I also found this from Jensrasmussen here on this forum in another thread :
Hi,
For BTL operation you need to generate a balanced signal (one is inverted of the other) and connect this to the input (P102 pin 5 & 8).
Output is between pin 1 and 4 of the output connector (P101) (BTL only)
Remember to pull BLT sync pin low (to gnd) .... (P102 pin 1)
I hope this helps
Warm Regards
Jens
Hi,
For BTL operation you need to generate a balanced signal (one is inverted of the other) and connect this to the input (P102 pin 5 & 8).
Output is between pin 1 and 4 of the output connector (P101) (BTL only)
Remember to pull BLT sync pin low (to gnd) .... (P102 pin 1)
I hope this helps
Warm Regards
Jens
Thanks for that! Still a bit confusing and pin-outs from the above don't match the 50ASX2 SE layout.Are those instructions for 125asx BTL mode?
Thanks for that! Still a bit confusing and pin-outs from the above don't match the 50ASX2 SE layout.Are those instructions for 125asx BTL mode?
125asx is easily bridgeable without extra parts as i understand, the 50asx is not.
Do i understand it correctly?
Yes. The 125ASX (and 250ASX) is configurable by the user in either SE or BTL-mode. The 50ASX is sold factory-configured in either SE or BTL-version.
/U.
/U.
Yes. The 125ASX (and 250ASX) is configurable by the user in either SE or BTL-mode. The 50ASX is sold factory-configured in either SE or BTL-version.
/U.
Yes.
Have you had any success in turning the 50ASX in BTL mode, or know anything more about it?
Well yeah, I don't mind re-soldering the jumper pin 🙂 ... but just wondering if anything else needs to be done, apart from connecting speakers to P104.
Old(ish) thread, but FWIW I've converted an SE module to BTL by simply moving the jumper and I believe it works.
If there is a way to measure this (maybe the voltage gain) then let me know and I'll see if I can give it a go 😀
/U.
myself said:I haven’t actually measured anything (not sure what to measure to be honest) but I get clean audio out on the BTL speaker connector (P104) and a very loud buzzing noise on the other output, so at least it isn’t running stereo anymore. No guarantees on anything yet though, but it’s definitely promising.
If there is a way to measure this (maybe the voltage gain) then let me know and I'll see if I can give it a go 😀
/U.
Old(ish) thread, but FWIW I've converted an SE module to BTL by simply moving the jumper and I believe it works.
If there is a way to measure this (maybe the voltage gain) then let me know and I'll see if I can give it a go 😀
/U.
Sounds good. What you did was soldering as you described in post #75?
I have 20pcs of the 50ASX2SE lying here brand new 🙂
Yes, move the jumper to the BTL-position and then connect the amp as shown in the data sheet (p. 22 in my version).
EDIT: You'll need either a balanced source or a phase splitter** to make this work with an SE source.
**Can be a transformer, a DRV134/THAT1646 type driver as I've used or an opamp-based circuit similar to what is shown in the designer's manual.
Then you wouldn't mind trying with a module or two to see if you can replicate my results, would you? 😀
/U.
EDIT: You'll need either a balanced source or a phase splitter** to make this work with an SE source.
**Can be a transformer, a DRV134/THAT1646 type driver as I've used or an opamp-based circuit similar to what is shown in the designer's manual.
I have 20pcs of the 50ASX2SE lying here brand new 🙂
Then you wouldn't mind trying with a module or two to see if you can replicate my results, would you? 😀
/U.
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Yes, move the jumper to the BTL-position and then connect the amp as shown in the data sheet (p. 22 in my version).
EDIT: You'll need either a balanced source or a phase splitter** to make this work with an SE source.
**Can be a transformer, a DRV134/THAT1646 type driver as I've used or an opamp-based circuit similar to what is shown in the designer's manual.
Then you wouldn't mind trying with a module or two to see if you can replicate my results, would you? 😀
/U.
I will be using unbalanced rca from Minidsp 2x4hd.
What would be the easiest way to do this, and where does the phase splitter go?
Tried to edit the previous message yesterday, unsuccesfully.
Thank you for the answers and your project with making this work.
I will hopefully use 3 of these for Beyma TPL-150H tweeters (LCR) active and 8 pcs to surround and atmos channels in my Home Cinema Setup.
Using 125ASx2 BTL bridged for midrange/midbass drivers active.
So i am reaaaaally hoping for this to work 🙂
Thank you in advance
Thank you for the answers and your project with making this work.
I will hopefully use 3 of these for Beyma TPL-150H tweeters (LCR) active and 8 pcs to surround and atmos channels in my Home Cinema Setup.
Using 125ASx2 BTL bridged for midrange/midbass drivers active.
So i am reaaaaally hoping for this to work 🙂
Thank you in advance
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And, the results are in 😀
So, I’ve done some more testing on my BTL-converted 50ASX-modules…
While I wouldn’t call what I have done “extensive testing” by any means, my gut feeling is that this works.🙂 It also ties in well with how the other ASX-modules work and some “insider knowledge” from years ago that I can still recall🙂
Note and disclaimer: I would very much appreciate if someone else tried this to verify and maybe do more testing, however I will accept no responsibility for damage to property, people or pets (or anything else for that matter) if you find a problem – this is DIY after all😀
You can of course hack this conversion anyway you like, but I opted for removing the old jumper altogether and soldering in a new one. If you do that, be advised that the ASX-board is four layers and soldered with lead-free solder, so it will take a bit more heat to reflow the joints than I am at least used to. If you use a soldering iron that is too small, you’ll just heat up the board and possibly damage it.
Bear in mind that what you end up with isn’t a “real” balanced (= differential) amplifier, but two SE amps referenced to ground and driven with opposite phase input signals to produced a bridged output. As such, the input ground is still required in order for the amp to produce a correct signal on the output.
I’ve found a good sketch here for LM3886 modules that should show the correct input wiring. Output on the ASX is taken from the P104 connector, so ignore what the sketch shows here (and of course the DC wiring is irrelevant as well).
If you do try this, let me know how you get on😀
Great, thank you SO much!
So if i dont have a balanced output from my dsp i can use this ?
Unbalanced to balanced Signal Converter Driver Board Buffer input low distortion | eBay
So if i dont have a balanced output from my dsp i can use this ?
Unbalanced to balanced Signal Converter Driver Board Buffer input low distortion | eBay
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Thank you for your work on this!
So if this is the case, what's the resulting output power vis-a-vis the BTL? Quadrouple like the BTL (170W) or "just" double (90W)? And is it still good for a 4 ohm load?
Bear in mind that what you end up with isn’t a “real” balanced (= differential) amplifier, but two SE amps referenced to ground and driven with opposite phase input signals to produced a bridged output.
So if this is the case, what's the resulting output power vis-a-vis the BTL? Quadrouple like the BTL (170W) or "just" double (90W)? And is it still good for a 4 ohm load?
The power is the same and there is no difference compared to the "real" 50ASXBTL. It's just that the amplifier is dependent on a ground connection on the input side, unlike a "real" differential amplifier.
/U.
/U.
OK great. Out of curiosity, have you tested and verified that your mod actually produces a bridged output and not just crippling one of the stereo channels (i.e. ending up with 1x20W instead of 1x80W into 8R)?
In short, no I don't. That's why I've asked for independent verification of my results 🙂
However, two things that you should consider here:
- We're not moving jumpers around entirely at random here 😀 . The jumper setting is marked on the board and visible on pictures of a "real" BTL board. The BTL wiring on the converted module is done as per the instructions in the data sheet.
- I happen to know for a fact that the original driver behind having two versions of the 50ASX was to be able to cost-optimise the BTL version (by removing parts that weren't required).
Now, I'm not sure that this means there are no other changes between versions, but it does mean I am quite sure as to why the visible parts were removed.
/U.
However, two things that you should consider here:
- We're not moving jumpers around entirely at random here 😀 . The jumper setting is marked on the board and visible on pictures of a "real" BTL board. The BTL wiring on the converted module is done as per the instructions in the data sheet.
- I happen to know for a fact that the original driver behind having two versions of the 50ASX was to be able to cost-optimise the BTL version (by removing parts that weren't required).
Now, I'm not sure that this means there are no other changes between versions, but it does mean I am quite sure as to why the visible parts were removed.
/U.
Hi.
Recebo hoje 02 50ASX2 SE .
Vou converter para BTL .
Sera usada em um cubo FENDER RUMBLE 150.
Depois escrevo os resultados.
Recebo hoje 02 50ASX2 SE .
Vou converter para BTL .
Sera usada em um cubo FENDER RUMBLE 150.
Depois escrevo os resultados.
Hi.
Recebo hoje 02 50ASX2 SE .
Vou converter para BTL .
Sera usada em um cubo FENDER RUMBLE 150.
Depois escrevo os resultados.

English only please.
Hi.
Get today 02 50ASX2.
I'm going to convert to BTL.
Will be used in a cube FENDER RUMBLE 150.
Then write the results.
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