cleaning my 3 year old Apex H900 still in good condition
Hi mr.remle 114 nice amp ,this is transister step driver pls share your pcb
greetings sir mile,
i already built this amp 1year ago with vrail +-65v, 125v respectively having 10 output transistors and tef. the vas supply is 135vdc separated from vrail with a current set at 15mA(1.5v across 100ohm) using MJE340/350. the step drive was using tlo72.
now if i push this far behind this rail, will it stand at vrail=160v?
what will be the vas transistors recommended with higher vce ratings for SOA?
i have this lately a transformer with dc output of (+-)50v,100v,150v and i'm planning to upgrade the amp having 2 step driver.
i'll share those amp picture tomorrow.
i already built this amp 1year ago with vrail +-65v, 125v respectively having 10 output transistors and tef. the vas supply is 135vdc separated from vrail with a current set at 15mA(1.5v across 100ohm) using MJE340/350. the step drive was using tlo72.
now if i push this far behind this rail, will it stand at vrail=160v?
what will be the vas transistors recommended with higher vce ratings for SOA?
i have this lately a transformer with dc output of (+-)50v,100v,150v and i'm planning to upgrade the amp having 2 step driver.
i'll share those amp picture tomorrow.
it rates 1800Wrms @8ohms, so the current would be Irms=15A or Ipeak=21A
but since it is 4ohm load, that gives twice the value stated above.
i'm using tef to avoid loading on vas. one driver gives off a gain of 34, while the other two near output transistor and vas i don't kniw how much gain gives off
using the Power into a resistor load gives the amplifier resistor loaded current.
Your speaker is not a resistor (except for a very few special types).
You need an estimate of the speaker transient demand.
Only AFTER you have that, can one decide what the amplifiers current capabilities need to be.
Your speaker is not a resistor (except for a very few special types).
You need an estimate of the speaker transient demand.
Only AFTER you have that, can one decide what the amplifiers current capabilities need to be.
okay since speakers are inductive load,considering the highest current almost twice as ohms law stated, then how much max current on vas to be considered that could sustain a 4ohm load?
the amp is not intended to use for that specific speaker, as long as it can handle a 4ohm load.
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Let's start with your 2times and 1800W into 8ohms assumptions.
1800W into 8r0 might become 3200W into 4r0.
that would be equivalent to 40Apk into a 4r0 dummy resistor load.
Taking your 2times factor, the amplifier would need to meet an 80Apk demand into the 4ohms speaker.
An 8pair output stage would have ~10Apk through each device to meet that 80Apk demand.
What does the datasheet for your chosen output devices suggest as typical hFE @ 10Apk and what is the guaranteed minimum hFE for 10Apk?
Decide where you think a group of 8devices would be as an average worst case for sharing that 80Apk. Remember to check both the PNP and the NPN halves, they might be different.
Now you can estimate the driver current to meet the 3200W into 4ohms reactive load.
The next step is to look at the datasheet for the driver device and see typical and minimum hFE for the driver peak Ie.
This lets you estimate the driver base current.
Now you can look at how the VAS can meet that demand.
See how many calculation/estimation/reading the datasheet steps between
Either YOU do the work, or you ask someone to dedicate their life to designing other Members custom installations. Apex can't do that for our 80000 Members.
Why expect any other Member to do that?
Either accept the APEX design as given, or learn to do it yourself.
1800W into 8r0 might become 3200W into 4r0.
that would be equivalent to 40Apk into a 4r0 dummy resistor load.
Taking your 2times factor, the amplifier would need to meet an 80Apk demand into the 4ohms speaker.
An 8pair output stage would have ~10Apk through each device to meet that 80Apk demand.
What does the datasheet for your chosen output devices suggest as typical hFE @ 10Apk and what is the guaranteed minimum hFE for 10Apk?
Decide where you think a group of 8devices would be as an average worst case for sharing that 80Apk. Remember to check both the PNP and the NPN halves, they might be different.
Now you can estimate the driver current to meet the 3200W into 4ohms reactive load.
The next step is to look at the datasheet for the driver device and see typical and minimum hFE for the driver peak Ie.
This lets you estimate the driver base current.
Now you can look at how the VAS can meet that demand.
See how many calculation/estimation/reading the datasheet steps between
and this final estimation of VAS current demand.
Either YOU do the work, or you ask someone to dedicate their life to designing other Members custom installations. Apex can't do that for our 80000 Members.
Why expect any other Member to do that?
Either accept the APEX design as given, or learn to do it yourself.
B600 without volume control
Hello Mr. Mile.. I'd like to ask if its ok to cut-off the volume control based on the original schematic? I remove it because I wanna use input buffer. Hoping you can give an advice because I wanna build this amp in HB TEF version.
Many thanks
Hello Mr. Mile.. I'd like to ask if its ok to cut-off the volume control based on the original schematic? I remove it because I wanna use input buffer. Hoping you can give an advice because I wanna build this amp in HB TEF version.
Many thanks
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nice project sir andrew...Hello
greetings feeling bored tested YAMAHA hd drive supports 180 0 180 dc +/-
with apex audio IR2117 step MV 75 VOLTS HV 150 VOLTS dc +/-
MUR 5060 used with 3 pair irf3710 parallel
warm regards
Andrew