2DIFFET amplifier

[OnAudio]

Its about time we gave this one a thread😉

 

[OnAudio]

PCB ideas welcome

Hi members am thinking of producing 100 free PCBs for this one. Any pcb ideas? The output devices will be TO247.

PCB ideas very much welcome.

kind regards,

Harrison.

 

[alex mm]

......C2 andC3 connected to ground ? should be, not across B , C ?🙄

 

[jkuetemann]

Harrison seems to have a penchant for shunt compensation. Guess it works but is rather unkind to the VAS. I found on my SYMEF build I had to reconfigure the compensation from shunt to miller.

 

[OnAudio]

Hi Alex, good to see you. Shunt or miller both are valid. Looking forward to your PCB ideas 😉

Hi Jason, yes could have used the miller instead of shunt, but ended up preferring the shunt where possible.😎

kind regards,

Harrison.

 

[jkuetemann]

Don't get me wrong here, Harrison, I'm not saying shunt compensation is evil and wrong. I agree that both methods of compensation, shunt and miller, among others being discussed elsewhere are valid methods of compensation. I just think that shunt is more of a 'brute force' method and miller is more elegant a solution.

 

[student_sound]

Hi Mr Harrison !

SYM-DIFF I have an idea pcb like this

 

[Holgi]

I tried a variant allowing the Vbe multiplier tranny to be mounted on the heat sink 😀




Pretty sure Alex can do a more sophisticated layout, anyway wanted to pay my 2ct.

BR,
Holgi

 

[Holgi]

Small Update to bottom layer (I missed one connection )

 

[OnAudio]

Hi student sound,

That is one very compact design 😉. Some tracks need a bit of widening to carry the supply and output current 😉. Thank you for joining the quest. Kindly give me more time during weekend to have a look at it just took a peek.

Hi Holgi,

Looking good. Could it be that you have followed SYMEF PCB Type1development 😀. For 2DIFFET thermal runway should not be a problem. So only mosfets need to be on main heatsink. However if thermal/bias tracking is needed then the bias stage will have to be redesigned. Thank you for joining the quest. Kindly give me more time during weekend to have a look at it just took a peek.

kind regards,

Harrison.

 

[alex mm]

@Holgi , nice PCB have you layout 🙂 My not finished layout .......

Alex

 

[raul_77]

Hello alex mm,

Sorry for the off-topic, but, What software do you use for your layout?

Kind regards

 

[Holgi]

@Holgi , nice PCB have you layout 🙂 My not finished layout .......

Alex

Same compliments to you, Alex - very good layout, but different power supply strategy. I prefer reasonable onboard caps accompanied by litte 100n's directly at the collectors.

BTW: On first sight I thought you managed to create single layer layout without any wire-bridges, but then I saw and counted the 0R's 😀

BR,
Holgi

 

[alex mm]

PCB rev 1.0

.......and PCB ready to be inspected by Q.C. .🙂 Comments are welcome ... 😉 .....
Regards ,Alex

 

[student_sound]

hi Alex !

Nice board ! track connect between B c1845 and B a992 ( +in ; -in )as short as possible to avoid outside noise.
Regards !

 

[OnAudio]

Thank you Alex. Busy weekend. But looks good with just a peak.😎. Your contributions speak for themselves.😉 More comments later.

kind regards,

Harrison.

.......and PCB ready to be inspected by Q.C. .🙂 Comments are welcome ... 😉 .....
Regards ,Alex

 

[OnAudio]

$70 Token of appreciation

Let me start a tradition.

The first person to post their complete build of this amplifier and a review of it gets a token of $70.😀

kind regards,

Harrison.

 

[OnAudio]

Hi Alex,

If possible modify the PCB and move the bias transistor as well as the output drivers away from main heat sink.😉

kind regards,

Harrison.

 

[OnAudio]

The price is not yet claimed. Is it gona be Holgi, is it gona be student sound, is it gona be San, is to gona be Alexmm, whos it gona be ? 😀😀😀

Let me start a tradition.

The first person to post their complete build of this amplifier and a review of it gets a token of $70.😀

kind regards,

Harrison.

 

[OnAudio]

Working on two versions of PCBs. You can never have too many PCBs 🙂