VBITNGC building & comment - Page 14

VT67 · 24th December 2005, 11:51 PM

Franz

I am trying to figure out how this delay circuit is connected. According to your drawing and the wiring diagram of the power supply the 47µF capacitor is connected between GND and pin 2 of the timer IC. On the PCB this capacitor goes from GND in series with the resistor and trimmer. Also the resistor (trimmer) is on one side connected to the +VDC, I can't see that on the PCB. Am I totally missing the point here or is there something wrong with the PCB. The thing that strikes me the most is that Hanzwillem has a working amp, we all have the same PCB's do we?

Regards

VT67 · 25th December 2005, 12:14 AM

According to the wiring diagram it should be something like this.

VT67 · 25th December 2005, 12:58 AM

Fellow builders

I just cut the trace on the PCB and made the two additional connections, as shown in the image of my previous post, and now the time delay works. At about 27 seconds after switching On the power the relay activates. And now it's time to go to bed!

Cheers

wim · 25th December 2005, 07:22 AM

Very sstrange that Hanzwillems amp is working without the fix you named GeWa.

Maybe hanzwillem can tell us how he did it, and mayby he is willing to make some detailed pictures of all the PCB's he made?

As i asked before, it shout be nice if there was a COMPLETE assume of bugs and fixes.

I do not work any further on this amp without such a summary. It it laying in my junkbox at the moment. I think that others think the same.

Franz G · 25th December 2005, 10:23 AM

Quote:

As i asked before, it shout be nice if there was a COMPLETE assume of bugs and fixes.

I am very sorry, but I cannot help you. Someone who assembled it successfully with all three boards from Zang could do it.

It was not always easy for me, to keep track but I never wanted a question a long time beeing unanswered.

Franz

Hanzwillem · 25th December 2005, 12:26 PM

I build it exactly as in this post:

http://www.diyaudio.com/forums/showt...836#post767836

a 470k resistor gave plenty of time to stabilize.

the only error on the two amp boards is the reversed tube socket. Just solder it on the other side and the amp can be completed.

I thought my post earlier (
http://www.diyaudio.com/forums/showt...426#post790426 ) was pretty clear.

The silkscreen for the high current diodes only is wrong. Just use common sense and mount all diodes in the same and propper direction. I am not at home at the moment, so I cannot post a picture.

It is all not as bad as it seems.

Do use a small sink for the LM317 by the way. You could do without, depending on the input voltage of course, but the IC will get really hot and may cause problems in the long run.

VT67 · 25th December 2005, 01:07 PM

Here I am again.
The picture in the post that Hanzwillem is reffering to states that the PCB layout of the timer circuit is indeed wrong. If you put a resistor (470K) on the PCB with the small bridge (red circle) everything works. Zang should have been a bit more clearly what he did and why he did it this way. If you populate the board with the trimmer and the resistor you have to follow the changes I made.
If one follows the traces on the PCB and compare them with the wiring diagram it shows what is wrong with the timer circuit. If somebody knows how to put up a wiki page I will post all the changes that have to be made to get a good working amp.

Wel, this is one of those projects where "Murphy's Law" is getting the upper hand. I can understand that some people are getting frustrated because of all the minor mistakes. I don't point a finger to Franz or Zang, you can check something over and over until you're blue in the face and still have screw ups.

Merry Christmas

Regards

Franz G · 25th December 2005, 01:33 PM

Quote:

Wel, this is one of those projects where "Murphy's Law" is getting the upper hand. I can understand that some people are getting frustrated because of all the minor mistakes. I don't point a finger to Franz or Zang, you can check something over and over until you're blue in the face and still have screw ups.

Thank you!

I MUST show you my christmas holiday project for this year: Renovation of a Scott Stereomaster 299, found in the garbage (!) on last friday

Merry christmas!
Franz

Franz G · 25th December 2005, 01:36 PM

And a picture of the p2p wiring...

Sorry screwing up this thread again, but at least, it deals with tubes

Franz

VT67 · 25th December 2005, 01:44 PM

Still looks quite shiny for something that's pulled out of the garbage.

Over the next few days I will try to post a pdf document with all the fixes for the VBITNGC so that everybody will be able to finish there amp.

Regards

25th December 2005, 12:58 AM	#133
VT67 diyAudio Member Join Date: Jun 2004 Location: Belgium	Fellow builders I just cut the trace on the PCB and made the two additional connections, as shown in the image of my previous post, and now the time delay works. At about 27 seconds after switching On the power the relay activates. And now it's time to go to bed! Cheers __________________ VBITNGC Krell KSA-50 Krell KSA-100MkII

25th December 2005, 07:22 AM	#134
wim diyAudio Member Join Date: Sep 2003 Location: Nootdorp, Netherlands	Very sstrange that Hanzwillems amp is working without the fix you named GeWa. Maybe hanzwillem can tell us how he did it, and mayby he is willing to make some detailed pictures of all the PCB's he made? As i asked before, it shout be nice if there was a COMPLETE assume of bugs and fixes. I do not work any further on this amp without such a summary. It it laying in my junkbox at the moment. I think that others think the same. __________________ Als er "X" artikelen benodigd zijn, blijken er "X" - 1 in voorraad te zijn.

25th December 2005, 12:26 PM	#136
Hanzwillem diyAudio Member Join Date: Nov 2002 Location: Hengelo, The Netherlands	I build it exactly as in this post: http://www.diyaudio.com/forums/showt...836#post767836 a 470k resistor gave plenty of time to stabilize. the only error on the two amp boards is the reversed tube socket. Just solder it on the other side and the amp can be completed. I thought my post earlier ( http://www.diyaudio.com/forums/showt...426#post790426 ) was pretty clear. The silkscreen for the high current diodes only is wrong. Just use common sense and mount all diodes in the same and propper direction. I am not at home at the moment, so I cannot post a picture. It is all not as bad as it seems. Do use a small sink for the LM317 by the way. You could do without, depending on the input voltage of course, but the IC will get really hot and may cause problems in the long run. __________________ They must have been holy chips or something - Pedro

25th December 2005, 01:44 PM	#140
VT67 diyAudio Member Join Date: Jun 2004 Location: Belgium	Still looks quite shiny for something that's pulled out of the garbage. Over the next few days I will try to post a pdf document with all the fixes for the VBITNGC so that everybody will be able to finish there amp. Regards __________________ VBITNGC Krell KSA-50 Krell KSA-100MkII

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