Preamplifier from German magazine Klang&Ton

[supernet]

Some time ago, Klang&Ton - German DIY speaker magazine-published a "top end" preamplifier which has an output impedance close to 0, so it should drive any cable any time.

input Z : 10 kohm
output Z : <1 ohm
signal to noise ratio : >100 dB
slew rate 9V /us
Rise falltime: <1,5 us
max output voltage : >8 V eff

What is your opinion about this preamplifier schematic??

 

[Cybergent]

Can you bring up the picture with better quality?

 

[peranders]

If the opamps are OPA134, OPA627, AD8610, LT1028 etc etc. I think it looks quite alright but can you get more info about the parts?

 

[Werner]

From what I can make from that schematic there is an almost total lack of care for the power supply.

 

[peranders]

The PS could be more serious maybe. The last thing, is it a power amp or is it only a buffer? Hard to see at the schematics.

 

[supernet]

Sorry about quality, because original circuit in pdf format is over 1,5 M and I could not post it here.Maybe try it with 500× zoom in Word.

This preamplifier has two stages. First is op 5532 and second is a "small amplifier" with bd 139/140 output transistors. Power supply is made with 7815/7915 regulators.

Maybe has anybody idea how to convert a large pdf file into something small indeed?

 

[arasuk]

preamplifier!!!!

hi,

could you post me the full Schematic of the preamplifier.

arasukumar@yahoo.com

thanks
arasuk

 

[Elso Kwak]

Sorry about quality, because original circuit in pdf format is over 1,5 M and I could not post it here.Maybe try it with 500× zoom in Word.
Maybe has anybody idea how to convert a large pdf file into something small indeed?

Hi supernet,
Probably a zipped Postscript file will be legible given the forum's restrictions of 800x 1200 Pixels and a maximum file size of 102400KB.
You could try Adobe Phoptoshop converting to GIF and/or resize resample with Irfanview.
Oops, I just see that Photoshop can also resize (just have it 15 minutes on my PC)

 

[destroyer X]

Cacilda Elso, Dear Elso.... are you sure?

It was 800 by 600!

Can we use 800 by 1200

Cacilda Elso!..... Regards Elso


Carlos

 

[Elso Kwak]

Re: Cacilda Elso, Dear Elso.... are you sure?

It was 800 by 600!

Can we use 800 by 1200

Cacilda Elso!..... Regards Elso


Carlos

Hi Carlos, The zipfile was 66kB.

 

[costiss]

not matter what precisely the circuit is, you ll need to match the transistors... and you can still get better with opamps, way over 5532.. thus the buffer isnt very fast..(bd135)..
you see, 9V/uS isnt a triamphant slew rate - a 8610 has 55V/uS if memory doesnt ellude me.. stil, it may be worth a try, with some attention to the psu..