Graphene

DAC and what it drives are equally important. But modern DACs are so good that it leaves only one spot that can make big difference and it is ouptput filters and driver. Big part in price of modern external DACs is not the DAC chip itself, but what it drives.

+-6V is output of 7806 and 7906 ICs. The task of these ICs is to stabilize and filter voltage. In JE780 these ICs are not mounted to lower the price of the unit. Also JB980 uses NJM2114D OP amps in DAC output and headphone amp wich are FAR more superior then 4558D OP amps used in JE780. I've never seen JB980 insides before, but judging from the circuit I think JE780 and JB980 actually share the same main board, Sony just removed some of the "optional" parts of the circuit in JE780 to cut the price, but left mounting spots on the board, so it is possible to "turn" JE780 into JB980 (well, at least on the inside).

Few days ago when I disassembled my MDS-JE780 to replace the battery I noticed that +-12v power supply of this deck is very simple. After a little searching I found that power supply of MDS-JB980 uses +-6v regulator ICs in this power line. it turns out that board of JE780 actually have places for regulator ICs, but they are not mounted. JE780 power supply JB980 power supply IC141 is for +6v and IC241 is for -6v So i decided to mount this part of the power supply in my JE780. There is 8 components in total: C141,142,143,241,242,243 and IC141,241. This is how it looked before: And this is how it looks now: I also replaced capacitors after rectifier: It's hard to tell if this upgrade did something in terms of sound and noise level, but it is definitely better than original 470u capacitors.