Aleph J Schematic

[carpenter]

In the preceding schematics there's a blip that shows up in LU1014Ds drain voltage. It occurs when the sine-wave dips across its position on the graph. This blip seems to transfer to the cascode Mosfet. By lowering the setting on VR1 to 36 percent, I was able to lower LU1014Ds drain voltage below the bottom leg of the sine-wave and remove the blip.

 

[thorstenlarsen]

Hi Carpenter !
To lower the current in the dif pair, you just have to put a resistor at the source of the SK 170. By ajusting the resistor value, you can ajust the current in the first leg of the dif pair.
Thorsten Larsen

 

[carpenter]

Hi Carpenter !
To lower the current in the dif pair, you just have to put a resistor at the source of the SK 170. By ajusting the resistor value, you can ajust the current in the first leg of the dif pair.
Thorsten Larsen

Thanks Thorsten. It's similar to the power resistors on the right hand side of the amplifier, yes? Each bank has a resistor. I should have realized..... I remember staring at the SK170 and wondering if there should be additional resistance. Excellent.

It's a good feeling to know that the members of this forum look out for one another.

 

[carpenter]

This one's just for fun (and strickly for my 110 db 1W1M horns)... the power through the LU1014Ds is around 33 watts each (a bit high, wouldn't you say ) and drastic means are required to remove the excess heat. I wonder how it would sound?

Pointless? Maybe.

Still, it's a fun exercise.

 

[Zen Mod]

This one's just for fun (and strickly for my 110 db 1W1M horns)... the power through the LU1014Ds is around 33 watts each (a bit high, wouldn't you say ) and drastic means are required to remove the excess heat. I wonder how it would sound?

Pointless? Maybe.

Still, it's a fun exercise.

that output CCS is rotten

remember - biasing of LU is same as for triode , or any little N Jfet ;

 

[carpenter]

remember - biasing of LU is same as for triode , or any little N Jfet ;

Do you mean it's self-biasing with only a source resistor? Kinda like JfetBOZ?

 

[Zen Mod]

Do you mean it's self-biasing with only a source resistor? Kinda like JfetBOZ?

(sometimes it's wise - if nothing else - to simulate simplest circs , just to have idea how they function )

 

[carpenter]

I dropped the extra current source, added a cap between LTP and power jfet's gate--to let the jfet bias itself. Lost the sine-wave.

 

[Zen Mod]

I dropped the extra current source, added a cap between LTP and power jfet's gate--to let the jfet bias itself. Lost the sine-wave.

you lost ME there , too

you can't drop CCS - its working LOAD for output Jfet ;

in fact - which CCS you dropped - additional one ( hangin' on drain of input Jfet) or output CCS ?

gimme that schematic , and somebody will tell you wher eis mistake

 

[Magura]

you lost ME there , too

you can't drop CCS - its working LOAD for output Jfet ;

in fact - which CCS you dropped - additional one ( hangin' on drain of input Jfet) or output CCS ?

gimme that schematic , and somebody will tell you wher eis mistake

Do you get anything out of that sim? Just curious

Naah, if you wanna play that game, better optimize the CCs instead.

And for Choky, read your mail!!!


Magura

 

[Manu]

And for Choky, read your mail!!!

You ll be disapointed but ...
Choky never read his own post ...

 

[Magura]

You ll be disapointed but ...
Choky never read his own post ...

Yeah, I ought to know


Magura

 

[h_a]

Carpenter, you need to ground reference the gate. I don't know why you don't simply read the posts you were linked at; you could avoid all these simple things.

Have fun, Hannes

EDIT: oh and I forgot: maybe you want to read a bit about differential pairs as well? Then you probably don't want to remove its tail current source.

 

[Zen Mod]

.......

And for Choky, read your mail!!!


Magura

who's that pooftaaah - Choky ?



- I didn't received any e-mail from you these days

 

[carpenter]

Carpenter, you need to ground reference the gate.

Which gate?

 

[Zen Mod]

Which gate?

give us last schematic

 

[carpenter]

give us last schematic

I don't know which one h_a was referring to...

That's why I asked.

 

[Zen Mod]

I don't know which one h_a was referring to...

That's why I asked.

I adore that usual game with you ....... where we all chasing own tales ......

give us last schematic you tried , with comments

 

[carpenter]

How about I post what I'm studying now? Your comments are valued; I'm not intentionally playing games. Sometimes I'm just a little dense in the head:

 

[carpenter]

This is a close-up of the output crossing over Q8 gate voltage. Q8 gate voltage can be altered (moved away from the amplifier output), but changing Q8s gate voltage changes the values between the source and drain of the LU1014D.