TDA7377 channels paralleled for more power
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- čas přidán 9. 09. 2024
- Feasibility of running the TDA7377 in parallel mode for more power into a low impedance load.
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Thank You!
It is truly frustrating to have to re-shoot a scene, but we're sure glad, and thankful, you took the time to do it.
Really Awsome, informative tutorial.
Thanks for sharing.
Worst is not realizing it till days later when you're trying to put it together!
@@HillsWorkbench so, so true my friend.
Congratulations on 40k subs!
Thanks! Only took 8 years. 100K seems so far off.
Your videos are amazing
now if i could get load sharing resistors for my girl friend to help share the load of life .
Sounds more like you need decoupling. 😎
@@worstuserever Badum TSHH
John you are not alone with the thinking you are on record. I once recorded all my setting up stuff and none of the actual footage I needed. Some things you just cannot re record. I changed my camera in the end!
This was so useful. Thank you. Couldn't find power ratings in 8 ohms for the 7377.
Hello John, Glad your doing good and I hope your Brother and Family are too, happy Summer. You do have an awesome channel, money or not, I realize it helps. You always provide such good information and the reason why, what I want to know. Give old Snickers a kiss on the lips for me, not, just a hug will suffice. Wishing you and yours all the best. No reply necessary, I know your getting your Brother back home. See ya, C.
Thanks. For the great vids
I really love all your wonderful videos
Thanks for addressing my issues!
Now it is the first time I went to be a patreon.👍🎶
I see now clearly how I connected it wrong.. And the TDA7377 is more suitable when my speakers drop to 3.5Ω at 300Hz. But I do not like the current draw at idle when paralleling and using a single channel is working excellent today. So I will be sticking to that with the two monoblocks that only use one of the two channels on the boards.
I will say that the TDA7297 in two mono setups, each at ~6w/8Ω on a car battery. Sounds better than what I used before a Pop pulse T150CA (2 x 60W/8Ω) that uses a TA2022 chip and a big toroidal.
My speakers are 90 dB/w/m so 2x6w will be able to produce 98.5 dB in my usage. So it will cover the biggest crescendos with ease anyway.
Will make a new video on the working setup. :)
Thanks for your videos! 😍
Thanks for the feedback. I'm glad it worked out.
I have ever paralleled two TDA7293. They work nice.
Total output watt after parallel?
In order to avoid DC current flow between the amplifiers due to offset differences, you can make the couplings using capacitors.
If they are large enough there will not be too much limit at low frequencies.
If you use electrolytic capacitors you can even bias them by connecting resistors to a DC voltage. The AC signal will not be attenuated and will close the circuit through the speaker.
In LA4446 datasheet (old car amp driven in BTL mode) they used decoupling capacitors on each amplifier output to keep bais imbalance from reaching the speakers.
Great video and explanation!
Thank you for all your vids. If you get the chance, please could you make one on oscilloscope probing the audio output of a Raspberry Pi, because I can’t seem to get anything remotely sensible!
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@Javier Cristiano you are welcome =)
Hi!
I've been watching your content for around 1 year and this is the first time I comment.
I just want you to know how valuable is to have such an experieced person like you uploading interesting videos about audio and electronics.
You channel inspired me to make my first amplifier and buy new equipment, wich I've been improving thanks to your videos.
I got my first bench oscilloscope today ( I had a handheld oscilloscope before ) suitable for testing my amplifier.
I'd like to ask the next:
1.- What happens if you put "big input capacitors" (a high capacitance like 47uF or 1000uF) in your amplifier?
2-. Wich are the most common errors when designing a class A, AB amplifier?
3.- What is better for a "portable" amplifier, rechargeable batteries or a switchmode power supply?
Sorry if I have problems with spelling, English is not my first language.
Answers from my knowledge
1. If you are not reducing value of input resistance (resistor going to ground after coupling capacitor) your low frequency amplification will be increased to such a level that even DC will get amplified, potentially burning speaker voice coil. (If you reduce input resistance) It will load down the signal source and end up being very weak signal at the input of amplifier.
2. Feedback design is the most challenging thing in amplifier design. Feedback determine stability of your amplifier.
3. If you have an AC outlet available, definitely SMPS makes sense. Or go with battery in that way you're not limited by wire length.
Thanks for watching! Glad to be inspirational. Your questions were answered before me, but here goes anyway:
1) Input caps should be of the value to provide reasonably flat response down to 20Hz. Larger caps can cause issues already mentioned.
2)Tough question (no short answer). There are many areas in the design that can go wrong.
3)Batteries if it is to be truly portable.
Like Engineering Essential wrote, open loop distortions should be lowest possible with wide bandwidth, then feedback and stability, especially with reactive loads since you don't want oscillations. Remember that loudspeakers vary in crossover design and high frequency transducers, plus some crazy audiophile may use cables with very high capacitance and $ value ;)
Also, Darlington double is more stable than triple - one less active device to compensate for.
DIYAUDIO.com forum has excellent designers and amps. Bob Cordell's book is very good one too have it.
You get more volume than one speaker , although not across all frequencies, due to an effect called mutual coupling with two speaker drivers on the same baffle .
The more the better😉
nice videos
You've inspired me to start playing with some class d amps. I've almost started a couple fires. :) Can you please explain (or do a video) why you cannot remove the input signal going to some of these amps and how to correct it so you can unplug the input without the amp going up in flames? Thanks!
Amplifiers may oscillate if you disconnect the input while powered up. The input can pickup the output of the amplifier causing a positive feedback condition which makes it oscillate at a high frequency. Shielded input cables can help. Reducing the input impedance can fix this problem. Place a resistor across the input (input to ground). It should be of the value that doesn't affect the source (impedance of the source). A low pass RC filter will also help keep HF out of the amplifier.
@@JohnAudioTech Thanks for the quick reply! I've only seen this with these pre-made chinese class D modules. I thought I had read somewhere that you can't lift the input to them, but I couldn't believe it. I mean who wants an amplifier that burns up if you unplug your input source? So I tried it with one turned on, and almost instantly a cap near the output burst into flames. I'm from a guitar amp background, so I'm picturing a 68k resistor across the inputs? Any idea why they wouldn't they put that on the board so it can be powered up (with no input source) without frying itself? Thanks again, love your videos.
Thanks for the video. Your setup also suffers from the fact that the circuit draws 5W at idle which is ridiculous. I measured the offset voltages and the difference is about 0.1V, which corresponds to about 0.1W. In fact the resistors are cool all the times. If 5W was consumed by the resistors, they would fry and burn. The only explanation I can find is the internal protection circuit, that somehow interferes in parallel mode. In theory you should observe higher efficiency and less power consumption in parallel mode.
I have question -
If an amplifier (bridged )circuit is working well for 10 minutes , playing music through it and then suddenly oscillating ( the speaker diaphragm moving forward and backward ) and even if the music is stopped but still it's oscillating. What could be the reason and how to fix it ?
Can you hook up output coupling capacitor in the output of the 2 amplifier to eliminate circulation current in the output??
A capacitor will prevent DC current flowing when the amplifier is idling, but as soon as you put a signal through it any imbalance will still cause currents to circulate between the amps.
@@ferrumignis but if the signal is balanced there should not be a current right? AC current cannot be generated through a DC voltage as far as i know.
@@EngineeringEssentials It will block the DC yet let the AC current pass to the load. No signal will pass without load when balanced. It will require two large caps for good low frequency response. It just makes paralleling these ICs all the less desirable.
@@JohnAudioTechSome IC AMP like TPA 3255 features a PBTL option. Exactly what you attempted to achieve in this video. But our experiment didn't go as expected, is there any problem with this specific ic or is it applicable to every ic amplifier?
But what if you would capacitively couple the output stages to stop the excessive current flow while idle? do you see any problems with that ? btw thanks for all these great videos, you really helped me setting up my first few amplifiers!
have you tried icepower amplifier modules yet? not cheap but audiophools like them and they got plenty of power for its size
Cool!
👍👌
wooow.. one single TDA2050 (fake chip) have much output power than that all output chanels in real life. with center tap transformer of course. i'm disapoint on tda7377 to see this video.. And in real world i tested TDA7297 and TDA7377, but i like much how sound TDA7297 on 8 ohm stand floor speakers even at 12v power supply. why do you not test at higher voltage like 16-17v DC ?
Please give a list of some low gain audio ICs
TDA1521
And you have a very young man voice too
These are not worth monking around with parallel - couldn't describe it better myself. Get 3886 instead.
Lm1875 can you use parallel mode.
Yes, these are great for paralleling.
Parallel connection is failed ..
Because current shareing resistor are burn and and output distortion sound. ..
Is it possible to bridge this amp?
It is already bridged inside the IC.