Current feedback headphone amp with super regulators

[peranders]

I will do that later but the results will be good. Current feedback amps are usually good.

 

[peranders]

[quote author="Michael_Hartlieb"]:shock: :shock: :razz: That beast is simply looking great! I suppose you´ve got some nice headphones also?[/quote]
Thanks, sorry but my headphones aren't so extreme, Sennheiser HD545 reference, bought them for half of the price.

 

[peranders]

[quote author="Swedish Chef"]that looks SO cool!
I must quote someone or other who said "it looks like it sounds good..."
Does it?[/quote]
If it looks nice it's more likely that it sounds good but if it looks ugly the odds are worse that it sounds good. This is valid pretty often.

 

[peranders]

I have made distortion measurements and they indicate much better performance than the Turle Beach Santa Cruz sound card. < 0.0065%

The results can be found here
http://www.sjostromaudio.com/hifi_files/qrv/qrv08_testreport/qrv08_testreport.html

 

[Svart]

:shock:

what do you estimate the total drive to be?

 

[peranders]

... by drive you mean...?

PS: Do you know that "svart" is "black" in swedish? DS.

 

[Svart]

"black".. Ja!

I meant what is the total drive capability.. impedance wise..

Looks like art!

 

[peranders]

I'll guess any headphone may be connected and driven _very_ high. I have 1.2 ohms (inside the feedback loop) as limitation of the output impedance and those resistors are of type 4 times 0805. The output transistors are good for 1 A peak.

 

[Samuel Groner]

Thanks for providing the measurements. Do you have an idea where the hum gets in? One would expect ghosty silence with those regulators. Perhaps the transformers?

Samuel

 

[peranders]

The hum is most likely coming from the test setup. The electrical environment isn't the best. The amp is dead silent when listening.

 

[Rochey]

what I'm most impressed with is the quality of that soldering!

You must have done reflow soldering for most of that! ?

 

[peranders]

This is DIY therefore handsoldered by myself. :grin: The pcb is also cleaned, looks nicer. It's not particular hard to solder such "big" components. 0201 etc. is a bit harder but I have so far soldered 0604 without problems.

 

[peranders]

About the measurements: I have seen a guy measured with a better soundcard and the results are exciting for those simple transistors that I have used. Notice also that I don't know how low distortion his soundcard had so I don't know exactly how low distortion my design had. I can see indications of extremely low distortion and this results in no mercy when it comes to covering up faults in the recordings. You sense that you hear "everyting".

http://www.jmd.szm.sk/Audio/Measurement/CF_amp/CF_amp.html
http://www.diyaudio.com/forums/showthread.php?postid=784679#post784679

 

[peranders]

The used soundcard had only 0.00004% distortion so you could claim that my design actually has 0.00043% => quite good don't you think?

http://www.jmd.szm.sk/Audio/Measurement/CF_amp/GEN.gif

 

[peranders]

Old thread, I know. I found it when I went through my statistics. 2005 I never thought anyone would dare to build this amp but in fact, this has happened. This is my second best design, a real surprise for me.

 

[Kingston]

Old thread, I know. I found it when I went through my statistics. 2005 I never thought anyone would dare to build this amp but in fact, this has happened. This is my second best design, a real surprise for me.

I built one as the brute force end of all headphone amps so I never have to bother any thought on headphone amps in my entire life again.

But wait, it's only the second best design? What's the best one? 

 

[mitsos]

the links to the schematics are down, possible to repost?  thanks!

 

[peranders]

Bringing life into this old thread again. Did some checking of my statistics of my home page and found this thread. Rather recently Tom from Canada (Tomchr) has used his advanced Audio Precision distortion analyser and the result is very nice. 0.00042% distortion.
https://neurochrome.com/pages/sjostrom-qrv08-headphone-amp