Reply by George Herold ●May 19, 20172017-05-19
On Thursday, May 18, 2017 at 11:58:01 AM UTC-4, srober...@gmail.com wrote:

> On Monday, May 15, 2017 at 10:49:56 AM UTC-4, Dave M wrote:
> > Has anyone used any of the consumer-grade audio power amps such as the 
> > LM1825, TDA2030, or TDS7297  as a basic DC power opamp?
> > Any reason they shouldn't be used as power supply regulators, TEC 
> > controllers, etc?
> > 
> > Dave M
> 
> As long as you configure it as a inverting opamp with a gain of 20 or more, LM3886 is one big op-amp that works down to DC.  We have them in some mechanical servo systems that need a DC to 2500 Hz response and +/- 12V of drive. . I'm driving 3 ohm and 7 ohm coils with them, no problems.  Must use a split rail, we use +/- 24 volt rails.  
> 
> Steve


Interesting thanks.  Are those air coils?  How bad is the crossover 
distortion.  I use LM675 for ~10 ohm/1 amp coils.  I tried some 
power opamps (OPA544) and the crossover was worse.  
No (zobel) compensation network.  

George H.
Reply by Jan Panteltje ●May 18, 20172017-05-18
On a sunny day (Tue, 16 May 2017 16:03:40 -0700) it happened Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in
<p71nhcpc8djf4im089o8js57gsg4q5ksuc@4ax.com>:



>Try listening to class-D crap via hearing aids that are class-D :-(
>
>Class-D is for audiophools.


Class D means interference.

I have this, nice fan at the back, 19 inch rack:
 http://panteltje.com/pub/301734-an-01-ml-MCCRYPT_ENDSTUF_POWER_PA3000_de-en-fr-nl.pdf
  mixed languages.
Good enough for the living room and street level.
Was only 70 Euro at the time...


It now seems there is a force in the EU, now that UK leaves EU, to move back towards French or German
as the main language.
I remember getting French lessons in kindergarten...
History repeats itself.
What the consequences are for 'the world' I don't know,
and about units, we use a comma where the US uses a dot.
12,5 means 12 1/2
that gets tricky if one needs 12,997 gram.

Will it ever be fixed?

1,999 percent distortion ;-)?
Could be useful in marketing...
Reply by ●May 18, 20172017-05-18
On Tuesday, May 16, 2017 at 10:53:27 AM UTC-7, Dave M wrote:

> Don Y wrote:
> > On 5/15/2017 7:49 AM, Dave M wrote:
> >> Has anyone used any of the consumer-grade audio power amps such as
> >> the LM1825, TDA2030, or TDS7297  as a basic DC power opamp?
> >> Any reason they shouldn't be used as power supply regulators, TEC
> >> controllers, etc?
> >
> > Consider how they handle (highly) reactive loads?
> 
> 
> The reason for my interest in these parts is because I came across a 
> half-full bag of them while helping a friend clean out his recently deceased 
> dad's garage, and while I'm not really interested in building audio stuff 
> anymore, I wondered if they could be useful in other applications.
> 
> Since their main purpose was to drive speakers, which are pretty reactive 
> over the audio range, Zobel networks are commonly used with them.  So I'm 
> sure they don't like to see a lot of reactance. Operating at DC, if they're 
> not asked to handle a lot of AC power, then compensation might not be too 
> difficult. That should be an interesting experiment.
> 
> I might give a shot at using one as a DC power supply regulator, or maybe to 
> drive a power transformer or audio output transformer to make an AC voltage 
> reference.  I've wanted one of those for a long time.  Hmmm... I wonder how 
> they would like being run as BTL amps?
> 
> Thanks for all the suggestions and advice!!
> 
> Dave M



Try selling them on eBay, then tinker with the ones that don't sell?

Michael
Reply by ●May 18, 20172017-05-18
On Monday, May 15, 2017 at 10:49:56 AM UTC-4, Dave M wrote:

> Has anyone used any of the consumer-grade audio power amps such as the 
> LM1825, TDA2030, or TDS7297  as a basic DC power opamp?
> Any reason they shouldn't be used as power supply regulators, TEC 
> controllers, etc?
> 
> Dave M


As long as you configure it as a inverting opamp with a gain of 20 or more, LM3886 is one big op-amp that works down to DC.  We have them in some mechanical servo systems that need a DC to 2500 Hz response and +/- 12V of drive. . I'm driving 3 ohm and 7 ohm coils with them, no problems.  Must use a split rail, we use +/- 24 volt rails.  

Steve
Reply by Phil Allison ●May 18, 20172017-05-18
Kevin Aylward wrote:

---------------------


> 
>
> 
> >Class-D is for audiophools.
> 
> I have 5 kW of pro audio power amps, none of them are class D.
> 
> The weigh a bit, but its just an addition to my few times a week weight 
> training at the gym. I am only 60kg, so I need the practice.
> 
>
>


** Have you come across the Behringer iNUKE amps yet ??  

SMPSs plus class D output stages. 

I tested an iNUKE 6000 recently and found it pretty much meets all its specs - with the switching transformer and output FETs running reasonably cool.

I found it puts out 2500wpc with low THD - about 0.3%. 

https://www.sweetwater.com/store/detail/NU6000

Weighs under 12 pounds and sells for around $US350. 

A real game changer. 



.....  Phil
Reply by Jim Thompson ●May 17, 20172017-05-17
On Wed, 17 May 2017 19:34:11 +0100, "Kevin Aylward"
<kevinRemovAT@kevinaylward.co.uk> wrote:


>"Jim Thompson"  wrote in message 
>news:p71nhcpc8djf4im089o8js57gsg4q5ksuc@4ax.com...
>
>On Tue, 16 May 2017 20:27:57 +0100, "Kevin Aylward"
><kevinRemovAT@kevinaylward.co.uk> wrote:
>
>>"Winfield Hill"  wrote in message news:ofdleo02voc@drn.newsguy.com...
>>
>>Dave M wrote...
>>> Has anyone used any of the consumer-grade audio power amps ...
>>
>>>Sorry, but these days "consumer-grade audio power amps"
>>> are all class-D.  In general most of these can perform as
>>> well as a linear amps.
>>
>>This, of course, depends on the colour of your ears, and their
>>reflectability...
>>
>>-- Kevin Aylward
>>http://www.anasoft.co.uk - SuperSpice
>>http://www.kevinaylward.co.uk/ee/index.html
>>
>>
>>
>
>>Try listening to class-D crap via hearing aids that are class-D :-(
>
>>Class-D is for audiophools.
>
>I have 5 kW of pro audio power amps, none of them are class D.
>
>The weigh a bit, but its just an addition to my few times a week weight 
>training at the gym. I am only 60kg, so I need the practice.
>
>-- Kevin Aylward
>http://www.anasoft.co.uk - SuperSpice
>http://www.kevinaylward.co.uk/ee/index.html 


I fondly remember my first UltraLinear... with power and output
transformers it took two people to carry it ;-)
		
                                        ...Jim Thompson
-- 
| James E.Thompson                                 |    mens     |
| Analog Innovations                               |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

     Thinking outside the box... producing elegant solutions.

"It is not in doing what you like, but in liking what you do that
is the secret of happiness."  -James Barrie
Reply by Kevin Aylward ●May 17, 20172017-05-17
"Jim Thompson"  wrote in message 
news:p71nhcpc8djf4im089o8js57gsg4q5ksuc@4ax.com...

On Tue, 16 May 2017 20:27:57 +0100, "Kevin Aylward"
<kevinRemovAT@kevinaylward.co.uk> wrote:


>"Winfield Hill"  wrote in message news:ofdleo02voc@drn.newsguy.com...
>
>Dave M wrote...
>> Has anyone used any of the consumer-grade audio power amps ...
>
>>Sorry, but these days "consumer-grade audio power amps"
>> are all class-D.  In general most of these can perform as
>> well as a linear amps.
>
>This, of course, depends on the colour of your ears, and their
>reflectability...
>
>-- Kevin Aylward
>http://www.anasoft.co.uk - SuperSpice
>http://www.kevinaylward.co.uk/ee/index.html
>
>
>



>Try listening to class-D crap via hearing aids that are class-D :-(



>Class-D is for audiophools.


I have 5 kW of pro audio power amps, none of them are class D.

The weigh a bit, but its just an addition to my few times a week weight 
training at the gym. I am only 60kg, so I need the practice.

-- Kevin Aylward
http://www.anasoft.co.uk - SuperSpice
http://www.kevinaylward.co.uk/ee/index.html
Reply by ●May 17, 20172017-05-17
On Tuesday, 16 May 2017 18:53:27 UTC+1, Dave M  wrote:


> I might give a shot at using one as a DC power supply regulator, or maybe to 
> drive a power transformer or audio output transformer to make an AC voltage 
> reference.  I've wanted one of those for a long time.  Hmmm... I wonder how 
> they would like being run as BTL amps?


I used to run TDA20nn as BTL without problem. Why wouldn't they?


NT
Reply by John Larkin ●May 17, 20172017-05-17
On Tue, 16 May 2017 16:02:47 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:


>On 05/16/2017 02:32 PM, George Herold wrote:
>> On Tuesday, May 16, 2017 at 2:20:04 PM UTC-4, John Larkin wrote:
>>> On Tue, 16 May 2017 10:08:44 -0500, Tim Wescott
>>> <tim@seemywebsite.really> wrote:
>>>
>>>> On Mon, 15 May 2017 11:18:36 -0700, John Larkin wrote:
>>>>
>>>>> On Mon, 15 May 2017 12:48:08 -0500, Tim Wescott
>>>>> <seemywebsite@myfooter.really> wrote:
>>>>>
>>>>>> On Mon, 15 May 2017 09:49:45 -0500, Dave M wrote:
>>>>>>
>>>>>>> Has anyone used any of the consumer-grade audio power amps such as the
>>>>>>> LM1825, TDA2030, or TDS7297  as a basic DC power opamp?
>>>>>>> Any reason they shouldn't be used as power supply regulators, TEC
>>>>>>> controllers, etc?
>>>>>>>
>>>>>>> Dave M
>>>>>>
>>>>>> If the super-est best-est performance isn't an issue, a plain old op-amp
>>>>>> driving an emitter follower stage often works well, particularly in a 1-
>>>>>> quadrant amplifier such as a regulator or TEC controller.
>>>>>
>>>>> Or an opamp driving the adjust pin of a 3T regulator. That has some nice
>>>>> points.
>>>>
>>>> Current limit and thermal shutdown not least among them.  What else?
>>>
>>> That's mostly it. C-load stability is good, too. And cost.
>>>
>>> I tried every imaginable way to destroy an LM1117 by abusing the Vadj
>>> pin, and it survived.
>> 
>> Student's managed to blow up an LM395, you are probably just not 
>> 'creative' enough. :^) (It involved mistakenly putting a big ass coil
>> on the output.)  
>> 
>> George H. 
>
>I remember that one--it hit the thermal limit, tried to turn off, and
>the inductive kick blew it up.  Creative, as you say. ;)
>
>Cheers
>
>Phil Hobbs


It just lost the will to live.


-- 

John Larkin         Highland Technology, Inc

lunatic fringe electronics
Reply by John Larkin ●May 16, 20172017-05-16
On Tue, 16 May 2017 20:27:57 +0100, "Kevin Aylward"
<kevinRemovAT@kevinaylward.co.uk> wrote:


>"Winfield Hill"  wrote in message news:ofdleo02voc@drn.newsguy.com...
>
>Dave M wrote...
>> Has anyone used any of the consumer-grade audio power amps ...
>
>>Sorry, but these days "consumer-grade audio power amps"
>> are all class-D.  In general most of these can perform as
>> well as a linear amps.
>
>This, of course, depends on the colour of your ears, and their 
>reflectability...
>


I can make a fortune selling golden ear makeup.


-- 

John Larkin         Highland Technology, Inc
picosecond timing   precision measurement 

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com