DIY Purifi Amp builds

[Streamc]

Cons is that input impedance is lowered. From my little experience, some DAC tend to distort a bit more. The best is a unity gain buffer to keep the input impedance high.

But what if DAC became first cascade of amp? And I need to keep High input impedance on DAC (as part of amp), not on buffer. I do not like that there is OPAMPS on DAC output and buffer input. To much opamps with gain. Also why buffer gain is more than 1?

 

[Streamc]

No amplification means vout / vin = 1

I mean it. Just buffering.

 

[Streamc]

Why can`t I consider DAC as gain buffer? So it would lower gain structure. And I would have high input impedance?

 

[tomchr]

What is attenuation?

Is Google broken? Here's what I get when I type in "attenuation" in Google's search bar:

Tom

 

[Streamc]

Is Google broken? Here's what I get when I type in "attenuation" in Google's search bar:
View attachment 209735

Tom

Why do I need reduce some force? I mean that. Why? Do you know word "context"?
Why do you answering only half a question? I mean I have input cascades on DAC with high input resistance and output power cascade. Why should I need buffer between them? high resistance? But Dac have big resistance.

 

[boXem]

@Streamc sorry I don't get your questions. There is no free lunch, if you drive the amp module directly from the DAC, noise will decrease but distortion will slightly increase due to low input impedance from the module.

 

[tomchr]

Why do I need reduce some force? I mean that. Why? Do you know word "context"?

Please read the second definition: "Attenuation: The reduction of the amplitude of a signal, electric current, or oscillation."

Tom

 

[Streamc]

Please read the second definition: "Attenuation: The reduction of the amplitude of a signal, electric current, or oscillation."

Tom

Please read word "context".

 

[Streamc]

Please read the second definition: "Attenuation: The reduction of the amplitude of a signal, electric current, or oscillation."

Tom

Also. What the concept of reduction (cause attenuation means it) of voltage and than to increasing that? Also buffer does not reduce voltage. It even not keep it with same ration. It amplifies it. Attenuation is wrong word.

 

[Julf]

Also. What the concept of reduction (cause attenuation means it) of voltage and than to increasing that? Also buffer does not reduce voltage. It even not keep it with same ration. It amplifies it. Attenuation is wrong word.

I think we have a language/communication problem here. Attenuation is exactly the right word. Of course, if your gain structure is exactly right, and you always listen at full volume, you don't need any attenuation.

 

[Streamc]

I think we have a language/communication problem here. Attenuation is exactly the right word. Of course, if your gain structure is exactly right, and you always listen at full volume, you don't need any attenuation.

I can regulate input level of power amp inside my so called DAC (preamp). So use another word instead of attentuator. Also buffer does not attentuate according to definition. It makes signal even stronger.

 

[Julf]

I can regulate input level of power amp inside my so called DAC (preamp). So use another word instead of attentuator. Also buffer does not attentuate according to definition. It makes signal even stronger.

Right. So the DAC contains an attenuator.

A buffer does not attenuate, but it might amplify the signal so much that you have to attenuate it in the subsequent amp (or in the DAC). It is all about gain structure.

 

[Streamc]

I wrote to Bruno Putzeys.

Should I use input buffer if without it sound is loud enough? I read that there should be high input impedance of amp.
But if I have dac should I consider DAC first cascade of amp system?
I do not like that I have opamp on DAC and on input buffer.
Like example DAC is SMSL M300MK2. What the pros and cons on input buffer with gain 13dB?

And I`ve got answer from him.

Actually the simplest solution is to try and compare by ear. On my system, the amp sounds best without buffer because my DAC can handle low impedance loads. But I have heard DACs that did not like the low impedance and in that case it sounded better with the buffer. It’s difficult to predict without knowing the exact output circuit of the DAC. So just try and hear what sounds best to you.
Cheers,
Bruno

Congratulations to him.

 

[maty]

Worth listening to, unlike so many other test audios

Sample Test - Purifi Eigentakt EVAL2 DIY kit, by Alpha Audio

System: - Purifi Eigentakt EVAL2 - Pass Labs XP-12 - TAD Evolution Two (E2) - Sonnet Pasithea DAC - Mutec MC3+ USB - Alpha Audio PC - YETI, Grimm and Driade cabling

Recording Gear: - DPA 4006A - Schoeps MK8 with CMC6 - Grace M108 pre-amp with Dante - Mutec MC3+ clock


About 3', Suzanne (Leonard Cohen) <- hummmmmmmmm. Vocal voices and instruments are not "real" to me. I have very good versions of these theme and LC records (vinyl and others).

 

[Julf]

Worth listening to, unlike so many other test audios

Why?

 

[maty]

These days I am listening to a few tests and only some have been well recorded. In the same very well conditioned room, changing only the amplifier, the differences in sound are clearly appreciated. With electronic music everything equals, but with good recordings...

 

[Julf]

In the same very well conditioned room, changing only the amplifier, the differences in sound are clearly appreciated.

Uh huh...

 

[SIY]

Uh huh...

Beat me to it.

 

[Julf]

If you do not appreciate the difference, it is that you have a bottleneck in your audio system that prevents you from doing so.

Yes, a bottleneck called "reality". You should try it...

 

[maty]

I deleted the post with the comment "bottleneck" because the video was without music.