Piccolo noise reduction

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ptmconsulting

Piccolo noise reduction
« on: 12 Mar 2012, 12:59 pm »
I've been very happy with my Piccolo for about 2 years now. It has bested several other step up devices I have tested against.

However, I recently picked up the vinyl remake of Patricia Barbers Mythologies. This album seems to have very low gain to it. I am a bit unhappy about that because I need to turn my preamp up to 3AM to get a decent level of volume out of it, and I hear some very noticeable noise coming through the system. When I turn off the Piccolo the noise is gone, meaning my other components are not contributing to this hiss. The Piccolo is the culprit.

I've tried it with both batteries and A/C and the noise level is similar. Same with different gain settings, it is still pretty noisy when the volume is turned up.

Any thoughts on how to rectify that within the Piccolo? Or should I just choke it up to the one album that I hear this on and get on with life?

Thanks,
Bob

poty

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Re: Piccolo noise reduction
« Reply #1 on: 12 Mar 2012, 09:03 pm »
It may be the noise from the turntable. What cart you are using?
If it is the Piccolo the noise should depend on gain. If there is not enough gain for your cartridge (phonostage?) the signal-to-noise ratio is reduced greatly.
Piccolo has noise (like other components in yor system), but if properly used - the noise is unnoticeable.

ptmconsulting

Re: Piccolo noise reduction
« Reply #2 on: 13 Mar 2012, 01:41 pm »
Stylus off the record, gain on any setting, preamp turned up to 3:00 = there is quite a bit of hiss.

Piccolo turned off, preamp turned up to 3:00 = the system is almost dead quiet

From this I infer that the Piccolo is adding most of this noise. My cartridge is  Transfiguration Temper, with a .25 mv output, so I need the highest ghain setting. The Piccolo feeds into a Trumpet.

poty

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Re: Piccolo noise reduction
« Reply #3 on: 13 Mar 2012, 06:34 pm »
Trumpet? How the Piccolo is connected t the XLR of the Trumpet?
26db of Piccolo + 44dB of Trumpet = 60dB total = 1000 times (voltage)
Assuming 0.25mV input from TT -> 0.25V output - the decent gain to feed (or even overdrive) any preamp, especially active. If "normal" listening level usually lies in the range of 11am of volume, 3pm means 15-20 dB more gain in preamp. I doubt that the "special" record has this big "mistake", so I may guess that it may be mono record (with different groove width, which needs different needle to play)???
It still doesn't explain big level of noise, in my system barely audible even at full 40W power into 91dB AS.

ptmconsulting

Re: Piccolo noise reduction
« Reply #4 on: 13 Mar 2012, 07:27 pm »
I'm runing Apogees (83db inefficient), so a "normal" volume level for vinyl on my preamp is about 1:00-1:30.

RCA inputs on my Trumpet.

poty

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Re: Piccolo noise reduction
« Reply #5 on: 13 Mar 2012, 07:37 pm »
Does the Trumpet initially come with RCA inputs (I do not have Trumpet, but schematic on hagtech.com shows XLRs) or someone alter it?
Main reasoning - if it was alteration, then it may has not be done properly.

If the Gain switch doesn't affect the hiss AND the problem is in the Piccolo - it should be in the last stage (strange, because it is not amplifying (voltage) stage). It is still possible that something wrong with current sink in the stage (Q3B, R11) or decoupling circuit (C1, R9).
It may be power supply filtering too (C10-C13). The Piccolo should work several seconds after switching off. What are you hearing during the period (how the hiss changes)?

ptmconsulting

Re: Piccolo noise reduction
« Reply #6 on: 13 Mar 2012, 08:56 pm »
Gotta be careful when switching the gain, or turning it off. Must mute first or there is a loud pop through the speakers that is loud enough to blow them. If I mute and turn it off then unmute I do hear music slowly dying down in volume.

I do remember finding, when I built it, that there was a fairly loud hum when it was off the box. Screwing the box to the top plate got rid of that. I also only have the tonearm ground wire to the ground on the Piccolo. Maybe I should run a ground wire from the Piccolo to the Trumpet? But I did that once and didn't hear any difference - got to try it again and see if there is any effect.

Don't get me wrong. I don't hear much noise (some, not much) when playing at normal volume levels. It's only when I turn things up considerably that this becomes overly obvious.


jostber

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Re: Piccolo noise reduction
« Reply #7 on: 13 Mar 2012, 11:51 pm »
It can also be PSU noise and/or hum that's coming from your TT. Can you check that?



BobM

Re: Piccolo noise reduction
« Reply #8 on: 14 Mar 2012, 12:04 am »
Nope, noise is definitely coming from the Piccolo

 - adding ground wire from Piccolo to Trumpet did not help
 - unplugged the tonearm wire into the Piccolo, hum is still there (no difference)
 - moved the Piccolo as far away from everything as I could reach with my 1 meter interconnects (no difference)
 - no difference on AC or battery power

I'm wondering if this is just what you have to deal with when using a head amp. Does anyone else hear hisssss and/or hummm when you turn your preamp up to 3:00 and the Piccolo is on?



ptmconsulting

Re: Piccolo noise reduction
« Reply #9 on: 14 Mar 2012, 12:07 am »
Nope - noise is definitely coming from the Piccolo

- ground wire from piccolo to Trumpet made no change
- unplugged tonearm lead into Piccolo (no change)
- moved piccolo as far away from everything as I can with my 1 meter interconnect (no change)

Simple question ... does anypone else hear a fairly prominent hisss or humm when turning your preamp up to 3:00 and the Piccolo is on? Maybe this is just what you have to deal with when using a head amp and not a step up transformer.

analog97

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Re: Piccolo noise reduction
« Reply #10 on: 14 Mar 2012, 12:35 am »
Quote
Simple question ... does anypone else hear a fairly prominent hisss or humm when turning your preamp up to 3:00 and the Piccolo is on?

In my experience, there is a problem any time you turn up a preamp to 3 O'clock.  Something is wrong here.   I run a low output Denon 103 and use the Piccolo into a Cornet2 and I NEVER get to 3 O'Clock........11AM is ear-splitting at 26db gain.   My Piccolo is dead quiet.   What the heck gives with that particular LP?   

poty

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Re: Piccolo noise reduction
« Reply #11 on: 14 Mar 2012, 11:28 am »
Hello again,
I'm not convinced with:
noise is definitely coming from the Piccolo
You've said nothing about RCA inputs of the Trumpet, for example, and it can be many problems outside.
I suggest to try Piccolo in different setup, maybe just connect to unused Phono or even Line input of a preamplifier (without everything connected to the inputs, better to short out the inputs) and turn volume up to max.
If I mute and turn it off then unmute I do hear music slowly dying down in volume.
More interesting is what is happening to noise? Disconnect everything from the inputs, use short bare wires to short out the input RCAs, listen to the amount of noise, do your trick with mute, switch off, unmute and listen what amount of the noise left and how it is changing. If it is slowly dying like you describe earlier for music - then there is not Piccolo power supply problem with great percentage.
I also only have the tonearm ground wire to the ground on the Piccolo. Maybe I should run a ground wire from the Piccolo to the Trumpet?
The ground wire should go to Piccolo only.
In my experience, there is a problem any time you turn up a preamp to 3 O'clock.  Something is wrong here.   I run a low output Denon 103 and use the Piccolo into a Cornet2 and I NEVER get to 3 O'Clock........11AM is ear-splitting at 26db gain.   My Piccolo is dead quiet.   What the heck gives with that particular LP?   
Good point! I also don't have any problems with gain. Maybe there is a problem with the cartridge? It has too small output? The most intriguing part is that the noise does not depends on gain in Piccolo... Very strange behaviour in my opinion...

ptmconsulting

Re: Piccolo noise reduction
« Reply #12 on: 14 Mar 2012, 12:28 pm »
There is noise at every gain setting on the Piccolo, however there is slightly more noise at higher gain. So yes, the gain does change the noise level somewhet.

There is nothing wrong with my preamp volume levels being as high as they are. My speakers are 83db inefficient (Apogees), so things have to be turned up louder than what is considered normal.

The Trumpet came with either XLR's or RCA's, depending on the option you chose. Mine came with RCA's.

Has anyone bothered to actually turn their preamp up to 3:00 and see if they also hear noise? That would be a very simple way of letting me know whether this is a problem in my Piccolo, or if it is just noise to be expected at such a high volume setting. I would vastly prefer this easy test before I start perfoming other complex shorting exercises.

poty

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Re: Piccolo noise reduction
« Reply #13 on: 14 Mar 2012, 06:58 pm »
The Trumpet came with either XLR's or RCA's, depending on the option you chose. Mine came with RCA's.
This question has been gone then.
There is nothing wrong with my preamp volume levels being as high as they are. My speakers are 83db inefficient (Apogees), so things have to be turned up louder than what is considered normal.
...
Has anyone bothered to actually turn their preamp up to 3:00 and see if they also hear noise? That would be a very simple way of letting me know whether this is a problem in my Piccolo, or if it is just noise to be expected at such a high volume setting. I would vastly prefer this easy test before I start perfoming other complex shorting exercises.
Begin with answering your question first, then you'll see that my answer (as other answers too for your question) has no use.
I have noticeable hiss and even some hum from Piccolo when I turn my volume at my integrated amplifier to the max, but if I ever try to listen to the music at this level I definitely will have some hearing problem and fry my speakers. Even half of this volume is VERY loud for me. Main problem why I can't speak for all Piccolo owners is I use not JH-engineered device, but Piccolo PCB as daughter card to my own "extender".
As you have already mentioned - the volume control position does not define hearing volume, because there are many options (outside Piccolo) involved: sensitivity of speakers, sensitivity of amplifiers, output power of the amplifiers, room reverberation and size, distance of listening and so on - you can sure know much more params of the equation. So - if you have inefficient speakers - it means that they attenuate all signal and noise in the same amount. So, to achieve the same level of noise it should be more in amplitude. You are able to hear the noise at "normal" listening level (then signal-to-noise ratio must be small), which is against of my experience and, for example, analog97 experience too, regardless of volume control position we or you use.
analog97 offer very good idea - either your cartridge has smaller-than-specified output or something wrong with the gain of some part of your system (including Piccolo).

ptmconsulting

Re: Piccolo noise reduction
« Reply #14 on: 14 Mar 2012, 08:34 pm »
Thanks Poty - you've confirmed what I suspected. At normal listening levels any hisss or hummm from the Piccolo is essentially unnoticed, unless your ear is right up to the speaker and you switch it in and out. This is what I hear also.

It is only when the volume is excessively loud that the noise becomes truly audible. I would never have broached this subject if I hadn't had this album with an excessively low signal level that required me to turn things up to what would be a ridiculous level. That's when I heard it and said "this little bugger can be noisy".

I've often pondered using a lower gain setting on the Piccolo and a higher gain setting on my preamp, because the preamp is a better quality unit for adding gain to the signal. However, in practice I've found that the using the top Piccolo gain setting gives me more dynamics in practice, so I've left it there.

Thanks for all your help guys.

hagtech

Re: Piccolo noise reduction
« Reply #15 on: 1 Apr 2012, 02:13 am »
Interesting.  Noise from a PICCOLO is entirely dependent upon its gain setting. 

jh

machine

Re: Piccolo noise reduction
« Reply #16 on: 3 Apr 2012, 01:49 am »
Don't know if this will be of any help, but I had lots of hum with my piccolo that was reduced significantly much by turning it 90 degrees on the shelf so the output were on the outside.

It is sitting next to my Bada DC-222 feeding my Cornet 2 on the shelf above.

I'm using a Pickering XLZ-7500, and it was unlistenable before the move.