Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

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 It is obsolete, I could not find a data sheet for it.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:
[-]
Recent Posts
462ron
Hi Dan, your original dial appears to be lighter, easier to allow light through. My original is similar except it’s crac...462ron — 12:07 PM
Philco 38-2 Automatic Tuning
I received my new 38-2 dial. I'm a little disappointed. As you can see in the picture the blues have a white shadow. The...dconant — 11:13 AM
Philco 38-2 Low Volume
I have been playing my 38-2 for a while now and it is doing very well. I did have to replace the 6A8 (osc) as it develop...dconant — 11:03 AM
Philco Speaker Spider
Hello, Does anyone with a 3 D printer make the spiders for those old Philco speakers? That might be a good idea for some...dconant — 09:41 AM
Philco 16B Parts
Hello, I'm looking to buy a 16B but I'm not so sure of what I am looking at. First as seen from the picture it looks lik...dconant — 09:17 AM
Looking for verification of correct schematic.
Klondike98, Thank you. I'll double check that SN and get back to you. GarySP, Thank you for the schematic.RossH — 12:13 AM
Looking for verification of correct schematic.
I think you have the correct take on your set. Ron's annotated early schematics that note the below B22000 serial numbe...klondike98 — 12:04 AM
Looking for verification of correct schematic.
Hello Ross. The Philco Radio Library located at the bottom of the page has the schematic with the tube count you have. ...GarySP — 10:48 PM
HiFi (Chifi) tube amp build - but my own design.
Tim It's be interesting if you put your schematic here. Who knows, you could get some advice from a few folks here. ...morzh — 10:01 PM
Philco 42-390, code 121 speaker
Thanks for that information. It would appear from the output transformer parts list that the transformer that was origi...Stevelog — 07:21 PM

[-]
Who's Online
There are currently 1233 online users. [Complete List]
» 3 Member(s) | 1230 Guest(s)
AvatarAvatarAvatar

>