Roland Bee Gee AF-60 schematic questions

[Mecha Money]

Hey all.

I've got my eye on the AF60 schematic - and I found some notes from Analogguru on another forum which, given AG's reputation, I am accepting whole heartedly.

My question really is about these funky triangles circled in this photo. Is this simply an alternate symbol for ground? and if so why would the 22K series resistors and 10uF cap (which are already grounded) need this additional ground?

Thanks for taking the time to help!

PS - apparently I am unable to link to the AG link - not trying to drive traffic away from DIYstompboxes - just trying to give the info:

"The resistor from the volume pot to gnd isn´t 47 Ohm, it is 470 Ohm. And one capacitor 10µF from V+ to ground isn´t drawn in the schematic.

BTW, the "beautiful TA7504M" has been "cannibalized" by the guys at Roland. Normally this chip has 8 pins. in the factory they cut two legs (pin 1 and 5) for easier assembly - have a look at the underside of the chip. From the chip architecture it is very similar (and compatible) to a 741.

analogguru"

sorry if I've broken etiquette!

[Mark Hammer]

No, they are reference-voltage or "floating ground" points.  The 9v supply voltage is produced by that 22k pair that nicely slices the 9v in half.  The other two triangle points are supposed to be with reference to that 4.5V midpoint (often presented as "Vref" in other schematics).  Just tie all the triangle points together (and separately from actual ground) and you'll be fine.

[anchovie]

It's the bias voltage for the op-amps. The pair of 22K resistors in series from 9V to ground form a voltage divider, so as they're equal the mid-point is 4.5V. As with the 0V ground connections, all you need to do in terms of a vero/perf/PCB layout is make sure that they're tied together.

Does a Bee Gee fuzz create a 3-part harmony several octaves higher? 

[anchovie]

Simultaneous information from Mr Hammer, except for my bad joke!

[Mecha Money]

very helpful guys - many thanks..

anchovie - there are no such things as bad jokes especially where the Bee Gees are concerned!

[Mark Hammer]

More than a fuzzboxxxx, more than a fuzzbox to meeeeeee........   

[Brymus]

So its a DOD 250 with a BMP tonestack and recovery stage ?