New PassDIY Headphone Amp (now available)

[aradan]

Hi All,

A quick question for Sennheiser 6XX i.e. 300ohm impedance what should be the
values of the R16,22,29,32 resistors ?




Thanks,
Oleg

 

[blackdod]

I used 10 Ohm and I can use all kind of headphones whithout problem: HD6X0, Grado, Akg, LCD...

 

[wayne]

For 300 Ohms 15 Ohms would be a good start.

 

[aradan]

Thanks Wayne and blackdog.

 

[Tix88]

Hi Weyne, how can i buy amplifier pcbs?

 

[6L6]

The diyAudio store will be stocking the PCBs soon, sometime after Burning Amp.

(Wayne will be presenting the amp at BAF)

A detailed build guide will follow shortly. 😀

 

[henryve]

Wayne

Thank you.

Finally received my boards today. Both in good shape.

 

[drpro]

Swapped the AD823 with a Sparkos SS3602. Has turned out to be a really nice match with the rest of the parts. Voices are pleasant, mids are present without being harsh, the highs are crystal clear and soft to the ears. Definitely worth a listen. To my ears really makes all of Wayne's work shine.

 

[wayne]

Wayne

Thank you.

Finally received my boards today. Both in good shape.

That sure took some time to get there. Have fun building.

 

[Tix88]

Hello
I have a Talema trafo 18v x2 10Va , can be fine for this project?

 

[wayne]

10 VA is a bit small 15 VA works with 22 Ohm source resistors but I think 10 is too small. Power usage is about 20 watts with 10 Ohm source resistors and 22 Volt secondaries. It may work with the lower rails and lower bias and you can certainly try it.

 

[AndrewT]

Hello
I have a Talema trafo 18v x2 10Va , can be fine for this project?

10VA 36Vac transformer has a maximum continuous AC output of 277mAac
Connect to a capacitor input filter and the maximum continuous DC output drops to approximately 50% to 60%, i.e. 140mAdc to 170mAdc.
If you take this much continuously the transformer will run hot.
I recommend for cool operation and a long reliable life you draw a continuous DC current of no more than 70mAdc to 80mAdc.

 

[stijn001]

...

A detailed build guide will follow shortly. 😀

Looking forward to your excellent work as usual. Although they make it feel a bit like cheating. 😉

 

[Shatto]

can be powered from the voltage +/-9 V?

 

[EUVL]

Yes, if you use Rail-to-Rail opamps and bipolar power transistors or Toshiba MOSFETs as output devices.

But wait till Wayne gives you an answer from the designer himself.


Patrick

 

[wayne]

can be powered from the voltage +/-9 V?

I will try it but if you want 9 Volt batteries they will drain fast.
I am wrapping up measurements and finalizing some little things for burning amp.

 

[ammel68]

Swapped the AD823 with a Sparkos SS3602. Has turned out to be a really nice match with the rest of the parts. Voices are pleasant, mids are present without being harsh, the highs are crystal clear and soft to the ears. Definitely worth a listen. To my ears really makes all of Wayne's work shine.

The Sparkos discrete op-amps are really nice and will easily compete head-to-head with the Bursons.

 

[wayne]

can be powered from the voltage +/-9 V?

The answer is yes. I brought the supply rails down to 9 Volts and it was still fine. It clips earlier but still way more power than you will ever need.

 

[Shatto]

wayne thank you!
If the DAC output is equal to 0, the input capacitors can be removed?

 

[wayne]

Sure the caps are optional.