Amplifier:
Those who have been following my post must be aware that I built my monoblocks in 2020 using KT88 and FAQ7 tubes. They initially had a very moderate bias current of 43.5mA and 5mA for the final and driver tubes. After taking recommendation from my mentor, I changed the driver tube from FAQ7 to 6E6P which is a pentode and used as a triode. After many listening sessions, I changed the bias current for the 6E6p from the recommended 15mA to 19mA which I believe is my sweet spot. For the finals I changed the bias current from 43.5mA to 55mA. I have also replaced the Chinese bypass capacitors with WIMA ones. Also added some bipolar capacitors to the cathode bypass of the driver to give a bypass frequency of around 2.11Hz. The final bypass frequency is around 1.77Hz. Also did a phase alignment for all the transformers heater voltages for the 5vac rectifier tube, 6.3vac for KT88 and 6.3vac for the 6E6P tubes so that all the heaters are in-phase with the main transformer. Also added a bypass switch for the thermistor and fuse (which my mentor used to call - attendant listening switch) which I engage after 10 minutes of amplifier turn on.
Speakers:
Readers might be aware that I used to use a open baffle main speakers along with H-frame subwoofers some years ago. I now since last year have switched to sealed box with the same Russian full-range driver. But this was supplemented by the H-frame subwoofer for the bottom end. Now I have down-graded everything and have retained the sealed and H-frame box. Now the sealed box and H-frame is in series with each other and they are directly connected to the above tube amplifier. The subwoofer is not used anymore. Also I have changed my speaker placement to be little inside the room and near the left and right wall boundary by 1.5 feet. This gives me separation of 7 feet between the left and right speakers which gives me perfect imaging and sound staging.
Wires:
speaker cable is still the same - 12+12+14 awg mill spec silver plated copper wire. For power cables its 12awg mill spec silver plated copper wire. For interconnects some time ago I was using canare coaxial cables. Past one month that is replaced with my time-aligned cables which has copper, silver(pure), manganin and brass as conductors. These are used between my RME DAC to the power amplifier monoblocks. The canare cables are still use to connect my other sources (Tape Deck & Phono Preamplifier) to the RME analogue inputs.
Digital Source:
DAC -
RME - ADI2 AD/DA convertor. This is a commercial product purchased 2 years ago and no modifications to this. I am quite ok with this product.
CDT -
Shangling ET-3 CDT. This is a commercial product purchased 1.5yrs ago and no modifications to this. I am quite ok with this product.
Analogue Source:
Tape Deck -
TEAC R-560. This is a commercial product and i had modified and completely changed the power supply of this deck. Post that i am enjoying daily this source.
Turntable -
Thorens TD145mk2 with Rega 330 tonearm with ATVM95 cartridge. I have changed the tonearm wire last month as it broke. Need to buy a new stylus to check its working.
Phono pre-amp. This is a DIY phono preamp with 2 12ax7 tube and combined with a MOSFET in the input and output stage to reduce impedance. I am quite happy with this one too.
The above setup gives me the maximum potential with good listening experience overall for all the source material with minimum coloration and audio compression.
Thanks for looking.
Those who have been following my post must be aware that I built my monoblocks in 2020 using KT88 and FAQ7 tubes. They initially had a very moderate bias current of 43.5mA and 5mA for the final and driver tubes. After taking recommendation from my mentor, I changed the driver tube from FAQ7 to 6E6P which is a pentode and used as a triode. After many listening sessions, I changed the bias current for the 6E6p from the recommended 15mA to 19mA which I believe is my sweet spot. For the finals I changed the bias current from 43.5mA to 55mA. I have also replaced the Chinese bypass capacitors with WIMA ones. Also added some bipolar capacitors to the cathode bypass of the driver to give a bypass frequency of around 2.11Hz. The final bypass frequency is around 1.77Hz. Also did a phase alignment for all the transformers heater voltages for the 5vac rectifier tube, 6.3vac for KT88 and 6.3vac for the 6E6P tubes so that all the heaters are in-phase with the main transformer. Also added a bypass switch for the thermistor and fuse (which my mentor used to call - attendant listening switch) which I engage after 10 minutes of amplifier turn on.
Speakers:
Readers might be aware that I used to use a open baffle main speakers along with H-frame subwoofers some years ago. I now since last year have switched to sealed box with the same Russian full-range driver. But this was supplemented by the H-frame subwoofer for the bottom end. Now I have down-graded everything and have retained the sealed and H-frame box. Now the sealed box and H-frame is in series with each other and they are directly connected to the above tube amplifier. The subwoofer is not used anymore. Also I have changed my speaker placement to be little inside the room and near the left and right wall boundary by 1.5 feet. This gives me separation of 7 feet between the left and right speakers which gives me perfect imaging and sound staging.
Wires:
speaker cable is still the same - 12+12+14 awg mill spec silver plated copper wire. For power cables its 12awg mill spec silver plated copper wire. For interconnects some time ago I was using canare coaxial cables. Past one month that is replaced with my time-aligned cables which has copper, silver(pure), manganin and brass as conductors. These are used between my RME DAC to the power amplifier monoblocks. The canare cables are still use to connect my other sources (Tape Deck & Phono Preamplifier) to the RME analogue inputs.
Digital Source:
DAC -
RME - ADI2 AD/DA convertor. This is a commercial product purchased 2 years ago and no modifications to this. I am quite ok with this product.
CDT -
Shangling ET-3 CDT. This is a commercial product purchased 1.5yrs ago and no modifications to this. I am quite ok with this product.
Analogue Source:
Tape Deck -
TEAC R-560. This is a commercial product and i had modified and completely changed the power supply of this deck. Post that i am enjoying daily this source.
Turntable -
Thorens TD145mk2 with Rega 330 tonearm with ATVM95 cartridge. I have changed the tonearm wire last month as it broke. Need to buy a new stylus to check its working.
Phono pre-amp. This is a DIY phono preamp with 2 12ax7 tube and combined with a MOSFET in the input and output stage to reduce impedance. I am quite happy with this one too.
The above setup gives me the maximum potential with good listening experience overall for all the source material with minimum coloration and audio compression.
Thanks for looking.
