hi jay,
how to identify if ur amp is class H?. just looking of the power brigde diode. if the there has 2 pcs. of brigde per channel, ur amp is class H two tiers supply, if it has 3 pcs. of power bridge diode per channel ur amp is class H also, at 3 tiers supply. it it is only one bridge diode per channel ur amp is class AB or B. now u said that the rated of power filter of the capacitor is only 63 volts, I think it is connected in series to come out a 126 volts per rail. if the power filter cap has 10000microfarad it will come out to 3333microfarad in series connection. just pararelling it by 3 it will go back to 9999microfarad per rail.
rlg
how to identify if ur amp is class H?. just looking of the power brigde diode. if the there has 2 pcs. of brigde per channel, ur amp is class H two tiers supply, if it has 3 pcs. of power bridge diode per channel ur amp is class H also, at 3 tiers supply. it it is only one bridge diode per channel ur amp is class AB or B. now u said that the rated of power filter of the capacitor is only 63 volts, I think it is connected in series to come out a 126 volts per rail. if the power filter cap has 10000microfarad it will come out to 3333microfarad in series connection. just pararelling it by 3 it will go back to 9999microfarad per rail.
rlg
Hi jay,
I think it look like a class AB. connected in 3 series capacitor and that 3 capacitor connected in series will also connected in parallel to produce 12 caps of power supply and that 12 cap combination in series and parallel will come out of 9999mf to round it that that is 10000mf per rail.
rlg
I think it look like a class AB. connected in 3 series capacitor and that 3 capacitor connected in series will also connected in parallel to produce 12 caps of power supply and that 12 cap combination in series and parallel will come out of 9999mf to round it that that is 10000mf per rail.
rlg
Hi Jay,
This is my recommendation in ur amp to run in long term operation.
@ 8 ohms only 1 pc. of 600 watts nominal power, 1000 watts maximum power.
@ 4 ohms only 2 pcs of 400 watts nominal power , 800 watts maximum power.(800 watts nominal power connected in parallel).
@ 2 ohms only 4 pcs. of 300 watts nominal power, 600 watts maximum power.(1200 watts nominal power connected in parallel).
all of that is for single channel only.
ps. Some of power amp will run 2 ohms load at short term only. if u used that in mobile disco. I think that is not recomended. unless if ur amp is class H # tiers supply.
rlg
This is my recommendation in ur amp to run in long term operation.
@ 8 ohms only 1 pc. of 600 watts nominal power, 1000 watts maximum power.
@ 4 ohms only 2 pcs of 400 watts nominal power , 800 watts maximum power.(800 watts nominal power connected in parallel).
@ 2 ohms only 4 pcs. of 300 watts nominal power, 600 watts maximum power.(1200 watts nominal power connected in parallel).
all of that is for single channel only.
ps. Some of power amp will run 2 ohms load at short term only. if u used that in mobile disco. I think that is not recomended. unless if ur amp is class H # tiers supply.
rlg
hi clem_o,
ok thanks clem_o for the support....
I was not contented with the Alpha 1200, i returned it a while ago to the store where i bought it. I replaced it with the Alpha 2000., 3U amp with bigger fans. from the manual it's class H amp.
then again I opened it, voiding the warranty, its ok i will just pay the repairs in case there will be problems.
when i opened it, there were 20 output transistors per channel. i noticed that there are still available space for power transistors 8 tranies in all per channel. so if I am going to add power transistors, it will be 28 tranies per channel.
I also noticed that the PCB board of the capacitors has available space with holes already for 4 capacitors. the capacitors is rated 100V 10,000 mf.
hmmmn, maybe the space availbale are for higher power one. maybe for the ALPHA 3000
so in case there will be modifiactions made, lets say add 8 transisitors per channel, then add the missing 4 capacitors.
Does the toroidal transformer voltage( secondary) need to be change also?
ok thanks clem_o for the support....
I was not contented with the Alpha 1200, i returned it a while ago to the store where i bought it. I replaced it with the Alpha 2000., 3U amp with bigger fans. from the manual it's class H amp.
then again I opened it, voiding the warranty, its ok i will just pay the repairs in case there will be problems.
when i opened it, there were 20 output transistors per channel. i noticed that there are still available space for power transistors 8 tranies in all per channel. so if I am going to add power transistors, it will be 28 tranies per channel.
I also noticed that the PCB board of the capacitors has available space with holes already for 4 capacitors. the capacitors is rated 100V 10,000 mf.
hmmmn, maybe the space availbale are for higher power one. maybe for the ALPHA 3000
so in case there will be modifiactions made, lets say add 8 transisitors per channel, then add the missing 4 capacitors.
Does the toroidal transformer voltage( secondary) need to be change also?
i've read the markings of the boards
in the PCB board for capacitors....
MA 10 or 1000 Watts 8 ohms = 100V, 10,000mf X 8
MA 14 0r 1300 Watts 8 ohms = 100V, 10, 000 mf X 12
same with the board were power transistors is soldered, maybe they are using the same PCB board for their high power one.
the voltage on the MAIN PCB per channel
HV = (+132volts 0 -132volts)
LV = ( +66volts 0 -66 volts
in the PCB board for capacitors....
MA 10 or 1000 Watts 8 ohms = 100V, 10,000mf X 8
MA 14 0r 1300 Watts 8 ohms = 100V, 10, 000 mf X 12
same with the board were power transistors is soldered, maybe they are using the same PCB board for their high power one.
the voltage on the MAIN PCB per channel
HV = (+132volts 0 -132volts)
LV = ( +66volts 0 -66 volts
Suggest you try it out and see if you like a class-H amp first, before even attempting to modify it.
Things you will notice - it should run a fair bit cooler, and it should also be apparent that this new one has more 'reserve' power.
Audio quality - well, listen to it and see if you are satisfied.
If you decide to keep it - well certainly putting in more transistors (if you can find ORIGINAL trannies - be careful!!) and upping the filter capacitance will give you more available short-term power. For continuous high power you may have to change the power transformer..
Cheers
Things you will notice - it should run a fair bit cooler, and it should also be apparent that this new one has more 'reserve' power.
Audio quality - well, listen to it and see if you are satisfied.
If you decide to keep it - well certainly putting in more transistors (if you can find ORIGINAL trannies - be careful!!) and upping the filter capacitance will give you more available short-term power. For continuous high power you may have to change the power transformer..
Cheers
hi clem_o
just wanna know if there are readily available toroidal transformers there in manila intended for high power amplifiers?
or do you know some manufacturer's that can do a high quality toroidal transformers?
About Soundstandard amplifers, ive seen their website, the specs.
they have good quality amps, some has three steps Class H output circuitry..
what does it means, two steps and three steps Class H output circuitry?
ive seen a lot of those amps here in our place, the MA series and the CA series
i like the CA20, can drive 2 ohms but in reality maybe three Loudspeakers(8ohms) wired in parallel.
thank you
just wanna know if there are readily available toroidal transformers there in manila intended for high power amplifiers?
or do you know some manufacturer's that can do a high quality toroidal transformers?
About Soundstandard amplifers, ive seen their website, the specs.
they have good quality amps, some has three steps Class H output circuitry..
what does it means, two steps and three steps Class H output circuitry?
ive seen a lot of those amps here in our place, the MA series and the CA series
i like the CA20, can drive 2 ohms but in reality maybe three Loudspeakers(8ohms) wired in parallel.
thank you
Got it, many thanks...
Toroidals not easy to come by, I think you will have to turn to places like RS to get it. Very expensive though!
Class-H circuitry - the basic idea is to feed an amplifier with "just enough" voltage supply for the power output demanded by the music at that instant. The goal of this approach is twofold: reduce (very significantly) the power dissipation in the output devices (keeping the amplifier cool), and to keep the output devices working in their SOA (safe operating area). The number of 'steps' or tiers are the number of discrete supply voltages the amplifier can "step to" to follow the demands of the music. The more the steps, the higher the potential for keeping the amp cool, and the greater the safety margin for the output devices.
Unfortunately, the dynamic switching of supply voltages often cannot be accomplished 'cleanly', i.e. the commutation diodes used to switch the voltages usually produces undesirable side-effects (sonically).
In Bob Carver's new amplifiers, this issue is sidestepped neatly by using a digitally controlled (tracking) power supply, using pulse-width modulation. The supply voltages vary instantaneously with the music, as long as the signal to be amplified remains 'slower' than the power supply's ability to ramp up its output. Supply voltges are maintained by the system to be just enough above the demand of the music, for proper operation/headroom while minimising dissipation.
Hope this helps!
Cheers
Toroidals not easy to come by, I think you will have to turn to places like RS to get it. Very expensive though!
Class-H circuitry - the basic idea is to feed an amplifier with "just enough" voltage supply for the power output demanded by the music at that instant. The goal of this approach is twofold: reduce (very significantly) the power dissipation in the output devices (keeping the amplifier cool), and to keep the output devices working in their SOA (safe operating area). The number of 'steps' or tiers are the number of discrete supply voltages the amplifier can "step to" to follow the demands of the music. The more the steps, the higher the potential for keeping the amp cool, and the greater the safety margin for the output devices.
Unfortunately, the dynamic switching of supply voltages often cannot be accomplished 'cleanly', i.e. the commutation diodes used to switch the voltages usually produces undesirable side-effects (sonically).
In Bob Carver's new amplifiers, this issue is sidestepped neatly by using a digitally controlled (tracking) power supply, using pulse-width modulation. The supply voltages vary instantaneously with the music, as long as the signal to be amplified remains 'slower' than the power supply's ability to ramp up its output. Supply voltges are maintained by the system to be just enough above the demand of the music, for proper operation/headroom while minimising dissipation.
Hope this helps!
Cheers
hi clem_o,
the input sensititivity for the Alpha 2000 is....
@ 0.775 V
@ 20X
@ 40X
from the above input sensitivity which is ideal for use?
others amps has different input sensitivity
e.g. @ 0.775 V
@1.0 V
@ 1.44 V...( for this type of sensitivity I usually select at 1.0)
does 20X is the same as 1.0V?
and same with 40X =1.44V?
best regards
life is beautiful...
the input sensititivity for the Alpha 2000 is....
@ 0.775 V
@ 20X
@ 40X
from the above input sensitivity which is ideal for use?
others amps has different input sensitivity
e.g. @ 0.775 V
@1.0 V
@ 1.44 V...( for this type of sensitivity I usually select at 1.0)
does 20X is the same as 1.0V?
and same with 40X =1.44V?
best regards
life is beautiful...
Input sensitivity is a function of gain, assuming a power output of 100watts at 8ohms this is something like 28volts.
now at 20x gain you will need an input of 1.4 volts to obtain 100watts at ouput.
now at 40x gain you will need half of 1.4 volts or 700mV.
so here you will see that as gain is increased, lower voltage input is okey.
this is all there is to this.
realize therefore that it is not a question of which is ideal, rather what is practical in your situation, the ouput level of the preceding stage will determine if you are to use 20x or 40x..
Hi jayrjoe,
Yep, Tony's right. I'd go with the lowest gain that still allows your mixer etc to get the amplifier to full output level, in order to increase S/N ratio, specially if there is a long cable run from your low-level electronics leading to the amp.
OTOH, XLR isn't really prone to picking up noise...
Cheers
Yep, Tony's right. I'd go with the lowest gain that still allows your mixer etc to get the amplifier to full output level, in order to increase S/N ratio, specially if there is a long cable run from your low-level electronics leading to the amp.
OTOH, XLR isn't really prone to picking up noise...
Cheers
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