Phenix G3/Chinese Earmax
This version utilizes three 6N11 tubes and appears to be identical to the Phenix model. The construction quality is notably high. The separate power supply, while somewhat bulky, functions effectively and contributes to a compact design for the main unit. The power switch is located on the power supply, which is not particularly convenient as it cannot be easily hidden under a desk; however, this placement is beneficial for sound quality. An alternative setup would require routing additional high voltage AC wires through the DC power cord. The first modification made was to replace the power cord with a Euro-plug. The power supply is filled with hot melt adhesive and double-sided foam tape to prevent resonance. The goal was to find a genuine tube amplifier compatible with a modified Muse NOS 4xTDA DAC to evaluate sound differences and improvements. The search focused on affordable options that utilized current tubes (avoiding models like the Little Dot) and were cost-effective for replacements. A recent discovery of Philips Miniwatt tubes, including several ECC8* variants, prompted further exploration. The $50 Indeed/Muse hybrid transistor amplifier exhibited significant high-frequency roll-off, limiting its performance. A suitable item was found in a Chinese seller's eBay store, which offered pre-modded equipment. Although the item did not include a photo, it matched the desired specifications. The G3 T7 model with the ECC81 tube was avoided due to its perceived weakness. Discrepancies in advertised components were noted, such as the Wima MKP 10 being replaced by Ero 1860 polycarbonate capacitors, which some users consider acceptable but not preferred. Initially, the power switch exhibited oxidation, resulting in unreliable operation, requiring multiple activations to function correctly. The volume potentiometer produced static due to the modification of the NOS DAC, which eliminated output capacitors, leading to some DC presence at the output. Overall sound quality was described as satisfactory, with good dynamics, bass, and midrange, though lacking the excitement associated with high-end audio. Subsequent modifications were planned, including the use of two Sprague 0.47 µF 200V PIO capacitors. Voltage measurements indicated that the unit briefly exceeded 200V upon startup before stabilizing below 150V, indicating no cold start issues and an acceptable safety margin for the capacitors. A three-wire ribbon connecting the input to the potentiometer was replaced with separate silvered OFC/teflon wire to minimize crosstalk. The original green LED was also removed, and the gold-plated input RCA connectors were noted to be of low quality, with loose fittings and easily damaged gold plating. Shrink wrap was added to protect the wiring against contact with a large electrolytic capacitor. The potentiometer used is an open-type Alps, which is susceptible to aging and clogging, and while a blue velvet potentiometer was desired, it could not be accommodated. Later, two Philips SQ E88CC tubes were installed to assess the effects of the capacitor modifications, leaving the middle Chinese 6N11 tube for future replacement, as it was deemed to have the least impact on sound quality. The signal path is structured as follows: volume potentiometer > middle tube (one side) > coupling capacitor > outer tube (channel 1) > channel 2 > output.
The described circuit is a tube amplifier featuring three 6N11 tubes, which are dual triodes, providing a balanced audio output. The power supply design incorporates a separate unit to manage high voltage requirements while maintaining a compact main amplifier box. The careful selection of components, including capacitors and wiring, is critical to achieving optimal sound quality and minimizing interference. The use of high-quality materials, such as silvered OFC wire, enhances signal integrity, while the choice of capacitors can significantly affect the amplifier's tonal characteristics. The modifications to the power supply and signal path reflect a commitment to improving audio fidelity, addressing issues like crosstalk and resonance. The overall design indicates a thoughtful approach to both functionality and performance, ensuring that the amplifier can deliver a satisfying listening experience while allowing for further enhancements as needed.This is the version with 3 6N11 tubes. And as far as I can see identical to the Phenix. It looks and feels very well made. The separate power supply is a bit bulky but works well and keeps the size of the main box small and cute. The on/off switch is situated on the powersupply. Not very convenient because you can`t tuck it away somewhere under the desk. But is is sensible in respect to sound quality otherwise you would have to loop an extra 2 high voltage AC wires through the DC power cord. First thing I did was put a power cord with a euro-plug on the powersupply. The powersupply is full of hotmelt and double-sided foamtape, so nothing will resonate. I was looking for a real tube amplifier I could hook up to my modded Muse NOS 4xTDA DAC so I could listen to any difference or improvements in sound. I wanted something not too expensive (there goes the majority of HP-amps), using tubes that are current (so no Little Dot), not too expensive replacing and good for audio.
I have come upon a batch of Philips Miniwatt tubes last month that had several ECC8* tubes. The $50 Indeed/Muse is a hybrid transistor that has severe high rolloff so there wasn`t much left out there. Then I stumbled upon this (item had no photo) in the Ebay store of a Chinese seller that has some nice pre-modded stuff.
This turned out to be exactly what I was looking for. I wouldn`t opt for the G3 T7 with the ECC81 in the middle because that`s a bit of a wimpy tube. Even though the inside wasn`t exactly what was advertised (Wima MKP 10 turned out to be Ero 1860 polycarbonate which some find to be very good but I didn`t). The power switch seems to be a bit oxidized in storage because it wasn`t very reliable at first. I needed to flip-flop it a few times to work the first week. Yhe volumepot gives me some static because I modded my NOS DAC so it has no output caps and thus quite some DC on the output.
Actually quite good. A bit muffled and the sense of space could be better. It is dead quiet. Good dynamics, good bass, nice mids and highs. Overall very good but not sensational and grabbing as in real high end. So, on to the soldering iron for some improvements. Well, that`s easy. I am fortunate to have 2 Sprague 0. 47 µF 200V PiO left. I measured the unit while switching on and it went just over 200V for a few seconds and then dropped again considerably (<150V) and rather quickly. So, no problem with a cold start and margin on the caps (safetymargin is related to time and temperature).
I also didn`t like the 3-wire ribbon from input to pot (crosstalk). So I replaces that with some seperate silvered OFC/teflon wire. And the oldstyle green LED had to go. And the input RCA`s are guilded, but one whiff and the gold is gone. They are also very loose because you see the grooves from machining. Later I notices why they used these because on the inside of the case they are very short. Mine were a bit longer so the wire is pressed against the big elco. I put some shrinkwrap around the wire. I don`t especially appreciate the little white plug on the wires but it`s easier to disassemble that way. So I just put it in again. The potmeter is an open type Alps (prone to aging and clogging up). But I can`t fit in a blue velvet. And of course I put in my 2 Philips SQ E88CC a bit later so I could hear the difference of the cap-mod first.
I left the middle Chinese 6N11, to be replaced later. That one has the least influence on sound. The stock tubes are actually very good. The signal path is volumepot>middle tube 1 side> coupling-cap> outer tube channel 1> channel 2> out. Well, this is 🔗 External reference
The described circuit is a tube amplifier featuring three 6N11 tubes, which are dual triodes, providing a balanced audio output. The power supply design incorporates a separate unit to manage high voltage requirements while maintaining a compact main amplifier box. The careful selection of components, including capacitors and wiring, is critical to achieving optimal sound quality and minimizing interference. The use of high-quality materials, such as silvered OFC wire, enhances signal integrity, while the choice of capacitors can significantly affect the amplifier's tonal characteristics. The modifications to the power supply and signal path reflect a commitment to improving audio fidelity, addressing issues like crosstalk and resonance. The overall design indicates a thoughtful approach to both functionality and performance, ensuring that the amplifier can deliver a satisfying listening experience while allowing for further enhancements as needed.This is the version with 3 6N11 tubes. And as far as I can see identical to the Phenix. It looks and feels very well made. The separate power supply is a bit bulky but works well and keeps the size of the main box small and cute. The on/off switch is situated on the powersupply. Not very convenient because you can`t tuck it away somewhere under the desk. But is is sensible in respect to sound quality otherwise you would have to loop an extra 2 high voltage AC wires through the DC power cord. First thing I did was put a power cord with a euro-plug on the powersupply. The powersupply is full of hotmelt and double-sided foamtape, so nothing will resonate. I was looking for a real tube amplifier I could hook up to my modded Muse NOS 4xTDA DAC so I could listen to any difference or improvements in sound. I wanted something not too expensive (there goes the majority of HP-amps), using tubes that are current (so no Little Dot), not too expensive replacing and good for audio.
I have come upon a batch of Philips Miniwatt tubes last month that had several ECC8* tubes. The $50 Indeed/Muse is a hybrid transistor that has severe high rolloff so there wasn`t much left out there. Then I stumbled upon this (item had no photo) in the Ebay store of a Chinese seller that has some nice pre-modded stuff.
This turned out to be exactly what I was looking for. I wouldn`t opt for the G3 T7 with the ECC81 in the middle because that`s a bit of a wimpy tube. Even though the inside wasn`t exactly what was advertised (Wima MKP 10 turned out to be Ero 1860 polycarbonate which some find to be very good but I didn`t). The power switch seems to be a bit oxidized in storage because it wasn`t very reliable at first. I needed to flip-flop it a few times to work the first week. Yhe volumepot gives me some static because I modded my NOS DAC so it has no output caps and thus quite some DC on the output.
Actually quite good. A bit muffled and the sense of space could be better. It is dead quiet. Good dynamics, good bass, nice mids and highs. Overall very good but not sensational and grabbing as in real high end. So, on to the soldering iron for some improvements. Well, that`s easy. I am fortunate to have 2 Sprague 0. 47 µF 200V PiO left. I measured the unit while switching on and it went just over 200V for a few seconds and then dropped again considerably (<150V) and rather quickly. So, no problem with a cold start and margin on the caps (safetymargin is related to time and temperature).
I also didn`t like the 3-wire ribbon from input to pot (crosstalk). So I replaces that with some seperate silvered OFC/teflon wire. And the oldstyle green LED had to go. And the input RCA`s are guilded, but one whiff and the gold is gone. They are also very loose because you see the grooves from machining. Later I notices why they used these because on the inside of the case they are very short. Mine were a bit longer so the wire is pressed against the big elco. I put some shrinkwrap around the wire. I don`t especially appreciate the little white plug on the wires but it`s easier to disassemble that way. So I just put it in again. The potmeter is an open type Alps (prone to aging and clogging up). But I can`t fit in a blue velvet. And of course I put in my 2 Philips SQ E88CC a bit later so I could hear the difference of the cap-mod first.
I left the middle Chinese 6N11, to be replaced later. That one has the least influence on sound. The stock tubes are actually very good. The signal path is volumepot>middle tube 1 side> coupling-cap> outer tube channel 1> channel 2> out. Well, this is 🔗 External reference