read the datasheet and the application note and download National's spreadsheet.Tripmaster said:What is the formula to calculate the LM3886 power output?
A 1 W amplifier will be able to drive your speakers to 88 dB at 1 m listening distance. How many dB do you want to achieve at what distance from the speakers? And will the speakers be up to that task?Originally posted by Tripmaster
I am wondering if there will be enough power to drive my 8ohm 88db speakers.
http://www.national.com/appinfo/audio/files/Overture_Design_Guide15.xls
pacificblue said:
A 1 W amplifier will be able to drive your speakers to 88 dB at 1 m listening distance. How many dB do you want to achieve at what distance from the speakers? And will the speakers be up to that task?
http://www.national.com/appinfo/audio/files/Overture_Design_Guide15.xls
Hi
I had a look at this spreadsheet last night, thanks for sending it anyway 🙂
I don't really get the chance to play my music loud for long...well not if the wife's at home

As you can see by the picture below the speakers are quite close. I intend to make some full range speakers soon so it wont be much of an issue.

I am also planning to build a P2P LM3886 dual mono amp. Is there a preferred configuration bearing in mind I wish to use these inefficient speakers and Pedja's discrete power supply?
I am currently looking at designs on the following sites.
http://dogbreath.de/Chipamps/CopperAmp/CopperAmp.html and
http://myweb.tiscali.co.uk/nuukspot/decdun/
Richard
GC's will drive speakers with less efficiency but the consensus of opinion is that a GC really comes into its own (ie sounds very good) when it had an easy load.
Nick
Would I run into any problems operating this amp with my speakers due to its lack of Zobel network.
http://dogbreath.de/Chipamps/ThreeResAmp/ThreeResAmp.html
Richard
Would I run into any problems operating this amp with my speakers due to its lack of Zobel network.
http://dogbreath.de/Chipamps/ThreeResAmp/ThreeResAmp.html
Richard
Tripmaster said:Nick
Would I run into any problems operating this amp with my speakers due to its lack of Zobel network.
http://dogbreath.de/Chipamps/ThreeResAmp/ThreeResAmp.html
Richard
Try it and see. If you do, add a Zobel. 😉
One part of engineering is to provide protection against all possible imaginable faults. That does not mean those faults will ever happen, but Murphy's law tells us that they will happen, if you don't take precautions.
The three resistor amp (with four resistors according to the schematic) does not provide protection for a bunch of possible faults. Spikes from the source or attenuator (Rb missing), DC from the source (Cin missing), excessive DC offset (Ci or DC servo missing), oscillations (Zobel missing), RF interference (Cn missing),...
The three resistor amp (with four resistors according to the schematic) does not provide protection for a bunch of possible faults. Spikes from the source or attenuator (Rb missing), DC from the source (Cin missing), excessive DC offset (Ci or DC servo missing), oscillations (Zobel missing), RF interference (Cn missing),...
Good afternoon Nick
I am currently using the SOAP pre-amp with my LM3886 and I also have a pair of Pedja’s discrete buffers from Justblair’s group buy a few months back (Built but currently unused)
Is there a schematic/parts list of Pedja’s chipamp circuit on your website?
Thanks
Richard
I am currently using the SOAP pre-amp with my LM3886 and I also have a pair of Pedja’s discrete buffers from Justblair’s group buy a few months back (Built but currently unused)
Is there a schematic/parts list of Pedja’s chipamp circuit on your website?
Thanks
Richard
pacificblue said:One part of engineering is to provide protection against all possible imaginable faults. That does not mean those faults will ever happen, but Murphy's law tells us that they will happen, if you don't take precautions.
The three resistor amp (with four resistors according to the schematic) does not provide protection for a bunch of possible faults. Spikes from the source or attenuator (Rb missing), DC from the source (Cin missing), excessive DC offset (Ci or DC servo missing), oscillations (Zobel missing), RF interference (Cn missing),...
You have a good point🙂
Tripmaster said:Good afternoon Nick
I am currently using the SOAP pre-amp with my LM3886 and I also have a pair of Pedja’s discrete buffers from Justblair’s group buy a few months back (Built but currently unused)
Is there a schematic/parts list of Pedja’s chipamp circuit on your website?
Thanks
Richard
Yes there is Richard.

Attachments
Nuuk said:Yes, that's the one. I don't think that you really need a parts list do you? 😉
You can personally guide my hand with the soldering iron as well whilst you’re at it 😉
Arghhhhh...my brain is likely to explode if I look at anymore P2P designs!!!!
I'm a little confused regarding Pedja's amp/buffer schematic.
If I were to opt for the 3886 P2P on your site what value resistor would you recommend for a Pedja's 27v supply?
'Pin 8, the mute pin is connected to the negative supply pin (pin 4) via a resistor. The resistor value depends on the rail voltage and for 35-37 volt rails a resistor value of 18-22K is recommended.'
I am essentially looking to improve upon my Chipamp.com LM3886 if possible.
Thanks
Richard
I'm a little confused regarding Pedja's amp/buffer schematic.
If I were to opt for the 3886 P2P on your site what value resistor would you recommend for a Pedja's 27v supply?
'Pin 8, the mute pin is connected to the negative supply pin (pin 4) via a resistor. The resistor value depends on the rail voltage and for 35-37 volt rails a resistor value of 18-22K is recommended.'
I am essentially looking to improve upon my Chipamp.com LM3886 if possible.
Thanks
Richard
- Status
- Not open for further replies.
- Home
- Amplifiers
- Chip Amps
- Transistor Question