New PassDIY Headphone Amp (now available)

[Alex_d15z6]

Sorry for impatience - any news about next GB for the boards or when it will be available in DIYaudio store ? Thanks a lot

 

[jameshillj]

Aah - not so simple after all

 

[6L6]

I agree. However, an entirely new (and official) guide is being worked on at this time, and I'll just put it all there.

6L6

It would be nice if the circuit was added to the first post.

 

[EUVL]

Aah - not so simple after all

That was only necessary because there is no chipamp IC that is fully differential.
But there are plenty of opamp's that are, e.g. OPA1632.
So add 2x source follower per channel inside the NFB loop and you are done.


Patrick

 

[EUVL]

Just to illustrate working principle using standard library components from LT Spice.
Cannot be simpler.


Patrick

.

 

[Alex_d15z6]

Sorry once again -I think my previous question can be answered later))
Wayne Colburn presentation on Burning Amp 2017:

YouTube

Thanks

 

[jameshillj]

Thanks Patrick for going to all that trouble program - still waiting for the program that translates asc to be installed from the Microsoft Store - I REALLY dislike the crap Win 10 upgrade

Okay, I assume it's done the job, I've got a list of letters/numbers about 50 tall - these are the list of the LT Spice components, yes?

So, Next. I just download an LT Spice program (or is there a particular version?) and the circuit develops itself?

Cannot be simpler. I just love that bit!

 

[EUVL]

Just download LT Spice and open the asc file.
Then run.

Time to learn how to use Spice.


Patrick

 

[EUVL]

The full blown version.


Patrick
.

 

[Fabian85]

Any headphone recommendations?

 

[craigtone]

Any headphone recommendations?

This amp will drive anything! Loves my Grado GH1's, Beyerdynamic DT-770's and soon to find out when my Massdrop Sennheiser HD-6XX arrive!

FWIW, the best headphone I have heard to date was the Oppo PM-2 ... soundstage for D-A-Y-S!

 

[Eslheadphone]

I just finished my headphone amp with lm4562 and c7 at 100 pf. The amp is oscillating at a very high frequency. I substituted a NJM4558 and the oscillation went away. Does any one know what value of C7 will work with the LM4562, I really like the LM4562 and would like to use it.

 

[greyhorse]

I just finished my headphone amp with lm4562 and c7 at 100 pf. The amp is oscillating at a very high frequency. I substituted a NJM4558 and the oscillation went away. Does any one know what value of C7 will work with the LM4562, I really like the LM4562 and would like to use it.

100pf works great with my amp and the LM4562 using the 2SJ313/K2013. Do you have any extra caps kicking around? You could keep adding more in parallel and seeing if it makes a difference.

 

[Eslheadphone]

Took the feed back caps out and put it back on the scope. It is now dead quiet. Don't understand why but I will go with it. Thanks for you quick reply.

 

[Eslheadphone]

Finished the amp and am quite happy with it. I am going to give it to my son for Christmas

 

[Danger Mouse]

Took the feed back caps out and put it back on the scope. It is now dead quiet. Don't understand why but I will go with it. Thanks for you quick reply.

Had oscillations too. #815


Took out C2 / C7 was the solution for me.
Answer is hidden somewhere in the thread.
Had to do with the OPAMP Feedback capacitor and how it affect the Phase shift.
Somewhere i read, with OPA2604 there are no Need for Feedback caps.

 

[klin]

Can I use 0,47uF instead of 1uF capacitors on the input?

 

[wayne]

.47 uf will work not much difference in low end corner. You can also eliminate them if your source has no DC.

 

[Tix88]

Hi guys I completed the amplifier, and before I plug in a headphone and opamp, I made a measure on the power that goes to the opamp, I have a 32v voltage ... why????

 

[wayne]

What pin has 32 Volts? If it is measured between 4 and 8 that is okay. If referenced to ground you have a bad or floating regulator.