P 1.7 schematic help - Page 2

jh6you · 18th June 2005, 04:02 PM

Buy Horowitz&Hill THE ART OF ELECTRONICS . . .
And read Appendix A, HOW TO DRAW SCHEMATIC DIAGRAMS, on page 1056.
No . . . ! ! ! Just go to a book shop, and read it, then return it into the shelf . . .
Or, stealing book for studying is no sin . . .

. . .

Regards
jH

GRollins · 18th June 2005, 04:20 PM

Nope. Nelson draws his schematics using the Foresthills dialect of the language. In the local argot, a line that crosses straight over another line is a no connection. A line that connects is a dead end, such as the connection of R47 to the +input. Of course, there are incongruities just as in any language, in that C9 and R52 (can't read the number clearly) get a straight line connection instead of an offset one. That's the way it goes. It's a small hurdle that he puts in to test your commitment to building the circuit.
In any event, only the middle MOSFET (IRF610--Q?--number completely illegible, less than optimal scan) is active signal-wise. The upper one (IRF9610--Q?) and the lower one (IRF610--Q?) are current sources, and undriven ones at that, i.e. they are not Aleph current sources or anything of that nature. Nelson is just letting the collector of Q11 and Q12 connect via R46. How much AC goes across there, I couldn't say as I haven't built the circuit, but it might qualify as a sort of backdoor feedback. Note that the connection isn't part of the signal path, per se, as the ZTX parts only serve to set the current and tighten up the two current sources. They are DC servos that correct for AC signals across R44 (Q11) and R55 (Q12). Any deviation from pure DC gets passed back to the Gate of the MOSFET as a corrective signal, thus setting things right again.

Grey

Blues · 18th June 2005, 04:44 PM

Quote:

Originally posted by Nelson Pass

Maybe you are thinking about bleeder too much: Easy cure
for that - stop thinking and start experimenting.

Amp should die instantly? Amp might deserve to. Gets stake
driven right through heart!

We are fearless amplifier builders. Unafraid to stop simulating
and start building. What's the worst that can happen? You die?

No, amp dies! Maybe speaker, too!

Lose a couple of $$$!

MuuuuHahahahahahaha........!!!!

Moderators, please move this to the other thread...where amps need to be bled

MikeW · 18th June 2005, 05:38 PM

Here is the schematic.

jh6you · 18th June 2005, 06:45 PM

Yes

The book says: "1. Wires connecting are indicated by a heavy black dot; wires crossing, but not connecting, have no dot . . . 2. Four wires must not connect at a point; i.e., wires must not cross and connect.

Ladies and gentle men . . . the one, the only . . . Starina . . .
wo! wo! wo! wo! wo! wo . . . ! ! !

Regards

MikeW · 18th June 2005, 07:10 PM

Any other mistakes?

jh6you · 19th June 2005, 02:31 AM

One misprint. The size of R27

Regards
jH

MikeW · 19th June 2005, 01:39 PM

I found that one 221K. I have one channel built. I still need to do some testing. Thanks for the help.
Do R44,59,55,70 have to be more than 1/2 watt? The prototype board has 2 watt, but it looks like they should only see .7 volts across them.

GRollins · 19th June 2005, 02:45 PM

1/2W will do just fine...or 1/4W if you want. You're correct, there's only a steady .65VDC across them.

Grey

MikeW · 19th June 2005, 05:19 PM

Should the minus input and output be shorted for single ended operation?

18th June 2005, 07:10 PM	#16
MikeW diyAudio Member Join Date: Sep 2002 Location: North of Boston	Any other mistakes? __________________ MikeW

19th June 2005, 01:39 PM	#18
MikeW diyAudio Member Join Date: Sep 2002 Location: North of Boston	Thank you I found that one 221K. I have one channel built. I still need to do some testing. Thanks for the help. Do R44,59,55,70 have to be more than 1/2 watt? The prototype board has 2 watt, but it looks like they should only see .7 volts across them. __________________ MikeW

19th June 2005, 05:19 PM	#20
MikeW diyAudio Member Join Date: Sep 2002 Location: North of Boston	single ended Should the minus input and output be shorted for single ended operation? __________________ MikeW

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18th June 2005, 04:02 PM	#11
jh6you Account Disabled Join Date: Aug 2002 Location: Near to the Pacific Ocean	Buy Horowitz&Hill THE ART OF ELECTRONICS . . . And read Appendix A, HOW TO DRAW SCHEMATIC DIAGRAMS, on page 1056. No . . . ! ! ! Just go to a book shop, and read it, then return it into the shelf . . . Or, stealing book for studying is no sin . . . . . . Regards jH

18th June 2005, 04:20 PM	#12
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	Nope. Nelson draws his schematics using the Foresthills dialect of the language. In the local argot, a line that crosses straight over another line is a no connection. A line that connects is a dead end, such as the connection of R47 to the +input. Of course, there are incongruities just as in any language, in that C9 and R52 (can't read the number clearly) get a straight line connection instead of an offset one. That's the way it goes. It's a small hurdle that he puts in to test your commitment to building the circuit. In any event, only the middle MOSFET (IRF610--Q?--number completely illegible, less than optimal scan) is active signal-wise. The upper one (IRF9610--Q?) and the lower one (IRF610--Q?) are current sources, and undriven ones at that, i.e. they are not Aleph current sources or anything of that nature. Nelson is just letting the collector of Q11 and Q12 connect via R46. How much AC goes across there, I couldn't say as I haven't built the circuit, but it might qualify as a sort of backdoor feedback. Note that the connection isn't part of the signal path, per se, as the ZTX parts only serve to set the current and tighten up the two current sources. They are DC servos that correct for AC signals across R44 (Q11) and R55 (Q12). Any deviation from pure DC gets passed back to the Gate of the MOSFET as a corrective signal, thus setting things right again. Grey

18th June 2005, 06:45 PM	#15
jh6you Account Disabled Join Date: Aug 2002 Location: Near to the Pacific Ocean	Yes The book says: "1. Wires connecting are indicated by a heavy black dot; wires crossing, but not connecting, have no dot . . . 2. Four wires must not connect at a point; i.e., wires must not cross and connect. Ladies and gentle men . . . the one, the only . . . Starina . . . wo! wo! wo! wo! wo! wo . . . ! ! ! Regards

19th June 2005, 02:31 AM	#17
jh6you Account Disabled Join Date: Aug 2002 Location: Near to the Pacific Ocean	One misprint. The size of R27 Regards jH

19th June 2005, 02:45 PM	#19
GRollins diyAudio Member Join Date: Feb 2001 Location: Columbia, SC	1/2W will do just fine...or 1/4W if you want. You're correct, there's only a steady .65VDC across them. Grey

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