LM380 Amplifier Volume Not Working
Bookmark this page:
 Yahoo!
 Google
 Windows Live
 del.icio.us
 digg
 Netscape
|
|
||||||||||||||||||||||
|
Posted by Dave.H on June 6, 2008, 10:27 am
Please log in for more thread options LM380 chip. The volume control isn't working, all it does it change the amount of crackle in the speaker when iPod volume is up high, and also isn't loud. I had the prototype amp working excellent (with same pot) and even tried two different chips, same result. I really want to get this amp working for a regen radio, so any help is appreciated. I checked everything against the schematic (which can be found in the link below) a few time, but my tired eyes could have missed something. I'm running the whole thing of a single 9 volt battery. http://www.dse.com.au/cgi-bin/dse.filereader?4849476303bce49a273fc0a87f9c06fd+EN/catalogs/SUPZ6080 Thanks Dave | ||||||||||||||||||||||
|
Posted by John Popelish on June 6, 2008, 11:18 am
Please log in for more thread options If the prototype works then I suspect you have made some error in the final construction. I think the design would be better if the two input 2u2 caps were in series directly at the input, one turned each way, to handle a DC bias in either direction (with the pot wiper connected directly to pin 6), but that is not your problem. If you want help with a visual inspection, You will have to post a link to some close up photos of your assembly. If that is difficult, you might post a list of pin voltages with the negative probe on pin 7. -- Regards, John Popelish | ||||||||||||||||||||||
|
Posted by Dave.H on June 6, 2008, 11:47 am
Please log in for more thread options > Dave.H wrote:
> > I am having trouble with a small battery operated amp based on the
> > LM380 chip. The volume control isn't working, all it does it change > > the amount of crackle in the speaker when iPod volume is up high, and > > also isn't loud. I had the prototype amp working excellent (with same > > pot) and even tried two different chips, same result. I really want to > > get this amp working for a regen radio, so any help is appreciated. I > > checked everything against the schematic (which can be found in the > > link below) a few time, but my tired eyes could have missed > > something. I'm running the whole thing of a single 9 volt battery. >
> >http://www.dse.com.au/cgi-bin/dse.filereader?4849476303bce49a273fc0a8...
>
> If the prototype works then I suspect you have made some > error in the final construction. I think the design would > be better if the two input 2u2 caps were in series directly > at the input, one turned each way, to handle a DC bias in > either direction (with the pot wiper connected directly to > pin 6), but that is not your problem. > > If you want help with a visual inspection, You will have to > post a link to some close up photos of your assembly. > > If that is difficult, you might post a list of pin voltages > with the negative probe on pin 7. > > -- > Regards, > > John Popelish List of pin voltages 1: 4.13 2: 011.9 - 012.0 3: 0 4: 0 5: 0 6: 0 8: 4.09 10: 0 11: 0 12: 0 13: 7.82 I won't post pictures as the wiring isn't the neatest, and it's hard to tell what's going on from a photo. 3: Thanks, Dave | ||||||||||||||||||||||
|
Posted by Dave.H on June 6, 2008, 11:49 am
Please log in for more thread options >
> > > > Dave.H wrote:
> > > I am having trouble with a small battery operated amp based on the
> > > LM380 chip. The volume control isn't working, all it does it change > > > the amount of crackle in the speaker when iPod volume is up high, and > > > also isn't loud. I had the prototype amp working excellent (with same > > > pot) and even tried two different chips, same result. I really want to > > > get this amp working for a regen radio, so any help is appreciated. I > > > checked everything against the schematic (which can be found in the > > > link below) a few time, but my tired eyes could have missed > > > something. I'm running the whole thing of a single 9 volt battery. >
> > >http://www.dse.com.au/cgi-bin/dse.filereader?4849476303bce49a273fc0a8...
>
> > If the prototype works then I suspect you have made some
> > error in the final construction. I think the design would > > be better if the two input 2u2 caps were in series directly > > at the input, one turned each way, to handle a DC bias in > > either direction (with the pot wiper connected directly to > > pin 6), but that is not your problem. >
> > If you want help with a visual inspection, You will have to
> > post a link to some close up photos of your assembly. >
> > If that is difficult, you might post a list of pin voltages
> > with the negative probe on pin 7. >
> > --
> > Regards, >
> > John Popelish
>
> List of pin voltages > 1: 4.13 > 2: 011.9 - 012.0 > 3: 0 > 4: 0 > 5: 0 > 6: 0 > 8: 4.09 > 10: 0 > 11: 0 > 12: 0 > 13: 7.82 > > I won't post pictures as the wiring isn't the neatest, and it's hard > to tell what's going on from a photo. > 3: > > Thanks, > Dave 13 on that list should be 14. | ||||||||||||||||||||||
|
Posted by Dave.H on June 6, 2008, 11:51 am
Please log in for more thread options >
> > > > Dave.H wrote:
> > > I am having trouble with a small battery operated amp based on the
> > > LM380 chip. The volume control isn't working, all it does it change > > > the amount of crackle in the speaker when iPod volume is up high, and > > > also isn't loud. I had the prototype amp working excellent (with same > > > pot) and even tried two different chips, same result. I really want to > > > get this amp working for a regen radio, so any help is appreciated. I > > > checked everything against the schematic (which can be found in the > > > link below) a few time, but my tired eyes could have missed > > > something. I'm running the whole thing of a single 9 volt battery. >
> > >http://www.dse.com.au/cgi-bin/dse.filereader?4849476303bce49a273fc0a8...
>
> > If the prototype works then I suspect you have made some
> > error in the final construction. I think the design would > > be better if the two input 2u2 caps were in series directly > > at the input, one turned each way, to handle a DC bias in > > either direction (with the pot wiper connected directly to > > pin 6), but that is not your problem. >
> > If you want help with a visual inspection, You will have to
> > post a link to some close up photos of your assembly. >
> > If that is difficult, you might post a list of pin voltages
> > with the negative probe on pin 7. >
> > --
> > Regards, >
> > John Popelish
>
> List of pin voltages > 1: 4.13 > 2: 011.9 - 012.0 > 3: 0 > 4: 0 > 5: 0 > 6: 0 > 8: 4.09 > 10: 0 > 11: 0 > 12: 0 > 13: 7.82 > > I won't post pictures as the wiring isn't the neatest, and it's hard > to tell what's going on from a photo. > 3: > > Thanks, > Dave Also pin 6 is 11.3 mV. | ||||||||||||||||||||||
| Similar Threads | Posted |
| LM380 Amplifier Volume Not Working | June 6, 2008, 10:27 am |
| DC device working from outlet, but not working on batteries | February 1, 2007, 8:57 pm |
| So what are you working on right now? | December 30, 2005, 10:11 am |
| Working of BJT & FET Transistors ? | October 8, 2004, 4:52 am |
| Working of telephone | December 23, 2005, 5:42 am |
| transistor working | August 5, 2006, 1:45 am |
| Working with SMT components | August 7, 2006, 10:55 pm |
| $60 to anyone who builds and gets this working for me! | January 22, 2007, 1:32 pm |
| Max volume for condensor mic | November 6, 2005, 4:07 pm |
| volume attenuator | July 27, 2006, 11:24 am |
| Triac Circuit Not working right ? | November 24, 2004, 12:16 pm |
| newb: I've got my 1st circuit working, but it can be better.. | February 17, 2005, 5:41 pm |
| Ceiling light not working | January 10, 2007, 5:21 pm |
| LC notch filter not working! | April 26, 2007, 5:32 am |
| Can volume control be part of a pre-amp? | January 11, 2007, 1:27 pm |
> LM380 chip. The volume control isn't working, all it does it change
> the amount of crackle in the speaker when iPod volume is up high, and
> also isn't loud. I had the prototype amp working excellent (with same
> pot) and even tried two different chips, same result. I really want to
> get this amp working for a regen radio, so any help is appreciated. I
> checked everything against the schematic (which can be found in the
> link below) a few time, but my tired eyes could have missed
> something. I'm running the whole thing of a single 9 volt battery.
>
>