[intlplby]

i got a LaRocco Dynobias and it is a different size than the regular diamond buffer module and doesn't seem to fit on my PPA i am building.

the old module sat between C1 and the trimpots..... the dynobias doesn't seem to fit unless i was to remove the three trimpots and replace them with discrete resistor values

anyone with a DynoBias got one installed? got a pic so i can see how you did it

 

[thrice]

I had the same problem. There are three ways to solve it:

1) Use fixed resistor values

2) Contact Larocco and see if they can take the module back and extend the pins to allow room for the trimpots (I don't know if they are willing to do this, but it couldn't hurt to ask)

3) I knew I was going to use a Larocco DB so I bent the leads of the trimpots to allow for the DB module.

 

[Juergen]

Is this the new version? I e-mailed them about getting one last November and haven't heard back from them.

 

[MisterX]

Just install the trmmers in the other holes.
I had to do that with the last one I built and I was DUH...that is why there are two sets of holes there.

 

[intlplby]

ooops... i found them... i never noticed 2 sets of holes before..... sweet.....

all i am missing now is some switches and the ZNR and R4 which i think i am gonna make around 3k

 

[morsel]

Actually, the extra holes in PPA v1.1 by the opamp bias trimmers were originally intended for mounting fixed resistors, but if sliding the trimmers down 100mils fixes your problem, more power to you.

 

[intlplby]

can i power up my PPA without the ZNR even though i have installed the CRD already? i kinda want to test it without having to wait for parts


also, just to make sure.. the dynobias has a differrnt pin set than the instructions i got that refer to the original diamond buffer..... i basically install the buffer as far to the right on the board so the right most pins go in the last rightmost hole on the board right?

 

[MisterX]

Quote:

Originally Posted by morsel Actually, the extra holes in PPA v1.1 by the opamp bias trimmers were originally intended for mounting fixed resistors, but if sliding the trimmers down 100mils fixes your problem, more power to you.

Woot.
Mark up another creative solution by yours truly then.

Seriously, It does indeed solve the clearance problem he is having.

intlplby:
look at the board and you notice there four holes on the board for R9
Just relocate the trimmers so they occupy the three holes closest to the C4's and you will be good to go.
Maybe this picture will help show you what you get.

Edit:
lol
I hate it when people edit and then you post a reply to the old reply and never even noticed they edited till it's to late.

 

[intlplby]

yeah i didnt see the extra holes until after i desoldered and removed the trimpots... thanks for the pic though... it's good to have because now when someone else has the same problem they can search for this thread.

 

[MisterX]

Good point.

As far as the CRD goes... without the Zener there is no path to ground so you will be ok.
As far as the buffer goes... yup.

 

[Sovkiller]

Place some sockets over the existing ones, on top, just hook them over, and that will raise the board maybe over the trimpots...I did that on mine and it works, as the board was touching some transistors on the right side....