amps...
Very nice.
As far as soft start, inrush supressors a-ka thermistors are widely used by Nelson Pass in his designs, so it can't be that bad. Put one CL-60 or similar in primary of each toroid and forget.
There seem to be enough room for a mains DC blocker too. They can be useful if your mains is "dirty". Even best toroids can buzz under load if even small amount of DC is present. Though, at low bias Greg uses in his SKA's it may not be as critical as in hungry A class monsters. Still, planning one from the start saves you redesigning later (who, me, never
)
Very nice.
As far as soft start, inrush supressors a-ka thermistors are widely used by Nelson Pass in his designs, so it can't be that bad. Put one CL-60 or similar in primary of each toroid and forget.
There seem to be enough room for a mains DC blocker too. They can be useful if your mains is "dirty". Even best toroids can buzz under load if even small amount of DC is present. Though, at low bias Greg uses in his SKA's it may not be as critical as in hungry A class monsters. Still, planning one from the start saves you redesigning later (who, me, never
)
imjatse said:As usual, your work looks like junk.
Seriously, very nice! Was there a link further back in the thread to the amp kits / housing?
And they even look to match the speakers!
[edit] 4 channels right? That might be exactly the project I was looking for.
Thanks. As for the bits, they came from these places:
GB300D amp modules and GB300S PSU's are kitsets designed by Greg Ball and available here:
http://www.ska-audio.com/diy/
Chassis is the ATI 639M from ATI Research:
http://www.atiresearch-anodized.com/products.html
m0tion said:
I'm still debating where to put them and will have to experiment with positioning to ensure a hum free amp. Most likely spot will be vertical squeezed down the side of the transformers.
The soft starts are a pair of Hypex types:
http://www.hypex.nl/docs/softstart.pdf
Transformer specs are four 500VA with 240v primary and 45v secondaries.
Re: amps...
Hi
I have a few of the thermistors and they work well but the Hypex soft starts allow the amps to be turned on via a relay meaning I can run a wire using a 2 pin connection between the amps and preamp. The preamp is then able to power up or down all 10 channels channels of amplification spread across three cases when it itself is powered on or off.
Bratislav said:Very nice.
As far as soft start, inrush supressors a-ka thermistors are widely used by Nelson Pass in his designs, so it can't be that bad. Put one CL-60 or similar in primary of each toroid and forget.
There seem to be enough room for a mains DC blocker too. They can be useful if your mains is "dirty". Even best toroids can buzz under load if even small amount of DC is present. Though, at low bias Greg uses in his SKA's it may not be as critical as in hungry A class monsters. Still, planning one from the start saves you redesigning later (who, me, never
Hi
I have a few of the thermistors and they work well but the Hypex soft starts allow the amps to be turned on via a relay meaning I can run a wire using a 2 pin connection between the amps and preamp. The preamp is then able to power up or down all 10 channels channels of amplification spread across three cases when it itself is powered on or off.
Can anyone help me correctly identify where baffle step is occurring please. I'm not sure whether its 800hz or 1.2Khz or maybe something completely different.
This is an unsmoothed plot of a single 5" AT mid running fullrange and with some basic correction:
This is a smoothed(24dB/oct) overlay of raw response, corrected response and corrected with XO in place. Ignore the data below 300hz as it isn't accurate.
Here is a comparison of Audiotechnology's measurement of the 5" driver I use on an IEC baffle vs. my driver mounted in the enclosure.
Thanks
Ant
This is an unsmoothed plot of a single 5" AT mid running fullrange and with some basic correction:
An externally hosted image should be here but it was not working when we last tested it.
This is a smoothed(24dB/oct) overlay of raw response, corrected response and corrected with XO in place. Ignore the data below 300hz as it isn't accurate.
An externally hosted image should be here but it was not working when we last tested it.
Here is a comparison of Audiotechnology's measurement of the 5" driver I use on an IEC baffle vs. my driver mounted in the enclosure.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Thanks
Ant
The baffles have a height and a sand clock expansion and you have a room too. Your plots show needing moderate BSC from 450Hz to my eye, nothing more. You will swamp the dynamics else, me thinks. Plus 4 are going to be at play and then the power response is going to go heavy. I would shape and use from 350Hz to 3500Hz. Vocal decade bliss.
White is with the suggested baffle step and purple is without. Looks better. Thanks for that. Don't pay too much attention below 200hz because its not accurate.
An externally hosted image should be here but it was not working when we last tested it.
richie00boy said:
Yes, that's pretty much it. You can either build your own mic and preamp or buy something cheap like the Behringer ECM8000 and MIC100 which should run to about £70-80. Plug the mic into the pre and the pre into your line in on the PC soundcard. Then its upto you regarding software, my favourite is ARTA and this was used to produce the plots I posted recently.
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