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May 20, 2024, 05:10:44 AM

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Fender Champion 40 DSP (PR4222)

Started by Fritter, March 03, 2024, 07:01:35 AM

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Fritter

I just picked up this Amp for a great price and it's all working but I'm considering some modifications (I'm a retired EE) and I would like to get the correct schematic for it.

I have searched all the links and sites for this* and found schematics but they all are for PR2432 version (made in Indonesia I think) but mine is a PR4222 and is made in China.

Can anyone provide a schematic and/or comment on the differences between the PR2432 and the PR4222 versions?

Thanks in advance.

Ted (aka Fritter)

[EDIT] I did find a small sticker inside the speaker area that says 092022 which means this is pretty new, less than 2 years old so I think the PR4222 model is the latest?

* The Fender Schematics link in this forum sends me to a generic Fender page but there's no list of schematics - I did find a Fender list of schematics but, again, they are not for the PR4222.

g1

This is the schematic for a Champion 40.  Not sure which PR, but it has DSP and the output IC is TDA7294.
PR number is 'production release' and does not necessarily mean it uses a different schematic.  Schematics go by model name and revision number.
Check if this schematic matches your unit.  If not, what is the output IC in yours?

Fritter

Quote from: g1 on March 03, 2024, 09:00:05 PMThis is the schematic for a Champion 40.  Not sure which PR, but it has DSP and the output IC is TDA7294.
PR number is 'production release' and does not necessarily mean it uses a different schematic.  Schematics go by model name and revision number.
Check if this schematic matches your unit.  If not, what is the output IC in yours?
Thanks, it's similar to the one I already have; if you look at the small table at the top right of each page, it says "PR2432" but, for some reason, the one I have shows the Amp as a stereo output to 2 speakers which I think is maybe for the Champion 100?

g1

PR2432 can be Champion 20,40, 100. 
One side of the power amp with extra speaker is shown in a dotted line.  The 2 versions are AC100 and AC150 (mono or stereo).

No offence intended, but if you can't tell whether your unit matches up to this schematic, a different schematic won't get you anywhere.
TDA8950 power module is obsolete, maybe the new unit has a different module.  You would not be able to modify anything in the power amp, so that would not matter.
But just to speculate, the preamp might be the same.
Fender has really tightened up on any of their schematics getting out in public, so we have to work with what we can get.

Fritter

#4
No offense taken.  When I replied to you, I had not received the Amp but I have now and looked inside.  Thanks for clarifying that the PR2432 document covers all 3 20/40/100 Champ Amps so I think this is the one.

I've looked inside.  You can see that the PCB is now all surface mount but that doesn't phase me as I have designed and built prototypes of many SOIC and 0603 component sized PCBs.

Now I've fitted the Eminence Cannabis Rex speaker (see pics) it sound way better, better bass and improved clarity overall (it needs to sound better, the new speaker cost nearly as much as I paid for the Amp!)

I can't make out the markings om the power amp IC, even under UV light.


Fritter

Having studied the schematics a bit more, I'm pretty sure that the following statements are correct.

1. Your pdf above page 1 is the schematic for the Champion 20 only (has no footswitch)
2. Your pdf above page 2 is the PSU+PA schematic for Champion 20 & 40 and shows that the Amp module (for 40 only) is the TDA7294 which looks like it's the correct footprint as per my pictures and is available on Digikey for $9.46 (1,063 in stock).
3. My pdf (attached below) page 1 is the correct schematic for the Champion 40 (includes the footswitch)
4. My pdf pages 2 & 3 are NOT for the PR4222, they are PSU+PA for the PR841/899 models only (whatever they are).

g1