JFET input, MOSFET VAS, LATERAL output = Perfect!!

[mikelm]

".......but what's the point of wasting 20 years to end up right where we started ? "

For me this is the circuit that was really the birthplace of what this thread developed into and I believe that if this simple circuit concept is developed & implemented well it would rival some of the best sounding amplifiers in the world.

link now here

http://www.diyaudio.com/forums/soli...vas-lateral-output-perfect-3.html#post2552013

I wonder did you read through this thread ? it really isn't about low THD as the be all & end all of amp design - in fact, quite the opposite.

 

[AndrewT]

http://www.Topic Related Searching at HTTP.COM.
This is a copy of the link you posted.
It does not link.
What is wrong with it?

 

[mikelm]

What is wrong with it?

Dunno - I tried to insert a hyperlink, never did that before, seemed to work at first, then stopped working.

 

[AndrewT]

deleted all the extra http:// s and it took me to post29. Is that location correct?

Just go to the post right click on the post's number and "copy link location".
Go back to your reply and paste in the copied link.

How do we change the "title" that gets adopted?

 

[radio]

For me this is the circuit that was really the birthplace of what this thread developed into and I believe that if this simple circuit concept is developed & implemented well it would rival some of the best sounding amplifiers in the world.

link now here

http://www.diyaudio.com/forums/soli...vas-lateral-output-perfect-3.html#post2552013

I wonder did you read through this thread ? it really isn't about low THD as the be all & end all of amp design - in fact, quite the opposite.

Hi
Let's give the PCB making this amplifier a good-easy!
Give PCB and immediately to create one!
thanks

 

[mikelm]

29 is correct

that's what I did at first and it worked ok but I was trying to find out how make the word "this" a link to a link

 

[mikelm]

Several PCB versions of this design have been made - one of them I believe is still widely available. Send a PM to AKSA ( hugh deans )

 

[Ian Finch]

Hi Radio
The Group buy at AKSA's manufacturers forum here for the Fetzilla amp, as it's named, is now closed - fully subscribed and shipped out to members already, unfortunately.
The double-sided PCB images are still posted in the thread, however.

 

[kees52]

".......but what's the point of wasting 20 years to end up right where we started ? "

Harmonic Distortion over the Decades



------------------------------

Seems that the tube entiousiasts have right, some harmonics can richen the sound, special the first couple of harmonics, as you can see in the graph the distortion of modern amps is far lower but are more clinical, you now the reason is not the distortion below 5 khz, but the distortion above it, the high frequentie behavior of amplifiers is important to get good sound, the fase distortion there high in the sky where it is of much important is not plotted, just take a scope a tone generator and follw the input and output, if it go shift in high frequenties you're in trouble, I talk then between 5 khz 50 khz..

if it is equal to input then it is fine, also tune the amp with a square wave, get rid of the overshoots, so I do it always and it is hearable.

 

[radio]

Hello People!
Poor'm doing this English ... because with you we communications is catastrophic!?

Let's go ahead and move on ...!
thanks and cheers!!

P.S.
Come on, ... I love all the enthusiasts,...!!!!
Come on, ... I love all the enthusiasts,...!!!! ... and of course every enthusiast-honor!
Cheers!!

 

[kees52]

Hello People!
Poor'm doing this English ... because with you we communications is catastrophic!?

Let's go ahead and move on ...!
thanks and cheers!!

P.S.
Come on, ... I love all the enthusiasts,...!!!!
Come on, ... I love all the enthusiasts,...!!!! ... and of course every enthusiast-honor!
Cheers!!

hmm I think you have some Pivo there

 

[keantoken]

Hey, maybe someone should bring a Fetzilla to the Burning Amp thing?

- keantoken

 

[AKSA]

Why?

 

[keantoken]

I dunno. Why not?

Pardon me, I've never been to a festival.

- keantoken

 

[AKSA]

Well, I just don't think it would attract any attention. For starters, it's not Class A.

Hugh

 

[keantoken]

Okay, that makes sense.

Thanks,
- keantoken

 

[AndrewT]

Let someone bring along a 2pr output stage biased into ClassA along with the 1pr ClassAB version for all to hear.

 

[spind]

Hey, maybe someone should bring a Fetzilla to the Burning Amp thing?

- keantoken

I'd say that is not a bad idea at all K-T, if anyone has one built by then. From what I've read over the past few years the particpants that go to this gathering are very receptive to all kinds of DIY efforts, Class A, chip-amps, tubes, DACs, error correction, turntables, speakers... etc.

Steve.

 

[SP7LZA]

Hi again,

I've build modified FETzilla and results are impressive. Both in the measurements and in the way how it is sound. The modifications is in using BS884 as VAS transistor. THD is reduced for about 50%.

Please see attached schematic and measurements results. The results should be better in final version as current one was mad using old PCB without path optimization and with poor quality power supply.

Schematic:
http://mach-audio.eu/media/1289/prosty_wzmacniacz.jpg

Measurements (using Juli@ soundcard at 8ohm):
Mach Audio - Profesjonalny Sprz?t Audio

Welcome you to try BSS84 and also share your impressions.

 

[lineup]

Good circuit SP7LZA.
You use IRFP140, IRFP9140 for output and LED to set bias.