Hi guys
i just received my new amplifier last week
Sharing some thoughts and pics about the same since its a made in india product that makes me proud to own
designer and builder is an ex forum member "cranky" - in Kolkatta
Below is the power amp that arrived last week
heres the primary bank before the 1st floor was installed
heres the booster bank with the gain stages and soft starts and relays
maybe a part of the amp boards showing the caddocks that require heatsinking as well and an ingenious "heat pipe" along the spreader for even heat distribution between all sinks
Some pics show the primary capacitor bank that are cornel dublier ( black ones ) laid out on the floor of the amp,other pics show the 1st floor with the Booster cap Bank ( orange ones )
Initial listening tests have me over the moon.In pure mode I have probably not owned a more resolving and tonally correct amplifier. The amp was designed to match my relatively low sensitivity ATC stand mounts and the designer has done his job well with the amp disciplining the speaker nicely almost with a whip in one hand .Simply put it is probably the best amplifier I have had in my setup yet .I am happy
All PCBs including the amp boards , gain stages etc were custom ordered from a chinese vendor except for the booster cap bank which was made here, components have been imported from farnell including all CADDOCK resistors.
The chasis, transformer and primary capacitor bank were reused from my last build- however the rest is all new including the amp design,gain stage boards soft start speaker protection relays etc
Following are the specs and the one performance shot taken. Noise level is below -110dB, only 2nd and 3rd harmonic rest under noise floor. This is at 4W output (-18dBfs). 1W performance is significantly better,
But usually testing is done at 4W as its the maximum the designer has had to use with almost all speakers he has access to.
Note the total absence of higher order harmonics and the noise floor below -110dB. The calculated THD would be about 0.003% at this output level, and would remain below 0.1% to maximum output
The specs are
55w/8ohm, 110w/4 and 220/2 @ Pure Class A operation (8ohms)
Current limited at 60 amperes for the output and without limiters at 120A
Output protected against DC and overload.
Total amplifier gain 30dB (21db power amp + 9db gain stage)
Input impedance 47k
Capacitor bank (original+ boosted)= 420,000 uF
Biased at 1.9 amps/channel
Continuous power consumption: 400Watts
Heatsink temp above ambient at this bias level 24 degrees
(in a typical ac room they will run at 50degree C and in a non ac open ventilated room expect close to 60 degree on the sink which is actually lower than what many other class A amp heatsinks run at )
Weight : 68 kgs
Size : 19W and 24D
The power amp also includes a discrete jfet preamplifier circuit to enhance gain for a total of 30dB so that it can be driven from low-output sources like a pro audio soundcard or direct from DAC output - if DAC has volume control. This extra gain stage ckt sound signature has been tweaked for a midrange bump with 2nd and 3rd harmonic distortions to imitate tubes. The ckt has two boards, one for each channel with an independent transformer and power supply bank
THIS Preamp gain stage is also featured with a bypass making it possible to run the power amp in PURE mode if you do not require the GAIN or prefer the tone without the gain stage)
This pre gain stage was purely my idea since I wanted to be sure that a low output source could directly drive the power amp and may or may not actually be how the designer would normally prefer
its a pity i am constrained by my room/bathroom
i am sure this amp would be lovely in a large room
The amp has been heard by some FMs in kolkatta
im sure they have their own opinions as well
pratim and Asit da has also heard and appreciated an amp i think from the house of the same designer
i just received my new amplifier last week
Sharing some thoughts and pics about the same since its a made in india product that makes me proud to own
designer and builder is an ex forum member "cranky" - in Kolkatta
Below is the power amp that arrived last week
heres the primary bank before the 1st floor was installed
heres the booster bank with the gain stages and soft starts and relays
maybe a part of the amp boards showing the caddocks that require heatsinking as well and an ingenious "heat pipe" along the spreader for even heat distribution between all sinks
Some pics show the primary capacitor bank that are cornel dublier ( black ones ) laid out on the floor of the amp,other pics show the 1st floor with the Booster cap Bank ( orange ones )
Initial listening tests have me over the moon.In pure mode I have probably not owned a more resolving and tonally correct amplifier. The amp was designed to match my relatively low sensitivity ATC stand mounts and the designer has done his job well with the amp disciplining the speaker nicely almost with a whip in one hand .Simply put it is probably the best amplifier I have had in my setup yet .I am happy
All PCBs including the amp boards , gain stages etc were custom ordered from a chinese vendor except for the booster cap bank which was made here, components have been imported from farnell including all CADDOCK resistors.
The chasis, transformer and primary capacitor bank were reused from my last build- however the rest is all new including the amp design,gain stage boards soft start speaker protection relays etc
Following are the specs and the one performance shot taken. Noise level is below -110dB, only 2nd and 3rd harmonic rest under noise floor. This is at 4W output (-18dBfs). 1W performance is significantly better,
But usually testing is done at 4W as its the maximum the designer has had to use with almost all speakers he has access to.
Note the total absence of higher order harmonics and the noise floor below -110dB. The calculated THD would be about 0.003% at this output level, and would remain below 0.1% to maximum output
The specs are
55w/8ohm, 110w/4 and 220/2 @ Pure Class A operation (8ohms)
Current limited at 60 amperes for the output and without limiters at 120A
Output protected against DC and overload.
Total amplifier gain 30dB (21db power amp + 9db gain stage)
Input impedance 47k
Capacitor bank (original+ boosted)= 420,000 uF
Biased at 1.9 amps/channel
Continuous power consumption: 400Watts
Heatsink temp above ambient at this bias level 24 degrees
(in a typical ac room they will run at 50degree C and in a non ac open ventilated room expect close to 60 degree on the sink which is actually lower than what many other class A amp heatsinks run at )
Weight : 68 kgs
Size : 19W and 24D
The power amp also includes a discrete jfet preamplifier circuit to enhance gain for a total of 30dB so that it can be driven from low-output sources like a pro audio soundcard or direct from DAC output - if DAC has volume control. This extra gain stage ckt sound signature has been tweaked for a midrange bump with 2nd and 3rd harmonic distortions to imitate tubes. The ckt has two boards, one for each channel with an independent transformer and power supply bank
THIS Preamp gain stage is also featured with a bypass making it possible to run the power amp in PURE mode if you do not require the GAIN or prefer the tone without the gain stage)
This pre gain stage was purely my idea since I wanted to be sure that a low output source could directly drive the power amp and may or may not actually be how the designer would normally prefer
its a pity i am constrained by my room/bathroom
i am sure this amp would be lovely in a large room
The amp has been heard by some FMs in kolkatta
im sure they have their own opinions as well
pratim and Asit da has also heard and appreciated an amp i think from the house of the same designer
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