of the Xfrmr primary and the on condition of the SIT. Coils don't have much response to DC, only AC creates reactance. When AC signal comes along, the inductance developes much more "Impeadance" (AC Resistance) than the dc resistance in the primary. This inductance can actually develope more opposing voltage than the power supply is providing due to the current passing thruogh it, which gets transfered thru to the secondary.
Using inductors as a load for the gain device is a different circumstance and requires understanding of coils and such vs CCS or Light bulbs or Resistors.
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