[irose]

Hi
I am experiencing some white noise through the speakers while the
apm is on, and also a quiter white noise when the unit is in standby.
Is it a problem with my unit? and how can it be fixed?
It is not a noise that I can hear from my listening spot.
thanks

[Bill Baker]

Having a small amount of noise without music playing can be normal in these amps. It maybe be the amp itself rather introduced by the interconnects or slight microphonics from the tubes.

  Also, sensitive speakers hooked to this amp will allow you to hear some noise from the digital portion of this amp. Being a remote unit, this type of circuitry can introduce small amounts of noise.

  If it is not audible while listening, have no concern.

  One way to check for cable noise: disconnect your interconnect cables and see if the noise continues.

  As far as not having the amp turned off and only in standby? I have not heard of this. Are your source components turned on when you hear this noise in standby? Very unusual. I would like to hear more details about this experience.

[irose]

Yes, I can hear some noise coming out the speakers, while no source is connected. Only when I turn off the main breaker (in the back), the noise
disappears.
My speakers are 91 Db sensitive.
Two more questions:
I tested the 1701 and the 1501, and I found a very noticeable difference
between the two in every aspect and in every volume. Is their a big difference between this two units?
How would I know which tube is the best suited for me?
thanks.

[Bill Baker]

Yes, I can hear some noise coming out the speakers, while no source is connected. Only when I turn off the main breaker (in the back), the noise
disappears.

 I have not experienced this before but then agin, never paid much attention. I will have to give mine a listen this evening.

I tested the 1701 and the 1501, and I found a very noticeable difference
between the two in every aspect and in every volume. Is their a big difference between this two units?

Yes there is. I feel the 1701 has a better presentation due to a different output stage circuitry. Some have noticed the 1701 not having the bass impact of the 1501.

How would I know which tube is the best suited for me?

  Trial and error is theonly way to know for sure. I would recommend getting other impressions on various tubes to give you a better indication of a good starting point. In general, I have found a 12AX7WA and 5751 type tubes to be fuller and warmer sounding while others such as the Svetlana 12AX7, EH12AX7 and similar to be a bit more precise and forward.

[irose]

Quote
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Yes there is. I feel the 1701 has a better presentation due to a different output stage circuitry. Some have noticed the 1701 not having the bass impact of the 1501.
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Do you mean the 1701 sounds better than the 1501?
To me the 1501 sound smoother and with more authority.
I ran a full range floor standing speakers in a large room, is this may be the reason I found the 1501 better?

[Bill Baker]

Basically, these two amps do sound a bit different without one sounding any "better" than the other. I personally find the 1701 a better presentation while others will obviously have a different view.
  It comes down to which one sounds better to YOU and will fill your requirements.
 In all honesty, I personally own two 1501s witgh one being the RC. My larger custom speakers are very difficult to drive, 3.1 ohm load, and I need the power and higher current of this amp to drive them.
  Personal taste and preferences will always be the deciding factor when auditioning any audio component.

[irose]

Did you had the time to check the noise from the amp. while in standby.
As one who have both 1501's, does the RC sounds different from the
one without the RC?

[Bill Baker]

Hello irose,
  I have checked my 1501RC and I do get a bit of noise when the unit is powered up but absolutely no noise at all when in standby.

As one who have both 1501's, does the RC sounds different from the one without the RC?

I have not done a side-by-side between the two units. I have also been using a verity of different tubes which does have an effect of the sonic presentation. I cannot honestly give a personal opinion at this time. The basic circuitry is identical so ther should, in theory, not be any sonic differences.

[irose]

you have been a lot of help.