JLE TPA3255 Build and Modifications

Jump to Latest
D

Deleted member 148505

About the harshness of the highs of TPA3255 modules, it can be reduced by using / adding 47pF to 220pF 0603 C0G feedback caps on the opamp. Tradeoff is that some airiness and openness will be reduced. (using WIMA caps may help but there's no more available PCB area) This mod can be applied on all TPA3255 modules with opamp sockets.
 

Attachments

  • 166432342_1168297730266809_349473631120343818_n.jpg
    166432342_1168297730266809_349473631120343818_n.jpg
    708.9 KB · Views: 443
M

mikey_audiogeek

Member
Joined 2004
JLesterP said:
Here is bypassing of opamps if you want it with blocking caps.
You can safely connect your DAC with this config.
The amp will not start though if there is no source connected.
Click to expand...

Hi J,
Received my modules yesterday - thanks!

I'm going to use Jensen JT-11P-1 input transformers with these modules. Can I use pin 1 and pin 7 of the opamp socket? What else is between pin1/7 and the TPA3255? (Can't quite see on your picture).
https://www.diyaudio.com/forums/att...6209-jle-tpa3255-build-modifications-byp2-png

Thanks again,
Mike
 
D

Deleted member 148505

Hi Mike,

I've sent the schematic on your mail. Also check spam folder if it's not in your inbox.

Remove any opamps on the socket and tap the coupling caps' pins on the attached image.

Regards,
Lester
mikey_audiogeek said:
Hi J,
Received my modules yesterday - thanks!

I'm going to use Jensen JT-11P-1 input transformers with these modules. Can I use pin 1 and pin 7 of the opamp socket? What else is between pin1/7 and the TPA3255? (Can't quite see on your picture).
https://www.diyaudio.com/forums/att...6209-jle-tpa3255-build-modifications-byp2-png

Thanks again,
Mike
Click to expand...
 

Attachments

  • 166432342_1168297730266809_349473631120343818_n.jpg
    166432342_1168297730266809_349473631120343818_n.jpg
    701.9 KB · Views: 402
D

Deleted member 148505

PFFB: Remove any opamps on the socket, tap opamp pins 1(IN+) and 7(IN-)
Non-PFFB: Remove any opamps on the socket and tap the coupling caps' pins on the attached image in post #205.

If you remove the opamps, PFFB requires 5.4Vrms balanced full scale to clip the output. Wick out SJ3 to SJ6 to remove PFFB in order to get more gain, since on Jensen JT-11P-1, signals higher than +4dBu (1.23Vrms) has less performance. Only 2Vrms (balanced full scale) is required to clip the output in non-PFFB.

Regards,
Lester
 
D

Deleted member 148505

reddish75 said:
Just bought a 260btl module from the classifieds, what are the current recommended mods for it?
Click to expand...

Hi, where did you buy it and what version? An external buffer will be the best upgrade. And changing input coupling caps to 4.7uF polypropylene type will make the highs smooth and clear.

I'm developing an addon buffer and it will be available in 2 to 3 months.

For recommended mods, kindly check my previous posts.

Regards,
Lester
 
C

Chrisr3521

Member
Joined 2006
Hi, bought it from the classifieds here, I believe its version 1A

Which caps are the coupling ones? Wima caps ok for these?

Also have some lm49720ha in to-99 can im considering using with it unless there's another opamp that's known to sound better?
 
Last edited by a moderator:
4

454Casull

Member
Joined 2004
JLesterP said:
Hi, where did you buy it and what version? An external buffer will be the best upgrade. And changing input coupling caps to 4.7uF polypropylene type will make the highs smooth and clear.

I'm developing an addon buffer and it will be available in 2 to 3 months.

For recommended mods, kindly check my previous posts.

Regards,
Lester
Click to expand...
This buffer will allow for full power (with highest PFFB) from a 1.0 Vrms or 1.5 Vrms input, both SE & balanced?
 
D

Deleted member 148505

reddish75 said:
Hi, bought it from the classifieds here, I believe its version 1A

Which caps are the coupling ones? Wima caps ok for these?

Also have some lm49720ha in to-99 can im considering using with it unless there's another opamp that's known to sound better?
Click to expand...

For V1A, V1B, here are the important mods:
Short out or use 0ohm 0603 for R8, R10, RA6, RA7
Use 47pF to 56pF 0603 C0G for CA3, CA6, CB3, CB6

There is a grounding mistake on V1A, V1B TICore260BTL versions so you need to do the capacitor ground fix.

Disabling PFFB and using external buffer will be good. Similar to Brad's idea. I'm currently doing daughter card for it.

I haven't tried LM49720HA but using OPA1656 smoothens out the highs / treble by a lot.

For coupling caps (C1, C2, C3, C4) I tried WIMA MKS2B044701K00KSSD in my latest Sylph-D200, the highs are superior to ELNA Silmic II, but the voice rendition is slightly thinner sounding, but maybe a good compromise since Elna Silmic II's treble is exaggerated. You need to find poly caps with long leads to fit them to TICore260BTL
 
Last edited by a moderator:
You must log in or register to reply here.
Top Bottom