400 WOPL Pics

[laatsch55]

If he was as active in the DIY forum, I would think he would know about 21195/96's...

 

[Gepetto]

Who knows, could turn into a great member...

Guess we will see.

 

[Gibsonian]

Free, I gave you the link to White Oak Audio in post #24. Joe sells the MJ21195G and MJ21196G output transistors on the website. If you bothered to look, you would know this. And why would they be anything other than a T03 package? That is what Phase Linear used in the 400 and 700 amps. The output protection is current limiting, very similar to the original design without the obsolete germanium transistors which are hard to source today. The input OPAMPs are OPA134PA, which are selected for ultra-low distortion, low noise, and high speed. They have a true FET input stage and a wide output swing, to within 1 V of the rails, allowing increased headroom and making it ideal for performance audio applications.
Here is the datasheet if you want to read about it: https://www.ti.com/lit/ds/symlink/opa134.pdf?ts=1607482254063&ref_url=https%3A%2F%2Fwww.ti.com%2Fproduct%2FOPA134

The input impedance to the WOPL amp is the same as the original Phase Linear amplifier, which would be 33K Ohms, minimum and typically 39K Ohms. A blank board, but why would you want do that? Have you seen the price of Joe's board kits? There is no way you could source the parts required in the materials list for less than Joe gets them in large quantities.

If you want to be a part of this group, you have to play by the rules. The rules are: 1) attempt to do some research yourself before asking the questions that would be obvious to someone who did a tiny amount of research. 2) buy the WOPL parts and then discover why they are as good as we say they are. 3) learn just like all of us did. We will help you, but we expect you try to learn yourself, first.

If you don't play by the rules, you will get flamed by other members, or at least get a HUH? as a response.

I'd have to agree, this was a bit of a rough welcome. Those rules, first time I heard of em. Hope he does come back, normally really easy going here, one of the nice things we got going here me thinks.

 

[mlucitt]

I'd have to agree, this was a bit of a rough welcome. Those rules, first time I heard of em. Hope he does come back, normally really easy going here, one of the nice things we got going here me thinks.

Clearly, I am not an Admin so I cannot make any rules related to the Forum or the membership. Those statements by me were intended to make a point.
I researched Freecrowder on DIY Audio. He made many posts (458) and some asking for blank circuit boards from other designers and was refused. Then he tried it here on our Forum and when he was told that he could not buy blank boards, he became belligerent. I gave him the tools to find the information he was seeking and instead of using those tools he continued to challenge any information that was given to him. I offered to help him and I was rebuffed, as if he knew more than others on this Forum. Maybe he does, but he picked an odd way to demonstrate it.