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Ross Phaser notes(for those who care!)

11/21/2002 5:51 AM
kluson guy Ross Phaser notes(for those who care!)
I just picked up a Taiwanese Ross Phaser in the hopes that it might provide me with a reference to debugging my dead USA orange Ross Phaser.  
Its a totally different circuit!  
Orange Ross, has a 4 transistors (2SC842 & 2SC37)and four RC4558's  
Black Taiwanese circuit is IC based. 1 RC4558 and 3 LM13600N's  
Just thought I'd throw this out.  
11/21/2002 2:54 PM
Thanks for the infro it might come in useful.  
This appears to be a different circuit to the original Ross phaser, it didn't use LM13600N's.  
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11/21/2002 3:10 PM

Can you take pictures or scan both sides of the board?  
It is an OTA based phaser, like the small stone. I can imagine this one sounding very good.  
11/21/2002 4:15 PM

I have the US Ross Dist/Phaser. The Phaser portion has three LM13600 and one 4558.
11/21/2002 4:42 PM
Mark Hammer
With 3 dual OTAs, it will have 6 stages. That's certainly not a night and day difference from a 4-stager, but my DOD FX20 Phaser has a similar configuration (three 13600's) and it sounds quite pleasant.
11/21/2002 5:25 PM
Sean Costello
Could one of the OTAs in the Ross phaser be used for a voltage-controlled VCO? Or is it pretty obvious that all three of the dual OTAs are used for phase shifting stages?  
Sean Costello
11/21/2002 6:23 PM

It is likely that one of the OTAs is the LFO, and probably the dual opamp is an input buffer/output mixer/buffer.  
I'd really like to see this LM13600 based phaser schem.  
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