• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

xrk971 Pocket Class A Headamp GB

Founder of XSA-Labs
Joined 2012
Paid Member
I’m sorry, I don’t know what you are referring to? This is the PCA thread and I don’t recall a part called SQ4284?

Or are you talking about the headphone SSR? In the headphone SSR, SQ4284 is the main relay MOSFET. If you want to swap, look for a dual N channel MOSFET with SOIC-8 package and with low RDson around 15mOhm. They are in stock at Digikey for $1.50 ea.

LCSC doesn’t have a lot of parts. You may need to order those at Mouser or Digikey.
 
Last edited:
Founder of XSA-Labs
Joined 2012
Paid Member
I didn’t realize you were in Kazakhstan. All I can say is search the web for places that may sell SOIC8 dual N channel MOSFETs. Look for keywords “Trenchfet” “Automotive”.

Have you tried Aliexpress? I tried searching for SOIC8 dial N channel MOSFET and got a lot of hits.

This might work:
AO4818B SOIC-8 Dual N-Channel 30V / 8A patch MOSFET (FET)
https://a.aliexpress.com/_mqky5NS

Or this:
FDS8949 SOIC-8 Dual FET, MOSFET, double N channel, 6A, 40V
https://a.aliexpress.com/_mrXuQwY

Hope that helps.
 
  • Like
Reactions: 1 user
Founder of XSA-Labs
Joined 2012
Paid Member
Yes, perfect! The RDson is just a tad higher at 24mOhm but suitable for a SSR. Can handle 40v too so that’s even better. As you can see specs are very similar and with same pins.

IMG_9965.jpeg

IMG_9966.jpeg


If you want to continue discussing the headphone SSR I would suggest moving discussion to that thread.

https://www.diyaudio.com/community/...ne-amplifier-dc-protection-modules-gb.349294/
 
  • Like
Reactions: 1 user
hello

am having real trouble sourcing the 390 uF 20V capacitors for C2_1. does anyone know where i can find these? i've looked online a bit and only found them at mouser, who want around 20.- to send them (i'm in switzerland). tayda doesn't stock these. seems like a non-standard value.

many thanks for any help!