Re: ONE repair in all my years...

[Trevor Wilson[_2_]]

"Trevor Wilson" > wrote in message
news:...
>
> "ScottW" > wrote in message
> ...
>>
>>
>> Now I'm confused again....isn't all that power supply stuff
>> technically decoupling?
>
> **Of course it is. For some reason, Arny wants to argue the point. I have
> no
> idea why. He's wrong.
>
>>
>> Bypassing is shunting to ground at the source...not at the
>> power supply.
>
> **Bypassing is a similar term, but relates to the use of a (say) film cap
> across an electro. Or, in the case of a tube amp, when the Cathode is
> coupled to ground, through a resistor, which is bypassed with a capacitor.
> It gets a little muddy, however.
>
>>
>> Here's a reputable app note on high speed digital
>> circuits which have far greater need .....
>>
>> http://hsi.web.cern.ch/HSI/s-link/devices/g-ldc/decouple.pdf
>
> **That particular cite is MUCH better than your earlier one. I concur with
> the description.
>
>>
>>
>>>
>>> **Nope. I checked. ALL use electros for decoupling. Every single one.
>>> Some have film caps as well.
>>
>> Well...I picked one op amp (BTW..I didn't see any obviously in the
>> audio circuits..only video)..and it was decoupled with a ceramic.
>
> **Duh. What did you expect?
>
>> So would you mind specifying a schematic and an op-amp.
>> PITA to scroll back and forth between schematic and parts list.
>
> **Find it yourself. I just jumped through hoops for Arny. I'm not
> doing it again. OK, ONCE. You get ONE example only. Here goes:
>
> NAD 5000 CD player. Page 34.
> IC109, IC110, IC111, IC112, IC113, IC114, IC117.
>
> Happy?
>
> Don't **** me off again. Do your own damned legwork. I listed a bunch of
> models for you and Arny. Arny can't be bothered searching for proof and
> neither, it seems, can you.
>
> All the other models listed have similar topologies.
>
> Trevor Wilson
>
>
>
>
>
>

[Arny Krueger]

"Trevor Wilson" > wrote in message
...
>
> "Trevor Wilson" > wrote in message
> news:...
>>
>> "ScottW" > wrote in message
>> ...

>>> Now I'm confused again....isn't all that power supply stuff
>>> technically decoupling?

Often, a mixture.

>> **Of course it is. For some reason, Arny wants to argue the point. I have
>> no idea why. He's wrong.

Yawn.

>>> Bypassing is shunting to ground at the source...not at the
>>> power supply.

Bypassing has more than one meaning.

>> **Bypassing is a similar term, but relates to the use of a (say) film cap
>> across an electro.

That's one meaning. But its not the only one.

>> Or, in the case of a tube amp, when the Cathode is
>> coupled to ground, through a resistor, which is bypassed with a
>> capacitor.

That's another meaning.

>> It gets a little muddy, however.

So much so that certain dogmatic posturing about other people being wrong is
itself wrong.

>>> Here's a reputable app note on high speed digital
>>> circuits which have far greater need .....

>>> http://hsi.web.cern.ch/HSI/s-link/devices/g-ldc/decouple.pdf

Here's a definition of the difference between bypassing and decoupling:

"Decoupling: The art and practice of breaking coupling between portions of
systems and circuits to ensure proper operation."

"Bypassing: The practice of adding a low-impedance path to shunt transient
energy to ground at the source. Required for proper decoupling."

Note that bypassing can provide a certain amount of decoupling, depending.

Note that were I Trevor, I might say that the given definition of bypassing
proves his definition of bypassing to be wrong. But it isn't. Both
definitions can be correct in the appropriate context.

>> **That particular cite is MUCH better than your earlier one. I concur
>> with
>> the description.

>>>> **Nope. I checked. ALL use electros for decoupling. Every single one.
>>>> Some have film caps as well.

Trevor is wrong again. I made a post this morning that provided numerous
counter-examples, based on the service manual of a receiver that Trevor
cited as proving his point. I cited page numbers and part numbers.

>>> Well...I picked one op amp (BTW..I didn't see any obviously in the
>>> audio circuits..only video)..and it was decoupled with a ceramic.

Decoupling circuits generally include a series element, the output end of
which is connected to a capacitor that is grounded at the other end. The
series element can be either a resistor or an inductor.

>> **Find it yourself. I just jumped through hoops for Arny. I'm not
>> doing it again. OK, ONCE. You get ONE example only. Here goes:
>>
>> NAD 5000 CD player. Page 34.
>> IC109, IC110, IC111, IC112, IC113, IC114, IC117.

>> Happy?

Yes, especially since I provided numerous counter-examples from a Denon
receiver that Trevor cited.

>> Don't **** me off again.

I'm sure I did that! ;-)

>> Do your own damned legwork.

I did, and proved that Trevor was not looking at the whole picture.

>> I listed a bunch of models for you and Arny.

Many of which were dead ends, showing that Trevor wasn't checking his
sources.

> Arny can't be bothered searching for proof

Nonsense. But I know that Trevor is likely to go into denial mode.

> and neither, it seems, can you.

>> All the other models listed have similar topologies.

Again, proof that Trevor hasn't done *his* homework.

[Trevor Wilson[_2_]]

"ScottW" > wrote in message
oups.com...
> On Oct 17, 10:05 pm, "Trevor Wilson"
> > wrote:
>> "Trevor Wilson" > wrote in message
>>
>> news:...
>>
>>
>>
>>
>>
>> > "ScottW" > wrote in message
>> ...
>>
>> >> Now I'm confused again....isn't all that power supply stuff
>> >> technically decoupling?
>>
>> > **Of course it is. For some reason, Arny wants to argue the point. I
>> > have
>> > no
>> > idea why. He's wrong.
>>
>> >> Bypassing is shunting to ground at the source...not at the
>> >> power supply.
>>
>> > **Bypassing is a similar term, but relates to the use of a (say) film
>> > cap
>> > across an electro. Or, in the case of a tube amp, when the Cathode is
>> > coupled to ground, through a resistor, which is bypassed with a
>> > capacitor.
>> > It gets a little muddy, however.
>>
>> >> Here's a reputable app note on high speed digital
>> >> circuits which have far greater need .....
>>
>> >>http://hsi.web.cern.ch/HSI/s-link/devices/g-ldc/decouple.pdf
>>
>> > **That particular cite is MUCH better than your earlier one. I concur
>> > with
>> > the description.
>
>
> Wow...google remains hosed....your post is all listed as
> quoted text...hence the double > .... not my fault.

**I'n using a new nes service. It has problems with Outlook Express and long
threads. I've yet to figure out a workaround. Sorry.

>
> Anyway comparing Arnys article and the Cypress one
> appears to contradict each other...Cypress uses decoupling
> for what the Analog design calls bypass.
>
> You see why they often get confused?

**The Cypress site is 100% correct. Your other cite is wrong. Simple.

>>
> >>> **Nope. I checked. ALL use electros for decoupling. Every single one.
>> >>> Some have film caps as well.
>>
>> >> Well...I picked one op amp (BTW..I didn't see any obviously in the
>> >> audio circuits..only video)..and it was decoupled with a ceramic.
>>
>> > **Duh. What did you expect?
>>
>> >> So would you mind specifying a schematic and an op-amp.
>> >> PITA to scroll back and forth between schematic and parts list.
>>
>> > **Find it yourself. I just jumped through hoops for Arny. I'm not
>> > doing it again. OK, ONCE. You get ONE example only. Here goes:
>
> I was looking at the AVR 485 where I didn't see electrolytics
> on the one op amp but a ceramic (.047 uf) ..but I see now from Arny's
> article
> that you two lack agreement on decoupling.

**Arny is acting like an idiot, for reasons best known only to him. The
AVR485 has numerous OP amps which are decoupled, using electros. These are
some of them:
IC781, IC782, IC783, IC784
There may or may not be more. I really can't see why I need to jump through
hoops for idiots. I cited a large number of examples. That should be the end
of it.

>
>>
>> > NAD 5000 CD player. Page 34.
>> > IC109, IC110, IC111, IC112, IC113, IC114, IC117.
>>
>> > Happy?
>>
>> > Don't **** me off again. Do your own damned legwork. I listed a bunch
>> > of
>> > models for you and Arny.
>
> And I wandered around the schematic of one and didn't see
> what you were talking about...so is it wrong for me to ask
> for specifics? Or would you prefer I just scream bloody
> liar?

**No. I'd prefer that you REALLY looked. I did.

>
> I'm not going to knit about is ceramic or an electrolytic
> used for bypass/decoupling.

**I ONLY listed units where electros were used for decoupling. Film caps may
have been used as bypass caps as well.

> IME..its very common..almost std practice to have a
> ceramic at the power pins. Much easier for close
> placement. Larger values aren't necessary unless the
> power lines have high impedance which should be addressed
> by proper PWB layout IMO.

**And in audio, electros are very commonly used for decoupling supply lines
for OP amps.

Which is back to where we started.

Which is why there may well be a large number of electros in the Linn
analogue crossover cited by Stephen.

Whew!

Trevor Wilson

[Trevor Wilson[_2_]]

"Arny Krueger" > wrote in message
. ..
>
> "Trevor Wilson" > wrote in message
> ...
>>
>> "Trevor Wilson" > wrote in message
>> news:...
>>>
>>> "ScottW" > wrote in message
>>> ...
>
>>>> Now I'm confused again....isn't all that power supply stuff
>>>> technically decoupling?
>
> Often, a mixture.
>
>>> **Of course it is. For some reason, Arny wants to argue the point. I
>>> have no idea why. He's wrong.
>
> Yawn.
>
>>>> Bypassing is shunting to ground at the source...not at the
>>>> power supply.
>
> Bypassing has more than one meaning.
>
>>> **Bypassing is a similar term, but relates to the use of a (say) film
>>> cap
>>> across an electro.
>
> That's one meaning. But its not the only one.
>
>>> Or, in the case of a tube amp, when the Cathode is
>>> coupled to ground, through a resistor, which is bypassed with a
>>> capacitor.
>
> That's another meaning.
>
>>> It gets a little muddy, however.
>
> So much so that certain dogmatic posturing about other people being wrong
> is itself wrong.
>
>>>> Here's a reputable app note on high speed digital
>>>> circuits which have far greater need .....
>
>>>> http://hsi.web.cern.ch/HSI/s-link/devices/g-ldc/decouple.pdf
>
> Here's a definition of the difference between bypassing and decoupling:
>
> "Decoupling: The art and practice of breaking coupling between portions of
> systems and circuits to ensure proper operation."
>
> "Bypassing: The practice of adding a low-impedance path to shunt transient
> energy to ground at the source. Required for proper decoupling."
>
> Note that bypassing can provide a certain amount of decoupling, depending.
>
> Note that were I Trevor, I might say that the given definition of
> bypassing proves his definition of bypassing to be wrong. But it isn't.
> Both definitions can be correct in the appropriate context.
>
>>> **That particular cite is MUCH better than your earlier one. I concur
>>> with
>>> the description.
>
>>>>> **Nope. I checked. ALL use electros for decoupling. Every single one.
>>>>> Some have film caps as well.
>
> Trevor is wrong again.

**Nope. Trevor is 100% correct.

I made a post this morning that provided numerous
> counter-examples, based on the service manual of a receiver that Trevor
> cited as proving his point. I cited page numbers and part numbers.

**I cited the OP part numbers where decoupling is used.

>
>>>> Well...I picked one op amp (BTW..I didn't see any obviously in the
>>>> audio circuits..only video)..and it was decoupled with a ceramic.
>
> Decoupling circuits generally include a series element, the output end of
> which is connected to a capacitor that is grounded at the other end. The
> series element can be either a resistor or an inductor.
>
>>> **Find it yourself. I just jumped through hoops for Arny. I'm not
>>> doing it again. OK, ONCE. You get ONE example only. Here goes:
>>>
>>> NAD 5000 CD player. Page 34.
>>> IC109, IC110, IC111, IC112, IC113, IC114, IC117.
>
>>> Happy?
>
> Yes, especially since I provided numerous counter-examples from a Denon
> receiver that Trevor cited.

**I cited the numbers of the OP amps where decoupling is used. I suggest you
get someone to explain schematics and how to read them to you.

>
>>> Don't **** me off again.
>
> I'm sure I did that! ;-)

**Sure. You're frustratingly obtuse.

>
>>> Do your own damned legwork.
>
> I did, and proved that Trevor was not looking at the whole picture.
>
>>> I listed a bunch of models for you and Arny.
>
> Many of which were dead ends, showing that Trevor wasn't checking his
> sources.

**Cite these alleged "dead ends".

>
>> Arny can't be bothered searching for proof
>
> Nonsense. But I know that Trevor is likely to go into denial mode.
>
>> and neither, it seems, can you.
>
>>> All the other models listed have similar topologies.
>
> Again, proof that Trevor hasn't done *his* homework.

**Incorrect. Examine all the cites I provided. I did.

Trevor Wilson

[Arny Krueger]

"ScottW" > wrote in message
oups.com...
> On Oct 18, 3:05 pm, "Trevor Wilson"

>> **Arny is acting like an idiot, for reasons best known only to him. The
>> AVR485

http://www.hifiengine.com/download_centre/index.php?denon_av-r1505_485_service.pdf

>> has numerous OP amps which are decoupled, using electros. These are
>> some of them:

>> IC781, IC782, IC783, IC784

Actually, the 7 op amps in this part of the schematic are named IC781A,
IC781B... ...IC784A.

VCC+ and VCC- for the entire group of op amps are decoupled by R791 and R792
100 ohm resistors in series with C791 and C792 47 uF/25v electrolytics,
other ends grounded.

But we were talking about power for individual op amps. Each op amp's VCC+
and VCC- line is bypassed to ground by 47 NF (0.047 uF) type Z ceramics.
There is no decoupling for individual op amps. There are no individual
electrolytic capacitors for each op amp.

> Well.....I looked at them and they appear to be bypassed with ceramics
> (as I noted above)

Agreed.

> and all decoupled with a common electrolytic and a resistor
> per the definition Arny provided.

Agreed.

[Trevor Wilson[_2_]]

"Arny Krueger" > wrote in message
. ..
>
> "ScottW" > wrote in message
> oups.com...
>> On Oct 18, 3:05 pm, "Trevor Wilson"
>
>>> **Arny is acting like an idiot, for reasons best known only to him. The
>>> AVR485
>
> http://www.hifiengine.com/download_centre/index.php?denon_av-r1505_485_service.pdf
>
>>> has numerous OP amps which are decoupled, using electros. These are
>>> some of them:
>
>>> IC781, IC782, IC783, IC784
>
> Actually, the 7 op amps in this part of the schematic are named IC781A,
> IC781B... ...IC784A.

**Standard nomenclature.

>
> VCC+ and VCC- for the entire group of op amps are decoupled by R791 and
> R792 100 ohm resistors in series with C791 and C792 47 uF/25v
> electrolytics, other ends grounded.

**Yep. The OP amps are decoupled.

>
> But we were talking about power for individual op amps. Each op amp's VCC+
> and VCC- line is bypassed to ground by 47 NF (0.047 uF) type Z ceramics.
> There is no decoupling for individual op amps. There are no individual
> electrolytic capacitors for each op amp.

**The OP amps are decoupled. You asked for examples. I provided them. That
particular model does not have individual decoupling for each OP amp.
Nevertheless, decoupling is used for audio OP amps in that model.

Trevor Wilson

[Arny Krueger]

"Trevor Wilson" > wrote in message
...
>
> "Arny Krueger" > wrote in message
> . ..
>>
>> "ScottW" > wrote in message
>> oups.com...
>>> On Oct 18, 3:05 pm, "Trevor Wilson"
>>
>>>> **Arny is acting like an idiot, for reasons best known only to him. The
>>>> AVR485
>>
>> http://www.hifiengine.com/download_centre/index.php?denon_av-r1505_485_service.pdf
>>
>>>> has numerous OP amps which are decoupled, using electros. These are
>>>> some of them:
>>
>>>> IC781, IC782, IC783, IC784
>>
>> Actually, the 7 op amps in this part of the schematic are named IC781A,
>> IC781B... ...IC784A.
>
> **Standard nomenclature.
>
>>
>> VCC+ and VCC- for the entire group of op amps are decoupled by R791 and
>> R792 100 ohm resistors in series with C791 and C792 47 uF/25v
>> electrolytics, other ends grounded.
>
> **Yep. The OP amps are decoupled.

But not individually as you said, Trevor. There are almost 4 op amps for
every electrolytic decoupling capacitor, not the pair of electrolytic
capacitors per op amp that you initially claimed.

>> But we were talking about power for individual op amps. Each op amp's
>> VCC+ and VCC- line is bypassed to ground by 47 NF (0.047 uF) type Z
>> ceramics. There is no decoupling for individual op amps. There are no
>> individual electrolytic capacitors for each op amp.

> **The OP amps are decoupled.

But not as you said.

> You asked for examples. I provided them. That particular model does not
> have individual decoupling for each OP amp.

Which differs from your initial claims, Trevor. If the AVR had a pair of
electrolytic caps per op amp as you inititally said, it would have 14
electrolytic caps. Instead, it had only 2 electrolytic caps. No way is the
AVR 485 support for the idea that an electronic crossover would have 150
electrolytic capacitors.

> Nevertheless, decoupling is used for audio OP amps in that model.

Not in the way you initially suggested, or even how you were suggesting
earlier today.

[Arny Krueger]

"ScottW" > wrote in message
...
>
> "Arny Krueger" > wrote in message
> . ..
>>
>> "Trevor Wilson" > wrote in message
>> ...
>>>
>>> "Arny Krueger" > wrote in message
>>> . ..
>>>>
>>>> "ScottW" > wrote in message
>>>> oups.com...
>>>>> On Oct 18, 3:05 pm, "Trevor Wilson"
>>>>
>>>>>> **Arny is acting like an idiot, for reasons best known only to him.
>>>>>> The
>>>>>> AVR485
>>>>
>>>> http://www.hifiengine.com/download_centre/index.php?denon_av-r1505_485_service.pdf
>>>>
>>>>>> has numerous OP amps which are decoupled, using electros. These are
>>>>>> some of them:
>>>>
>>>>>> IC781, IC782, IC783, IC784
>>>>
>>>> Actually, the 7 op amps in this part of the schematic are named IC781A,
>>>> IC781B... ...IC784A.
>>>
>>> **Standard nomenclature.
>>>
>>>>
>>>> VCC+ and VCC- for the entire group of op amps are decoupled by R791 and
>>>> R792 100 ohm resistors in series with C791 and C792 47 uF/25v
>>>> electrolytics, other ends grounded.
>>>
>>> **Yep. The OP amps are decoupled.
>>
>> But not individually as you said, Trevor.

> Now that is a nit....

No, its actually original basis for the whole argument, because Trevor
brought the issue of individual decoupling of op amps up, in order to
justify there being 150 electrolytics in Stephen's Linn crossover.