It would seem that you posted the problem here also. With your kind permission, I will repost my excerpts of my responses that others may benefit on similar concerns.
A. Most current receivers no longer include a PHONO input. Perhaps what
could be done is to purchase a phono to line level pre-amplifier to go
along in your purchase for a new receiver.
I was made to understand that the Pioneer SX-1600 is prone to speaker output problems which could either be:
1. the speaker relay (protection); and/or
2. the amp, STK4191II Stereo Module.
should be relatively easy to work on and perhaps you can try the
services of a locally available qualified electronic technician since
the repairs would not be too specialized. The service manual
may be of help (or at least a schematic , they may be downloaded from here
B. To recap what you need is a receiver that can accommodate:
4 - Pioneer S-DF1-K (15-100W, 8 ohms)
1 - Pioneer PD-F407 25 Disc CD Player
1 - Pioneer CT-300 dual tape deck
1 - Kenwood KD-491F turntable
C. Possible choices are (keeping in mind that the power output should be less if not equal to 100 watts and a turntable/phono input):
i. Onkyo TX-8522
ii. Yamaha RX-397
100 Watt Natural Sound AM/FM Stereo Receiver;
iii. Sony STR DE695
iv. Teac AG-790
200 Watt Stereo Receiver;
v. Denon AVR 888
- AV receiver - 7.1 channel.
Some of the above also includes feature(s) to hook up to your video system. Some may even require a fifth speaker (subwoofer).
Incidentally, you can also choose another brand/model even without a turntable/phono input. As initially posted, a turntable/phone to line level pre-amplifier is only required. Here are some examples:
Turntable Preamp - Nano Series;
b. Pyle® Pro PP999
c. Pro-Ject Phono Box
d. Radial J33 RIAA
Turntable Preamp Direct Box
Good luck with your project.