John Curl's Blowtorch preamplifier

[Wavebourn]

Not an issue.

It is an issue, since it is a solid state forum, instead of "thus high distortion tube gear."[/] where it is not an issue.

 

[PMA]

dv(out)/di(out) as a function of v(out) into 600 ohm:

 

[Wavebourn]

dv(out)/di(out) as a function of v(out) into 600 ohm:

Impressive!

Did you use this meter?

http://www.solarlight.com/download/...ext=PMA Series Capabilities and Applications (.pdf)&VID=98110&uid=-93941239&frmtrk=alert

 

[PMA]

pointless

 

[Wavebourn]

pointless

Ok, let me rephrase: was it metered, or SIMed?

 

[john curl]

Throttle back, Wavebourn or else we will have to teach you where the bear sits.

 

[PMA]

Right now simmed, the real thing is operated few months and measured, not especially for this, but can give you preamp response into 1uF:

 

[Wavebourn]

Throttle back, Wavebourn or else we will have to teach you where the bear sits.

I know already: it sits near zero crossing, on higher frequencies.



Edit: switching off computer, going to listen to Santana.

Talk to you later!

 

[jacco vermeulen]

to drive it.

Mr Curl,

question i've been wanting to ask for some time, ever considered doing a monaural version of the BarB & Q with balanced inputs ?

 

[john curl]

The active circuitry is naturally balanced input and output, BUT it is VERY expensive to make it balanced input. Balanced output is natural for this design, however, and not really more expensive.

 

[PMA]

I know already: it sits near zero crossing, on higher frequencies.

Class A, not slew rate limited, very fast and very stable, no deep saturation problems, fast instant recovery from limitation, measured THD up to 100kHz. The bear does not sit near zerro crossing on higher frequencies then.

 

[Wavebourn]

Hi Pavel;
sorry for the joke: it was a double - folded one: measurements VS simulations, and did they ask you before using your initials. No offence at all, great design! I pearsonally prefer everything: transistors, tubes, transformers, for optimal end results, so have nothing against properly used transistors.

 

[Edmond Stuart]

Much noise about nothing.

Speaking about noise.

BTW, that balanced input thingy is also pretty lousy. What's the CMRR? Probably no more than a meagre 30dB.

 

[Wavebourn]

Speaking about noise.

BTW, that balanced input thingy is also pretty lousy. What's the CMRR? Probably no more than a meagre 30dB.

30 db down already slight ground issues? Not bad at all, good transformer would cost $200 for each channel for all consumers that may be don't need a balanced XLR in.

 

[Edmond Stuart]

And the added distortion?

 

[Wavebourn]

And the added distortion?

Inaudible due to spectral character.

 

[Edmond Stuart]

Sure, due to that sonically intangible 'features'.

 

[VivaVee]

syn08 wrote

You could even find dual (not matched) JFETs as the MMBF4416/MMBFJ177 pair from OnSemi

MMBF4416/MMBFJ177 are single JFETs in a SOT23 package. Were you thinking of something else?

 

[john curl]

Use an op amp then, Edmond.

 

[Edmond Stuart]

Use an op amp then, Edmond.

Only One? That's not enough.