Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

Stereo MPX Decoder for old Sony
#16

I was thinking the same. There are many +12 Ground to -12 polarity converters in the market (mainly for old cars) but not one like that. I would even take +12 to-12 converter.

I thought this Sanyo chip is probably not necessarily positive ground. I can see the legs where the L and R channels are coming out. I can bypass the headphone amp they have built in. But what can I use for a ground? Would the chip's negative supply be the new negative ground. I got stuck there.

In a Yamaha receiver, the same chip is used with a negative ground. I have schematic for it but could not find one for the Sanyo.
#17

Hello Toptip,
First all what is the IC part no . and what is the sony model number ?

Sincerely Richard
#18

The chip is Sanyo A3311. It is obsolete, I could not find a data sheet for it. All my information is from a Yamaha CR500 receiver where it was also used.

The Sony? If you mean Sanyo, it is called RB9000. There are two versions of it, with and without a headphone permanently attached.
#19

Toptip,
Because Sanyo did make a LA 3361 because most sanyo IC chips had LA I used to be a factory Warranty and service for Sanyo/Fisher .

Sincerely Richard
#20

Yes, in fact when I was searching for the A3311, I came across LA3361. It looked quite different. I will send you the schematic of this chip from the Yamaha manual.
#21

Is there a way to load an image?
#22

And you are right. While chip says A3311 on it, elsewhere it does come up as LA3311:

https://icompplus.com/en/others/LA3311
#23

Hi,

This is the schematic showing the chip (which I highlighted in yellow, as I found it confusing).

Is this chip made for a positive ground or is that how Sanyo has used it? 

If possible, I would like to change it to negative ground.

All the best


Attached Files Image(s)
   
#24

The quick answer is "not possible". The VCC to the circuit is negative voltage, the filter caps positives are connected to gnd and the transistors are NPN.
#25

This is the same chip, used with negative ground. I suppose I could do enough surgery to change things from positive to negative but might be easier to build a new circuitboard. I wish I could find the original datasheet with a simple schematic.


Attached Files Image(s)
   




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 71 Code 125
Ok guys. Thanks for the input. As for AI this is why I ask the experts. Dandconant — 07:39 AM
Philco 71 Code 125
Technically, that's C-. B- is chassis ground. The resistor between chassis ground and the HV center tap makes the HV c...MrFixr55 — 11:24 PM
54C Cabinet Refinish
hello Roy, I’d follow Arran’s suggestion and use automotive gasket material, which I keep around for situations like th...radiorich — 10:22 PM
Philco 71 Code 125
This might be one of those cases where it's a ground to an AC voltage and B- to DC.RodB — 08:22 PM
Philco 71 Code 125
Really Rod? I know you would not steer me wrong but AI say this is a short circuit? What if I moved the 6 volt center ta...dconant — 06:40 PM
54C Cabinet Refinish
Roy; Personally I would have left the asbestos alone if it were my set, but you can find a modern substitute that som...Arran — 04:51 PM
Philco 71 Code 125
Looks like that might be the B- buss, so that would be correct.RodB — 01:32 PM
Philco 71 Code 125
I noticed on the code 121 schematic the center tap for the 6 volt winding and hv winding are tied together. Is this corr...dconant — 12:16 PM
Philco 45-6365 Universal IFT Instruction Manual
The Philco Parts Catalog for 1942 shows it as usable for 175 kHz, 260 kHz, and 465 kHz. The instructions will show how t...DaleHCook — 11:19 AM
Stromberg Carlson 1500 Squeal
Hello Rob, I agree with you—I have one here at my house that I need to check out. It’s way over-engineered just to make...radiorich — 11:05 AM

[-]
Who's Online
There are currently no members online.

>