I changed the heatsink for mine too.I replaced the heatsink on the JLS board (on the BD139 transistor). The combination of a 4VDC power supply and a slightly larger heatsink gives a slightly lower temperature. One cooler rib can be shortened by 2-3 mm so that it does not touch the spacer or the nut. Isolator is silicone washer. The original heatsink does not have thermal paste or good contact, which means that we do not know the temperature of the transistor. Now it is safe.
Do it! There was one recent buy that seems to have gone OK but generated some bad feelings. It's not hard to do well, see post #92 here for info: https://www.diyaudio.com/community/...d1865n-j-dac-chips.368012/page-5#post-7119053
I think codyt isNo, and as far as I know nobody has yet......
In this case, DOR and DOL come from six 74HCT164 and are not galvanically separated from the dac i.c as BB did(as well as BCO and WCK), the BB equivalent would be a digital isolator between the six 74HCT164 and the PCM1702 or other dac itself.JLsounds is isolated output..
For example, I have to have I2S and shift registers because I want more digital inputs besides USB. Otherwise, I don't know if there is any card other than JLS that can be connected directly to various DAC chips. Let's say I have WaveIO in another DAC (PCM1794 also with shift registers) and from that card there are only I2S and SPDIF in variants of galvanically isolated and non-isolated outputs.
There are 2 separate use cases here. BB PCM1702 evaluation board which @grunf refers to uses PMD100 as digital filter. BB evaluation board has digital isolators between PMD100 and PCM1702 which IMO is not where they should be placed. Instead PMD100 datasheet recommends that the generated output PCM signals (LE, WCK, DR, DL) should be reclocked which BB evaluation board does not do. The reclocking of JLSounds does not solve the issue if PMD100 is used as the reclocking takes place before PMD100. But without PMD100 the reclocking of JLSounds works better.
Who only wants a USB DAC with JLS board and nothing more, can connect directly without shift registers, like @skrstic did for example. If you want universality, or another USB board, then you put shift registers, it's very simple. If someone changes their mind, it's easy to add six ICs and ceramic capacitors.