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-   -   15W kit schematic errors! (http://www.diyaudio.com/forums/chip-amps/120454-15w-kit-schematic-errors.html)

N9VOC 30th March 2008 09:34 PM

15W kit schematic errors!
 
2 Attachment(s)
While blundering through some sources on the internet, I ran across Qkits out of Ontario Canada. They distribute the "Futurekit" line, out of southeast Asia.

I ordered two of the FK607 units, listed as 15 watt amplifier stages. they are based upon the TDA2005 chip, and I am quite pleased with the quality and ease of assembly, it comes with what I would consider an excellent heatsink, and the little circuit boards will become the power stage of a twin 15 watt amplifier I am building.

HOWEVER, the schematic included with the kit is wrong! With this post, I have attached a pdf of the original schematic (redrawn for clarity, with the errors as published.) I will attach a pdf of the corrected schematic on the following post

N9VOC 30th March 2008 09:36 PM

fk607 corrected schematic
 
2 Attachment(s)
I have attached of pdf of the corrected schematic for the FK607 assembly - borne out by tracing the circuit paths on the circuit board.

Future kit claims in this configuraqtion, the voltage gain is 30. In my next post, I will show the pdf that includes the modifications I made to the circuit, which boosted the gain to 40, and improved low end response.

N9VOC 30th March 2008 09:41 PM

FK607 Mods
 
2 Attachment(s)
Attached is a pdf of the FK607 15 watt solid state module that I ended up building, with the modifications I made to the circuit.

Specifically, I ran a wire rather than the 4.7 k "R1" in series with the input, and changed the 1.0 uF C5 input capacitor to 2.2 uF.

The circuit as modified has a voltage gain of 40.

I found the modules at Qkits.com

Just thought I'd throw this out there, I can use these modules and the "stereo" version in a current and some future projects stewing around in the back of my mind! ( I know, 15 watts isn't a LOT of power, but it is enough to suit my needs - and the price was good too!)

:D Cheers!

N9VOC 30th March 2008 09:47 PM

oop!
 
Sorry, folks, looking at the pdf's I see I left the value of one of the zobel network resistors out - they are both 1 ohm :rolleyes:

Tube Radio 24th February 2012 06:24 PM

New to this site and found it as I was looking for a schematic for this kit.

I am using the amp kit in a DIY TRF AM radio using the MK-484 AM chip. I removed the 10K volume control as I am using a 100K panel mounted control. I will try the capacitor mod and see how well it improves the bass.

Tube Radio 24th February 2012 09:28 PM

Didn't realize till I posted that this was an old thread.


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