Bought a XY LM3886 Kit.

[Aguilabrava]

Hi:

I am new to this forums here at DIYAUDIO, I found this site searching help for some issues I was having with speaker's crossovers.

Now, I have learn a lot from you all, it's been really nice, and this have encouraged me to experiment and learn more.

I recently purchased a XY LM3886 amplifier kit at eBay. It is composed of 2 amplifier boards and a regulated power supply unit. I have attached a picture of the actual kit I bought. I have not received it yet, but I want to know your opinions about this kit, and if there is anything to improve it.

I also purchased a ALPS potentiometer for it, I have seen that they also sell "speaker protection boards", do I need one of those?.

I also know I will need a transformer, I was thinking about a toroidal from Antek, the AS4222 22V 400VA, is this OK for this setup?.

Thank you very much.

[malibujeff]

Take a look at this thread on the same amp --->> 3886 Ebay kit Build

[nigelwright7557]

There arent a great deal of components in the 3886 amp to change.
Maybe a larger input coupling capacitor to lift the bass end.

[Minion]

And that power supply isn"t regulated , it is just a regular unregulated PSU ......

[Aguilabrava]

Can I replace the Wima input capacitors with Audiophiler MKP 4.7uf 400V axial capacitors?. If not, what would be the best replacement?.

Do I need to get the "speaker protection board"?.

Thank you.

[Minion]

Originally Posted by Aguilabrava

Can I replace the Wima input capacitors with Audiophiler MKP 4.7uf 400V axial capacitors?. If not, what would be the best replacement?.

Do I need to get the "speaker protection board"?.

Thank you.

If you can fit them in there then go for it ..... i put in some huge 4.7uF mylar caps in my boards (got the boards for $2.50 each on e-bay) and was able to get them to fit but it is a really tight squeeze ......

As for the speaker protection I guess it is optional ......

Cheers

[AndrewT]

have you got pics of the top and bottom of the blank PCB?

Many of these PCBs have commoned the Signal Ground with the Power Ground.

In a monoblock amplifier, you need to move the Main Audio Ground onto the PCB.
In a dual mono amplifier and in a stereo amplifier, you must cut the Signal Ground connection to the Power Ground. Then select an off board location for a single Main Audio Ground shared between the two channels.

If you have bought a parts kit from China, or nearby, then check that all the components are what is written on the labeling. You may have to discard many of the supplied Chinese components.

[AndrewT]

Originally Posted by malibujeff

...look at this thread on the same amp --->> 3886 Ebay kit Build

and 118posts later he has successfully built his amplifier. All because there is no support from the retailer.

What if the Forum was not here?

[triode_al]

in my opinion, you need not use a relay, as long as you use the muting signal (pin 8) to disengage the output for some time while the circuit is stabilizing.

[pacificblue]

The speaker protection is optional, but recommendable. It protects the speakers in case the power transistors fail and rail voltage presents itself at the speaker output. In such a situation the muting pin can obviously not help.