So I needed a break, and I took one. Got some old iron out and built this thing in about a week and a half start to finish. (Of course Matt H helped me, he always does because he's awesome.) The input stage is adapted from an old HIFI schematic, added adjustable LNF, and a CF into a 6BQ5/EL84.
It uses a simple 3 resistor network to sum stereo into mono, and a switch for straight up mono input. Also a treble bleed switch. I have it wired backwards so I can just call it a bright switch.
The transformers all showed their age, so I DA sanded them with 500 and clear coated them. The chassis I hit with 800 and gave it a really quick buff so it all had the same look.
Originally was going for a 12AU7, but the 12AT7 sounded much nicer to my ears, and ended up smack where it should voltage-wise without even modding anything.
PT is from an old defunct Heathkit TV tester thing. It has a ~124v secondary hitting a doubler, giving somewhere around 330VDC after the choke loaded. Choke is from an elder television. For the life of me, I can't remember where I nabbed the little OT from... It's 4.5k at 8 ohm load.
Sounds great, super happy with it! Especially hooked up to a big and or efficient speaker, it really has some booty to it. As well as high end, hence the switch for that. Suppose, I could call it an "old" switch.
