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- LSES Experiment SE 6CB5
- The RH84 experiment ...
- SE 7B4 DC 2A3 Experiments
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- Early LSES Experiment
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- Low DCR Filter Chokes
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SE DC Breadboard Amp: 7c5 6V6 6Aq5 finals 2/2022
Featuring LOW DCR PS Filter
SE DC breadboard amplifier project was started in June 2018.
The amplifier features a LOW DCR "Flywheel" power supply filtering and variable feedback modes: loop, local, combination loop & local and ZERO feedback.
SE DC Breadboard amp signal circuit
Signal Circuit Schematic
The following measurements were taken with a 1KHz sine wave test signal created by the ARTA internal signal generator with amplifier loop feedback activated.
Left Channel
THD = 1.06% @ 1W power output
THD = 1.77% @ 2W power output
THD = 3.67% @ 3W power output
Bandwidth PN sweep : -3dB @ 24Hz , -1dB @ 81KHz (limit of PC FFT)
Right Channel
THD = .92% @ 1W power output
THD = 1.70% @ 2W power output
THD = 2.73% @ 3W power output
Bandwidth PN sweep : -3dB @ 27Hz, -1dB @ 81KHz (limit of PC FFT)
SE DC BreadBoard AMP Cathode Bypass Caps
Finals Cathode Bypass Capacitors : Creating The Cap Bundles
DT 667 has added some new cathode bypass capacitors to the 7C5 final stage in his ongoing SE DC breadboard amplifier project.
The MAIN cathode bypass cap is : Audiophiler MKP 15uF @ 400VDC.
The "bundle" of smaller uF cathode bypass caps are added in parallel to the MAIN cap:
.68uF 400VDC generic Mylar film
.068uF 400VDC Russian K40Y-9
.033uF 400VDC Mylar film
.01uf 600VDC Sprague HYPASS oil
The total uF of the cathode bypass cap "bundle" = 15.79uF
Note : a few of the smaller uF value caps in the "bundle" have had their leadout wires replaced with higher quality mil spec PTFE jacked silver plated copper wires.
DT 667's implementation is on the "value minded" side of the cost equation being this is a breadboard experimental circuit and not going into a permanent chassis.
DT 667 will allow sufficient "break in" time before making any subjective comments on how it sounds on his Altec horn speaker system.
DT 667 3/18/2021
SE DC Breadboard Amp Power supply
LOW DCR Power Supply Filter
The power supply filter is a LOW DCR LCLCRC type featuring Triad and Edcor chokes.
All chokes are 21 ohms DCR (direct current resistance) or lower. HiFi but not Ultra Fi in terms of DCR.
LOW DCR PS Filter :
35mH/2A -> 10uF ->2H/21 ohm ->200uF (final plate + G2) ->3K -200uF (driver plate) .
DT667 6/2018
DC Panel Meters
Power Supply Monitoring
Power Supply Monitoring
Power Supply Monitoring
DT667 has added DC analog panel meters to the SE DC breadboard amp project to monitor the main power supply DC voltage and current.
The meters were attached to a wooden board and secured to the breadboard with wood screws. A crude but effective solution. The meters seem to be fairly accurate.
Note: a CL-80 thermal resistor needed to be installed on the AC primary HOT lead of the ICT (industrial control transformer) aka B+ transformer to control PIV upon startup and protect the panel meters.
DT667 3/19/2023
Shurite Model 850
Power Supply Monitoring
Power Supply Monitoring
Shurite Model 850 8118 is a 0 - 500VDC analog panel meter that monitors the main DC voltage of the power supply.
There is a 50K ohm power resistor that connects from the (-) of the meter to ground.
CHHUA SO-45
Power Supply Monitoring
CHHUA SO-45
CHHUA SO-45 is a 0 - 200maDC analog panel meter that monitors the main DC current of the power supply.