Very low MID-bass in TDA7293

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Hi pete


Did you find Astaro´s schematic? i looked for but cant find it


thx
chris

Chris: I only saw this on the translated Russian build article...
 

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We did a TDA7293 with DC servo and 100uF bootstrap caps here:
Xmas Amp - Dibya's TDA7293 by Jhofland

There is no lack of mid bass - it sounds very good, in fact. This is with +/-35v rails.

One thing that might help with mid bass punch is sufficient bulk rail caps. I am using 20,000uF per rail for two amps.

Here is schematic (note that R15 should be from 10k to 47k and C1 should be 4.7uF):
904725d1608921278-xmas-amp-dibyas-tda7293-jhofland-tda7293-amp-rev1-1-schematic-main-amp-jpg
 
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We did a TDA7293 with DC servo and 100uF bootstrap caps here:
Xmas Amp - Dibya's TDA7293 by Jhofland

There is no lack of mid bass - it sounds very good, in fact. This is with +/-35v rails.

One thing that might help with mid bass punch is sufficient bulk rail caps. I am using 20,000uF per rail for two amps.

Here is schematic (note that R15 should be from 10k to 47k and C1 should be 4.7uF):

As I have enthusiastically stated X, the Xmas amp does not suffer, at all, from mid-bass richness and lower bass response. Dibya did a great job in designing a great build using this chip. My comment about most (simply designed) chipamps lacking bottom punch is regardless of how much capacitance one put on the rails. LM3886 & 1875 are wonderfully lyrical chips.

Pete
 
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YW! In his schematic, C5 is incorrectly reversed BTW. Then "+" side of the cap should attach to Pin#6 of the 7293.

I’ve actually built up two boards that are made from this schematic. Other than having to mount C5 in the opposite direction (than how it’s stenciled on the board) AD825 was used as the opamp. Still burning it in but it sounds pretty good. Some dislikes....The board wasn’t made big enough so things crowd each other a bit and onboard PS requires a CT transformer. I also had to mount some resistors on the bottom of the board so some caps would fit correctly on top. Bass is quite good.

I’m awaiting boards from a Russian fellow (Audiokiller) for another 7293 build up. His boards have a lot more information provided along with a good amount of technical explanations of his design implementation. His design uses a unique negative feedback design. His website needs Russian-to-English translation (by the web browser) as well.

Cheers Pete
 

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Hi Pete
Fine that you try it.:)

Things to keep me occupied while we here, in my country, wait for the society to be able to safely open back up. As a side note, I’m finding a prefer the sound out of many chipamp builds based around LM3886 or this TDA7293 than any of the Class D amps I’ve tried over the past two years. I also prefer the component choice control using thru-hole mounting instead of the SMD used by most Class D amps.

JMHO. ;)

Pete
 
Things to keep me occupied while we here, in my country, wait for the society to be able to safely open back up. As a side note, I’m finding a prefer the sound out of many chipamp builds based around LM3886 or this TDA7293 than any of the Class D amps I’ve tried over the past two years. I also prefer the component choice control using thru-hole mounting instead of the SMD used by most Class D amps.

JMHO. ;)

Pete


Congratulations on defeating my little "monster" and figuring out what I had already forgotten about (a capacitor with an inverted polarity). This was the second board I developed (drawn in the sprint). Please do not judge strongly biased .- ) I hope the sound is not worse than others. The unique design of the "Audiokiller" is T-shaped feedback? I didn't hear the difference with mine, but who knows, try it. About the fact that You like the details with output contacts more than the SMD I will say. Put Melf or thin-film resistors, and not the usual thick-film ones, love it then. -) And here is a really interesting circuit on the TDA with a reduced gain, which increases the depth of feedback and reduces distortion (see figure). I'm thinking of making some boards for myself...
Your comments, friends?
 

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If I were making an amp now, I would do something similar to this
 

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