No true analog bypass on RSP-1066???

[Martinf]

Prior to committing to a multi-channel pre-amp (RSP-1066), I’ve been studying the specifications and user manuals for both the Rotel RSP-1066 and very new RSP-1098.

1. Some observations from RSP-1098 manual:-

(a) On page 13 in the RSP-1098 manual it has an explicit paragraph: " . . . Normally the RSP-1098 converts analog inputs to digital signals. // . . . // Alternatively, there is an analog bypass surround mode which routes 2-ch analog inputs to the directly to the volume control and pre-amp outputs, bypassing the digital processing entirely for pure analog stereo."
(b) then on page 14, regarding the "MULTI Inputs", it says: These inputs bypass all digital processing in the RSP-1098 and are routed directly to the volume control and pre-amp outputs." (note the qualifier: "in the RSP-1098").
(c) Finally, on the specification page at the back, it says: "Frequency response: 10Hz-120kHz, +-3dB for analog bypass; 10Hz-95kHz, +-3dB for digital input.

2. Now, some contrasting observations from RSP-1066 manual:-
(a) firstly, there’s no explicit mention of "pure analog" at all from the "Multi Inputs".
(b) And most tellingly, on the specification page, under "Frequency response, it says:- "10Hz-95 kHz +- 1dB for line-level; 10Hz-20kHz for digital level".

I note that for the RSP-1098’s digitized inputs the frequency response also only goes out to 95kHz, which is exactly the same upper cut-off limit, surprise, surprise, as the RSP-1066’s "line-level" inputs (whatever that means!).

Perhaps Rotel is hiding something? And why the difference in the language terminology used? Another observation is that in the RSP-1098’s manual, the explicit justification for the "Multi-inputs" is to maintain the purity and frequency response of DVD-Audio and SACD analog input sources. HOWEVER, for the RSP-1066, the justification for the 6.1 "Multi-inputs" is to be future-proofed for "surround formats" — which doesn’t mean very much.

In short, does anyone here REALLY know what is going on inside the RSP-1066, as the lack of a pure analog signal path all the way from the "Multi-inputs" out to the pre-outs would be a big deal-breaker for me. I would obviously really like some affirmative positive assurances in this regard.

Martin.

[Scarp]

First you have to realize that the manuals for 1098 and and 1066 where written at different times. The 1066 is older and the 1098 is very recent. So the difference in mentioning the usage of the multi channel input is very clear, sacd/dvd-audio where not much in the picture at that time.

As mentioned in another topic on the 1066 faq on rotel, they explain that the 1066 will pass the two channels also directly to the output, but it will also digitize the signal to create an LFE channel from it. So what you get is full range for the front speakers (I tested this once and indeed the small/large setting for the front speakers have no effect on the two front channels for an analogue input) and an additional LFE channel depending on the small/large and subwoofer setting.

The bypass mode in the 1098 was added to make sure no digitizing takes place, i.e., the two analogue inputs are send to the volume control directly and nothing is done. Also contour settings (bass/treble) are not used anymore. On the normal stereo I do not know if now also the whole stereo input is digitized as opposed to the 1066, I assume it does now, since we have the bypass mode.

Make sure your 1066 gets the multi channel resistor cut fix (do a search through this forum), then for your multichannel inputs you get the best direct bypass sound. For analogue inputs the analogue inputs are also bypassed (i.e., not digitized), but it can create an additional LFE channel for you.

[Martinf]

Thanks for the informative post.

>> Also contour settings (bass/treble) are not used anymore. <<

Are these done in the analogue domain?
Furthermore, is how is master volume done in analogue when one no longer has a conventional potentiometer knob to turn? i.e. all on most receivers these days it just rotates infinitely in either direction. And also what about the -1066’s the channel-level dB calibration settings for the five Multi-input channels, which are accessed via the remote?

[Glenn]

I tested this once and indeed the small/large setting for the front speakers have no effect on the two front channels for an analogue input

If a DVD player is used to play 2 channel music CD's via a digital coax cable connection to a 1055 or 1066, will the small/large speaker settings then have an affect on the two front channels?

[will1066]

Yes.

[eelco74]

I wonder, if the tone-controls work when using the 5.1 input ? Or are they simply bypassed on the 1066 ?

[hanser]

As far as I remember, they work, but only on the front channels.

[Scarp]

Thanks for the informative post.

>> Also contour settings (bass/treble) are not used anymore. <<

Are these done in the analogue domain?
Furthermore, is how is master volume done in analogue when one no longer has a conventional potentiometer knob to turn? i.e. all on most receivers these days it just rotates infinitely in either direction. And also what about the -1066’s the channel-level dB calibration settings for the five Multi-input channels, which are accessed via the remote?

I dont have a clue how this is done, i just know that on the 1066 they are done on analogue inputs.

Digital inputs always have bassmanagement settings applied to them.

[Martinf]

Scarp, you wrote:- >> I dont have a clue how this is done, i just know that on the 1066 they are done on analogue inputs.<<

Well, I'M PLEASE TO SAY that I now have the answer from Rotel in the UK:-

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Martin,

I can confirm that adjustment of tone and volume is accomplished in the analogue domain (actually at the end of the processing/switching chain) by means of two types of integrated circuit.

Regards,

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PHEW!!