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VTA ST-70 Power Tube Socket Upgrade

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Originally, the amp had poor quality power tube sockets. They were also flushed with the top surface of the chassis, causing the socket mounting screwheads to protrude above the chassis and socket. It could only fit narrow base power tubes. Here are some pictures showing the original flushed-mounted power tube sockets. A wide base power tube would sit directly on top of the mounting screws, and not be completely seated in the socket, as shown in this picture. This causes the amp to pop and short out the 3A fuse. One could carefully and firmly seat the power tube, but it was a crap shoot. It may not work, causing rectifier tube damage. It may work for a while, but eventually a power tube would work its way up / out, causing rectifier tube damage. This causes expense in the form of fuse and rectifier tube replacement - gotta pay to play! I took the amp to my trusted tech, who also worked on my McIntosh amplifiers (authorized). He replaced the power tube socket, and checked every...
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High-Quality RCA Connection Cables on AliExpress

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High-Quality RCA Connection Cables on AliExpress I am under no illusion that these are brand-name cables, but having listened with them personally, I can recommend these as high-quality RCA connection cables in general. The music is better defined compared with my AudioQuest cables. The treble and bass sound clearer with increased dynamic overall and electro-magnetic interference is definitely reduced - making the cables quieter. The WBT-style connectors are well-made and provide a secure connection. The cable jacket are heavy and bulky, but it provide the best EMI shielding. It is the quietest cable of the cables that I have collected over the years. Each conductor consist of one 0.8 mm core plus ten 0.3 mm cores, supposedly made of OCC copper. The purity in unknown. One can find these cables at AliExpress, with a little over two weeks shipping to the US at: https://www.aliexpress.com/store/group/RCA-interconnect-cable/1102221071_40000002345642.html
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MartinLogan Aerius i Bias Voltage Check

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Bias Voltage Check for Legacy MartinLogan Products Warning - High Voltages are present inside of the electronics box. Refer any repairs to a qualified technician. To remove the backboard, remove the speaker and power cables, then remove all the screws on the backboard. If needed, use a wide-tipped automotive trim removal tool and pry gently along the top edge of the backboard. You may have to go across the top edge more than once. It will eventually open from the top. This is the inside view of the backboard. The high-voltage power supply can be measured at the white terminal block. Use a one giga-ohm resistor in series with the red probe of a digital multimeter. Set the meter to measure DC Voltage. On mu Aerius i, I measured 20VDC (2,000VDC actual) on both power supplies (left and right units). Here are the official instructions from MartinLogan.
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