Looking at the value of the cathode resistor of the AX7 and the load resistors of the AU7, I would say he used only one of the two triodes of each tube. This makes it easier to tube roll for those so inclined. There are many that would replace the AX7 with a 5751 or 12AX7-LPS, and the AU7 with a BH7 or 5965A or 12AT7WC.
8417 Quicksilver
If memory serves me correctly, there were three versions of the 8417 amp. The original 8417 version used one 12DW7, a dissimilar dual triode (12AX7 single section and a 12AU7 single section). Supplies of the 12DW7 ran out and Sanders switched to the 12AX7 and 12AU7 or 12BH7 as shown in the schematic. The difference between version 2 and 3 was 2 used GE 8417 and 3 used RCA 8417 tubes. Then they ran out and onto the KT88 amp. To your original question, no paralleling of sections, single only.
If memory serves me correctly, there were three versions of the 8417 amp. The original 8417 version used one 12DW7, a dissimilar dual triode (12AX7 single section and a 12AU7 single section). Supplies of the 12DW7 ran out and Sanders switched to the 12AX7 and 12AU7 or 12BH7 as shown in the schematic. The difference between version 2 and 3 was 2 used GE 8417 and 3 used RCA 8417 tubes. Then they ran out and onto the KT88 amp. To your original question, no paralleling of sections, single only.
QS M60 Power Supply
My M60 is blowing the 2a slo-blo fuse. This PS uses a bridge rectifier coupled to 470uf cap. It also appears that a previous owner added another 250uf in parallel. Anyway this goes to a choke marked 244-C-8 which supplies B+ to output EL34s. This choke is showing less than 1 ohm resistance. Does anyone have specs for this choke? The amps have a second choke marked 244-C-6 which is showing 200 ohms and appears to supply the driver stage B+.
thanks
My M60 is blowing the 2a slo-blo fuse. This PS uses a bridge rectifier coupled to 470uf cap. It also appears that a previous owner added another 250uf in parallel. Anyway this goes to a choke marked 244-C-8 which supplies B+ to output EL34s. This choke is showing less than 1 ohm resistance. Does anyone have specs for this choke? The amps have a second choke marked 244-C-6 which is showing 200 ohms and appears to supply the driver stage B+.
thanks
QS M60 Power Supply
My M60 is blowing the 2a slo-blo fuse. This PS uses a bridge rectifier coupled to 470uf cap. It also appears that a previous owner added another 250uf in parallel. Anyway this goes to a choke marked 244-C-8 which supplies B+ to output EL34s. This choke is showing less than 1 ohm resistance. Does anyone have specs for this choke? The amps have a second choke marked 244-C-6 which is showing 200 ohms and appears to supply the driver stage B+.
thanks
My M60 is blowing the 2a slo-blo fuse. This PS uses a bridge rectifier coupled to 470uf cap. It also appears that a previous owner added another 250uf in parallel. Anyway this goes to a choke marked 244-C-8 which supplies B+ to output EL34s. This choke is showing less than 1 ohm resistance. Does anyone have specs for this choke? The amps have a second choke marked 244-C-6 which is showing 200 ohms and appears to supply the driver stage B+.
thanks
Quick Silver M60 Power Supply
After further review, I have made a sketch of the power supply. The 100M+100M cap appears to be a modification using a guitar amp cap. I would like to verify this and confirm the original design of the power supply so I can remove the cap. Thanks
After further review, I have made a sketch of the power supply. The 100M+100M cap appears to be a modification using a guitar amp cap. I would like to verify this and confirm the original design of the power supply so I can remove the cap. Thanks
Attachments
biker₂₉;4552185 said:
Dude… the "...–8" inductor is shorted out (dysfunctional) in the diagram. You could just use a PAIR of bridge rectifiers you know, and build one B+ supply for the final, and another one for the other plates (to decouple them from the final). Bridges are cheap, cheap, cheap, you know, and the simplicity of doing it that way makes cute little errors like this … really improbable.
Or if you're looking for the purity of not having some of the components in parallel, why not just use a pair of series diodes connected to the + terminal of the bridge, to guide power to a pair of B+ caps, one for the finals, one for the others, EACH thru an inductor, etc.? The diodes nominally will drop voltage only 1.5 to 2 volts (i.e. “nothing to worry about”), yet they do a stellar job protecting the cap-draining-audio-pulses on the finals from impacting the other supply chain. And vice versa.
Just saying.
GoatGuy
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QS M60 Power Supply
Goat Guy,
Thanks. I knew the choke was bypassed (shorted). This looked to be a non-oem mod. I am not the original owner and was not sure how the amp was designed.
Anyway per Quicksilver I have removed the bypass around the choke and will give this a try. Meanwhile I will digest the rest of your response. I am a solid state guy and this is my first dive into tubes. The power supply as now, is the same as solid state other than the choke and fairly low capacitance.
Goat Guy,
Thanks. I knew the choke was bypassed (shorted). This looked to be a non-oem mod. I am not the original owner and was not sure how the amp was designed.
Anyway per Quicksilver I have removed the bypass around the choke and will give this a try. Meanwhile I will digest the rest of your response. I am a solid state guy and this is my first dive into tubes. The power supply as now, is the same as solid state other than the choke and fairly low capacitance.
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