TPA3250 somebody is listening?

[saran008]

Here comes the area Doc.
Those are 13mm Diameter only

Done by Chris, in his amp!

 

[drMordor]

https://aliexpress.ru/item/40009658...5374.864374399.1594535057-34121377.1589576585

See 3th inductor 10uH, size 14x11x16

 

[drMordor]

And replace out cap, need use MKP 0,68-1U

 

[saran008]

And replace out cap, need use MKP 0,68-1U

See 3th inductor 10uH, size 14x11x16

Thanks Doc for inputs, will look into it!

1416B-10UH

 

[meq123]

Why do folks suggest replacing the coils? One of the reasons I got the FX502 was because it had air-core coils.


Given that ferrite coils can experience magnetic latency in the coil - which does not affect air-cored ones - I would have thought it better to stay with the originals, no?

 

[bucks bunny]

Aircoil - pro: absolutely linear, no additional THD
Aircoil - con: huge magnetic stray field, higher DC resistance

 

[drMordor]

Aircoil - con: huge magnetic stray field
For killing the crows on the fly))))
Bucks Banny -contra - Lowest SRF (Self resonance frequency)

 

[ekbrus]

pulse width modulation (PWM)) air coils they work, but not luchschim way

for air coils, the washout is too small to exclude mutual influence, current protection is triggered


limits the ability to use a 32-volt psu. Maximum current output and the decline in the bass

 

[ekbrus]

one of my experiments

 

[drMordor]

This is TPA3255?

 

[ekbrus]

no, this is a TPA3250. the goal is to reduce the resistance to 0.02 ohms and a higher q-factor of the filter

 

[ekbrus]

changing the ground

 

[saran008]

Chris & Doc,

before finalizing my shopping list in mouser, please take a look at the bypass cap & output filter cap
1. By-pass cap (parallel to main power cap)
MKS2-.22/63/10 WIMA | Mouser Singapore
2. Filter cap 0.68uF, TDK, 100V DC
B32529C1684J EPCOS / TDK | Mouser Singapore


Kindly comment, if any changes needed. thanks

 

[drMordor]

Saran, by-pass cap no need
Filter cap is good

 

[chermann]

Hi


cap 1
normally one very good cap should be sufficient.(panasonic FC 1800µF-3300µF)

but i follow this: - but i didn´t measure with scope....

EEVblog #859 - Bypass Capacitor Tutorial - YouTube


cap2 is fine - TDK are good- a i learned from the members here:
the output filter cap should be 3 or 4times bigger then the supply voltage -better(and if you have space) use 10x times bigger.
e.g. PSu 24V --> 100V


chris

 

[saran008]

Chris & Doc,

Thanks for the inputs. placed the order in mouser.

Chris,
How tough to remove the air coil inductor in FX502s Pro? I see some kind of solvent glue poured inside of the coils.
If i desolder coils from pcb, will they come off easily? or any special measures to be taken?

thanks

 

[chermann]

Coils are easy to de solder but they are fixed with glue

 

[saran008]

Coils are easy to de solder but they are fixed with glue

How to remove the glue, without damaging the pcb? thanks.
I am new to this, so please help to explain!

 

[chermann]

Hi saran


ok.
use a tool with small and sharp/hard edge - like a a small screw driver and scratch it carefully away. normally the glue around the coils is not too sticky. so after de-solder push a little bit with your fingers and its gone. on the pcb there is a isolated cover....no problem to do so.


chris

 

[saran008]

Hi saran
ok.
use a tool with small and sharp/hard edge - like a a small screw driver and scratch it carefully away. normally the glue around the coils is not too sticky. so after de-solder push a little bit with your fingers and its gone. on the pcb there is a isolated cover....no problem to do so.
chris

Thanks Chris for guidance.
Mouser order placed yesterday, Inductor coil order in aliexpress placed today.
Inductor may be very long to deliver. lets see.
will update here, when there are any changes to the amp.