Ultra-high performance, yet rather simple - hybrid and more!

[still4given]

Hi Valery,

I started populating the IPS today. I have some questions.
I see two separate inputs. What are their purposes?
Why are there two 2.2uF input caps? Would one 4.7uF work?
Is the trimmer necessary since there is a servo?
What do schotty diodes do that standard diodes don't?

Thanks, Terry

 

[vzaichenko]

Hi Terry,

Ok, answering one by one 🙂
- Two inputs - one is DC-decoupled (via the cap), the other one is direct - DC-coupled. Just to have both options available.
- Two 2.2uF caps - one 4.7uF will be fine, it was just difficult for me to find the one of appropriate size.
- Trimmer - not mandatory, can be jumpered. You're right, DC offset is controlled by servo, the trimmer potentially allows to set the best possible local balance for the input LTP for the minimum distortion. However, you need a THD meter or a good spectrum analyzer to see where the minimum is, also, the influence if rather subtle.

So, all three points - not mandatory 🙂

Cheers,
Valery

 

[vzaichenko]

Also, the leds close to VAS - there are 2 placeholders at each VAS shoulder, but you can use either one blue LED and jumper the second placeholder, or use 2 red ones (at each shoulder), occupying all of those places.

 

[vzaichenko]

Those Schottky diodes - they are faster and they have lower voltage drop, than the normal ones. They limit LTP's maximum differential swing, allowing even better (softer) clipping, then "super VAS" normally offers.
I have checked in simulator - 1N4148 will work there just fine. Again - very subtle difference 🙂

 

[thimios]

Hi Valery ,have you any of this pcb for selling?

 

[still4given]

Hi Valery ,have you any of this pcb for selling?

I have some extras. PM me.

 

[still4given]

Hi Valery,

Can you produce a components view that has only the part numbers and not the values? Some of them overlap on the screen print and make it hard to read. It would make locating the parts much easier.

Thanks, Terry

 

[vzaichenko]

Hi Valery,

Can you produce a components view that has only the part numbers and not the values? Some of them overlap on the screen print and make it hard to read. It would make locating the parts much easier.

Thanks, Terry

Sure - no problem.

Sorry, I was too lazy for aligning them properly on such a "busy" board 🙂
Promise to improve in the future 😉

 

[still4given]

Awesome! I wish I had said something Yesterday. I do know the circuit better for it though. 😀

Blessings, Terry

 

[Carl_Huff]

Valery & Terry,

Watching this is making me twitchy. I just may have to build a channel pair for myself. Are the gerbers available?

 

[vzaichenko]

Hi Carl, either Terry may have some extra boards, or PM me your e-mail - I will send you the gerbers.

 

[still4given]

Hi Valery,

Have you tested the FetSuMo? I am planning to build that one as well. If you have, can you do a BOM for it?

Thanks, Terry

 

[didiet78]

Do C5303 and a1381 have to on same heatsink ?

 

[still4given]

Yes Post 139

 

[didiet78]

So i can't use Alex MM PCB ?

 

[vzaichenko]

Do C5303 and a1381 have to on same heatsink ?

No, not necessarily the same one. Those may be separate heatsinks.

 

[vzaichenko]

So i can't use Alex MM PCB ?

You can

 

[vzaichenko]

Hi Valery,

Have you tested the FetSuMo? I am planning to build that one as well. If you have, can you do a BOM for it?

Thanks, Terry

Hi Terry, not yet - I had only one set of PCBs initially.
But no problem - I will update the BOM and drop it here.

Cheers,
Valery

 

[still4given]

Sorry I misread that. Thought he was asking if they needed to be on a heatsink.

Thanks Valery. I'm not sure I will have enough boards now. I may be sending them all out. If the interest keeps up I may have to order some more if that's OK with you.

 

[vzaichenko]

Sorry I misread that. Thought he was asking if they needed to be on a heatsink.

Thanks Valery. I'm not sure I will have enough boards now. I may be sending them all out. If the interest keeps up I may have to order some more if that's OK with you.

Sure, no problem 🙂