Pioneer SM-B200B Valve Receiver

[damiena]

A few pics of my newly acquired Pioneer SM-B200B. It’s a curious beast.









Put the valves in




Now need to work out how to connect it up

[damiena]

I say curious as it has 2 separate tuners. One is medium wave and short wave, the other is medium wave and FM. You can play both tuners at once, apparently to support an early form of stereo where once channel would go out on AM and the other on FM. Not sure what use I'll make of that!

[Tomcat1969]

Oh man! Very, very nice.

[damiena]

Oh man! Very, very nice.

The pictures aren’t great due to the light earlier, will try and get some better ones when conditions permit. The frontage to me though reminds of a late 50s car dashboard!

I have a nagging suspicion the double “magic eye” tube that glows between the two frequency scales doesn’t work, which will be a pain as I think they are pretty rare tubes (my fault for not confirming with the seller). And I know the FM channel doesn’t work (cos the seller told me). So I may have a bit of a project on my hands! However, if the valve sound is nice I’ll be happy. Just need to work out where to put it next.

Step down transformer arriving tonight, so all will become clear later when I attempt to power it up.

[niclaspa]

Very nice!  Well worth a bit of restoration effort.   

[damiena]

Trying to work out how to wire this up.

I think I have the speakers connections understood. Hoping i doesn't need the middle speaker, because I don't have one.

My connection info on the back is all in Japanese. But I found a picture online of an english version, which I thought would sort me out. However the English picture is for a SM-B200A and I have a SM-B200B. Mine has all the same RCA sockets as the A, but has an extra 2 RCA sockets and a 5-pin din mounted above the back plate.

The A


The B


In the A it looks like you can only record onto tape, but not playback in. But then there are 2 Aux sockets but it only shows an FM /MPX connection going into one...
On the B the extra two horizontal RCA sockets and the DIN look like a dedicated tape in.

I think I understand it, but the diagrams just ain't completely accurate and consistent.

[damiena]

And what is this "centre chan amp" thing?!

[Fidel Costar]

Hi Damien,

Believe me, some of these old Japanese valve amps and receivers are really very nice. Many moons ago, I bought a Sansui SM 80 receiver. The poor old thing looked like a wreckage, but once I found a way to connect it to the outside world, it sounded tremendously good. Much better than my Jadis Orchestra valve integrated amp...

[damiena]

It works! It didn’t blow up! I’m alive, and so is the MAGIC EYE!!

[analogadikt]

Please check the capacitors before further powering up. Many of these old jap amps are notorious for leaky caps.

Regards,

Anwesh

[g8ina]

I have one of these coming in for service at the end of August, customer wont post

Any suggestions as to what I should be looking for welcomed.

[damiena]

I’ve seen recommendations/warnings online from others with these receivers that all the grey elna caps should be replaced as they are notorious for being leaky.

Apparently mine has had all the main filter/mains caps replaced, but I will need to do my own checks

[damiena]

Going in deeper. It’s fairly clear which capacitors have been replaced, you can see the fresh solder and the new capacitors. Pretty much all the larger ones are new, but there’s still plenty of smaller original ones to check.



I also need to identify the FM circuit. I have 2 fairly good quality schematics but for the SM-B200A and one just labelled SM-B200 (with no end letter); the third schematic I have for the SM-B200B is not so good resolution and looks like a photocopy of a crumpled paper version. I’m going to have to use them in combination to work out some of the less clear elements of the correct schematic.

[g8ina]

Damien, I have a fairly clear pdf cct diagram if you would like a copy ?
David

[damiena]

That would be fantastic David. I’ll pm you.
Thanks,
Damien