Hi all! New member here.
I'm an electronic beginner, and as a first analog project (until now I played with arduino and similar) I wanted to make a simple chip amplifier with some controls.
I managed to find a TDA1557q and a TA7630P.
So, I breadboarded the TDA1557q sample circuit from the datasheet and the TA7630P sample circuit, also from datasheet (single power supply one).
The main problems are two:
1. When i plug my phone aux into the TA7630P circuit the output volume is really low, instead, when i plug the phone directly in the amplifier, is much higher. I read something about audio buffer, it can be that?
2. When i connect the TA7630P circuit with the TDA1557q one I hear only noises and I am able to hear some music (low volume) only by placing a 470ohm resistor to ground before the input cap
I've been working on this two chip since two weeks, I'm running out of ideas. 🙁
Any help would be appreciated, thanks.
I also uploaded some photos.
I'm an electronic beginner, and as a first analog project (until now I played with arduino and similar) I wanted to make a simple chip amplifier with some controls.
I managed to find a TDA1557q and a TA7630P.
So, I breadboarded the TDA1557q sample circuit from the datasheet and the TA7630P sample circuit, also from datasheet (single power supply one).
The main problems are two:
1. When i plug my phone aux into the TA7630P circuit the output volume is really low, instead, when i plug the phone directly in the amplifier, is much higher. I read something about audio buffer, it can be that?
2. When i connect the TA7630P circuit with the TDA1557q one I hear only noises and I am able to hear some music (low volume) only by placing a 470ohm resistor to ground before the input cap
I've been working on this two chip since two weeks, I'm running out of ideas. 🙁
Any help would be appreciated, thanks.
I also uploaded some photos.
Attachments
hi loree,
are you sure the TA7630P is working?
what is your supply voltage?
if you post a schematic you might get more answers!
regards + buona pasqua
are you sure the TA7630P is working?
what is your supply voltage?
if you post a schematic you might get more answers!
regards + buona pasqua
Hi! Thanks for the reply!
I actually dont know if the chip its working properly or not, I found it in an old box.
I assume it's working since I tested it with another amp board I made, but with the low volume problem (no hissing and the tone and balance controls work well).
Anyway I ordered a couple of replacement some days ago, since I'm not sure.
My power supply is a 12v smps.
Sry for the schematics, here they are! I connected pin 11 and 6 of the TA with pin 1 and 13 of the TDA1557.
I'm also not sure how to connect pin 2 (signal ground) of the TDA1557q, I read in an old thread of this forum to connect pin 2 to gnd with a 1-100ohm resistor, but when i do, the chip starts to pump 3 and more amps.
Ciao e buona Pasqua!
I actually dont know if the chip its working properly or not, I found it in an old box.
I assume it's working since I tested it with another amp board I made, but with the low volume problem (no hissing and the tone and balance controls work well).
Anyway I ordered a couple of replacement some days ago, since I'm not sure.
My power supply is a 12v smps.
Sry for the schematics, here they are! I connected pin 11 and 6 of the TA with pin 1 and 13 of the TDA1557.
I'm also not sure how to connect pin 2 (signal ground) of the TDA1557q, I read in an old thread of this forum to connect pin 2 to gnd with a 1-100ohm resistor, but when i do, the chip starts to pump 3 and more amps.
Ciao e buona Pasqua!
Attachments
just a silly question, as i see you only connected one channel of the preamp to the power amp: are you sure you had signal on both channels of the preamp?
unless you have humming/ground loop issues i don't think you need to split up signal and power ground.
regards
unless you have humming/ground loop issues i don't think you need to split up signal and power ground.
regards
The channels behave the same.
I'm testing the setup only with one speaker so i use one channel at the time, and I switch them every now and then to see if something changes.
I'm testing the setup only with one speaker so i use one channel at the time, and I switch them every now and then to see if something changes.
hi loree,
just a few thougths, maybe they help finding the problem:
TDA1557 has 46 dB of gain, so you get maximum output already at about 50 mV input. this is lots of gain and might explain the noise you hear.
TA7630 does not have any gain (except for boosting bass or treble). max input is 1 volt and you want to use this headroom in order to have good S/N ratip - so these devices alone are not an ideal combination.
connecting a 470 ohm resistor to the output of TA7630 (if i did understand correctly) would mean you heavily attenuate the signal and get some output - maybe without this attenuation the power amp is overloaded by your input and protection activates?
you could include a voltage divider (~1/10) between the two circuits to solve this problem.
I would also suggest to check all the control voltages for the TA7630 (around 6 volts should give you neutral settings for all) at pins 7, 8, 9, 10.
just a few thougths, maybe they help finding the problem:
TDA1557 has 46 dB of gain, so you get maximum output already at about 50 mV input. this is lots of gain and might explain the noise you hear.
TA7630 does not have any gain (except for boosting bass or treble). max input is 1 volt and you want to use this headroom in order to have good S/N ratip - so these devices alone are not an ideal combination.
connecting a 470 ohm resistor to the output of TA7630 (if i did understand correctly) would mean you heavily attenuate the signal and get some output - maybe without this attenuation the power amp is overloaded by your input and protection activates?
you could include a voltage divider (~1/10) between the two circuits to solve this problem.
I would also suggest to check all the control voltages for the TA7630 (around 6 volts should give you neutral settings for all) at pins 7, 8, 9, 10.
Hi stv!
I've got a brand new TA76 and now the volume problem seems gone.
I spent two weeks on a faulty ic, sigh.
Despite of that, I am not able to make the circuit to work properly.
Sometimes it sounds just fine, but, two seconds later, horrible noises come from the speaker.
Cracking noise also come when I touch the pots.
It's not stable at all.
I think it's cause of the breadboard, right? I'm planning to make a pcb this time.
Also, I get some noises when the phone is unplugged, you think is a good idea to decrease the 100k TA76 input resistance?
I attached some of the noise/cracking I've got.
Turn down the volume while listening 🙂
Regards.
I've got a brand new TA76 and now the volume problem seems gone.
I spent two weeks on a faulty ic, sigh.
Despite of that, I am not able to make the circuit to work properly.
Sometimes it sounds just fine, but, two seconds later, horrible noises come from the speaker.
Cracking noise also come when I touch the pots.
It's not stable at all.
I think it's cause of the breadboard, right? I'm planning to make a pcb this time.
Also, I get some noises when the phone is unplugged, you think is a good idea to decrease the 100k TA76 input resistance?
I attached some of the noise/cracking I've got.
Turn down the volume while listening 🙂
Regards.