Anyone who owns a Technics SU-R1000, can you answer a quick question


I’ve been getting familiar with the new SU-R1000 for the past couple of weeks and I’m thrilled with it so far. Selling all my other gear, sounds amazing, couldn’t be happier and all that jazz.

But I am wondering if anyone here who owns one can answer a question about the phono preamp noise floor?

Stereophile measurements appear to be impeccable, but I hear a definite noise floor in the phono pre, even when the source is turned off. It is a hiss that is inaudible until the unit is turned up much beyond 40 on the volume knob.

I have swapped out my Pure Fidelity table with my Technics SL-1200, optimized both cartridges, and both have the sound. When the amp is muted it mutes the sound.

It is not audible on any of the other inputs.

So if anyone else has this preamp - could it be mine has a defective phono pre input, or is it just a higher noise floor?

128x128Ag insider logo xs@2xjsqt

Hard to guess with no information on your cartridge or phono amp setting. What stands out to me is that you have high efficiency horns and that might make the built-in phono amp stand out. That's why most prefer a separate phono pre-amp with gain and load adjustments. Your phono amp probably has more gain than you need (or want).

Thanks, sorry I wasn't more clear. 

My question pertains specifically to the SU-R1000's internal phono preamp, specifically to anyone who may own one and can tell me if they have a similar experience. 

I am moving from a Parasound JC3+ and separates (Backert Labs Rhythm, Luxman M900u) so I have never had noise floor issues with the Parasound or any other phono pre - external or internal. 

The R1000 has some signal DSP processing internally on the phono pre that may make the noise floor higher - it hasn't been mentioned in any reviews and doesn't appear in the measurements so I'm concerned my unit may be defective.

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Thanks all, this is not a ground issue. The issue is that only on the phono pre channel (RCA, not XLR), when I turn up the sound beyond a certain threshold, there is a “hiss” noise floor not unlike a tube amp. It’s not a 60 cycle hum or a buzz or noise. It’s just not a “black” noise floor like all the other channels. It also goes away when the unit is muted.

The Line In input has a totally black background no matter what the volume, as does the digital input. 

The hiss is there whether I turn on or off the subsonic filter, crosstalk filter, or cartridge optimizer. 

It’s also not audible when music is playing. The R1000 does seem to accentuate surface noise a bit with its digital processing but this is not record surface noise, it’s just a “not-black” noise floor that is almost like a gain staging issue when you are turning up gain but input is not very high. 

It’s definitely “live with-able” but I was wondering if this was a factor on all units or just mine. I have to turn it up beyond 40 to hear the hiss.

The question that remains unanswered is when you are listening to the RCA input phono section “hiss” is the amp set for a MM cartridge input or the increased amplification factor of a MC cartridge.  I do not find the actual amplification in the R1000 specifications.  Many MC phono amplifiers with 60db to 72db amplification factors can have a more present noise floor when no signal is being put through them.  It could also be present with the MM setting which is usually around a 40db amplification but probably not as present as when MC is selected.  

Definitely a gain issue what's the output of your cartridge? And does the Technics have adjustable gain settings for phono?

Thanks, the SU-R1000 has an “Intelligent Phono EQ” which calibrates the gain, phase, and cartridge optimizer which is supposed to set the proper impedance based on the calibration. So in using that feature, there is no manual entering of gain or impedance settings, it is all optimized for you. My cartridge is a Pure Fidelity Stratos which is a LOMC cart, but the audible noise floor is there when the phono DSP is engaged or not. 

@jsqt-

Sorry- meant to ask did you run the optimization with the calibration record that is provided with the receiver?

There are threads on Agon regarding this unit- I didn’t read them but seems like there are others that may own this unit. 

@designsfx yes, I did do the calibration and the effects are definitely audible so that’s working. The noise floor is there regardless of whether I engage the calibration DSP or not, but after working through the weekend on this, I think it’s just that the gain is so low on this input that I’m having to turn it up to where the noise floor is audible.

The sound overall is exceptional but it’s so much quieter than my Line 1 or USB inputs, there is like a 10dB difference between streaming and the phono pre.

Technics’ lack of customer support was a concern when I bought this thing and now I’m thinking I’ll have to give them a shot regardless. My hope was that there are other SU-R1000 owners on Audiogon that can verify their experiences with the unit.

If there’s something that is wrong with the phono pre input on the unit that would suck. I did test this with my MM Ortofon Blue cart on my SL1200MK2 (also calibrated with the LP) and the gain was also quite low in this case.

In both cases I had the "MM" or "MC" set properly. There is a way to add 3dB of gain to the phono pre input but that defeats the calibration setting/optimization. 

For those of you in the future who may be looking for an answer on this issue (low gain after calibrating the SU-R1000 phono EQ), this was a combination of poor manual instructions and user error. Apparently if you are using a LOMC you must set the +3dB gain to “on” before running the calibration. If you calibrate and THEN try to turn the gain on, it defeats the calibration settings.

I did go back and set the gain to +3dB, and turned the volume on the amp way down before re-calibrating with the LP and the phono pre and line level inputs are MUCH closer. Plus if I want them to be practically matching there is a setting to attenuate the Line In inputs to get them almost level.

This was very helpful when trying to compare the phono pre in (vinyl), my NDX2 DAC (line in), and the internal DAC (USB in), getting the levels between inputs much closer and eliminating the noise floor on the phono pre input.

I doubt anyone here knows what “40 on the volume knob” means on that device or in the context of your listening system.  How bad is the noise on the phono stage input at normal listening volume?  Btw, I don’t think I have heard a phono stage input that was completely silent when turning the volume all the way up.  It’s the noise at normal listening levels that counts.

@plinko  thanks! Sorry for the "40 on the volume knob" comment, I guess when I wrote that I had specifically posed the question to owners of SU-R1000 who would know specifics about this piece of gear and know what I was talking about. I had seen others post about the SU-R1000 and hoped that this would be a good place to get some owner feedback but that didn't seem to be the case.  Anyway I was able to re-calibrate the phono optimization, setting the gain BEFORE the optimization which was what made the difference in results. The SU-R1000 manual is unclear how this all works together in the optimization process. 

@jsqt:  Thanks for describing your solution, as that might help others having a similar problem.  Your Technics look sweet — enjoy!