John Curl's Blowtorch preamplifier part II

[RayCtech]

Hi Joshua, yes, it is almost impossible to find 'good equipment' in audio. By that definition, I mean, completely EMI proof, so that external line filtering would not be helpful. Everything that I own or make has benefited from power line filtering. However, the worst example that I have found is my STAX vacuum tube headphone amp. Go figure!

I would rephrase "almost impossible" to "completely impossible" for products that are possible to buy...

Both my practical evaluations and simulations have clearly indicated that physical and practical limits prevents the creation of a perfect product.

 

[jneutron]

Both my practical evaluations and simulations have clearly indicated that physical and practical limits prevents the creation of a perfect product.

Those who stand in the middle lane of the expressway shouting at the top of their lungs that something is impossible are usually run over (mid yell) by the tractor trailer of progress.



Define perfect.

To me, it meets all requirements. No more, no less.

jn

 

[DF96]

It is hardly profound to declare that a perfect product cannot be created.

In our next news item, scientists discover that perpetual motion is impossible.

 

[jneutron]

In our next news item, scientists discover that perpetual motion is impossible.

Scientists obviously never had to take care of triplets.

jn

 

[Joshua_G]

Noise are one of the affecting factors..

Indeed, one of the factors, though there are other factors.

Have you tested the 2SD786 transistors yet?

Not yet, I was preoccupied with other projects.

 

[Joshua_G]

Hi Joshua, yes, it is almost impossible to find 'good equipment' in audio. By that definition, I mean, completely EMI proof, so that external line filtering would not be helpful.

Indeed.
Tell it to SY…

 

[SY]

Indeed.
Tell it to SY…

No, his job is to keep the True Belivers believing.

 

[jan.didden]

are they supplying them in the SOT packages jan? (the LSJ74)

TO-92

 

[bcarso]

TO-92

Jan, do we also get a datasheet? I couldn't find one on their site as yet.

 

[SY]

One came with my samples.

 

[jan.didden]

I don't have one - maybe SY can scan his and I will post it on the L|A website.;

jan

 

[bcarso]

I don't have one - maybe SY can scan his and I will post it on the L|A website.;

jan

Good idea, but I guess the LIS guy should be consulted, as it may be a work in progress. EDIT: I'm particularly interested in how they do on breakdown voltage.

 

[john curl]

OK everybody, BELIEVE in what you hear is real!

 

[SY]

I'll find it and scan.

 

[gpapag]

As long as the caps don't blow up during discharge..
jn

This seems to be the main reason for using the step down transformer.

I do have hands on experience…

Thank you for communicating it to us all here (and clear the shorts)

George

 

[Joachim Gerhard]

I am not perfect but i am perfect for you
grace jones

http://commons.wikimedia.org/wiki/File:Gracejones-thehurricantour.jpg

 

[SY]

EDIT: I'm particularly interested in how they do on breakdown voltage.

25V min for Vgd and Vgs.

 

[fas42]

As long as the caps don't blow up during discharge..

Just use enough caps in parallel - if you need 200A say, it's DIY after all, just stick in 50 of them, say, to give you a reasonable margin of reliability.

 

[fas42]

Indeed, though probably low level distortion isn't the only thing that in itself ensures high degree of realism in music reproduction.

Over the couple of decades that I've been looking at things from this angle it's been a rock solid metric of where a system is at, it's never failed me. It's completely automatic for me these days to be able to tune into this aspect of reproduction - the bling factor is a big fat zero for me ...

A good example, after a very long break from the audio 'dance', was listening to the best MBL gear you could buy, easily 1/2 mill or more of kit. It started well, very clean, believable sound, then the first hint of a distortion artifact, and it slowly got worse - there was some gremlin inside the expensive boxes of bits building up a clearly audible, disturbing distortion component ...

 

[Waly]

Ever heard of the Frey effect ?

(all in all, you're just another brick in the wall)

Better than a sad clown with popping ears, I suppose.