The circuit in the grounding diagram doesnt seem to include all the components. this is where i have 50v. Ive eliminated all the recommended decoupling caps and just used Nichicon FG 470uF 50V caps in C7&C8 while in the PS build Ive used four Nichicon 12000uF 50V caps (LKS1H123MESB). Wow! What happens to long waveband signals and very high power VLF signals like from time signal transmitters? Okay, thank you. I will try bypassing the zener diode and check again.. does it means my IC is damaged even after diode jumping doesnt work??
Henning, if you read the SET THE LOW FREQUENCY CUTOFF AT THE FEEDBACK LOOP section the author does state that a non-polar polypropylene could be used but the size of such a cap would be huge so an electrolytic cap is substituted. The downside to rotary switches is that the contacts get dirty over time and will need cleaning but all the circuitry is back on the board keeping the signal path short. the answer is Great article, thanks a lot. A good location is near the speaker output terminals, separated a bit or at 90 angles to each other to prevent magnetic field coupling between them.
Ill explainwhat each part of the circuit does, andshow you how to calculatethe right component values withexamples from the amplifier Im building. Comments folks? Rsnlimits the high frequency current so there isnt a direct short to ground, which could exceedthe current limit of the LM3886. If the Fc of this filter ishigher than the input filter, the amplifier will pass low frequencies to the feedback loop that itcant handle.
I think that only 25v DC will make it
Maximum Forward Voltage Drop 1.7V
They also filter noise and radio frequencyinterference in the power supply. Second, Im trying to design the amp to go with a pair of Bose Interaudio 4000 speakers, which have a rating of 10-100W and 4-8 ohms. most likely its a ground fault. the amp stops playing music).
Sounds fine to me. Start soldering the smallest components first, andwork yourway up to the larger components. The negative supply pinneeds itsown set of decoupling capacitors andthe positive supply pins share a separate set of decoupling capacitors. I think many of the posters are from countries where English is not the primary language. In that configuration, Ccfilters radio frequency and electromagnetic interference picked up by the input wires. which one is right??
great Project, well explained! This is 3u flight case for power amplifier. Your suggestion is to pair V+(L) on psu with V+ on left amo board, and PWR GND on psu with V- on left amp board(for sure ill give it 25v volts. great, thanks so much, you just made my day! This will give good protection to the actual amp circuit but will not blow for shorted bridges or lytics! Many thanks! 
Also, due to the sweeter and softer nature of the sound Im able to comfortably listen to it on a volume which I would hardly stand listening to on the Yamaha. My design is intended to be used with a bluetooth module, having the option to connect any bluetooth compatible device, has a radio receiver, an option for usb/SD card insertion as well as an AUX input. The resulting capacitance is of course 1/2 of the rated of each cap so make sure to take that into consideration.
You should be able to find yourspeakers impedance on the back of the speakeror in the user manual. Email me new tutorials and (very) occasional promotional stuff: Determine the Required Power Supply Voltage and Power, Find the Maximum Supply Voltage Needed by the Amplifier, Find the Maximum Supply Voltage Output by a Transformer, Find the Output Power from a Transformers Voltage Rating, Convert the Total Power to a Transformer VA Rating, Find the Maximum Thermal Resistance of the Heat Sink, Set the Low Frequency Cutoff at the Amplifiers Input, Set the Low Frequency Cutoff at the Feedback Loop, Set the High Frequency Cutoff at the Amplifiers Input, 330280 mm Galaxy model with a 10 mm black anodized aluminum front panel, 10 Watt stereo and bridged amplifiers with the TDA2003, Best Practices for Designing a PCB Layout, https://www.circuitbasics.com/design-hi-fi-audio, http://www.antekinc.com/as-4428-400va-28v-transformer/, https://www.diyaudio.com/forums/chip-amps/234032-my_ref-fremen-edition-build-thread-tutorial.html, https://www.diyaudio.com/forums/group-buys/330082-my_ref-fremen-edition-gb-13th-gb-6.html, https://www.tindie.com/products/hicoco/audio-input-selector-switch-relay-module-board/, https://drive.google.com/file/d/1pk3knK2XnM-miUWUE3pPuHc-KMmIOE6N/view, https://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886, http://www.decdun.me.uk/gainclone_psu.html, Hot and neutral AC mains wires from the input terminal to the transformer, AC zero and secondary voltagewires from the transformer to the power supply, V+, V-, and power ground wires from the power supply to each amplifier PCB, Speaker output and speaker ground wires from the amplifier PCB/main system ground to the chassis terminals, Audio input and input ground wires from the input terminals to the amplifier PCBs. Jackson, Im not trying to be condescending here, but as a start did you combine SIG_GND, the (-) line from the input signal and the (-) line from speakers out and send them all to a common earth ground (some folk call this a star ground connection in your case)? I used solid core 22 AWG, which works well because it can be twisted into a tight coil. Its not fancy audiophile cable but the tight, twisted +&- pair has been used successfully by a lot of builders. Ifyoure building a stereo amplifier, you want Ri and Rf1to have closeresistance tolerances.
Yuval, I built them amp just as described and Im using it with my 8 ohm speakers. I started with 1.5 Hz, but you can use higher or lower values if you want. The most effective way to reduce the total thermal resistance is by lowering sawith a more efficientheat sink.
I have the same ground for both signal input and output, signal ground, which is then connected at one point with the power ground. At least to me, but Ive been listening only to Yamahas for the past 10 plus years.
The power supply is all important and IS a part of the signal path, it controls it. I made an amp with LM3876 in 2015. Although its a bit more work, I prefer the T version for the 0.8 C/W increase over the other. The gain is calculated withthis formula: This givesyouthe voltagegain(Vo/Vi), or the factor of amplification. The info you seek is there. On this web site its the #content-area DIV that is set to display: flex, that causes Firefox to print only the header on the first page, then whatever part of the article fits on the second page, followed by third page with just the footer. thanks man. How would this alter component values? Are the links broken? Great Job! My suggestion would be to not just follow the instructions, which are very well explained, but to take full advantage of the instructions as a starting point to a better understanding of exactly what each component is doing. Fusing both AC line input and power rails are the best but more work and expense.
Its well below the lowest AM broadcast frequency (535 kHz), so radio frequencies and most electromagnetic interference should be filtered out. I think I found a misbehaving (though physically intact) decoupling 22uf cap as a suspect and replaced it . At the same time, you could install a balance control. Thnx in advance, Very nice tutorial. High frequency oscillation current will be impeded by the inductor and be forced to flow through the resistor, which will dampen it. The LM3886 has one negative power supply pin (pin 4) and two positive power supply pins (pins 1 and 5). Use this formula to calculate the maximum supply voltage required by your amplifier: For my40 Watt amplifier, the maximum supply voltage it needsis: So mypower supply will need to deliver a peak voltage of30.2 V for my amplifier to output40 Watts into 6 speakers. So, my Rm will need to be less than 54k for the current atpin 8 to be greater than0.5 mA. I was wondering the same thing. Most of the time the controls pcb will be mounted parallel towards the front of the amplifier. How did you obatin electrical continuity between the front, back, side, top and bottom panels? I really enjoyed reading this awesome guide! I have built 98db sensitive speakers, without physically large speakers its a little difficult to achieve sensitivity R5 should be a 10K (or something less than 58K) now, correct? Its a great project and I really liked it.
I purchased almost all the parts as new with only a few parts from my junk box. Questions About the transformer:
i`m really a new i the pcb design is it possible to get the cad file for pcb layout so i can order the pcb.. would really appreciate it. Before soldering the components to the PCB, use a piece offine grit sandpaper to remove any oxidation from the component leads. Like wise you can remove all electrolytics and test them as well (if you have a meter to do so). ); I have just finished my build and I noticed right away that I had massive crossover distortion with poor, crackling sound as a result. it seems people like the foil in oil because the oil allows movement which causes distortion in 2nd order harmonics, which people perceive as warm. You explain in the tutorial (and as the actual photo of the cap shows) the actual value of the polypropylene is .22uF. Number of Elements per Chip 1 Wery nice article! That can be found with this formula: For my amplifierrunning on a29.6 V supply voltage. Ones the module is connected to the amp input, the hum vanishes, and Im left with a very clear sound. thanks for sharing this great product and for making the design files available. Tech-lobby MagicBox (No Audio) Pre-Amp 0.5 W AV Control Amplifier.for Convert Old Amplifier to tech Amplifier (Silver). If you orient the input side of theamplifier PCBs nearthe input terminals on the chassis, the wires canbe kept short and away from sources of interference. What output power will it give used 220uf then 3x470uf bipolar nichicon 50v electrolytics, Power ground is between V+ and V-
I wasnt sure if the volume potentiometer should be in the signals input path or the amps output (does it matter?). Pin Count 2 This is the best explained I ever came across. The symbol indicatesthat the voltage is +30.2 V on the positive rail and -30.2 V on the negative rail. noticable difference from polyprop, (I know?the rf oscillation fiter makes a difference) hmmm, could be subjective, signal in paralleled 0.2uf silver mica, 1uf teflon and 4uf polystyrene Please have a look at the pics. i am not sure how that will be done though. Package is still on ship. Realistically. 2-Cim,Rb,Rin A comparison with the TDA7294 should be interesting. I also checked to make sure that sound from my smartphone gets into the amp. Cc before or after Cin? I do not care particular brands of capacitors or any other components as long as their specs meet requirements. If possible please post on Power Supply, Speaker Protection, Soft Start and Pre-Amp. NASEOH, Chembur. However If amp is run at near full load (not likely) heating effects of the transformer and bulk storage caps should be cooled as well. All at amazing prices when compared to what they would cost here if obtainable without custom order. Congratulations! Should I still include a ground loop protection circuit or is it not needed for this approach? Quick question, Im making these amplifiers to work in my car, so I will be using a 12V-30V DC transformer to power it. The LM3886T has a metal flange on the back of the case, andthe LM3886TF is all plastic. That is what Ill be using in my amplifier. Since Cinis directly in the path of the audio input signal, thetype of capacitor used will have an influence on sound quality. Typicalvalues are between 470 F and 2200 F. This is the output voltage of the audio source youll be amplifying. I would be gratefull if someone could point me to some schematics or diagrams that could explain the difference..Thnks. everything were very well explained. https://www.diyaudio.com/forums/group-buys/330082-my_ref-fremen-edition-gb-13th-gb-6.html Ill also show youhow to layout the PCB and wire the amplifier in an enclosure for minimal noise and hum. Its very easy to bend them together, when they are mounted, which will result in the metal backs touching & causing a short. You are seeing this ad based on the products relevance to your search query. One could even double-up the two 26AWG strands as the + signal wire while using the copper shielding as the common (-) return connection.
Henning, if you read the SET THE LOW FREQUENCY CUTOFF AT THE FEEDBACK LOOP section the author does state that a non-polar polypropylene could be used but the size of such a cap would be huge so an electrolytic cap is substituted. The downside to rotary switches is that the contacts get dirty over time and will need cleaning but all the circuitry is back on the board keeping the signal path short. the answer is Great article, thanks a lot. A good location is near the speaker output terminals, separated a bit or at 90 angles to each other to prevent magnetic field coupling between them.
Ill explainwhat each part of the circuit does, andshow you how to calculatethe right component values withexamples from the amplifier Im building. Comments folks? Rsnlimits the high frequency current so there isnt a direct short to ground, which could exceedthe current limit of the LM3886. If the Fc of this filter ishigher than the input filter, the amplifier will pass low frequencies to the feedback loop that itcant handle.
I think that only 25v DC will make it
Maximum Forward Voltage Drop 1.7V
They also filter noise and radio frequencyinterference in the power supply. Second, Im trying to design the amp to go with a pair of Bose Interaudio 4000 speakers, which have a rating of 10-100W and 4-8 ohms. most likely its a ground fault. the amp stops playing music).
Sounds fine to me. Start soldering the smallest components first, andwork yourway up to the larger components. The negative supply pinneeds itsown set of decoupling capacitors andthe positive supply pins share a separate set of decoupling capacitors. I think many of the posters are from countries where English is not the primary language. In that configuration, Ccfilters radio frequency and electromagnetic interference picked up by the input wires. which one is right??
great Project, well explained! This is 3u flight case for power amplifier. Your suggestion is to pair V+(L) on psu with V+ on left amo board, and PWR GND on psu with V- on left amp board(for sure ill give it 25v volts. great, thanks so much, you just made my day! This will give good protection to the actual amp circuit but will not blow for shorted bridges or lytics! Many thanks! Also, due to the sweeter and softer nature of the sound Im able to comfortably listen to it on a volume which I would hardly stand listening to on the Yamaha. My design is intended to be used with a bluetooth module, having the option to connect any bluetooth compatible device, has a radio receiver, an option for usb/SD card insertion as well as an AUX input. The resulting capacitance is of course 1/2 of the rated of each cap so make sure to take that into consideration. You should be able to find yourspeakers impedance on the back of the speakeror in the user manual. Email me new tutorials and (very) occasional promotional stuff: Determine the Required Power Supply Voltage and Power, Find the Maximum Supply Voltage Needed by the Amplifier, Find the Maximum Supply Voltage Output by a Transformer, Find the Output Power from a Transformers Voltage Rating, Convert the Total Power to a Transformer VA Rating, Find the Maximum Thermal Resistance of the Heat Sink, Set the Low Frequency Cutoff at the Amplifiers Input, Set the Low Frequency Cutoff at the Feedback Loop, Set the High Frequency Cutoff at the Amplifiers Input, 330280 mm Galaxy model with a 10 mm black anodized aluminum front panel, 10 Watt stereo and bridged amplifiers with the TDA2003, Best Practices for Designing a PCB Layout, https://www.circuitbasics.com/design-hi-fi-audio, http://www.antekinc.com/as-4428-400va-28v-transformer/, https://www.diyaudio.com/forums/chip-amps/234032-my_ref-fremen-edition-build-thread-tutorial.html, https://www.diyaudio.com/forums/group-buys/330082-my_ref-fremen-edition-gb-13th-gb-6.html, https://www.tindie.com/products/hicoco/audio-input-selector-switch-relay-module-board/, https://drive.google.com/file/d/1pk3knK2XnM-miUWUE3pPuHc-KMmIOE6N/view, https://www.circuitbasics.com/design-hi-fi-audio-amplifier-lm3886, http://www.decdun.me.uk/gainclone_psu.html, Hot and neutral AC mains wires from the input terminal to the transformer, AC zero and secondary voltagewires from the transformer to the power supply, V+, V-, and power ground wires from the power supply to each amplifier PCB, Speaker output and speaker ground wires from the amplifier PCB/main system ground to the chassis terminals, Audio input and input ground wires from the input terminals to the amplifier PCBs. Jackson, Im not trying to be condescending here, but as a start did you combine SIG_GND, the (-) line from the input signal and the (-) line from speakers out and send them all to a common earth ground (some folk call this a star ground connection in your case)? I used solid core 22 AWG, which works well because it can be twisted into a tight coil. Its not fancy audiophile cable but the tight, twisted +&- pair has been used successfully by a lot of builders. Ifyoure building a stereo amplifier, you want Ri and Rf1to have closeresistance tolerances.
Yuval, I built them amp just as described and Im using it with my 8 ohm speakers. I started with 1.5 Hz, but you can use higher or lower values if you want. The most effective way to reduce the total thermal resistance is by lowering sawith a more efficientheat sink.
I have the same ground for both signal input and output, signal ground, which is then connected at one point with the power ground. At least to me, but Ive been listening only to Yamahas for the past 10 plus years.
The power supply is all important and IS a part of the signal path, it controls it. I made an amp with LM3876 in 2015. Although its a bit more work, I prefer the T version for the 0.8 C/W increase over the other. The gain is calculated withthis formula: This givesyouthe voltagegain(Vo/Vi), or the factor of amplification. The info you seek is there. On this web site its the #content-area DIV that is set to display: flex, that causes Firefox to print only the header on the first page, then whatever part of the article fits on the second page, followed by third page with just the footer. thanks man. How would this alter component values? Are the links broken? Great Job! My suggestion would be to not just follow the instructions, which are very well explained, but to take full advantage of the instructions as a starting point to a better understanding of exactly what each component is doing. Fusing both AC line input and power rails are the best but more work and expense.
Its well below the lowest AM broadcast frequency (535 kHz), so radio frequencies and most electromagnetic interference should be filtered out. I think I found a misbehaving (though physically intact) decoupling 22uf cap as a suspect and replaced it . At the same time, you could install a balance control. Thnx in advance, Very nice tutorial. High frequency oscillation current will be impeded by the inductor and be forced to flow through the resistor, which will dampen it. The LM3886 has one negative power supply pin (pin 4) and two positive power supply pins (pins 1 and 5). Use this formula to calculate the maximum supply voltage required by your amplifier: For my40 Watt amplifier, the maximum supply voltage it needsis: So mypower supply will need to deliver a peak voltage of30.2 V for my amplifier to output40 Watts into 6 speakers. So, my Rm will need to be less than 54k for the current atpin 8 to be greater than0.5 mA. I was wondering the same thing. Most of the time the controls pcb will be mounted parallel towards the front of the amplifier. How did you obatin electrical continuity between the front, back, side, top and bottom panels? I really enjoyed reading this awesome guide! I have built 98db sensitive speakers, without physically large speakers its a little difficult to achieve sensitivity R5 should be a 10K (or something less than 58K) now, correct? Its a great project and I really liked it.
I purchased almost all the parts as new with only a few parts from my junk box. Questions About the transformer:
i`m really a new i the pcb design is it possible to get the cad file for pcb layout so i can order the pcb.. would really appreciate it. Before soldering the components to the PCB, use a piece offine grit sandpaper to remove any oxidation from the component leads. Like wise you can remove all electrolytics and test them as well (if you have a meter to do so). ); I have just finished my build and I noticed right away that I had massive crossover distortion with poor, crackling sound as a result. it seems people like the foil in oil because the oil allows movement which causes distortion in 2nd order harmonics, which people perceive as warm. You explain in the tutorial (and as the actual photo of the cap shows) the actual value of the polypropylene is .22uF. Number of Elements per Chip 1 Wery nice article! That can be found with this formula: For my amplifierrunning on a29.6 V supply voltage. Ones the module is connected to the amp input, the hum vanishes, and Im left with a very clear sound. thanks for sharing this great product and for making the design files available. Tech-lobby MagicBox (No Audio) Pre-Amp 0.5 W AV Control Amplifier.for Convert Old Amplifier to tech Amplifier (Silver). If you orient the input side of theamplifier PCBs nearthe input terminals on the chassis, the wires canbe kept short and away from sources of interference. What output power will it give used 220uf then 3x470uf bipolar nichicon 50v electrolytics, Power ground is between V+ and V-
I wasnt sure if the volume potentiometer should be in the signals input path or the amps output (does it matter?). Pin Count 2 This is the best explained I ever came across. The symbol indicatesthat the voltage is +30.2 V on the positive rail and -30.2 V on the negative rail. noticable difference from polyprop, (I know?the rf oscillation fiter makes a difference) hmmm, could be subjective, signal in paralleled 0.2uf silver mica, 1uf teflon and 4uf polystyrene Please have a look at the pics. i am not sure how that will be done though. Package is still on ship. Realistically. 2-Cim,Rb,Rin A comparison with the TDA7294 should be interesting. I also checked to make sure that sound from my smartphone gets into the amp. Cc before or after Cin? I do not care particular brands of capacitors or any other components as long as their specs meet requirements. If possible please post on Power Supply, Speaker Protection, Soft Start and Pre-Amp. NASEOH, Chembur. However If amp is run at near full load (not likely) heating effects of the transformer and bulk storage caps should be cooled as well. All at amazing prices when compared to what they would cost here if obtainable without custom order. Congratulations! Should I still include a ground loop protection circuit or is it not needed for this approach? Quick question, Im making these amplifiers to work in my car, so I will be using a 12V-30V DC transformer to power it. The LM3886T has a metal flange on the back of the case, andthe LM3886TF is all plastic. That is what Ill be using in my amplifier. Since Cinis directly in the path of the audio input signal, thetype of capacitor used will have an influence on sound quality. Typicalvalues are between 470 F and 2200 F. This is the output voltage of the audio source youll be amplifying. I would be gratefull if someone could point me to some schematics or diagrams that could explain the difference..Thnks. everything were very well explained. https://www.diyaudio.com/forums/group-buys/330082-my_ref-fremen-edition-gb-13th-gb-6.html Ill also show youhow to layout the PCB and wire the amplifier in an enclosure for minimal noise and hum. Its very easy to bend them together, when they are mounted, which will result in the metal backs touching & causing a short. You are seeing this ad based on the products relevance to your search query. One could even double-up the two 26AWG strands as the + signal wire while using the copper shielding as the common (-) return connection.