Can someone confirm for me how long the delay is before the relay connects the speakers at turn-on? Is disconnection instantaneous? I need to make sure I can switch on/off all equipment simultaneously.
Also, I’d like some help understanding the difference in power out between V2.0 and V1.1B:
-What supply voltage is necessary to get 2x80W @ 8 ohm from V1.1B?
-I take it the STA508 is current limited at 4 ohm in this application? How will the board handle 8 ohm nominal speakers that dip down to 6-7 ohm?
-Is the reason the V1.1B is recommended for 8ohm loads because it can handle (thermally or otherwise) the higher power supply voltage needed to get more power at 8 ohm? Why not just use V2.0?
Thanks
Also, I’d like some help understanding the difference in power out between V2.0 and V1.1B:
-What supply voltage is necessary to get 2x80W @ 8 ohm from V1.1B?
-I take it the STA508 is current limited at 4 ohm in this application? How will the board handle 8 ohm nominal speakers that dip down to 6-7 ohm?
-Is the reason the V1.1B is recommended for 8ohm loads because it can handle (thermally or otherwise) the higher power supply voltage needed to get more power at 8 ohm? Why not just use V2.0?
Thanks
Turn on is around 1 sec.
Turn off is the same, because of the voltage stored in the PSU caps. I had connected a DAC to the same power source as the amp earlier, and when cutting the power I got the loud noise the DAC makes while powering off.
I think this is general to all amps, you have to turn off the amp before you turn off the source.
The V1.1B board has a power switch on board.
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Direct from cs4397 DAC chip
Today I tried connecting my dac chip directly to the amp. Took signal from pin 19 and 24 and 21(gnd) from cs4397. The sound is outstanding! more detailed, wider soundstage. Is this ok for the amp? I think it should be because of the input caps on the amp. I'm using 2.2uf now. Should I cut the signal from cs4397 going to its regular places inside the dac to get all the juice come to the amp, will that make any difference?
Today I tried connecting my dac chip directly to the amp. Took signal from pin 19 and 24 and 21(gnd) from cs4397. The sound is outstanding! more detailed, wider soundstage. Is this ok for the amp? I think it should be because of the input caps on the amp. I'm using 2.2uf now. Should I cut the signal from cs4397 going to its regular places inside the dac to get all the juice come to the amp, will that make any difference?
not the technician at all but your mentioned disadvantages I could not listen out
with my 10 ampere SMPS. It´s regulated and from a popular japanese brand. They invest millions in research and best engineers. I think voltage and current is more complex than I or the simple DIY people can imagine.Regard this for example ... a battery can provide on demand 100 amperes very fast. Maybe faster than a SMPS but what about the main impedance issue in a audio chain: the speakers ? I can imagine that a simple designed speaker demands a very wide range of current. And should this demand really provided in any time with the equal intense ?
What´s the practical result ? Some SMPS are best solutions valued by listening impressions
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Direct out from dac is amazing!
Isn't running a V out dac chip directly out to the amp amazing! I have been running my AK4395 chips this way for 5 years. You will need a blocking cap on both sides of the pot. One to block the dc on the dac output before it shorts through the pot and the one for the amp board to prevent it's 2.5vdc from shorting through the pot. You might hear another slight improvement from lifting the rest of the original circuits following the dac chip in case there is any slight noise or load in them.
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Isn't running a V out dac chip directly out to the amp amazing! I have been running my AK4395 chips this way for 5 years. You will need a blocking cap on both sides of the pot. One to block the dc on the dac output before it shorts through the pot and the one for the amp board to prevent it's 2.5vdc from shorting through the pot. You might hear another slight improvement from lifting the rest of the original circuits following the dac chip in case there is any slight noise or load in them.
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Hi, 35V supply is needed for 80W from v1.1B, andyou can use down to 6ohm, but we suggest the supply voltage will be down to about 30V then, which will keep the chip away from damage. If use 4ohm, the supply voltage should down to about 20V, with same reason.
I think v2.0 can output same power to 8ohm load as v1.1B does. But if your speakers are 8ohm, we suggest v1.1B, it's better for 8ohm(less heat, better channel balance and so on).
Now i run without a cap before the pot, its works. Will it sound better with a cap there, is that the reason I need one?
dc
Measure to see if there is any dc between the dac output and ground. If there is then you need caps on both sides of the pot.
Hi, 35V supply is needed for 80W from v1.1B, andyou can use down to 6ohm, but we suggest the supply voltage will be down to about 30V then, which will keep the chip away from damage. If use 4ohm, the supply voltage should down to about 20V, with same reason.
I think v2.0 can output same power to 8ohm load as v1.1B does. But if your speakers are 8ohm, we suggest v1.1B, it's better for 8ohm(less heat, better channel balance and so on).
hifimediy, If driving 4ohm speakers with 30v supply would I be exceeding the voltage rating on the v2.0 board? I'd rather not smoke this board with too much voltage. Also, maybe a 1 sheet instruction manual shipped with the various versions showing wiring diagrams and required power supplies would be great for the novice or otherwise. Great board! Thanks
Dan
not the technician at all but your mentioned disadvantages I could not listen out
Regard this for example ... a battery can provide on demand 100 amperes very fast. Maybe faster than a SMPS but what about the main impedance issue in a audio chain: the speakers ? I can imagine that a simple designed speaker demands a very wide range of current. And should this demand really provided in any time with the equal intense ?
What´s the practical result ? Some SMPS are best solutions valued by listening impressions
yes, you're right to say it is not easy to manage voltage current in relation to time.
I think you've heard such an amplifier. 2x200W esoteric with big transformer and large capacity, the feeling is beautiful, the timbre of the instruments is natural.
problem is groped to emulate this with an SMPS. (although professional does not mean that it is designed to have these characteristics).
if you have an oscilloscope, you can make a simple measure.
put CH1 at Vcc, ch2 at output of amp on load. Amplifier drives with burst signal 60Hz or 100Hz 33mS duration and see voltage decrease on oscilloscope.
There is 2.5V on the dac side. Will i damage the dac if running like this?
How big cap do i need?
no damage
shorting the dc probably won't damage the dac especially since it is only loaded by 50k but it might sound better with a cap to block the load. Try another of the same cap you are using for the amp. Any value between 1uf and 3uf usually works well and gives enough extension in the bass.
Hi there SOSx,
his board has the 5V on-board, no need for a separate 5V input.
For the DC offset over a different power range, this should not be effected, as the offset is taken from the on board 5V supply (7805) the trimmer trims that to 2.5V DC on the analog audio in on the TC2000. so if the input voltage changes that 2.5 Volts will not change.
The IC can run well off of 16V, with reduced power, im not sure how the HIFImedly board performs if you give it less than 20 volts.
for Don,
The 2.2uF or 3.3uF will not make a difference at that impedance, but if you make the size smaller than 2.2uF the cap starts acting as a high pass , and it will reduce the bass that comes thru. so if you need less bass, 1uF is just fine, i know from my amps that 2.2uF is also perfect, larger is not needed.
Greetings,
Arjen Helder
his board has the 5V on-board, no need for a separate 5V input.
For the DC offset over a different power range, this should not be effected, as the offset is taken from the on board 5V supply (7805) the trimmer trims that to 2.5V DC on the analog audio in on the TC2000. so if the input voltage changes that 2.5 Volts will not change.
The IC can run well off of 16V, with reduced power, im not sure how the HIFImedly board performs if you give it less than 20 volts.
for Don,
The 2.2uF or 3.3uF will not make a difference at that impedance, but if you make the size smaller than 2.2uF the cap starts acting as a high pass , and it will reduce the bass that comes thru. so if you need less bass, 1uF is just fine, i know from my amps that 2.2uF is also perfect, larger is not needed.
Greetings,
Arjen Helder
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