John Curl's Blowtorch preamplifier part II

[kamskoma]

Just a reflection on audio electronics, I can understand that it is almost unpossible to design and build a real good sounding preamplifier.

You can't use any component that are made from magnetic material.

No capacitors or transformers can be used in the signal path.

Only JFET from Toshiba is the optimum and they don't make any JFET semiconductors for state of the art audio.

So how can we make a real good amplifier, can we find other components that are useable for high tech audio, and if so where?

Maybe it is the dead end street for the DIY people, only the audio industry can make SOTA audio electronics.

John Curl's advanced circuits maybe can be turned to thick film "integrated circuits" made only for audio maybe some company can take this as a hint.

Kamskoma

[jan.didden]

Originally posted by kamskoma
Just a reflection on audio electronics, I can understand that it is almost unpossible to design and build a real good sounding preamplifier.

You can't use any component that are made from magnetic material.

No capacitors or transformers can be used in the signal path.

Only JFET from Toshiba is the optimum and they don't make any JFET semiconductors for state of the art audio.

So how can we make a real good amplifier, can we find other components that are useable for high tech audio, and if so where?[snip]

Maybe you need to ask those people that make those real good sounding preamps out there?

jd

[john curl]

Real designers can still make good products. This is not helpful.

1/2 blind, geo challenged, please no simple or unnecessary questions.

[kamskoma]

Somebody suggest me to ask the manufacturer out there!


"Maybe you need to ask those people that make those real good sounding preamps out there?"


Ok, so they may use not so good devices and makes the best of these "second best semiconductors" so to say.

A SOTA preamplifier consists of JFET transistors and some high grade resistors, maybe a servo as cream.

Even if this special thread is a SOTA expert forum, one can expect some indulgence from the so called SOTA experts, I don't think that this forum is a place for top secret audio electronics if it is why bother to answer.

[anatech]

I think the newer crop of great parts will be surface mount. They already supply matched NPN and PNP parts. These are fantastic for some things I do.

I guess it's time to start looking at these surface mount parts.

BTW, I'm not sold on this magnetic stuff. I have a hard time believing that a constant magnetic field is going to cause any grief, otherwise we are all in trouble.

Time to break out the pyramids and align them to the Earth's field (which wanders occasionally).

Hi John,
Back onto the topic of your designs then. Have you considered any new parts that will deliver the performance you need? I do expect that you could build a top flight preamp with current production parts.

-Chris

[kamskoma]

Thank you Anatech, I was really a bit confused so I browsed the Farnell and RS-Components sites for some SMD JFET, I'll try out some of them, exactly which I don't know.

I have to get some references from old Toshiba data sheets,"doing my own dental floss" as Zappa once told.

[anatech]

Hi kamskoma,
Why not browse the actual manufacturer sites instead? Fairchild and others have some really nice stuff hiding in there. Disties only stock what they are told will sell, which has very little to do with what we might want. I think Zetex is another candy store for us.

-Chris

[jan.didden]

Originally posted by kamskoma
Somebody suggest me to ask the manufacturer out there!


"Maybe you need to ask those people that make those real good sounding preamps out there?"


Ok, so they may use not so good devices and makes the best of these "second best semiconductors" so to say.

A SOTA preamplifier consists of JFET transistors and some high grade resistors, maybe a servo as cream.

Even if this special thread is a SOTA expert forum, one can expect some indulgence from the so called SOTA experts, I don't think that this forum is a place for top secret audio electronics if it is why bother to answer.

Sorry, I was serious. You question whether it is still possible to build SOTA preamps. There are SOTA preamps on the market. So naturally, their manufacturers have the answers. As John said, good designers can still build SOTA preamps.


Edit: I mean by SOTA in this context, preamps with sound the very best of class, worldwide.

Jan Didden

[kamskoma]

Originally posted by janneman



There are SOTA preamps on the market. So naturally, their manufacturers have the answers.


Jan Didden

Mr Didden can you list the SOTA preamps on the market it would be very nice to see what they have done.

Kamskoma

[jan.didden]

Originally posted by kamskoma



Mr Didden can you list the SOTA preamps on the market it would be very nice to see what they have done.

Kamskoma

I would start by looking at the preamp reference section of, say Stereophile. Or other sources that are trustworty to you. The usual supects: Ayre, ML, Jeff Rowland, Pass Labs, etc.
I don't want to take that pleasure away from you.

jd