Hello and welcome to my Gain Clone page, the previous page to this one is the build of my pair of Frugel Horn Mk3's

I made the amplifier using point to point wiring in this case a printed circuit board would just get in the way.



From left to right a 100uf capacitor with an 0.1 uf capacitor bypassing it from pin 1 the +V supply and right hand caps from the -V supply.
The resistor from pins 3 to 9 is the 22K feedback one
The 1k one to the right is the input resistor
Between those two and pointing out of the pic off pin 9 is the 680R feedback loop to ground resistor
And tucked away at the back is a 120K resistor from pins 4 to 8 this together with a 47uf cap off pin 8 to ground disables the mute facility.



This is the power supply a sort of truncated Mick Feuerbacher (lots more GC information on his site as well) one the large caps are 10,000uf and the smaller ones 1,000uf the other caps and resistors as per Micks design. I didn't use a Diode array just a pair of bridge rectifiers with 0.1 uf caps across the DC output.



This is one channel wired up to see if it works just on the baseboard, across the output is a Zobel network, a 10R  resistor and a 0.1uf cap. The green cap you can see on the Blue Tack is the 47uf pin 8 to ground. And the star ground point is between the power supply and the chip boards.



Here is the amp in its box, and yes it's made from wood and no I've never had any RF interference. You can see the pot extensions I made from bits of square wood with a hole drilled in them and some wooden dowels to go through to the volume control knobs.

I'd be the first to admit that it doesn't look that good, but as I listen in a little room I made at the back of the garage the cosmetics are of no consequence whatsoever.

I'd made another GC years ago with just some 1,000uf caps on the chip and fed straight from the rectifiers as per Mr Sakura's Gain Card and I thought it sounded OK. Until I listened at Colins Topps house to his 300b my goodness it made that GC sound just so thin and weedy, it was quite frankly embarrassing.

That was one of the things that made me build this and the fact that the CHP70's are 4 Ohm drive units. The transformer you see here is one I got off eBay, 12 Volt goodness knows how many Amps too many I think :-) It sounds a lot closer to the 300b with a big fat rounded sound and people who've come round to have a listen and make up their minds about a GC + FH3 setup always ask. "Where have you hidden the sub, I can't believe all that is coming from a 4" drive unit".

Well there we are, the other link in the chain is a much modified Philips CD723 I bought for 10 and spent 30 on the mods.