Yes, good point: parts number!
Would you describe your pleasure in reproduced sound music listening ?
What's the minimun at the max, and inverting ? 😛😕
Just for the record, an input buffer is about 8 resistors + 2 Bjt per channel
and ( four caps !)
A mixer+lowpass is about the same passive components + quadruple Op-amp
A passive mix, often derived from the main channels amplified output( gain)
is about 2 resistors+RCRC 😉
0.30$ 10 kOhm dual potentiometer...
Then comes in the game the amplifier/speaker system, just as before the input,talking about electricity and electronics, the source 😕
Would you describe your pleasure in reproduced sound music listening ?
What's the minimun at the max, and inverting ? 😛😕
Just for the record, an input buffer is about 8 resistors + 2 Bjt per channel
and ( four caps !)
A mixer+lowpass is about the same passive components + quadruple Op-amp
A passive mix, often derived from the main channels amplified output( gain)
is about 2 resistors+RCRC 😉
0.30$ 10 kOhm dual potentiometer...
Then comes in the game the amplifier/speaker system, just as before the input,talking about electricity and electronics, the source 😕
Hi Pico,
I guess you haven’t read the thread since you appear not to understand the main topic, the title itself is quite open but at this point we are discussing an specific audio system mainly to be use on a PC environment thou it could be any source for that matter.
The system has rather small speakers and used as near field.
You may want to read first pages of the thread to get to speed.
Antonio
I guess you haven’t read the thread since you appear not to understand the main topic, the title itself is quite open but at this point we are discussing an specific audio system mainly to be use on a PC environment thou it could be any source for that matter.
The system has rather small speakers and used as near field.
You may want to read first pages of the thread to get to speed.
Antonio
Hi, me Antonio as you😛
So, well, yes, I had quite focused on the various aspects which are very easy TBH
As talking about dektop speakers to be listened...well...nearfield !?
Any other suggestions ?
Indeed, the various test shouldn't be corrupted/limited/congested/etc.
by what the system itself implies as given by its construction.
Same way, you could have focused more on box resonance-say
and ask whether a dynamat costly solution or maybe bitumen to stop...😕 or acoustic insulators...cable resistance/purity
Noble materials for dielectic insulator in high capacitance caps.
Why not Mundorf or any MPK for the 220 uF output cap ?
Putting the electronics outside the box ?
What about a higher sens. woofer ? and satellites ?
Such a simple construction as everytime offers many fields to investigate.
So, well, yes, I had quite focused on the various aspects which are very easy TBH
As talking about dektop speakers to be listened...well...nearfield !?
Any other suggestions ?
Indeed, the various test shouldn't be corrupted/limited/congested/etc.
by what the system itself implies as given by its construction.
Same way, you could have focused more on box resonance-say
and ask whether a dynamat costly solution or maybe bitumen to stop...😕 or acoustic insulators...cable resistance/purity
Noble materials for dielectic insulator in high capacitance caps.
Why not Mundorf or any MPK for the 220 uF output cap ?
Putting the electronics outside the box ?
What about a higher sens. woofer ? and satellites ?
Such a simple construction as everytime offers many fields to investigate.
TDA8566 is already arranged as bridged stereo and that's my fave for powers up to around 12W/8ohm or 25W/4ohms. Above that power level I've recently started playing with TDA1521 (which needs paralleling due to its relatively low current output) but will swing a lot more volts. Over here in China all these TDA parts are dirt cheap, recycled out of consumer gear. For example my last batch of 8566s were marked 'Bose'.
Pico,
Some of your suggestions have already been discussed. System must be maintained practical and for the purpose it was intended or designed, no outboard electronics and no 220u Mundorf polyprop or MKP (?) those if they existed would be the size of a PC. Please keep on topic with sensible contributions.
Some of your suggestions have already been discussed. System must be maintained practical and for the purpose it was intended or designed, no outboard electronics and no 220u Mundorf polyprop or MKP (?) those if they existed would be the size of a PC. Please keep on topic with sensible contributions.
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Abrax,
Beautiful place you live in, as you say those TDA’s are quite cheap, today I went to the local supplier and they have most of the TDA models available and took one suggested by Arty (TDA1557) and might be testing it. Your suggestion also looks good for the application, looked to the spec sheet. All the other part numbers I saw today actually don’t say me much until I look to the spec sheet, so learning chipamps will take me some time.
Antonio
Beautiful place you live in, as you say those TDA’s are quite cheap, today I went to the local supplier and they have most of the TDA models available and took one suggested by Arty (TDA1557) and might be testing it. Your suggestion also looks good for the application, looked to the spec sheet. All the other part numbers I saw today actually don’t say me much until I look to the spec sheet, so learning chipamps will take me some time.
Antonio
Hi Antonio,
Thanks - yes living here has some good points 🙂 The TDA1557 looks to be identical to the TDA8561 - there are lots of variations on a single theme in these parts. I tried the TDA8561 - this was the first of this family I built into an amp, it sounds indistinguishable to me from the TDA8566 - just a bit less convenient to use with SE inputs.
I have a blog post related to a design with these parts here - http://www.diyaudio.com/forums/blogs/abraxalito/960-high-end-chipamp-build-project.html.
Also a related thread is here - Possibly the most frugal high-end sounding amp?
http://www.diyaudio.com/forums/blogs/abraxalito/960-high-end-chipamp-build-project.html
Thanks - yes living here has some good points 🙂 The TDA1557 looks to be identical to the TDA8561 - there are lots of variations on a single theme in these parts. I tried the TDA8561 - this was the first of this family I built into an amp, it sounds indistinguishable to me from the TDA8566 - just a bit less convenient to use with SE inputs.
I have a blog post related to a design with these parts here - http://www.diyaudio.com/forums/blogs/abraxalito/960-high-end-chipamp-build-project.html.
Also a related thread is here - Possibly the most frugal high-end sounding amp?
http://www.diyaudio.com/forums/blogs/abraxalito/960-high-end-chipamp-build-project.html
freqvency range, the tda car chips are inferior to lm chips and tda72xx.
yes, output power is allso inferior.
lack of ability to adjust gain, sometimes pro, sometimes con.
for ease of use, it is a pro.-
but otherwise its con.
a bridged class ab quality depends on how well are the amps matched.
best is a class a, non bridged solution, and lm1875 for example can do that.
the tda car chips can not.
or even if you would trick one in some way, the power would only be enough for a headphone or so...
yes, output power is allso inferior.
lack of ability to adjust gain, sometimes pro, sometimes con.
for ease of use, it is a pro.-
but otherwise its con.
a bridged class ab quality depends on how well are the amps matched.
best is a class a, non bridged solution, and lm1875 for example can do that.
the tda car chips can not.
or even if you would trick one in some way, the power would only be enough for a headphone or so...
placing outside the trafo+amp&filter pcb is the first thing I do.
A minimal change in DF due to the longer wire lenght 🙄
Pico
A good idea, no question there, but will look awkward with a trafo and pcb out of da box and won’t go with the general appearance of the studio.
A good idea, no question there, but will look awkward with a trafo and pcb out of da box and won’t go with the general appearance of the studio.
Just to keep the thread alive, I’m working on a small (perf board) chipamp as per Arty’s suggestion TDA 1557Q with passives I had around, taking some time to do since lots of small jumpers and too close leads for my old eyes. It will be wired as bridged for the satellites, has a RC supply from the main cap on the system so the chip will see a CRC PSU. Will also sport an independent vol control which is not very practical but best to level woofer and satellites as desired even thou it was not my first intend. After the pot it has a 0.1u cap and a resistor to ground as a high pass filter with a knee at 100 Hz to limit unwanted response from the small speakers.
In the other hand I ordered a pair of Vifa’s TC9FD-18-08 3-1/2" Full Range Paper Cone speakers to replace the satellites but this will take more time to do.
😉
In the other hand I ordered a pair of Vifa’s TC9FD-18-08 3-1/2" Full Range Paper Cone speakers to replace the satellites but this will take more time to do.
😉
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Not to take away anything from what you're doing, Antonio, but in one sense you are going away from what I thought what the original intent of the thread, which was to see how far you could go with the original components, what they could deliver if all weaknesses and restrictions were eliminated - if you end up replacing all the core stuff then you might as well have built something brand new, from scratch!
Which then leads people to believe that the only way to 'fix' less than optimum sound is to replace all the big, costly things - and we're back on the same old merry-go-round! If what you start with is relatively costly components - and you have less than brilliant sound - then everything rapidly gets very expensive - and the point of the exercise gets lost ...
Sorry to inject a bit of a "downer" ... 😱
Which then leads people to believe that the only way to 'fix' less than optimum sound is to replace all the big, costly things - and we're back on the same old merry-go-round! If what you start with is relatively costly components - and you have less than brilliant sound - then everything rapidly gets very expensive - and the point of the exercise gets lost ...
Sorry to inject a bit of a "downer" ... 😱
Frank
The system is sounding very musical and took away the main bumps on the response and could live with it. But the slight grittiness in the upper MR persisted. After a somewhat deeper inspection I found out that the small chip was running way above the rated rail voltage for a 4 Ohm speaker in fact more than double according to the spec sheet. I could have gone to correct that in some way like adding a 3 legged regulator but I was in doubt if this would correct the problem or maybe adding others. So it was easier for me to attempt the change of the chip to a higher power one which could also run with actual rail voltage.
Sorry about this Frank, I know that the original aim was another one but my audio nature sent me to a different direction. Maybe I should have opened a different thread for these mods. 😱
Antonio
The system is sounding very musical and took away the main bumps on the response and could live with it. But the slight grittiness in the upper MR persisted. After a somewhat deeper inspection I found out that the small chip was running way above the rated rail voltage for a 4 Ohm speaker in fact more than double according to the spec sheet. I could have gone to correct that in some way like adding a 3 legged regulator but I was in doubt if this would correct the problem or maybe adding others. So it was easier for me to attempt the change of the chip to a higher power one which could also run with actual rail voltage.
Sorry about this Frank, I know that the original aim was another one but my audio nature sent me to a different direction. Maybe I should have opened a different thread for these mods. 😱
Antonio
Fair enough 🙂 ... if one finds an actual out of spec situation while running, as you have, it makes excellent sense to go to the next level - hopefully, you retain all the positives, and more, without any new negatives creeping in!
The fact that the current chip was handling it, and the company was happy to go with this use, shows how "tough" these chip amps can be - why are people so down on them, then ... 😀 ?
The fact that the current chip was handling it, and the company was happy to go with this use, shows how "tough" these chip amps can be - why are people so down on them, then ... 😀 ?
if you limit the supply voltage, then you will limit the output power.
and will have clipping at far less volume.
upgrading the chip is a nice idea, question if the powersupply has enough beef, or not.
if not, then the power rail will collapse, and you end up with no gain at all.
hence i did mention to build a proper amp, as its cheap enough to be well worth it.
and use the computer psu to power it, as that has beef inside.
if you plan to get a system, and improve it without re-building the thing, this is not the set to choose. genius made some decent systems that really just need some attention to be well worthy instead of medicore.
if someone is after a cheap, and good quality system then far best is to build one from zero.
it will not at all be costly. about the price of a midrange factory system.
with far superior quality.
for the last time, DIY is not equal to expensive.
DIY is not equal to inexpensive.
DIY IS medicore at price, and yields brilliant price/value.
there is absolute no need to spend big bucks to build a decent system.
purchasing a decent system consumes a LOT more.
attempting to mod a cheaper, lesser quality system to be decent will cost MORE than a decent system in the first place.
uhh, allso forgot, I seen You are building a proper amplifier.
that is the way to go.
I do absolutely hope you will post it, those chips are simply lovely 😀
and will have clipping at far less volume.
upgrading the chip is a nice idea, question if the powersupply has enough beef, or not.
if not, then the power rail will collapse, and you end up with no gain at all.
hence i did mention to build a proper amp, as its cheap enough to be well worth it.
and use the computer psu to power it, as that has beef inside.
if you plan to get a system, and improve it without re-building the thing, this is not the set to choose. genius made some decent systems that really just need some attention to be well worthy instead of medicore.
if someone is after a cheap, and good quality system then far best is to build one from zero.
it will not at all be costly. about the price of a midrange factory system.
with far superior quality.
for the last time, DIY is not equal to expensive.
DIY is not equal to inexpensive.
DIY IS medicore at price, and yields brilliant price/value.
there is absolute no need to spend big bucks to build a decent system.
purchasing a decent system consumes a LOT more.
attempting to mod a cheaper, lesser quality system to be decent will cost MORE than a decent system in the first place.
uhh, allso forgot, I seen You are building a proper amplifier.
that is the way to go.
I do absolutely hope you will post it, those chips are simply lovely 😀
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looks nice.
do not forget the 100nf cap between supply pin and power ground.
oscillation is not friendly 😀
do not forget the 100nf cap between supply pin and power ground.
oscillation is not friendly 😀
i hope you did not mean the input DC block capacitor.
that should be fine at 470 nf.
the 100 nf cap i mean goes from +supply to power ground.
if You experience "plop" when You switch the amp on, I can digg a soft-start circuit for it.
it will make the plop go away, and requires like if i recall a transistor 2 resistor and a capacitor or so.
inexpensive too.
btw, did You finish the amp build ?
be carefull with PC power supplys, the chip is rated for no more than 18 volt surge , some cheapo pc psu have far greater than that, it kills the IC instantly.
For first try i would say use 3x4.5 batterys in series, 13.5 volts is more than enough for this chip in this application.
that should be fine at 470 nf.
the 100 nf cap i mean goes from +supply to power ground.
if You experience "plop" when You switch the amp on, I can digg a soft-start circuit for it.
it will make the plop go away, and requires like if i recall a transistor 2 resistor and a capacitor or so.
inexpensive too.
btw, did You finish the amp build ?
be carefull with PC power supplys, the chip is rated for no more than 18 volt surge , some cheapo pc psu have far greater than that, it kills the IC instantly.
For first try i would say use 3x4.5 batterys in series, 13.5 volts is more than enough for this chip in this application.
This chip will only see the upper bass-high freq so input caps are only 0.1u for a natural roll of at LF. Will see if the intended effect is ok or I’ll replace the caps accordingly.
I did change the bypass to 0.1u instead of the 0.47 I had before, while I was at it also change the main rail cap to 2.2mf.
For testing I use a fuse on the rail, add load resistors at the outputs and test for DC.
It’s a PITA working with a perf board, next time I’ll use a proper pcb. Tomorrow will probably be the test run.
Antonio
I did change the bypass to 0.1u instead of the 0.47 I had before, while I was at it also change the main rail cap to 2.2mf.
For testing I use a fuse on the rail, add load resistors at the outputs and test for DC.
It’s a PITA working with a perf board, next time I’ll use a proper pcb. Tomorrow will probably be the test run.
Antonio
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