NEW schematic layout

bracoraab · 22nd April 2007, 07:43 PM

Hi everybody,

This is my first aproach to this forum.
I piked up this circuit from an amplifier of a friend of mine(it sounds great !!!).
I would like to know the value of each the three marked components (because they are SMD).
What do you think about this design?
I wish to duplicate this amplifier.
Is the data OK?
Thanks to everybody.

Best regards.
Braco

bracoraab · 22nd April 2007, 10:06 PM

The previous image is the input stage, here is the output stage:

darkfenriz · 22nd April 2007, 10:47 PM

Base of MJE350 is missing a connection, should be a mirror image of what is going on with MJE340.
The ?marked diode can be an industry standard 1n4148 or similar, I guess it sould be not on heatsink while bd139 should be on heatsink.
The ?marked capacitors is a hard question, try asking your friend, I can estimate they are in 10p-150pF range.
Generally I think this amplifier can be good with high bias current of output mosfets (>150mA), current of op-amps is charging mosfets' gates which is not very nice together with low bias.

Have fun DIYing!!

regards

Adam

bracoraab · 23rd April 2007, 02:22 AM

Hi Adam,
you are right with the base connection of the MJE350, here is the correction.
You are right too with the BD139 he is on heatsink.
Thanks with thd diode code, sorry with my english and I'm rookie in electronics, thats why I am asking for help.

Here is the correction on the schema
Cheers
Braco

bracoraab · 23rd April 2007, 02:22 AM

Otherwise, I have to be sure vith the two BC546's here is the picture:
Tha SMD code seams to be 4GP (41)
Thanks in advance
Braco

bracoraab · 23rd April 2007, 02:22 AM

On the other hand, are the BC556's, the SMD code are 2gp (39).
I have to be sure too.
Thanks to everybody
Cheers

Braco

daatkins · 23rd April 2007, 08:24 AM

Hi Braco,
A question about identifying SMD transistors came up in another thread recently and a very helpful member supplied the link below. It's a large table in PDF format, sorted by package marker numbers with corresponding device number, manufacturer, pin-out and the leaded-equivalent device info.
http://www.kipa-bg.com/html/SMD_CODS.pdf

I have yet to use the table, so I can guarantee its accuracy!

Nice one,
David.

bracoraab · 23rd May 2007, 08:01 PM

A few weeks ago I posted this treath with 3 pictures, well here is the complete schema in one piece.
Would you be so nice to criticize thewholecircuit. Remember I'm rookie in electronics.
Thanks in advance

PS: sorry it's my first time with Express SCH.

destroyer X · 23rd May 2007, 09:26 PM

Soldering parts over the copper foil board.

I do this way since the sixties.

Better to see this late than never.

Sorry the fast off topic, but it is not easy to find people doing this way.

I am not lonely anymore

regards,

Carlos

bracoraab · 23rd May 2007, 09:54 PM

A long time ago I tried once, it becomes a headache to try to weld this way.
For you, seems to be very easy.

Saludos hermano.
Braco

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22nd April 2007, 10:47 PM	#3
darkfenriz diyAudio Member Join Date: Jun 2004 Location: Warsaw	Base of MJE350 is missing a connection, should be a mirror image of what is going on with MJE340. The ?marked diode can be an industry standard 1n4148 or similar, I guess it sould be not on heatsink while bd139 should be on heatsink. The ?marked capacitors is a hard question, try asking your friend, I can estimate they are in 10p-150pF range. Generally I think this amplifier can be good with high bias current of output mosfets (>150mA), current of op-amps is charging mosfets' gates which is not very nice together with low bias. Have fun DIYing!! regards Adam

23rd April 2007, 08:24 AM	#7
daatkins diyAudio Member Join Date: Aug 2001 Location: Bath, UK	Hi Braco, A question about identifying SMD transistors came up in another thread recently and a very helpful member supplied the link below. It's a large table in PDF format, sorted by package marker numbers with corresponding device number, manufacturer, pin-out and the leaded-equivalent device info. http://www.kipa-bg.com/html/SMD_CODS.pdf I have yet to use the table, so I can guarantee its accuracy! Nice one, David.

23rd May 2007, 09:54 PM	#10
bracoraab diyAudio Member Join Date: Sep 2004 Location: under the boardwalk	A long time ago I tried once, it becomes a headache to try to weld this way. For you, seems to be very easy. Saludos hermano. Braco