Simple Speaker Protection for Power Amplifier with Balanced Outputs

[EUVL]

There are literally hundreds of circuits on the net for speaker protection, so we thought we wanted to add one as well.

http://xen-audio.com/documents/f5x/XEN Balanced Speaker Protection Public 131003.pdf

Disclamer :

We try our best to be error free. And the circuit has been proven many times.
But until someone actually double check the schematic, we do not guarantee 100% no drawing error.




Patrick

 

[ticktock]

cool, thanks

 

[EUVL]

There is a 2nd (improved) version using NJFET as input devices.
I have no time right now to test build, but I'll see if I can publish in the near future.
This version also has a PCB design to go with, which is however not yet verified.


Patrick

 

[EUVL]

As promised the article for Version 2 circuit.

http://www.xen-audio.com/documents/SSP/XEN Balanced Speaker Protection Public V2a 140506.pdf


Patrick

 

[EUVL]

Referring to questions posted by an Aleph X builder :

http://www.diyaudio.com/forums/pass-labs/28336-aleph-x-builders-thread-49.html#post3918736

If you are interested to alpha test the PCB for us, please send a email to me and I shall get you in touch with those who can take care of it for you.
You only need to pay postage & packing, since it is alpha test and I have right now no time to nurse you through.

I also have no time to write a proper assembly instruction in the next 2 months.
But I shall try to put together a basic BoM for you.
Component placement should be clear on the PCB. If not, please ask here.

The junctions of c1/r7 and c2/r8 are connected to amplifier ground.
It is good practice that they have a ground reference, though in theory you could leave it floating.
The power supply for the protection board is +/-15V after the on-board 7815 / 7915 regulators.
I presume you can handle the rest (Tx with 2 secondaries, 2x bridge rectifier).
Connection from PSU to protection board is +Vs, Gnd, -Vs.
Protection board Gnd can be connected to amplifier Gnd via a 10R 2W resistor if you wish to have some isolation.


Hope it is clear,
Patrick

 

[buzzforb]

Thanks for this. I will give it a go.

 

[EUVL]

As an excception (due to lack of support from me), I attached herewith a Spice file of the circuit.
Those skilled DIYers would be able to change things in simulation for fine adjustment to theri needs before building.


Patrick

 

[buzzforb]

Very considerate. THank you.

 

[EUVL]

Buzzforb,

I trust that you are skilled enough to do this without any input from me.
If you would help to verify the prototype PCB, please send MarkLai a email.
He will send you, and Jason, each a proto PCB for test at our cost when it is ready.
It might take a few weeks. Ans you only need to pay postage.

I'll prepare a preliminary BoM and post it before then.


Patrick

 

[buzzforb]

Will do.

 

[EUVL]

Proto PCB arrived.


Patrick

 

[EUVL]

We manually checked the PCB and can only find a very small layout mistake.

The two gentlemen doing Alpha Testing please kindly get in touch after receiving the PCB.
I shall then send you information for a simple jumper fix.


Patrick

 

[EUVL]

We have a few enquiries expressing interested in the XEN SSP.

We shall only relesase the PCB as well as associated documents after it has been tested bug-free by the two gentlemen receiving prototype boards.
Until then please be patient.

Of course if you are suffieicntly skilled, there is no stopping you building and adapting from scratch.
All necessary information have been published, schematics and Spice file alike.


Thank you for your interest,
Patrick

 

[EUVL]

PS Prototype boards sent off to testers by registered post yesterday.


Patrick

 

[Maousse]

Hi there, very neat and clean layout, I like !

 

[EUVL]

That is what we are known for.
You can see many other examples, e.g in the F5X and F5X Preamp threads.


Patrick

 

[EUVL]

I have been asked today by PM whether there were any test results.

I have not heard anything since, and I have had things to take care of at home since.
I hope the two gentlemen could report back their build before too long.
Right now I just have no time at all to support yet another prototyping ......
Family & work always come first.


Patrick

 

[buzzforb]

I am one of the members who have the boards. I have recently taken over the family business, so pretty swamped at the moment as well. That being said, I am beginning to layout the case for my symmetrical F6 and this will be used in that amp. It may not happen fast, but surely in the next couple of months.

Hope life gives you a chance to have a break, Patrick. I am sure it would be both deserved and welcome.

 

[turbotoy]

I was the one who had contacted EUVL regarding the status of this project. My interest is somewhat selfish as this board is exactly what I need for a balanced amplifier project that I am working on. If availability of the board is still months away, I will probably just need to layout a point to point implementation using the information EUVL has already kindly provided. Of course, I very much understand the time constraints of those involved.

 

[EUVL]

Gogowatch will see if he has time to support your needs.
But he decides.


Patrick