Pioneer SX-7730

For the three and more legged things
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colin.hepburn
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#16

Post by colin.hepburn »

colin.hepburn wrote:You do have a rare SX-7730 version if you're looking for the service manual try vinyl engine look for the SX-737 or the 727 close to it
http://www.hifiengine.com/manuals/pioneer/sx-737.shtml
Or Here http://www.eserviceinfo.com/newfiles/new_9400.html
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pre65
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#17

Post by pre65 »

Thanks for those links Colin.

I have switched it on now, with a dummy load (2 x 15R ceramic resistors) and volume control set at min. After 30 mins everything seemed OK, but the heatsink did not get warm.

So I powered it down for a while, then checked the transistor bias as per the instructions. Bias should be 20mv after 10 mins, and first side started at 15mv and rose to 19.4mv after about 15 mins. The other channel was about the same. Still no heat in the heatsink though.

Might rig up some old speakers later (it's got crap screw connectors) and see if it makes a noise. :wink:
The only thing necessary for the triumph of evil is for good men to do nothing.

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pre65
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#18

Post by pre65 »

Firstly, my Freecycle wanted ad did say that non working hi-fi would be accepted !

Seems the Pioneer is down on the RH channel. With the balance control full right the RH speaker does "speak" but at a lot lower level than LH. Have only tried it on AM so far, so will confirm the diagnosis with a line input after lunch.
The only thing necessary for the triumph of evil is for good men to do nothing.

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G-Popz THE easy listening connoisseur. (Philip)
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pre65
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#19

Post by pre65 »

With a line source (CD) I do get sound from each channel, and the balance control works as it should, so it would seem the output stage is fully functioning.

With crap speakers it sounds crap (what one would expect) so a try with something better is in order.
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
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pre65
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#20

Post by pre65 »

Looks like the source selector switch is the guilty party for the lack of volume experienced on AM radio. Fiddling with it brings up the volume on both speakers. :)
The only thing necessary for the triumph of evil is for good men to do nothing.

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G-Popz THE easy listening connoisseur. (Philip)
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Mike H
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#21

Post by Mike H »

Switch cleaner?




 
 
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Dave the bass
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#22

Post by Dave the bass »

Mike H wrote:Switch cleaner?

I think he does it himself........

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Mike H
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#23

Post by Mike H »

:lol:


Doesn't have a woman come in "to do"



 
 
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pre65
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#24

Post by pre65 »

Mike H wrote::lol:

Doesn't have a woman come in "to do"

I wish. :lol: :lol:
The only thing necessary for the triumph of evil is for good men to do nothing.

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G-Popz THE easy listening connoisseur. (Philip)
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