Attn Dickythebricky A400 Mod

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Hi Richard,

I have attached some photos to help you with this mod but its up to you to decide if you want to go as far as i have gone in terms of removing the existing RCA inputs to intstall some higher quality ones.

Assuming you want to install high quality RCA sockets like I have done then you will need to remove some of the existing ones - not expecially difficult but you will need to take the rear panel off the unit. Note that I have left some of the original RCA sockets in situ to make sure that the PCB is properly supported when the unit is reasemmbled.

Check here for quality RCA sockets:

http://www.hificollective.co.uk/components/rca_sockets.html/

Once you have installed the RCA sockets you will need to wire them directly to the volume pot - you need to make sure you get this right though otherwise you will bypass the volume pot and blow your speakers! It is quite simple though as you will see from the pic.

The ground wires from both RCA sockets will need to be soldered as shown to the earth pin on the rear of the volume pot -this is the pin on its own.

The signal wire from the Left RCA is attached to the row of pins at the rear of the pot - make sure you solder it to the 2nd pin from the left (that is the left as you are looking at the rear of the pot).

The signal wire from the Right RCA is attached to the row of pins at the front of the pot - make sure you solder it to the 2nd pin from the left (that is the left as you are looking at the rear of the pot).

There you are you are now finished! You can tidy up the cable as you see fit but you shouldd prepare yourself to hear so much more detail from your music - i was gobsmacked when I first did this mod and I hope you are too...

If you dont want to use aftermarket RCA sockets then you can still do this mod - all you need to do is choose one of the exisiting pairs of RCA sockets and wire them directly to the volume pot. With the original RCA sockets, the signal is carried by the part of the socket that has an "L" shaped profile when viewed from above.

I hope this helps

http://imageshack.us/photo/my-images/863/a400004.jpg

http://imageshack.us/photo/my-images/821/a400002.jpg

http://imageshack.us/photo/my-images/37/a400003.jpg

Please let me know how you get on with the mod for the A400. If you have any questions just let me know.

 

[Anonymous]

So Dickythebricky have you managed to do the mod yet? be interested to hear your thoughts...

 

[Anonymous]

That's an interesting mod, though doubt I have the patience to do it these days.

One thing to keep in mind about changing the original RCA sockets is that the originals may seem of poor quality and possibly the outer metal may have worn off revealing copper or have many marks......however they were tin plated to minimise the electrical changes you get when one metal meets another. i.e. the electrical qualities remain more of the same from when they enter the amp and leave it. tin RCA- tin solder etc... however I have to admit I used a higher silver % solder when replacing my caps.

I think the speaker output sockets are tin plated too.

 

[Anonymous]

That's an interesting mod, though doubt I have the patience to do it these days.

One thing to keep in mind about changing the original RCA sockets is that the originals may seem of poor quality and possibly the outer metal may have worn off revealing copper or have many marks......however they were tin plated to minimise the electrical changes you get when one metal meets another. i.e. the electrical qualities remain more of the same from when they enter the amp and leave it. tin RCA- tin solder etc... however I have to admit I used a higher silver % solder when replacing my caps.

I think the speaker output sockets are tin plated too.

Hi Dav,

Nice to see another A400 owner on here. What mods have you done to yours then?

With regard to the speaker binding posts on my amp I replaced those long ago with silver plated ones too. I understand what youre saying about the tin plating but for me its too late to go back now and Im very happy with the results!

In fact I have just finished another mod recently - replaced the inductors in the signal path with some new ones i made with solid silver wire! Wasnt a huge difference but there was definately an improvement in the fine detail coming through. :cheers:

 

[Anonymous]

I'm mudan in diyaudio.

See the link:

http://www.diyaudio.com/forums/solid-state/34327-pioneer-a400-coupling-caps.html

though I replaced the Panasonic TSUP mains smoothing caps with Mundorf MLytics quite a while back and once run in they sound much better. My amp still sounds great though I do wonder if the faster sounding TSUPs would be better than the more refined and smoother MLytics. I don't plan to do any more changes as not really into hifi mods these days!