[Rav]

Just got my CanAmp (from http://www.needles-and-spins.co.uk/ - very nice service too) and I notice that it isn't totally silent. With no source and volume at zero there's a very slight hiss with my HF-1s plugged in. Just wondering if this is normal for this (and any other) amps, since this is my first mains powered amp. My 2 battery CMoy is silent under the same circumstances even with the volume at max. Normal listening I can't hear it at all though, being drowned out even by tape hiss on the recording.

So far I've resisted the urge to take a peek under the hood, but i might do just to make sure the caps are in the right way, as it runs fairly warm.

 

[dw6928]

mine has been dead silent since October.

 

[Hi-Finthen]

Mine has been DEAD quiet for the past month!

 

[Rav]

Hmm, that's a little worrying then. I'll try a few different power outlets, as this house isn't particularly well wired...

 

[dw6928]

Quote:

Originally Posted by Hi-Finthen /img/forum/go_quote.gif Mine has been DEAD quiet for the past month!

Bill, very funny.

 

[sacd lover]

Quote:

Originally Posted by Rav /img/forum/go_quote.gif Just got my CanAmp (from http://www.needles-and-spins.co.uk/ - very nice service too) and I notice that it isn't totally silent. With no source and volume at zero there's a very slight hiss with my HF-1s plugged in. Just wondering if this is normal for this (and any other) amps, since this is my first mains powered amp. My 2 battery CMoy is silent under the same circumstances even with the volume at max. Normal listening I can't hear it at all though, being drowned out even by tape hiss on the recording. So far I've resisted the urge to take a peek under the hood, but i might do just to make sure the caps are in the right way, as it runs fairly warm.

The specs on the HEED give the unweighted noise floor as 85db. Under some conditions that can be audible.

 

[carlosgp]

I am able to hear some noise with the HF1s if the ambient is totally silent.

 

[Rav]

Quote:

Originally Posted by carlosgp /img/forum/go_quote.gif I am able to hear some noise with the HF1s if the ambient is totally silent.

Interesting ... not sure if Hi-Finthen and dw6928 use less sensitive headphones, or maybe the euro canamps are just a little noisy with the extra voltage?

 

[carlosgp]

I have written to Alpar and maybe he will be able to shed some light over the issue. Probably sacd lover is right.
With higher impedance headphones like the HD650 I can not hear the slightest hiss.

 

[Hi-Finthen]

Quote:

Originally Posted by Rav /img/forum/go_quote.gif Interesting ... not sure if Hi-Finthen and dw6928 use less sensitive headphones, or maybe the euro canamps are just a little noisy with the extra voltage?

Honestly, I never did notice any background hiss or noise at all with any of my cans while using the Heed CanAmp... And I'm sure I checked by turning the volume pot to full power without music, as a check for same.

 

[dw6928]

The headphones I used to test this Heed issue were: AKG 701s and Sennheiser
HD650s

 

[hassan14a]

I have AKG K701 and i can't hear any hiss unless i turn it half way up.

 

[daggerlee]

The Grados are 32 ohms, there will be slight hiss...

 

[Iron_Dreamer]

Quote:

Originally Posted by sacd lover /img/forum/go_quote.gif The specs on the HEED give the unweighted noise floor as 85db. Under some conditions that can be audible.

Indeed, and considering that it uses an UNregulated power supply, it's possible that dirty AC power could make the amp noisier.

 

[Hi-Finthen]

Quote:

Originally Posted by Hi-Finthen /img/forum/go_quote.gif Honestly, I never did notice any background hiss or noise at all with any of my cans while using the Heed CanAmp... And I'm sure I checked by turning the volume pot to full power without music, as a check for same.

EDIT to my previous remark above...

I did just now plug into the Heed CanAmp to test for hiss with music on pause, with full at the 5 o'clock position: 701s begin to very slightly hiss at the 4:30 o'clock position, and my RS2s begin to hiss at the 3 o'clock position, my 501s do not hiss at all and the 990('05e) do not hiss at all...

Apparently I did not test all my phones for this with the Heed and perhaps only did so with the 990s and 701s as that is what got most of the early time paired with my CanAmp.
I should not have said otherwise without making sure by testing again as I just did and listening intently.
Sorry for having said otherwise, but most of my listening as of late has been with my other amp(s), the Mapletree with the 701s & RS2s ....

I hope this clarifys what I hear with the Heed and my cans without music playing, for others diagnosis.....

However, the dial never goes over 12 o'clock on any of these cans