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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 10th Jun 2021, 2:36 pm   #1
barrywebb
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Default Select model 8208 no output

Hi I have got hold of a old 8 track player with no sound output on opening it up there were 4 transistors in a bag inside.
My problem is I don't know what way they go in the board.
The transistors in the bag were cracked.
I have replacements just need help as there are 12 holes .
Any help or if anyone has service manual for this it would be very helpful.
Barry
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Old 10th Jun 2021, 2:42 pm   #2
barrywebb
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Default Re: Select model 8208 no output

A picture of the old transistors.
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Old 10th Jun 2021, 4:12 pm   #3
DMcMahon
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Default Re: Select model 8208 no output

Barry I tried to find info back in December without success.

https://www.google.com/url?client=in...xybwaMYkRFvVhl

David
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Old 10th Jun 2021, 7:28 pm   #4
barrywebb
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Default Re: Select model 8208 no output

It's my fault for removing them and not taking any pictures of them in the board.
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Old 10th Jun 2021, 7:32 pm   #5
barrywebb
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Default Re: Select model 8208 no output

Do you still have it if so are the transistors in place on the amp board.
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Old 10th Jun 2021, 10:05 pm   #6
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Default Re: Select model 8208 no output

At the time I was looking at buying it but never did.

No help but pretty sure those transistors will be 2SA509 & 2SC509.

Are there any identification markings around the 12 holes ?

Seems strange they have got cracked in that way, maybe thermal or voltage stressed ?

A real shame you did not photo them before removal, would have made replacement hugely easier.

David
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Old 11th Jun 2021, 8:44 am   #7
barrywebb
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Default Re: Select model 8208 no output

Hi there are no marks on the board what so ever.
So maybe one day I'll pick another one up for spares.
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Old 11th Jun 2021, 10:37 am   #8
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Default Re: Select model 8208 no output

Reverse engineer for a skeleton schematic around where the transistors fit, you should then be able to figure out which is EBC.

Lawrence.
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Old 11th Jun 2021, 10:53 am   #9
barrywebb
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Default Re: Select model 8208 no output

I've also noticed that it was made by Senn- Sound with the same model number 8208
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Old 11th Jun 2021, 1:58 pm   #10
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Default Re: Select model 8208 no output

I was wondering if it was a clone/rebadge of a more well known make that may have a schematic available but like Select, Senn-Sound is not really known to me.

David
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Old 11th Jun 2021, 2:15 pm   #11
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Default Re: Select model 8208 no output

Senn Sound looks like a Swiss company under Auto-Senn AG.

No obvious sign of any documentation.

David
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Old 11th Jun 2021, 2:35 pm   #12
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Default Re: Select model 8208 no output

I was assuming that it is a desk model for home use rather than a car model.

Just wondering because if it is a car player, then because of its age it possibly could be +ve earth. If so then if tried on a modern car with -ve earth it would not work and possibly could get damaged ?

David
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Old 12th Jun 2021, 9:43 am   #13
barrywebb
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Default Re: Select model 8208 no output

Hi David it's a home model sorry for not making that clear at the start.
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Old 13th Jun 2021, 7:59 am   #14
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Default Re: Select model 8208 no output

Are there any other transistors on the board or just these 4, some basic players may only have 2 transistors per channel.

These transistors appear to be a PNP/NPN complementary pair which to me is unusual in a basic player amp, when used typically would be in an output stage driving a speaker, (although these particular transistors are not really power output type) in that case there would be other transistors. Does this player have internal speakers ?

A photo of the player and its PCB would be interesting to see.

David
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Old 13th Jun 2021, 8:10 am   #15
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Default Re: Select model 8208 no output

Quote:
Originally Posted by barrywebb View Post
Hi there are no marks on the board what so ever.
So maybe one day I'll pick another one up for spares.
These appear to be very rare so you will have a job finding another.

Lawrence's suggestion of reverse engineering a schematic is only practical way forward if you have the technical ability to do it.

David
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