2stageEF high performance class AB power amp / 200W8R / 400W4R

[rsavas]

diyralf,

suggest to read Bob Cordell's new book release, it explains a lot about modern day power supply design for very high power amp applications. I am sure Toni realizes that SMPS is a viable option and potential $/size saver just like fan vs big heatsink or class of op.

because of to much work...

can you elaborate on what kind of work?

 

[astx]

You need for that +-90V=180V. No need for transformer anymore. Direct mains connection!

Hopefully you are kidding -
Never use mains direct!


BR, Toni

 

[astx]

...
I am sure Toni realizes that SMPS is a viable option and potential $/size saver just like fan vs big heatsink or class of op.

Definitely an option to use SMPS and active cooling.
The output stage needs 2 supply voltages: +/-20V (maybe regulated; at least good filtered) and a high voltage DC supply ~ +/-90V.
The idle dissipation is below 30W per channel and the first 4W are delivered in Class A.
The design is mostly the SA2014 with 8pairs IRFP240/9240 for the high voltage part. The inner power transistors are 8 pairs TTC5200/TTA1943 or 2SC6145A/2SA2223A
Fast schottky diodes are switching from 20V to high voltage.
If I get it stable as prototype the high power part will be presented here.

can you elaborate on what kind of work?

Mostly software development ...
BR, Toni

 

[Freecrowder]

Where would I find the latest corrected versions of Gerbers and PDFs of the power supply boards?

 

[astx]

See post #1 - there is an updated index.
Have a look at projects F) and G)
There are direct links to the corrected schematics and gerber files.


BR, Toni

 

[thimios]

Hopefully you are kidding -
Never use mains direct!


BR, Toni

 

[astx]

FYI - just playing

EVERYBODY PAYS / MARK KNOPFLER from GREATEST HITS CD2
​

using AURO 3D and 17 Speakers mostly powered by SA2012 Class D (Chocoholic's ClassD LiteAmp bridged modules; 4 x Subwoofer), SA2014 (Front active crossover for separated Bass / Mid-treble), SA2017 (Top Front/Rear), SA2015 (Surround and Surround back)
My Denon AVC-X8500H currently powers only Center, Top Center and VOG speaker.


It sounds like Mark Knopfler is playing live in my homecinema! Wow!
AURO 3D: It's a really good upmixer codec optimized for 3D sound - IMHO the developers have done a very good job!

Have fun, Toni

 

[SGK]

After a long break I'm peeking back in here. About to try to convert my SA2014 amp to 120V...!

Looking forward to the next productions from astxLabs.

 

[astx]

Dear Steve,

nice to see you here! During winter time I normally have more time for my hobbies...

Thread just reached > 500000 page hits. wow!

My raspberry pi adventure comes to an end. The next project will be the SA2020 monster amp...

BR, Toni

 

[astx]

...
About to try to convert my SA2014 amp to 120V...!
...

Do you need to buy new transformers or have you initially ordered them with primary 2 x 115V?

BR, Toni

 

[vargasmongo3435]

Before soldering the heat sinks place pvc washers between pcb and heatsink solder legs to avoid short circuit with rail voltages. Do this even if your pcb has a very good stop paint!

hello thank you for share your work question what is the part number of that heat sink? I was able to import the gerber to Sprint file today

 

[astx]

Fischerelektronik SK76


BR, Toni

 

[vargasmongo3435]

Fischerelektronik SK76


BR, Toni

thank you so much



Best Regards
Juan

 

[SGK]

Do you need to buy new transformers or have you initially ordered them with primary 2 x 115V?

BR, Toni

I ordered the transformers with twin primaries. I have finished the conversion now (both SA2014 amps, my audio server and headphone amp) but haven't dragged my speakers out of storage. I did not have the will to use my Quasimodo to re-optimise the power supply snubber resistors for the new primary configuration though...

 

[astx]

Very good! Just use the snubber values I have added as new standard for the SA2014 reworked power supplies. See index - first post.

The SA2014 input stage has very high power supply rejection so you should have no problems.


BR, Toni

 

[SGK]

Mark Johnson's work with snubbers showed that a snubber circuit really needs to optimised for the individual transformer and primary configuration - and his Quasimodo provided a handy jig for doing so. For me to reoptimise the snubbers across my DIY builds (4 pieces of equipment) would have involved optimising 16 resistors and pulling the builds completely apart and reassembling them. I decided to pass! I'll be happy just to listen to anything other than the Harmon Kardon speakers attached to this computer!

 

[SGK]

Toni this thread has been quiet for a very long while. I hope all is ok.

 

[astx]

Dear Steve,

you are right - not much conversation the last months...
So many other projects - new roof for the house, new photovoltaic modules (21kWp), new home power station with 39kWh lion batteries ...
(S10 E PRO - E3/DC GmbH)

High bias for my amps is now CO2 friendly
The new class G / class H high power amp is on my roadmap, but not yet really done after successful simulation ...
How is the state of your 230V => 115V conversion of your SA2014 amps?

BR, Toni

 

[SGK]

Hi. Glad to hear all is well. That's quite a few projects! My two SA2014 amps are all converted to US voltage (alongside my audio server and Thetadigital Casablanca). My Egglestonworks speakers are in for a refresh (new paint color, replacing granite with aluminum etc) and should be back soon. Then I can finally start setting things up again! Maybe then I think about a 4-channel build to run my surrounds and/or ceiling speakers...

 

[astx]

Perfect!

Maybe this project?
2stageEF high performance class AB power amp / 200W8R / 400W4R
Or a quad channel SA2014? (btw: pcb's are on stock for both project variants)

BR, Toni