thd measurements are published.
If you look carefully at the graphs, you will see that the 2nd harmonic distortion is at the forefront. This means the TUBE SOUND we aim for.
Proof of why listeners love this amp.....
If you look carefully at the graphs, you will see that the 2nd harmonic distortion is at the forefront. This means the TUBE SOUND we aim for.
Proof of why listeners love this amp.....
Not to be negative here, but where are the measurements "published" and why have none of these folk who love this amp (at least your design) published any build pictures in this sub-forum? I'm just sayin'...normally when people build a DIY amp there are always loads of question and build issues..
You right. Because my some friends dont use diyaudio Website and dont have electronic knowledge. So i build for them.(they are two people ) secondly we compared 3 amps ( rotel vssa and tda7293) with my friends. They liked to; 1.Tda7293, 2.vssa, 3.rotel. İf you want to try. Schematics and all informations are on post. Please try and share your experience, i will be very glad…I'm definitely not saying this is the best amplifier or anything like that. But it's really one of the best in the chip amplifier category and among the ones I've listened to...
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Hey, nice job.
I just can't see much difference between the THD of your composite and the conventional implementation of TDA7293.
According to my understanding the meaning of the composite architecture is to increase the open loop gain significantly, which in turn improves linearity and decreases THD.
Another benefit is the thermal decoupling of the input stage which results again in better linearity and lower distortion at low output power, respectively.
As an illustration of I mean you can have a look here - https://www.diyaudio.com/community/threads/chip-amp-photo-gallery.79303/post-7848240
As the increase in the open loop gain is the main object of composite implementation, can you clarify how is it affected in your case?
Regards
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Good Job Sercan,
I have been listening to this amplifier continuously for about 2 months. Moreover, since I could not install the original low noise regulators of the input stage, I am operating the system with a standard LM317/337 regulator stage.
As a result, it is not the lowest noise amplifier I have ever listened to or the one with the lowest THD. However, it is possible to talk about a warmer tone here. There is a serious softening especially in the upper and middle vocals. It makes you want to listen for a long time. Frankly, I have made and listened to tens of amplifiers, including a few full tube amplifiers. I can say that this one is in the top 5 among the ones I have listened to.
After all, the components you have are clear: a simple power opamp from ST and a few discrete semiconductors... It would be better not to have too many expectations.
But as a conclusion, I can say that such a good sound with such little effort is impressive, to be honest...
I have been listening to this amplifier continuously for about 2 months. Moreover, since I could not install the original low noise regulators of the input stage, I am operating the system with a standard LM317/337 regulator stage.
As a result, it is not the lowest noise amplifier I have ever listened to or the one with the lowest THD. However, it is possible to talk about a warmer tone here. There is a serious softening especially in the upper and middle vocals. It makes you want to listen for a long time. Frankly, I have made and listened to tens of amplifiers, including a few full tube amplifiers. I can say that this one is in the top 5 among the ones I have listened to.
After all, the components you have are clear: a simple power opamp from ST and a few discrete semiconductors... It would be better not to have too many expectations.
But as a conclusion, I can say that such a good sound with such little effort is impressive, to be honest...
https://www.diyaudio.com/community/threads/a-new-ec-composite-lm3886-amp.419558/
A DIYer on the forum made real measurements of the famous chip amplifier and saw no improvement between the native data of the 3886 and the composite. Moreover, these are real measurements.. like mine..
I will soon take out my old modulus and measure it and present the results and comparisons to you.
Attachments
You misunderstood my posts. Please read carefully.
That's because my Ferrite Solo setup has a very limited THD+N capability (0.002%). For example you used a unit with minimal 1% THD+N limit to measure an amp with 0.01%. What would you get?
I said in the posts
I could only measure its THD+N very roughly using Focusrite Solo 3rd, which has a minimal line-out and line-in THD+N of 0.002%.
It does not support your claim at all
"A DIYer on the forum made real measurements of the famous chip amplifier and saw no improvement between the native data of the 3886 and the composite. Moreover, these are real measurements.. like mine.."
That's because my Ferrite Solo setup has a very limited THD+N capability (0.002%). For example you used a unit with minimal 1% THD+N limit to measure an amp with 0.01%. What would you get?
I said in the posts
I could only measure its THD+N very roughly using Focusrite Solo 3rd, which has a minimal line-out and line-in THD+N of 0.002%.
It does not support your claim at all
"A DIYer on the forum made real measurements of the famous chip amplifier and saw no improvement between the native data of the 3886 and the composite. Moreover, these are real measurements.. like mine.."
As I look at the measurements, the 2nd order harmonic is just 15% higher then the 3rd order one.
Such 2nd/3rd harmonics ratio can not produce rube amp sound, in which the second harmonic is at least 50-75% higher.
BTW your THD plots are very similar to the LM3886 (conventional circuit) THD plots. Probably the sound is quite similar as well.
My aim never to this. I Have made a lot of LM3886 amplifier. I haven't loved LM3886 sound even I Had been listened more than 5 years. So i designed alternative amplifier.
BR
Dear Sherab,
If you look closer to the 1W FFT results, 3rd harmonic is about -98dB while the 2nd harmonic is like -88dB level.. That makes about 10dB difference (more than 300%) and not 15%..
So if "you can hear" -90dB harmonics level than you should hear 10dB difference! Theorically 3dB difference is enough to hear difference.
Epic Q is not available now. Epic S and Epic W are available.
Ideal transformers are;
150-160VA 2x24VAC to 28VAC For S
300VA 2x24VAC to 28VAC For W
PSU 5x2200uf/50V (min 10000uf) each rail for Epic S
PSU 2x10000uf/50V each rail for Epic
W ( i have started psu desing for Epic W because it will publish in a gfew week)
Ideal transformers are;
150-160VA 2x24VAC to 28VAC For S
300VA 2x24VAC to 28VAC For W
PSU 5x2200uf/50V (min 10000uf) each rail for Epic S
PSU 2x10000uf/50V each rail for Epic
W ( i have started psu desing for Epic W because it will publish in a gfew week)
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Have you ever had a close look at the datasheet? There's s the answer to your question!
Best regards!
