Rotel RCD 965BX - upgrades?

[Brit01]

Has anyone made upgrades/mods to this model of Rotel CDP?

How can improvements be made to this one?

I'm usually in the valve posts, this is new world to me.

[Mooly]

Not familiar with this player, however subtle (but to a music lover huge) gains might be possible by looking to swap the op amps in the analogue output stages.

So what's in there ? are they NE5534's or NE5532's

[awpagan]

It has been moded

diyAudio - Search Results

[jameshillj]

I think the 965Bx is built like the other 855, 865, 955, etc machines but with an extra pcb holding the clock and O/P stage, and possibly the 7310 chip instead of the old 7210 - if so, the same basic upgrades apply - I'm doing a 955Ax now with recaps, bipasses, transport damping, NOS, clock, shunt reg p/supplies and D1 o/p stage - transformers in external box - next stage involves reclocking of I2S, DEM, etc as per EC Design techniques and possibly an optional valve buffered volume control - I do expect good results.

This player uses the standard Phillips

[Mooly]

Originally Posted by awpagan

It has been moded

diyAudio - Search Results

Don't understand
The link doesn't go anywhere either.

[Bill Fuss]

The 965BX uses a CDM4 and a bitstream dac chip. I had the LE Discrete model for a couple years. It's great used as a transport, lackluster performance compared to what's out there today, IMHO. I put a Tent Clock in it and it made it edgier,took it out.

[jameshillj]

Yeah Bill, the full series of upgrades is worth while but it's quite a bit of effort - interesting project.

Brit, there are a cuple of old threads about this player here and a lot of the digital upgrades of the giant Marantz 63 thread apply to this player, too (TeddyRegs power supplies, etc) and the long running "Ultimate 1541A Nos dac ..." thread has a good collection of mods, data and other explanations about the inner workings of the 1541A dac chip.

[amc184]

I think the 965Bx is built like the other 855, 865, 955, etc machines but with an extra pcb holding the clock and O/P stage

No, the 965BX uses a single board (as does the 865BX). Unfortunately, unlike the 865 and 965AX, you can't convert this player back from bitstream SAA7323GP to multibit TDA1541A.

There are three modifications that I would consider doing:

- Upgrade the single opamp in each channel of the output stage (U114 and U115). Candidates could be the OPA604, OPA134, LME49710 and many others. It's probably best to install a DIP socket and get a variety to try, as this often comes down to personal taste.
- Remove the SAA7220 if you're not using the digital output. The SAA7220 in this CDP is used for generating a SPDIF signal only, and this IC is very power hungry. It will propagate noise into its power supply, and this noise will contaminate parts of the power supply for the rest of the player.
- Install a low jitter clock. Every CD player will benefit from a good low jitter clock.

Overall though, I don't think this is a very promising player. It uses a good transport, but it is hobbled by the poor quality first generation bitstream DAC it uses. I think the best use of this player would be to install a completely new filter, DAC and output stage.

[Brit01]

Thxs for the advice guys.

There are three modifications that I would consider doing:

- Upgrade the single opamp in each channel of the output stage (U114 and U115). Candidates could be the OPA604, OPA134, LME49710 and many others. It's probably best to install a DIP socket and get a variety to try, as this often comes down to personal taste.
- Remove the SAA7220 if you're not using the digital output. The SAA7220 in this CDP is used for generating a SPDIF signal only, and this IC is very power hungry. It will propagate noise into its power supply, and this noise will contaminate parts of the power supply for the rest of the player.
- Install a low jitter clock. Every CD player will benefit from a good low jitter clock.

I'll do some research into this. No I'm not using the dig output.