Toroidal Transformer

[73's de Edd]

Sir Gatesheadkeith . . . . .

That's quite a variance in your troubleshooting trip and changing from a toroid transformer to a dual voltage controlled low noise amplifier chip.
How low noise is it ? . .well if you had it in your audio processing loop, you would be able to hear the sound of a mouse peeing on a cotton ball .
The parent developer of that PA381 chip is On Chip Systems.
But it has been second sourced in its supply at Curtis Electro Music Specialties.
Researching for a supplier ends up at the " Alibaba" far east sources.
You are just going to have to seek out the supplier that will sell you just one chip and at the best price .

Thaaaaaatsit . . .

73's de Edd

 

[Gatesheadkeith]

Thanks Ed. I suppose the obvious question is this. Would it be possible to replace the chip with a different one that IS available? As you all know I am a total novice, so if that's a dumb question, I apologise. Anything to get the sound back!!

I am due to contact the Orla engineer in about 10 days when he gets back from his vacation in the States, and I am hoping that he may have some scrap boards or even the chip, but no guarantees on that.

What I'm basically saying is this. Is there any way to work round this?

As always. Thank you.

 

[73's de Edd]

Sir Gatesheadkeith . . . . . .

Gadzooks . . . . looks like your avatar . . .over to the side . ..is doing some real SERIOUS pixelating.

Add On:
HOWEVER . . .if you view it on your PROFILE . . .it becomes a blooming bloody animated GIF, wherein you totally go into self destruct mode !

Silly me . . .certainly you should INITIALLY try to go the Orla acquisition route . . .either in old new stock or cannibalization to yield a PA381 serviceable part.

I have used that IC family of voltage controlled amplifier in the past . . .just in acquainting myself in their manner of operation.
BUT they were in no way the specialized type that you are encountering here.
On the "Seek IC " site we are seeing proofferings of at least 5 companies of that specific OCS unit in an 8 pin DIP mounting:case configuration.
( I'm sort of questioning that Surface Mount Device casing at the bottom, as to whether they ever offered it in that housing profile . . .you are using 8 pin DIP. )

Also they are signifying some quantities . . . . not to say that some might not actually stock it . . .and just hot foot over and buy a copy from a stocking supplier. That's where the price confirmation comes in.

REF:

http://www.seekic.com/buyer/search.html?keyword=PA381

73's de Edd

 

[Gatesheadkeith]

Thank you Ed.

Well, I obviously hope the Orla guy will come up trumps with one, but in the meantime, I've emailed a couple of far east manufacturers.

Also spoke to Mouser UK who were very helpful and they feel that only the first parts of chip info are important. PA381 106-6D. They think the 0422 is probably the 22nd run or week of 2004 and the E26 a batch number.

So with PA381 106-6D Google started kicking up info which is helpful.

So I'll wait until I get the Orla guy back and if he can't fix it, then I'm going to have to write some begging letters to China to see if I can persuade them to let me have 2 or 3 off their reel of thousands!

Big thanks my friend. Wish I had your knowledge, and thanks for that link.

 

[Gatesheadkeith]

Just to say Thanks to you all. My Orla GT8000 now back in full working order. A signal switching issue due to the defective chip, an intermittent potentiometer problem on the main volume switch, and a crack on the swell pedal pcb were all related and although it's been a pain, I have learned a lot about the organ and how it's constructed.
Now very very interested in learning more about organ, keyboard, synthesiser and digital keyboard repair. Although almost 70, I need a new hobby, and all this has got me very interested.

BIG thanks guys.