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FREE: Preamp, LM1875 amp, speakers (Newcastle Aus)

Update: All items now gone.... listing closed.

I'm giving away a little system that consists of a preamp, power amp and loudspeakers. I just have too much stuff not being used. These will be detailed in the following 3 posts and can be for all items or individual.

No DC wall wart supply, leads, interconnects or cables are being supplied.

Pick up only is available in the Newcastle area and due to current COVID issues, only to those north of Swansea. If from other locations it's fine if you have a relative or friend in the Hunter Region and northern areas.
 

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Pre amp

The pre amp is based on the Silicon Chip Studio series with Zin=100K and Zout 100R. It has 3 lines in, 1 line out, 1 pre out.

LM4562 x 2 is used with stage 1 having 6dB gain and stage 2 a buffer. Volume is via a 10K Alps RK27 and all installed in a Modushop Galaxy case. The knobs may be changed as I have yet work out which ones to use.

Power supply is via a split rails and virtual ground which needs a 12-24VDC 1A wall wart. 5VDC is supplied on board for the LEDs and relays. The original AC wall wart power supply was replaced due to noise issues. There is still a very small amount of hum (ear 100mm from speaker)
 

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Power amp

Power amp is a LM1875 using eBay mono boards (see thread) but with all genuine components used. Most values are those that was used in ChipAmp.com Brian Bell's version which differs to the eBay mono components.

Power supply uses a Tortech 160VA 18-0-18, 35A BR, 4700uF Nichicon KG caps per rail. This gives ±27VDC rails and DC offset is -1.6mV/-1.8mV.

Installed in a Modushop Galaxy case. Power output is about 25W into 8 ohm. The power supply is a bit high for 4 ohm speakers driven at higher levels but fine at moderate levels.
 

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Speakers

SB19ST-C000-4 + Peerless 830870, Vb=3.5 litres, Fb=84Hz, F3=72Hz, 85dB SPL, 8 ohm nom (6R5 min), 25W PH, 150W x 250H x 172D made from 12mm marine ply. Grilles have been added since the pic was taken.

Crossover 2nd order at 4kHz.

Nothing fancy but an honest little speaker that works well in small to medium rooms when used within it's limitations. Enough bottom to satisfy and designed to be used close to the back wall for room loading.
 

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Thanks for your kind words jean-paul as it is appreciated. I had good guidance on building from Hugh Dean and Anthony Holton many years ago.

The amp probably has a taker.

Ted.... if you want the speakers, I can send them down to you.