[sdiy] SAJ110 help please

Oren Leavitt obl64 at ix.netcom.com
Sat Jun 19 08:27:01 CEST 2010



Bob Weigel wrote:
> On 6/18/2010 6:49 PM, Oren Leavitt wrote:
>>
>>
>> Bob Weigel wrote:
>>
>>> Voltage is -7.7V on pin 1
>>
>> Bob,
>> That -7.7V seems off. The Solina SE service manual specifies -9V to 
>> the SAJ110 dividers.
>> The low voltage could be causing the logic high/low threshold of the 
>> SAJ110 input to be borderline with the input signal to the dividers.
>>
>> I would double check all of the the power supply voltages against 
>> those called out in the service manual. Especially since the Solina's 
>> power supply is unregulated and uses hot-running resistor dividers to 
>> get the various voltages needed.
>>
>>
>> HTH,
>> - Oren
>>
>>
> I should have added... I tweaked it down a bit because that was the 
> optimal for the chips it seemed.  Maybe I've just somehow run into 
> multiple scrap units that all have crummy marginal chips?  The only 
> thing is..like I say..most of these worked in a crumar Organizer 2 I 
> tried a lot of them in just to see what was up!  It's like..only in 
> *this* environment do they need to be handled more carefully or 
> something :-)
> 
> Anyway thanks..I should have noted I only have the version of SM that 
> has the 11V supply to the SAA1005 which is the earlier design I 
> believe.  Absolute max on the SAJ110 is 11V so we don't want that. -Bob
> 

An interesting little dilemma it is.

The Eminent/Arp Solina SE I have is a 1974 one - the first year they 
were made. This doesn't have the modulation on/off switch or the small 
gate/trigger jacks. These were added in late 1975 (I think).

This uses SAJ110 operating at -9V.
I've have the original service manual that was enclosed in the unit.
I have scanned it - and if you need info, I can send you hi-res jpegs.

Eminent might have used SAA1005 in later models.

- Oren



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