In your comment is a very interesting description.
The DJ might need a quite "shouty" and loud rig to cover a large area. It is, after all, a bit difficult to fill a big space with sound.
You might need a "laid back" rig in order to have the audio more enjoyable at point blank range.
In my opinion, this difference is venue size.
Therefore, I happen to regard that high fidelity must be designed with an intended venue size. After all, it would be mighty unpleasant to be directly in front of that big DJ rig.
Using authentic DJ supplies inside a home doesn't work to re-create a concert (unless the home has the "great room" design). In order to avoid making noise like a piercingly loud television, what must be done is to not only re-scale the equipment but also the sound field itself.
Effects in mass market retail amplifiers block, erase, and replace details of the natural ambient in recordings. This is almost as bad as playing the same song all the time--can make you tired of listening. So, we need to re-scale the sound field without added effects.
Small scale bridge amplifiers are excellent in the task of fitting concerts into smaller rooms.
Wahab's amplifier does get the job done, without an effects box or preamplifier of any sort. That part is excellent. I'd just like to do it a bit cleaner so that it can be even more fun to hear. Of course, loud can be fun; however, some of these amplifiers don't require loud operation for making large presentations.
the tDA2040 is specified to a minimal gain of 24 db, that s about
16, to work stably..
A gain of 26 db ( 20 ) is a good balance...
to respond to irishpatrick, the distorsions figures are way
better than any dedicated 12v car radio chip...
the didodes i did add are proned by STM in case of
single supply with cap coupling, as it protect the chip from
currents coming back from the speaker, and i can tell you that
i did burn two chips for not having implement them..
i ll post a complete schematic that will help settle this one
safely....
a lot of 12V chips where tested by there...
the sanyo s, toshibas ,STM, phillips...none was a true hifi chip..
the TDA2040 was the better, and although of low power,
it is specified to as low as 5V capable operation..
the sad thing is that we are a very tiny market, and
manufacturers think that their 12V chips spec are enough
for the average user in a car audio, thus the absence of
high performance chips in that voltage ratings...
i didn t test the 8561Q, but i expect it to be in the same
league as his predecessor, apart from the vastly reduced gain...
i just wait for your evaluation of this one to have some clues...
Well, I'll do my best on the interview of TDA8651Q.
I know what you heard with the TDA1558Q and will be able to tell you if the TDA8651Q can do it.
Still awaiting the mailbox.
Thanks that's very kind of you.
I think it's a big mistake for these manufacturers to ignore this as well. For the simple reason 12V amps can be used in home or car. I think all the Tripath chip and some NuForce amps have figured this out. They can make one product for all three markets, seems smarter doesn't it?
I think that you should go ahead and build up your tda1558Q, since you have the chip already.
It makes a joyful noise.
EDIT: I mean, its worthwhile to hear it.
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Understood. I do this type of stuff all the time. I either try stuff and sell it. Or buy something/change my mind and sell it. I guess that's how you get 1,000 Ebay ratings. I can't count how many speakers and amps I have been through in the last few years. Fortunately, the used electronics market is a good one - so I get a good chunk of change back when sell. This is one reason I like the DIY path, makes it harder to get throw out my own baby.
I will probably build the 2040 and 8561Q. Pick which one I like better and stick with it - make a nice case out of it. And possibly build a car amp down the road. No reason to have worse audio in car if not necessary right?
Daniel, would you like one of my TDA1558Q's? A gift for your kindness.
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Thanks for the diagram! Very easy to understand.
Would you like one of my TDA1558Q's? A gift for your kindness.
Thank you for the kind offer; however, I already have 2, which is 2 too many TDA1558Q's. They have the most lovely presentation possible along with too much noise to ignore, and that's a heartbreaking combination.
So, I actually don't want more of them.
With the monster gain these have, I'm sure that the handbuilt FM radio guys would love to have them. It seems that these were designed to amp directly from the RF section to AF power amp without a preamp needed (aka extremely cheap car radios), because that's the application for such a very huge (and odd) gain setting. In fact, the gain setting of TDA1558Q matches exactly to the output of most chip-radios. Perhaps given the uber-shielding of a radio type build, this amp doesn't make quite as much noise. Or, perhaps its assumed that you couldn't hear the buzz over the car engine.
thank you, kind proposition..
but perhaps that rather to costly ship this IC from the us
to france, it would wonderfully fit for a kid, as a guitar
amplifier, who knows, you surely know one...
as pointed by daniel, it has a high gain, as 50 mV rms
are enough to reach full output, so it fill perfectly this
purpose..
surely that it was done for automotive radio k7, as the
magnetic head has trouble giving 1 mV output, a hard
task for the following premaplifier, usually a dual opamp,
so a part of the necessary gain was reported on the power
amplifier, not counting that the FM circuits has also low
ouput level, no more than 100 mV...
well, next time, i ll stick to the choice of the majority,
(among 3 !!) , and go for the 8561Q...
Well, the TDA8561Q was your idea, and I think its a good idea.
We'll find out more about it soon. Still awaiting the mailbox. . .If that doesn't work, then a good "Plan C" could be TDA1554Q, because those probably have a good tone, low heat, and reasonable gain. Also, pin 15 on that chip is supposedly n/c like pin 9, and non-connected pins can be joined with the ground very, very conveniently. For the bridge mode amp, this could shield the input pins nicely.
Okay, this was such a cool idea that I bought one of these too. Now a have a wealth of little amplifiers and less real money.
Maybe irishpatrick33 can give me a lesson on how to turn audio back into cash.
Hey man, do you have a link to your ebay store? I'll surely want to read your advertisements, and I might go shopping too.
I don't have a store per say. Just an ordinary person who buys/sells a lot of stuff. You can look for me on Ebay though. Go to Advanced Search and select Find Items By Member in the left hand column eBay Search: Advanced Search
Right now I only have two things for sale: RCA connectors and speaker input plate cups.
Maybe irishpatrick33 can give me a lesson on how to turn audio back into cash.
There's no trick to it. People will buy any kind of electronics. I have sold things which I couldn't imagine somebody would want. But they usually do.
I just take whatever I don't want and throw it on Ebay. Though I've also used Audiogon to sell a pair of Manley Mahi monoblocks and some tubes. I just start an Ebay auction for a penny and that seems to drum up interest. Any time you use a fixed price, interest is minimal and slow to sell unless cheaply priced.
In the mailbox, there were TDA1554Q amplifiers. The newer model TDA8561Q has not yet arrived.
I'll be building them up when both models arrive, and will report back with some observations.
Its "highly likely" that there is sufficient gain this way:
12vdc
MP3 player
However, I'll be checking to see if this combination has sufficient gain to reach full potential (of the more powerful amplifier).
15vdc
MP3 player
I'll be building them up when both models arrive, and will report back with some observations.
Its "highly likely" that there is sufficient gain this way:
12vdc
MP3 player
However, I'll be checking to see if this combination has sufficient gain to reach full potential (of the more powerful amplifier).
15vdc
MP3 player
Probably Mouser, Digikey, Ebay, Allied. . . will have some availability.
11W could be rather under-whelming in comparison to the ongoing experiments with the Philips chips.
Distortion becomes important in direct proportion to the amount of amplification. Proportionately, 1% of almost nothing is really almost nothing; however, 1% of 70w is a bit too much distortion.
For this project, the distortion relates to the gain setting, actually. If the gain is set needlessly high, then the noise floor (distortion) is also needlessly high. That's exactly why the upcoming redo is for a lower gain amplifier, with a "sufficient" amount of gain, but not more.
11W could be rather under-whelming in comparison to the ongoing experiments with the Philips chips.
Distortion becomes important in direct proportion to the amount of amplification. Proportionately, 1% of almost nothing is really almost nothing; however, 1% of 70w is a bit too much distortion.
For this project, the distortion relates to the gain setting, actually. If the gain is set needlessly high, then the noise floor (distortion) is also needlessly high. That's exactly why the upcoming redo is for a lower gain amplifier, with a "sufficient" amount of gain, but not more.
Tda1554q
TDA1554Q works appropriately, and is recommendable for a fun little project.
It runs surprisingly cool (hyper-efficient) and gives a nice size presentation. There's not audible noise while its running.
It appears to use a 20k pot (dual gang potentiometer for volume control).
This amp doesn't exceed the quality of a T-amp, and it is exactly as sensitive to power circuit and power cap quality.
The amount of gain is just about perfect for MP3 player and PC. This amp isn't as powerful as TDA1558Q, but the difference is minor, and was expected. I had to use that 15v econo replacement laptop cord to get as much power with TDA1554Q as TDA1558Q can do with 12v; however, there's a good reason for it. . .
Oddly enough, TDA1554Q has MUCH more bass, and the power difference could probably be corrected by choosing smaller size input caps. On these small scale amplifiers, there's no need to pass deeper bass than your speakers can reproduce--12" woofers, corresponding to 0.47uF input caps at the amp's input, with smaller woofers using smaller capacitance for efficiency.
Excellent news: The "uncompress" effect is present, similar to TDA1558Q; however, TDA1554Q plays more cleanly.
Soon, we'll see what TDA8561Q will do.
TDA1554Q works appropriately, and is recommendable for a fun little project.
It runs surprisingly cool (hyper-efficient) and gives a nice size presentation. There's not audible noise while its running.
It appears to use a 20k pot (dual gang potentiometer for volume control).
This amp doesn't exceed the quality of a T-amp, and it is exactly as sensitive to power circuit and power cap quality.
The amount of gain is just about perfect for MP3 player and PC. This amp isn't as powerful as TDA1558Q, but the difference is minor, and was expected. I had to use that 15v econo replacement laptop cord to get as much power with TDA1554Q as TDA1558Q can do with 12v; however, there's a good reason for it. . .
Oddly enough, TDA1554Q has MUCH more bass, and the power difference could probably be corrected by choosing smaller size input caps. On these small scale amplifiers, there's no need to pass deeper bass than your speakers can reproduce--12" woofers, corresponding to 0.47uF input caps at the amp's input, with smaller woofers using smaller capacitance for efficiency.
Excellent news: The "uncompress" effect is present, similar to TDA1558Q; however, TDA1554Q plays more cleanly.
Soon, we'll see what TDA8561Q will do.
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surely, the difference in basses is due to input capacitance
being too low in the 1558Q schematic from phillips.
personally, i did double the value, although, as you mention it,
it s somewhat useless considering the kind of speakers that are
used with it..
just waiting for your 8561Q investigations, i m dead curious
about it. Hope it will be successful, as this chip seems to be
a good replacement of its helder brother...
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