Dual Mono with just one transformer?
What do you think of this?
Virtural Dual Mono adaptation
Power board looks like:
Bridge-Rectifier, 3,300uF, PI-Resistor, 10,000uF, 0.1uF
Bridge-Rectifier, 3,300uF, PI-Resistor, 10,000uF, 0.1uF
Output end of power board has 2 of 16A Schottky or Fast Silicon for V+
Output end of power board has 2 of 16A Schottky or Fast Silicon for V-
V+ diodes at output point at amp board. There's 1 for left and 1 for right.
V- diodes at output point at power board. There's 1 for left and 1 for right.
Adding a pair of Cornell LP 2,200uF (high efficiency signal grade) very nearby the left channel amp board, And another pair of Cornell LP 2,200uF very nearby the right channel amp board.
Left speaker return cable is centerpoint of the 2,200uF caps at the left channel amp board.
Right speaker return cable is centerpoint of the 2,200uF caps at the right channel amp board.
Input system is with 4 pole rotary for source selector, insulated RCA jacks, and 4 conductor cable (2 conductors for left input, 2 conductors for right input).
There's Dual Mono, 2 individualized channels, only 1 transformer to buy?
What do you think of this?
Virtural Dual Mono adaptation
Power board looks like:
Bridge-Rectifier, 3,300uF, PI-Resistor, 10,000uF, 0.1uF
Bridge-Rectifier, 3,300uF, PI-Resistor, 10,000uF, 0.1uF
Output end of power board has 2 of 16A Schottky or Fast Silicon for V+
Output end of power board has 2 of 16A Schottky or Fast Silicon for V-
V+ diodes at output point at amp board. There's 1 for left and 1 for right.
V- diodes at output point at power board. There's 1 for left and 1 for right.
Adding a pair of Cornell LP 2,200uF (high efficiency signal grade) very nearby the left channel amp board, And another pair of Cornell LP 2,200uF very nearby the right channel amp board.
Left speaker return cable is centerpoint of the 2,200uF caps at the left channel amp board.
Right speaker return cable is centerpoint of the 2,200uF caps at the right channel amp board.
Input system is with 4 pole rotary for source selector, insulated RCA jacks, and 4 conductor cable (2 conductors for left input, 2 conductors for right input).
There's Dual Mono, 2 individualized channels, only 1 transformer to buy?
What's a Pi resistor?
It refers to the R in a CRC power supply. That is not directly related to virtual dual mono.
Why two schottky after the caps?
Power board has individualized left channel and right channel power outputs for both V+ and V-.
I count a total of 4 diodes added as the output of the power supply board.
diode V+ for left channel
diode V+ for right channel
diode V- for left channel
diode V- for right channel
This is the left, right splitter, diode isolated, that accomplishes the stereo separation of virtual dual mono.
It is less expensive and less complicated than individualized regulators/capmulti per left and right for virtual dual mono.
Why more diodes at amp board?
There's no extra diodes added to the amp board.
Why cornell caps between PSU and amplifier?
Pairs of high efficiency 2,200uF caps added to both amplifier boards. It is to stiffen the rails individually per left and right channels. It is unnecessary to add these caps.
Why speaker return connected to a dirty ground?
This particular virtual dual mono scheme works well with ordinary/orthodox star grounding.
Why dual wiring of the interconnections?
The V+, 0v, V- do "Y" per Left channel amplifier and Right channel amplifier at the output of the earthed power supply board. With the power board's 0v earth grounded, that is the location of central star ground. This implies simple ordinary 3 conductor power interconnect cables for each amplifier board. Individual left channel and right channel cables is because of dual mono.
Why one transformer for a dual mono arrangement?
That is because of transformer costs.
It refers to the R in a CRC power supply. That is not directly related to virtual dual mono.
Why two schottky after the caps?
Power board has individualized left channel and right channel power outputs for both V+ and V-.
I count a total of 4 diodes added as the output of the power supply board.
diode V+ for left channel
diode V+ for right channel
diode V- for left channel
diode V- for right channel
This is the left, right splitter, diode isolated, that accomplishes the stereo separation of virtual dual mono.
It is less expensive and less complicated than individualized regulators/capmulti per left and right for virtual dual mono.
Why more diodes at amp board?
There's no extra diodes added to the amp board.
Why cornell caps between PSU and amplifier?
Pairs of high efficiency 2,200uF caps added to both amplifier boards. It is to stiffen the rails individually per left and right channels. It is unnecessary to add these caps.
Why speaker return connected to a dirty ground?
This particular virtual dual mono scheme works well with ordinary/orthodox star grounding.
Why dual wiring of the interconnections?
The V+, 0v, V- do "Y" per Left channel amplifier and Right channel amplifier at the output of the earthed power supply board. With the power board's 0v earth grounded, that is the location of central star ground. This implies simple ordinary 3 conductor power interconnect cables for each amplifier board. Individual left channel and right channel cables is because of dual mono.
Why one transformer for a dual mono arrangement?
That is because of transformer costs.
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Hi all, anyone is doing Honeybadger. I am newbie and populating the board with sausages.
Is it a need to match transistors? Any recommended sites to buy match transistors?
An externally hosted image should be here but it was not working when we last tested it.
Is it a need to match transistors? Any recommended sites to buy match transistors?
You may just get away with it despite the introduced distortion. For well designed amplifiers that use negative feedback as a control measure you may just get away with it. Also note that these are on opposite sides of the swing
.Looking at the badger schematic, those are very sensitive transistors. It will sound so much better if matched.
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Thanks OnAudio for your advice! Could I know how much is in the acceptable range? Let's say in term of %! Is <10% considered good?
You may just get away with it despite the introduced distortion. For well designed amplifiers that use negative feedback as a control measure you may just get away with it. Also note that these are on opposite sides of the swing
Looking at the badger schematic, those are very sensitive transistors. It will sound so much better if matched.
Thanks OnAudio for your advice! Could I know how much is in the acceptable range? Let's say in term of %! Is <10% considered good?
Thats correct <= 10%
chunek said:
Driver:
OStripper's recommended drivers:
MJE15032/MJE15033, OnSemi
MJE15030/MJE15031, OnSemi
MJE15028/MJE15029, OnSemi
2SC4793/2SA1837, Toshiba
Optional drivers may or may not include:
I do not know if these are suitable
2SC5171/2SA1930, Toshiba
2SC2362/2SA1016, Sanyo
2SC1815/2SA1015, Sanyo
2SC2240/2SA970, Toshiba
2SC2238/2SA968, Toshiba
*HFE measure for higher current editions of TO220 Drivers: The HFE needs to be measured in realistic operating conditions, warmed up, loaded slightly, and on. The digital multimeter's test port might not be quite enough workout and the operating temperature at room temp, might not be realistic. See the respective datasheet HFE graphs for more information on what divergence, if any, that you could expect at room temp.
**Recently, smaller OnSemi devices may or may not be China fab at a different plant, in which case the HFE of that part may be a LOT lower. As troublesome as that is, the problem gets worse when sourced from two different fab plants, pairing a good device with a plonker. If the datasheet does not indicate the HFE should be strongly divergent at room temp, then the remaining solution is to purchase from a different vendor.
Output:
NJW0281/NJW0302, OnSemi
NJL0281/NJL0302, OnSemi
MJW0281/MJW0302, OnSemi
MJL0281/MJL0302, OnSemi
NJW3281/NJW1302, OnSemi
NJL3281/NJL1302, OnSemi
MJW3281/MJW1302, OnSemi
MJL3281/MJL1302, OnSemi
2SC3281/2SA1302, Mospec
NJW0281/NJW1302, OnSemi
NJL0281/NJL1302, OnSemi
MJW0281/MJW1302, OnSemi
MJL0281/MJL1302, OnSemi
NJW21194/NJW21193, OnSemi
MJL21194/MJL21193, OnSemi
MJW21194/MJW21193, OnSemi
MJ21194/MJ21193, OnSemi
NJL4281/NJL4302, OnSemi
MJL4281/MJL4302, OnSemi
2SC5200/2SA1943, Toshiba
FJL4315/FJL4215, Fairchild
FJP5200/FJP1943, Fairchild
KSC5200/KSA1943, Fairchild
*Lower HFE outputs need to be triple paralleled for HB; however, high current high dissipation high HFE outputs may work in double-parallel config that may or may not be easier to match. See the respective datasheets for more relevant information.
Amp sound tuning
Hi Everyone,
I was wondering whether anyone tuned this amp ?
Can you share the experience and procedure with me please ?
Just got the PBC, collecting the parts and currently soldering everything together.
However, the capacitor selection started with WIMA cap ?
My understanding of Amp building is started the most natural sound without any high end cap. This will give the most smooth response to begin with.
If you start with high end cap, a unique sound signature already build in and will be hard to find other cap to cancel this effect plus adding the new sound signature as you desired.
Thanks
Lou
Hi Everyone,
I was wondering whether anyone tuned this amp ?
Can you share the experience and procedure with me please ?
Just got the PBC, collecting the parts and currently soldering everything together.
However, the capacitor selection started with WIMA cap ?
My understanding of Amp building is started the most natural sound without any high end cap. This will give the most smooth response to begin with.
If you start with high end cap, a unique sound signature already build in and will be hard to find other cap to cancel this effect plus adding the new sound signature as you desired.
Thanks
Lou