Bride of Zen problem

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Kermit

Kermit

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Joined 2002
arold19 said:
I need some help please !!!
At the output of the power supply of my Bridge of Zen, I have 60 V, but when I connect it to the circuit, it drop to 28 V.
Can you help me, I don't understand....
I tried it with no cd player and with no amplifier....
Click to expand...

Hmm.. sounds like inverted emitter and base. I know cuz I did it ;)

Looking at the tip29 from the front you should have base, collector and emitter, from left to right.
The higher value R2 and R3 shouldn’t result in this. I know cuz I tried that too ;)
 
A

arold19

Member
Joined 2002
Thank you !!!
I get off the two resistor and place a wire..... now, I have 60V....
It is OK for the power supply, but I have 60V at the Drain of the mosfet to, it is suppose to be 20 V ....
The 7,5V at the gate is OK...... but how I can have 60 at the Drain ???
thank !!!
 
T

till

Banned
Joined 2002
ok, you gate ist ok at 7,5V. The drain is at 60V instead of 20V. This means there is no current flow trough the FET and the 1k resistor, because else there would some voltage of these 60V get lost across the resistor (40 of them ). This means a) your Fet is dead because with 7,5 V over the source at the gate there should flow current or b) you wired it not the right way/ check pinout, is there a connection between source and GND.
 
Anorgan

Anorgan

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Joined 2003
anorgan.com
In thease situations, it is best to google and download all the datasheats for all of the transistors, check everything twice, get some measured numberes from:
http://members.lycos.nl/Aren/id45.htm
and then hook your equipement as it would normaly be operating - the input and the output, and set voltage across R108 to be 2.8 - 4V (what are your values?), and get to the measured voltages. I just did this, and my boz is running OK. It is nice to know that you can make this preamp with only some fluitin, a solder iron, and a multimeter!! Happy DIY-ing.
 
A

arold19

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Joined 2002
It is Ok for the circuit now, I forget a resistor.......
but now, I have a serius problem with the power supply, When I get off R2 of the power supply, all was Ok, The 60 V at the output was perfect, but when I get off the resistor of the other channel. the TIP29 broke in fire !!!! I realy don't understand ! Now, I change the TIP 29, this new TIP29 doesn't burn but I don't have 60V at the output, I have nothing.
All the 93 V is in R1. I have nothing in the zener.
Do you know what is happening ???
 
Kermit

Kermit

Member
Joined 2002
arold19 said:
When I look with my multimeter, the resistance between the base and the ground is 0 ohmm this is normal ??? what mean arched ???
Click to expand...

Arched may not be the correct term, I mean "welded", closed by too much voltage.
If you take it out of the circuit and measure it with a ohm meter, and you get a low ohm reading it’s closed, and needs to be replaced.

Are you doing it p2p or are you using a pcb?
 
A

arold19

Member
Joined 2002
Today, I take out the capacitor of the circuit and the value is 2,3 M ohm I thing that the cap is Ok !!!
It is not normal to have 0 ohm between a zener ???
To see if the zener are ok, I can try the power supply without C2, I suppose to have 60V !!!!!

And I don't use PC Board !

what I can do ???
 
T

till

Banned
Joined 2002
what do you measure different than this?
 

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T

till

Banned
Joined 2002
or otherway: this means there is no connection between the R1 at + and the zehners, or the zehner chains resitance is 0. I don´t think you damaged all the zehners in the way they are 0 Ohm resitors now. So R1 needs to be replaced - or there is another reson why there is no connection -> check the connection.
 
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