heisthl wrote:Yes leave the 10k and remove it's ground end connection. Tie that to the mid pots ground and then lift that by 180k (more or less according to the volume jump you want).
Another tweak on this is to separate the two resistors used to lift the mid and bass pots. When I originally played around with this, I switched in and out two 500K pots (one hung off the bass, one off the mid pot - both to ground) and adjusted the pots such that I could tune the mid/bass balance when hitting the lift relay. I settled on 100K for the Bass lift, 270K for the mids. It wound up being a half-way boost between normal and the full D-style PAB with a tonal balance closer to non-PAB mode. Works really well with the clean channel too if you want it to start breaking up a bit. You can tune those resistors to suite your taste pretty easily and I highly recommend using pots to experiment with the values.
Bill
I think this is what you are suggesting, is this correct. I have blacked out the 10k R on the Bass pot so its not in circuit, just the two 500k pots tied together.
Hi, what I have in this config is the two 500k pots affecting the clean tone but not the PAB when its engaged?
I have the output ( ground lug ) of the Bass and Mid pot running to the input of each respective 500k pot then I tied the wiper of each pot together and ran that to my relay NC.
Don't you want to ground the wipers of the 500k pots and take the top of those pots separately to the relay NC's to have the pots shorted unless the relay is energized? Also, keep the 10k between the bottom of the bass pot and the top of its 500k pot.
Hi Ange,. i cant remember exactly what i did but you could try this. Send the ground lug connection on the mid pot to one of the relay commons. Send the bass ground lug to the other common via a 10k resistor. Tie both relay NCs to ground (earth). Finally connect one of your 500k pots between the NC and NO on one side of the relay, and the other 500k pot between the NC and NO on the other side of the relay. With the relay engaged, tune the pots to taste. Hope this clarifies!
Ok this works, very cool. PAB is very good and I can dial in bass or mids. I have two big 500k pots hanging in midair right now. I must get trimmers and do it right, but it works.
Thanks
Last edited by angelodp on Thu Jan 19, 2012 12:32 am, edited 1 time in total.
Pretty happy with this little tweak. Does allow an easy adjustment once inside. 500K trimmers are MIL spec so they should be good or the long haul.
270k on the Mid, 150k on the Bass side. PAB really shaped up nicely now. I had something in the mix that was giving me a bit of Honk on the PAB which is out of there now.
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