YAMAHA A-S701 - tear-down, thoughts about the internals & few measurements

[Redwine]

Thanks for the membership, new to the business here, but learning by reading

However, was looking at the Yamaha R-N602 vs the Yamaha A-S701.

Apart from the MusicCast facility, are there any major differences in terms of power and sound quality?

 

[Overseas]

Why not RN803D, that has YPAO ? If you can find it, as it was discontinued.

 

[ZolaIII]

Why not RN803D, that has YPAO ? If you can find it, as it was discontinued.

If in US CA:

Home amplifier recommendation

@Rednaxela curious your thoughts?

www.audiosciencereview.com

Think they still can be found regularly in EU.

 

[Redwine]

If in US CA:

Home amplifier recommendation

@Rednaxela curious your thoughts?

www.audiosciencereview.com

Think they still can be found regularly in EU.

If in US CA:

Home amplifier recommendation

@Rednaxela curious your thoughts?

www.audiosciencereview.com

Think they still can be found regularly in EU.

Both I am looking at are secondhand, so in case I don’t need room correction?

 

[ZolaIII]

Both I am looking at are secondhand, so in case I don’t need room correction?

He is selling a sealed box never opened one and in EU you can find it new in shops with warenty. Thing is It's really a good package for the price and if it's a user re-selling you can (at least) try to bargain. Fun part is those will usually be peaple who bought more than one and realise they won't need more than one for a very long time.
Best regards.

 

[telemike]

I am concerned about the 470pf capacitance on the phono preamp. My Ortofon 2M Blue recommends 150-300pf capacitance. How will this affect the 2M's sound?

 

[trl]

On pages 7-8 there are few thoughts about your concerns too. You may change the input capa yourself or in a local shop. I'm thinking that your Ortofon might not perfectly reproduce trebles above 15kHz with the default input caps, but this is something you could check by purchasing a test vinyl disc and measure the trebles prior and after input caps replacement.

 

[adaminnyc]

Hello, I just received the S701 and will be migrating my system to it over the next week. I'll have the following devices connecting to the line inputs:

Ifi Zen Phono (Fluance RT85)
lavaudio ds600 audio dac (Wiim Mini, Sonos connect(may move this to the coax on the S701 if DAC sounds better)
Oppo BDP-83 used for CDs and SACDs

Should I plan on connecting my most used source to the CD input to take advantage advantage of the CD Direct Amp? In this case it'll be the Ifi Zen Phone.

I plan on testing all the combinations myself, but just wondering what others have found.

Thanks

 

[Willem]

Just use the digital inputs.

 

[jaco61]

Hello, I just received the S701 and will be migrating my system to it over the next week. I'll have the following devices connecting to the line inputs:

Ifi Zen Phono (Fluance RT85)
lavaudio ds600 audio dac (Wiim Mini, Sonos connect(may move this to the coax on the S701 if DAC sounds better)
Oppo BDP-83 used for CDs and SACDs

Should I plan on connecting my most used source to the CD input to take advantage advantage of the CD Direct Amp? In this case it'll be the Ifi Zen Phone.

I plan on testing all the combinations myself, but just wondering what others have found.

Thanks

The cd direct is a real advantage over the other inputs.

 

[BDWoody]

The cd direct is a real advantage over the other inputs.

How so?

 

[ZolaIII]

The cd direct is a real advantage over the other inputs.

Best analog input A-S701 has is a phono input as it's done as dual op amp's balanced, rest are regular one's with 100 dB rated sensitivity so it's better to use optical input and embedded DAC in theory. Direct mode cuts processing of embedded DSP (which isn't great and leads to SINAD degradation). I don't know if A-S701 has an input stage authender (Volume trim) which is useful for getting tider bass response settings it down (to - 6~7 on older one's) as it really likes input of about 500 mV (as Yamaha mesured them, 2V - 6 dB is 500 mV), best regards.

 

[trl]

I wouldn't connect a Phono-out to A-S701's CD Direct input. I would instead connect to this input a DAC-out from another external source (your OPPO perhaps), or a device with a better SINAD than a Phono-out.

With CD-Direct pressed I personally get no noise coming out from my 92 dB/W @1m 4 Ohms speakers (tested 0,5m in from of tweeters), this is why I recommend connecting to CD Direct input only very low noise audio sources, to benefit from the lower noise feature of CD-Direct.

 

[ZolaIII]

@trl try with almost direct (ear) to lo end driver of speakers in "CD direct" vs Toslinks direct (YPAO and rest of). I am curious if there is a difference. Best regards and have a nice time.

 

[restorer-john]

I wouldn't connect a Phono-out to A-S701's CD Direct input. I would instead connect to this input a DAC-out from another external source (your OPPO perhaps), or a device with a better SINAD than a Phono-out.

With CD-Direct pressed I personally get no noise coming out from my 92 dB/W @1m 4 Ohms speakers (tested 0,5m in from of tweeters), this is why I recommend connecting to CD Direct input only very low noise audio sources, to benefit from the lower noise feature of CD-Direct.

The residual (noise in uV/mV) is measured with the volume at maximum and a shorted input. At any other position other than maximum, no conclusions can be drawn as to audibility/measurement of residual noise.

 

[trl]

@trl try with almost direct (ear) to lo end driver of speakers in "CD direct" vs Toslinks direct (YPAO and rest of). I am curious if there is a difference. Best regards and have a nice time.

I did tried, there is a significant noise diff. if the room is quiet enough. I think SINAD is also altered a bit, see my measurements from the first pages.

Thank you as well!

 

[trl]

The residual (noise in uV/mV) is measured with the volume at maximum and a shorted input. At any other position other than maximum, no conclusions can be drawn as to audibility/measurement of residual noise.

Retested now: with volume @12o'clock, difference between CD-Direct and CD is significant at both tweeter and midrange drivers.

With volume to the max. the diff. is insignificant, so volume should be at most at 3 o'clock to make a difference between CD-Direct or Pure Direct vs. regular input.

 

[TheBatsEar]

CD Direct Amp

Well, i don't think this makes much of a difference, but people seem to like it as a feature, so Yamaha added "CD Direct Amp". However, that wasn't enough, so they also added "Pure Direct" in a slightly redundant move.

If you can hear a difference between them on or off in a blind test i'll knit you a pair of ear caps.

 

[TheBatsEar]

Retested now: with volume @12o'clock, difference between CD-Direct and CD is significant at both tweeter and midrange drivers.

If you play the same test with a signal, you will not be able to hear any noise difference, but your neighbors might come to ram in your door while shrieking hysterically, so in either case, it's audible.

But seriously, it's not. This feature is purely added because it is expected, not because it sounds much better. Maybe there was a point to it 50 or so years ago, but todays opamps are pretty much flawless. You can measure some difference, but are you able to hear it with music?

 

[Steven Holt]

Thank you so much for this, I never ceased to be amazed by our membership. If I'm reading this correctly, it seem that the phono output section is somewhat average. Would it be a good idea to use a separate phono preamp and just run it to line in?