LM3080/CA3080 conversion to LM13600 help

[blackieNYC]

building the gator: http://gaussmarkov.net/layouts/gator/gator-schem.png
found a means of conversion: http://effectslayouts.blogspot.ru/2015/11/lm13700-to-ca3080-conversion-board.html#comment-form
And I have a 120 Hz half-wave coming out of the Lm13600. (the DC supply and Vb are clean. If I ground pin 6 it goes away. I have audio on the inputs 3&4 but no audio comes out pin 5.
Voltages on the 13600 are
1  .5v
2  .7v
3  4.5v
4  4.5v
5  1.1v
The substitutions are:
LM3080     LM13600
pin 1          nc
pin2          pin 4  this gets the input via a 30k resistor
pin 3         pin 3  tied to pin 4 with a 1k
pin 4         pin 6 (the V- receives the control signal?) output of side chain IC4B pin 7
pin 5         pin 1 (amp bias)  10k plus a pot to Vb (pin 1 and 6 seem odd)
pin 6         pin 5  output
pin 7         pin 11  +9
pin 8          nc
LM13600 pins 7,8,9,10, and 16 are grounded, as per the unused side of the Engineer's Thumb comp.
However, in the half of the LM13600 that I am using, there is no ground.  You see the momentary switch at the end of the side chain - I believe that when this is connected the signal should pass thru.  +9, then inverted. Is that a virtual ground?
The side chain looks right to me, and its DC output (with tone input) will hop up and down as I adjust the pot around the threshold.  I don't remember what those voltages were. from 2v down to 1v or something.  The chip and I are too hot to continue right now.
The 308 op amp - is this necessary?  It's behaving itself, but I would love to see an updated schematic of the gator.  thought maybe I'd have one to offer, but of course not.

[PRR]

Added pin-function notes:

The substitutions are:
pin  LM3080    LM13600
NC   pin 1     nc
-In  pin 2     pin 4   this gets the input via a 30k resistor
+In  pin 3     pin 3   tied to pin 4 with a 1k
V-   pin 4     pin 6   (the V- receives the control signal?) output of side chain IC4B pin 7
Iabc pin 5     pin 1   (amp bias)  10k plus a pot to Vb (pin 1 and 6 seem odd)
Out  pin 6     pin 5   output
V+   pin 7     pin 11  +9
NC   pin 8     nc

> The 308 op amp - is this necessary?

It is just a high impedance buffer. It may have been cheaper once. Today I would use a TL07x. If there are still TL071 chips, one should drop-in. I do wonder about '308 with 33pFd compensation at unity gain; I thot it was 300pFd? While a too-small cap might oscillate, I can't see it oscillating 120Hz.

> a 120 Hz half-wave coming out of the Lm13600

If this is in-tune with finger-buzz, it has to be stray AC field. Maybe high gain on unshielded build too close to a DC supply.

> the momentary switch at the end of the side chain

That looks dubious to me. It throws the TL072 outside its specs. This chip is notorious for doing different things when that happens. It may have worked on Markov's chips and not with yours.

> The chip and I are too hot to continue right now.

Is the chip hotter than you?? If so, something is very wrong. The "3080" should run cold; well couple degrees warmer than the room.

Shorting IC4B Out to ground should cause maximum gain. (TL072 will stand such a short unless the room is superheated.) Or put 100K in series with SW1 so it works as a comparator instead of an over-the-top gimmick.

Yes, the control signal here goes to "V-". The '3080 actually needs very little voltage. When "V-" is 1.2V lower then Vbias, there is no voltage across the R5 network, no current in '3080, no output. When "V-" pulls down toward ground, "Iabc" follows 1.2V higher, now we have up to 3.3V across R5+pot, current flows, '3080 amplifies.

[blackieNYC]

thanks Paul - I am using the 13600, to be clear.  I'll have a look at the V-/Vbias readings again.  And I'll try shorting pin 7 of IC4B.
Unless the chip is blown. 
This is on the breadboard, so any experiments are easy.  I'm not really making use of the momentary, I just tried it because it should let signal pass thru the OTA - right? close the switch and the gate is forced open?

But the 13600 is 2 3080s with a diode bias and buffers added - do any of the resistor values need changing to move from 3080 to 13600?

[blackieNYC]

Left out Vr on pin 3.
Now it is working (but I'll start a new thread with a mod question)

LM13600 voltages are pins 1 thru 5 are 4.8v, pin 6 bounces between 5v (gate closed) and 1v (gate open).
a swell sweller.