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Yamaha AS2000 - balanced input

I connected my PS Audio dac to a recently purchased Yamaha AS2000 integrated amp using the balanced connections and was disappointed to hear some audible distortion. The PS Audio dac has an output voltage of 5V though the balanced outputs and according to the Yamaha manual the AS2000 has a maximum input signal of 2.8V.

Are the dac's balanced outputs too hot for the amp and causing the distortion?

Is there a way to attenuate the dac's output with attenuators or modifying the dac, or would that affect sound quality? The amp sounds great with unbalanced connections, but I was hoping to take advantage of the balanced inputs since the amp and dac are both balanced.
128x128johsti
13 responses Add your response
swanny76109
382 posts
 
I bet you can reduce the output volume on the PS audio unit, since it functions as a preamp too.

I also bet the Yamaha is not a true balanced input as the PS audio is.

Also possible that input on the Yammie is fried or has a loose solder joint or any other possible scenarios.

For that reason, try the unbalanced RCA outputs into another set of inputs and see how it sounds. If it sounds good, forget about the way you are trying to do it using the balanced ins.

Good luck, let us know how you fare.
johsti's avatar
johsti OP
102 posts
 
Thanks Swanny.

The Yamaha AS2000 is fully balanced from input to output. It is actually a very impressive design and sounds amazing through the unbalanced inputs. I want to see if I can improve upon the sound by using the balanced inputs, but there is an obvious mismatch. I have a Cullen stage 4 PS Audio DLIII, so unfortunately there is no preamp function.

I just don't understand why the balanced inputs on the Yamaha AS2000 would be limited to a maximum input of 2.8V. This would make most balanced sources unusable with this amp. I've sent an email to Yamaha for an explanation.
geared4me's avatar
geared4me
219 posts
 
I feel for you Johsti as I have been there and done that. I had the same problem feeding the A-S2000 from my Oppo BDP-95 xlr output. The 95 does have an internal volume control but I ended up having to lower the volume so much to remove all traces of distortion that it effected the sound quality. Yamaha means for this amp to be used specifically with its own CD-S2000. You may have saved yourself some headache if you had read my comments in this thread http://forum.audiogon.com/cgi-bin/frr.pl?ramps&1299772563&&&/Yamaha-A-S-2000-Amplifier. I agree that the amp sounds very good but this was a deal breaker for me.
custodio
2 posts
 
Hi Johsti.

Did you have any answer from Yamaha? I'm using the Yamaha A-S2000 with the Musical Fidelity M1DAC and the MacMINI. Sometimes i can hear some distortion.The balanced output of the M1DAC is rated to 4.4v. It seems that if I reduce the gain with the mac mini(Amarra 2.4.1), the distortion is less frequent.
johsti's avatar
johsti OP
102 posts
 
Yes, Yamaha did respond and simply confirmed that the balanced input couldn't accommodate a source with a 5V output. They did not clarify how much the maximum input was, but the manual says 2.8V.
mbleming
33 posts
 
Has anyone using this amp found a good balanced dac that has an output of 2.8v or less? I'd like to buy a nice dac and use the balanced outs on my unit, so I was wondering what people here were using. Any recommendations? Benchmark looks like it has an adjustable output?
regismc
112 posts
 
The modwright transporter works very well. A really nice combo....!
miesdavis's avatar
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miesdavis
19 posts
 
I have the same question, Mbleming...
mbleming
33 posts
 
Not sure about the Modwright version, but the stock Transporter's balanced output is just slightly too hot...
custodio
2 posts
 
I Think that is a good option:
http://www.audiolab.co.uk/M-DAC%20Series.aspx?lang=En

It is rated 4.5v Output but you can reduce the gain.

I no longer use the M1DAC balanced output to the YAMAHA A-S2000. I'm now using the balanced input with the EMOTIVA ERC2 CD PLAYER with good results.
mbleming
33 posts
 
I'll keep an eye out, thanks Custodio
miesdavis's avatar
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miesdavis
19 posts
 
I just bought a TC Electronic Level Pilot (attenuator) and placed it between my A-S2000 and Musical Fidelity M1 DAC. I turned the amp to a level that I am very familiar with (9 o'clock). I then turned up the attenuator until the sound was roughly where it usually is at that volume. Ironically I found that the volume did not significantly increase when I turned the knob of the attenuator beyond that point. I'm not a very technically inclined audiophile and someone else may better understand this than I do. Seems to work but then I'd never noticed distortion--just wanted to be safe and not damage the amp.
miesdavis's avatar
Ag insider logo xs@2x
miesdavis
19 posts
 
I just bought a TC Electronic Level Pilot (attenuator) and placed it between my A-S2000 and Musical Fidelity M1 DAC. I turned the amp to a level that I am very familiar with (9 o'clock). I then turned up the attenuator until the sound was roughly where it usually is at that volume. Ironically I found that the volume did not significantly increase when I turned the knob of the attenuator beyond that point. I'm not a very technically inclined audiophile and someone else may better understand this than I do. Seems to work but then I'd never noticed distortion--just wanted to be safe and not damage the amp.
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