Pass X2 Preamp - Page 2

wuffwaff · 29th March 2005, 08:56 AM

yes

pinkmouse · 29th March 2005, 09:01 AM

Is there a thread with a definative schema for an upgraded BOSOZ? There seem to be several versions with different mods around on the forum.

wuffwaff · 29th March 2005, 09:17 AM

Hi,

I don´t think there´s a definite version cause everybody build it a bit different. I made one without CCS and plus and minus 60V supply and another one with CCS and +40V -20V supply.

Some use bjt´s for the current source others use fets. Some have 20mA bias, others up to 50mA.

Since the circuit is so simple and doesn´t use many (expensive)parts it is easy to build a few variations. The only thing you have to think of beforehand is if you want to try it without CCS. If so you´ll need a symmetrical power supply with at least +-30V.
A current source is always possible although with higher losses in case of a symmetrical supply.

What seems to be true for all those variations is that they sound very good without using all sorts of fancy caps and resistors.

William

steenoe · 29th March 2005, 09:17 AM

Kari is working on a X-CCS-BosoZ layout.
Heatsinks for Bosoz?
Can't wait to get some of those boards

Steen

jh6you · 29th March 2005, 09:30 AM

Quote:

Originally posted by pinkmouse
There seem to be several versions with different mods around on the forum.

Mine with +/-30V rail.
Two CCS tails.
30mA bias.
No X-feedback.
I am staying hear with full satisfaction of the sound.

So far, I do not see any motivation for further mods.

Regards

wuffwaff · 29th March 2005, 10:17 AM

Quote:

Originally posted by jh6you

So far, I do not see any motivation for further mods.

Regards

That seems to be the general problem and that´s why there won´t be a definitive version.......

William

thomasfw · 29th March 2005, 01:17 PM

So I like the one from "Metalman" (Terry)
CS_CSS_X_BOSOZ

Thomas

zygibajt · 29th March 2005, 08:30 PM

I think the big advantege of the schematic from the first post of this thread is lack of the input cap.

The circuit kind of remind me Aleph P 1.0, that I like soniclly very, very much. I think this might be just a better version of it - IRF610 instead of IRF244 and negative CCS that allows to use no cap at the input.

Bartek

jleaman · 29th March 2005, 08:33 PM

I bet the aleph P1.7 is better right ? Since i have one already i guss i should just finnish that instead : O )

And change all the caps to nicer one's.

thomasfw · 30th March 2005, 12:57 AM

I think it is good to review this from "Metalman"

CC-CCS-X-BZLS: It's alive!

Thomas

29th March 2005, 08:56 AM	#11
wuffwaff diyAudio Member Join Date: Aug 2001 Location: Ingolstadt Germany	yes __________________ een ooievaar is geen konijn want zijn oren zijn te klein!

29th March 2005, 09:01 AM	#12
pinkmouse diyAudio Moderator Join Date: Apr 2002 Location: Chatham, England	Is there a thread with a definative schema for an upgraded BOSOZ? There seem to be several versions with different mods around on the forum. __________________ Al I conceive of nothing, in religion, science or philosophy, that is more than the proper thing to wear, for a while. Charles Fort

29th March 2005, 09:17 AM	#13
wuffwaff diyAudio Member Join Date: Aug 2001 Location: Ingolstadt Germany	Hi, I don´t think there´s a definite version cause everybody build it a bit different. I made one without CCS and plus and minus 60V supply and another one with CCS and +40V -20V supply. Some use bjt´s for the current source others use fets. Some have 20mA bias, others up to 50mA. Since the circuit is so simple and doesn´t use many (expensive)parts it is easy to build a few variations. The only thing you have to think of beforehand is if you want to try it without CCS. If so you´ll need a symmetrical power supply with at least +-30V. A current source is always possible although with higher losses in case of a symmetrical supply. What seems to be true for all those variations is that they sound very good without using all sorts of fancy caps and resistors. William __________________ een ooievaar is geen konijn want zijn oren zijn te klein!

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29th March 2005, 09:17 AM	#14
steenoe diyAudio Member Join Date: Mar 2004	Kari is working on a X-CCS-BosoZ layout. Heatsinks for Bosoz? Can't wait to get some of those boards Steen

29th March 2005, 01:17 PM	#17
thomasfw diyAudio Member Join Date: Jan 2005 Location: Hong Kong	So I like the one from "Metalman" (Terry) CS_CSS_X_BOSOZ Thomas

29th March 2005, 08:30 PM	#18
zygibajt diyAudio Member Join Date: Jun 2003 Location: Wroclaw	I think the big advantege of the schematic from the first post of this thread is lack of the input cap. The circuit kind of remind me Aleph P 1.0, that I like soniclly very, very much. I think this might be just a better version of it - IRF610 instead of IRF244 and negative CCS that allows to use no cap at the input. Bartek

29th March 2005, 08:33 PM	#19
jleaman Banned Join Date: Apr 2002	I bet the aleph P1.7 is better right ? Since i have one already i guss i should just finnish that instead : O ) And change all the caps to nicer one's.

30th March 2005, 12:57 AM	#20
thomasfw diyAudio Member Join Date: Jan 2005 Location: Hong Kong	I think it is good to review this from "Metalman" CC-CCS-X-BZLS: It's alive! Thomas

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