Hi-Fi Guidance

[keithb7]

Hi folks, I am attempting to assist my brother who recently acquired a pretty nice 1968 Philips Solid State console stereo. I have mainly worked on tube guitar amps.
I have very limited solid state experience. We cannot locate a schematic. Is there anyone here who can help us identify a few things? Ground scheme? Cap polarity etc? There are some real good folks here who have helped me a lot with guitar amps. I was wondering if a few of you are into other electronics as well.

If this Hi-Fi stuff is not welcome here, do you have any recommendations for a good forum with helpful folks for us Newbies?

Model is a Phillips R448. If there is some help here, and ok to post, I will start uploading photos and asking questions. Thanks, Keith

[Enzo]

See if "Sams Photofact" has an issue for this model.

[g1]

It's odd that there is so little showing up for this model, (using single L philips spelling).
Is it a german unit? Any other model numbers on it? Post some pics?

[keithb7]

Thanks guys for checking in. No luck finding anything in Sams Photofact. It does appear that at least the guts were built in Germany. here are some pics. The final wood console may have been assembled in Canada.



This is the turn table:



Unsure where this is located:

[keithb7]

[keithb7]

The radio works and plays. There is some crackling. Upon initial inspection we see some blistering caps. For starters I thought all e-caps should be replaced.

First question:
How can we identify polarity on these original 1968 e-caps? I believe they are Plessey brand.



Another cap here. I am unsure of polarity. Black wire from cap node seen here does go to the chassis. I assume the chassis is ground. Does that seem logical? Power cord is two prong. No ground to wall it seems.

[gbarron]

It's odd that there is so little showing up for this model, (using single L philips spelling).
Is it a german unit? Any other model numbers on it? Post some pics?

Brother to keithb7 here...yes it is a German unit. The TT is a GC046 model ( I believe it is the same as a Grundig 46 series), and according to the original sales brochure the amp chassis is listed as model HC4. Not sure if the amp shares anything with Grundig components but so far I have not been able to track anything down online either.

I did check "Sams Photofact" but no luck there. Thanks for any help you might have!






G.

[Enzo]

Yours is a 448, but the one photo you posted shows the same chassis was used in the 458 and 468 models. A search for those two MIGHT turn something up.

As to your can caps, the upper one has a single terminal and can tabs. Unless otherwise indicated, I assume the single terminal is the plus, and the can tabs negative. See the tiny square stamped into that single post on its base?

Now look on the two legged cap. I see four diodes there making a bridge. The left terminal has the positive ends of the rectifiers. The right terminal has the negative ends of rectifiers. Note the left terminal has the tiny square stamped on it, while the right one has a tiny triangle.

On both caps, look for a legend stating the cap rating. See if there is not a square and triangle printed on there, with one claiming positive. On the single leg one, see if ther is a + on the side.

[keithb7]

Ahh yes! I see the square an triangle now. Thank you.

[keithb7]

Does this pic help with further polarity clarity?

[keithb7]

Not much on the caps to ID polarity it seems:

[Enzo]

perhaps further around the can to the right, is ther any symbol after the rating?

In general, I assume the can tabs are negative unless specified otherwise.

In the case of the two leg one with no can tabs, I stick with my diode theory.

[g1]

Enzo, what is up with the labelling on those diodes, seems backwards to me?

[g1]

We cannot locate a schematic.

It's worth a try to check with justradios.
They say 'antiques' but seem to have stuff right into the 70's :
Canadian Antique Radios Schematics Diagrams Service - JustRadios

[keithb7]

perhaps further around the can to the right, is ther any symbol after the rating?

Twisted to reveal, further to the right: