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Chip Amps Amplifiers based on integrated circuits

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Old 23rd August 2011, 05:44 AM   #21
crazifunguy is offline crazifunguy  United States
diyAudio Member
Join Date: Aug 2008
The main document never does specify what the exact use is. Since I most likley won't have the volume past 50% 2.2uF would give me around 100ms for the input. 22uf as said also gives me aorund 100ms at the output...

With active filtering can the passive filters be eliminated? Thanks for the education on how this better works. All caps are going to be poly film and resistors metal oxide 1%

In my version I removed the Q/Boost and the 4th order. I have 2 saleen key butterworth's. 40HZ High Pass and Variable Low Pass being fed into the phase adjustment. Any other recomended tips or tweaks? I am going to have a PCB made so I want to make sure I iron out all the "bugs".

This pre-amp is going to be installed into a Klipsch dual 6" sub using the stock class G? amplifier. The input is going to be from the LFE output on my Yamaha 6.1 RX. The sub has very good sound from about 35-180HZ. Insted of trash I decided to DIY it into a small HT sub and learn a few things on the way.

The 5 3ohm stable 160W A/B amp boards inside also make for a nice 5.1 AMP but thats the next project.
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Old 27th August 2011, 10:57 AM   #22
crazifunguy is offline crazifunguy  United States
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Join Date: Aug 2008
Almost done with the pcb it should be completed tonight.
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Old 28th August 2011, 05:21 AM   #23
crazifunguy is offline crazifunguy  United States
diyAudio Member
Join Date: Aug 2008
Here is what I have for the PCB
Click the image to open in full size.
The left side is the mains input. The center is the voltage regs for the amps and preamp. The right side is the audio filter.

Please have a look and comment. All connections are matched to the origional design to make it plug and play friendly. It is very similar to the origional PCB with the only differences being the fuse is going to be external and the filter is for the subwoofer only. The power plug was hard wired. I opted to use a switched and fused 3-prong socket to make it more like a standard sub.

I am still unsure that I am using the best filter design so please comment on that also. AndrewT pointed out some design issues that I have worked on but if there is a better proved design I can easily update the schematic and board.

The input voltage is +-33V from the SMPS. The regulated volatges are +-15V and + 20V
The amp voltage is variable 0-60V and controlled by the BASH circiut using amp level feedback.
The amp is a linear full bridge I believe in class A/B with an opamp feedback to the power supply which runs in class D or G?

Thanks for all the help. This has been a very fun project so far.

Last edited by crazifunguy; 28th August 2011 at 05:31 AM.
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Old 7th December 2012, 08:57 PM   #24
thejerrod is offline thejerrod  Canada
diyAudio Member
Join Date: Dec 2012
Location: Edmonton
Its been over a year since the last post - that being said I realise I might not get a reply: did you end up building your schematic? And did it work? The reason I ask is that i'd like to do the same as you, crazifunguy, and ditch the klipsch 4.1 control pod.

Last edited by thejerrod; 7th December 2012 at 09:14 PM.
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