Phono Preamp
Phono preamp
This phono preamp was built many years ago - some of the caps are date-coded '93 and '96 I found out when I took the pictures...

I have recommended the circuit to others before, so I thought I should write a bit about it here. The circuit it not mine. It was designed by Bob Danielak - his project page is here.

The circuit is quite simple - the schematic can be seen further down the page. The input stage is a paralleled 12SL7 (to lower the noise). The second stage is half a 6SN7, and the third and last stage is the other half of the 6SN7, which is used as a cathode follower. The RIAA eq. is passive and split in two parts placed between stage 1 and 2 and stage 2 and 3.

My power supply is quite simple. A 78S12 for the heaters, and two transistors + zeners for the B+.

The preamp sounds great and it's very quiet. The only potential problem is that the gain is a bit low.

Parts list
Bottom view
Bottom view

Close-up of one channel

Click for larger views

Comments? Questions? Just send me an e-mail!