6V6 line preamp

[stajo]

Thank you. I don't feel so alone

Hug back

Well heres Wavetek on max 20 V pp in and volume pot in the floor. I see no clipping.

 

[stajo]

and heres a pic to

 

[Salas]

OK, scale the wave with the V/div knob so it fits on screen for both ends, center it with the Y knob and post a pic to the mighty one, saying sorry but it asks for more to clip that I ain't got (predictably).

 

[stajo]

For all dodos

http://youtu.be/CLGf0hhlM_k

me moving the 20K pot

 

[stajo]

give me some other measures to take. Im not tired yet What to you guys say about loadline btw?

 

[Salas]

Moved to movie productions already I see. Ingmar Scopeman.

 

[buzzforb]

That's awesome. Your cutting edge now. YouTube plus cathode ray scope.

 

[stajo]

Moved to movie productions already I see. Ingmar Scopeman.

Yes. Want the lead on my new production "The Seventh Wave?

Heres a new scooping right on the 10 uF opt

 

[Salas]

What is this? The test tone moves 2kHz across?

 

[stajo]

Not sure. Just ran a test

Heres a new, 1 kHz sine

Loadlines loadlines...

 

[Salas]

When you do the last one what is the RMS on output using the DMM?

 

[stajo]

Uni-T says 0,549

 

[Salas]

Does it give the same 2nd harmonic (2kHz) each time if you repeat? Does that change if you move the pot from max to middle?

 

[stajo]

Pot on zero and max

 

[Salas]

Makes no sense. 549mV should be -3dBu and if that second peak is the circuit's 2nd harmonic it should vary much from zero to max. Also no test signal should appear on zero vol pot.

 

[Salas]

Go to Flathead for such. He seems to be well equipped and in the know. There you may tweak together for best load line as you watch THD.

 

[stajo]

ok ill make some more in the mornng.8 sharp ok9

 

[stajo]

Here is gen probe on RCA in and measuring probe on 100k load. Zero pot, half pot and full pot. 1 kHz start frequency, 1 V in. I guess that the repeats at 3, 5, 7 etc are harmonics. DMM reads 0,003 V, 0,066V and 0,812 V over those.

 

[Salas]

Only odd and so high...not that persuasive its done correctly.

 

[Salas]

I will go get one from mine to give you an idea.