Tom,
When you change the coupling caps you will really be surprised. As I've mentioned before, on that amp, it takes about 2 or 3 songs till the new PIO caps begin to bloom open. It's like a hash brownie kicking in (or so I've been told). And he tinny sound...that's those ceramics, I promise you. 7189 amperex will be hard to find and expensive. 6bq5/el84 amperex work fine in my amp. Best ones have the "D" getter (as compared to the "o" getter). Plenty of them out there labeled for "Hammond". Try and look at the codes for those made in Holland at the Herleen plant. A really clear sounding tube. If you're like me you'll like them so much that you'll pick up a spare quad. They blow away the newer tubes made in Russia.
Glad you're enjoying the amp!
Rich
Hi Rich ---- I am also working on a Standalone Version of the Fisher 481A and have a few questions about what you did as shown in your 481A Pictures on Page 2 or 3 of this thread.
In your picture showing the Speaker Binding Posts and the "rewired 6-pin Molex" for the speakers:
a) How did you physically mount the Binding Posts on the top and bottom of the chassis? From the picture, it looks like you would have had to drill out four of the speaker strip screw holes in order to accommodate the thickness of the binding post and then on the bottom grind off what was left and in the way of the bottom plate of the binding post pair. Is this what you did, or something else?
b) From the picture, it looks like you removed the 6-pin Molex's Audio Signal Yellow and Orange Wires from the Tag Strip, then ran 2 new wires from where Y-O were on the strip back to the 2 Positive Binding Posts. Then what was originally connected to the Ground Positions of the speaker strips was left alone. There were 2 ceramic caps originally on the Tag Strip ..... did you remove them? I can't tell from the after picture??? Let me know!
c) From the picture it looks like you ran a wire from each EL84 pin #2 to a position of the 6-pin Molex so you could monitor each of their Bias Voltages. When I compared your Stock 481A Bottom Picture (with 250 Ohm 20W Resistor in the wrong place) with the After Speaker Terminal Mods it looked like the 4 resistors that were originally connected to Pin #2 changed. Did they? What value? Let me know.
In your picture of the area under the Power Transformer and the AC input Line After Modifications:
a) You cleaned out all but 2 pins of the 12-pin Molex (Ground and the Position with a Yellow wire). Was the Yellow wire and Ground wire left for monitoring and what is being monitored?????? Please let me know.
b) It looks like any component that connected to the missing positions of 12-pin Molex was not needed since the Tuner/Preamp/Phono are no longer present) and was surgically removed. Is this correct? Any other wiring changed or re-directions that I am missing? Please let me know.
c) You added a power switch in the circular hole that originally had wires for the Phono and Pilot Lite Wires and wired the switch back to the 2 AC input recepticals (J18 and J19 ...... I think????).
Please let me know if I am right or wrong..
Thanks Stew
