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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
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.
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