[philipbraunstein]

Hello everyone.
I started some months ago a thread asking where to buy parts for my pimeta, now i replaced the AD8065AR and AD8066AR by two OPA2107 and the all BUF634U by LMH6321.

Link to old thread:
http://www.head-fi.org/forums/f6/whe...uf634u-416907/

I asked help of a friend to sold this chips to me, but later i realized that he forget to cut the pins 1 and 5 of all LMH6321. I'm getting some annoying problems as you can see below, the problems are only because the pins 1 and 5 are in contact with the board ?

Problems:
When i turn on the pimeta with a powersupply not regulated of 12v and 1000mA i got humming and others noise.

When i turn on the pimeta using a powersupply regulated and with filters of 12v and 800ma i still get some noise but no hum.
Recorded Noise

When i turn it on the volume its getting distorced, and the pimeta not seens able to drive my sennheiser hd600 anymore.
I recorded the output of my pimeta using low volume and later on high volume for illustrate.
Low Volume
High Volume

Final questions:
Cut all pins 1 and 5 of the buffers will solve the problem of distorcion and noise of pimeta ?

The power supply that i'm using (12v 800mA regulated) is enought for my pimeta and my sennheiser hd600 ?

Pictures of my pimeta:
before the new parts
after the new parts

That's all.
I hope someone can help me with this.

Thanks in advance for everyone that is reading it.

 

[FallenAngel]

OPA2107 is dual opamp, can't use it for ground channel.

 

[philipbraunstein]

Thank you FallenAngel.
So i need cut pins 1 and 5 and replace the OPA2107 on the ground channel for the AD8065AR right ? Do you think that this powesupply will be enough to me ?

Thank You.

 

[MisterX]

I think you may find the answers you seek in the Pimeta Part Selection Guide .

 

[philipbraunstein]

Hello MisterX.
Thank you, i already know this link. I just create this topic to make sure if i wasn't forgetting something and i was. Thank You. If someone has something more to share would be nice.

I will try replace the OPA2107 on the ground by the AD8065AR and cuts the pins and i will write here what happened.

 

[FallenAngel]

Look at the pinout of a dual vs single opamp here. They are not pin-compatible and it will take some serious pin-bending to work.

 

[philipbraunstein]

I have a AD8065AR, isn't easy to replace the OPA on the ground using this AD8065AR ?

 

[tacitapproval]

Yes, 8056 will work.

 

[philipbraunstein]

Thanks for everybody.
I got my pimeta working back.
I cut pins 1 and 5 of the LMH6321 and replace the dual opamp OPA2107 on the ground channell by the AD8065AR. And everything if working fine now.

My powersupply of 12v 800mA regulated is enough right ?

Really Thanks !

 

[tangent]

Yes, 12 V is adequate.

 

[philipbraunstein]

Thank You !