Removing Unused Preamp Connections

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22-01-2008, 01:07
Marco

Removing Unused Preamp Connections

If your preamp has most (or all) of its inputs used when your CDP, T/T, tuner, phono stage, etc, is plugged into it, have you ever tried disconnecting everything other than what's necessary for playing music at the time?

So if you're listening to, say, CD, disconnect the leads that are plugged into your other source inputs...

Doing so, in my experience, improves sound quality and gives a more natural, detailed, and 'focused' sound. Quite often, a lot of the stuff that's plugged into your preamp isn't used regularly so why not maximise the performance of the components that are? The improvement is subtle but in my opinion definitely worthwhile.

Marco.
22-01-2008, 20:01
Steve Toy

Perhaps running a single-source system is really the answer ;)
24-01-2008, 23:38
Vinyl Grinder

Quote:

Originally Posted by Marco

If your preamp has most (or all) of its inputs used when your CDP, T/T, tuner, phono stage, etc, is plugged into it, have you ever tried disconnecting everything other than what's necessary for playing music at the time?

So if you're listening to, say, CD, disconnect the leads that are plugged into your other source inputs...

Doing so, in my experience, improves sound quality and gives a more natural, detailed, and 'focused' sound. Quite often, a lot of the stuff that's plugged into your preamp isn't used regularly so why not maximise the performance of the components that are? The improvement is subtle but in my opinion definitely worthwhile.

Marco.

Marco:
It's called ground coupling, the signal ground of the other sources are interacting with each other causing breakthrough, degrading the signal in the process. You need ground switching Or like me one source only as steve says...
01-02-2008, 21:48
Mike Reed

Dis connected hypothesis

I'm quite sure there is deleterious interraction between plugged-in sources. However, the thought of fiddling around among a congested rat's tail of leads behind the pre-amp every time I wanted to listen to the radio, CDP, record-player or TV/video fills me with horror.

I'd gladly forsake a little quality for the convenience.

Mind you, having a separate pre. for each source, as has been mooted,(and separate amps, and separate speakers). Now, THAT'S something I haven't thought of!
02-02-2008, 00:20
Vinyl Grinder

Or you could just fit the selector switch that switches both signal & ground.Best fitting the best, Elma are pearlers.

http://i275.photobucket.com/albums/j...LPFAN/ELMA.gif
02-02-2008, 09:33
Filterlab

Quote:

Originally Posted by Steve Toy

Perhaps running a single-source system is really the answer ;)

And then use a pre-amp with a single input, or better yet avoid a pre altogether and go direct from source to power amp.
02-02-2008, 11:07
Mike Reed

Getting rid of a Naim 552?

Thanks for your replies, and of course what you say about 'straight to power amp.' makes sense:- theoretically!

However, re. the Elma switch selector (and excuse my senile naivety here), is one supposed to solder each interconnect to the terminals (effectively doing the job of the pre., I guess)? Then connect the (monoblock) leads to the output side in parallel? OR construct interconnect input sockets which are themselves hard-wired to the Elma? Thus effectively building a simplified passive control-less pre.?

To me this is quite a radical if hairshirt approach, though I can see financial and sonic merit therein. Pity about buggering up so many (expensive) i/connects, though. Furthermore, how would one control volume, use mute and generally introduce other kit/experiment/ record out, etc? Surely this is where the pucka 'control centre' (a.k.a. Pre.) comes into its own?

I believe I have one of the most revealing preamps. around (reflected in its cost, no doubt) and whereas I concede to the 'simple is best' path, I cannot see a viable alternative to my oft-used, multi-sourced, 24/7 powered, hard-wired to the mains system.

If you disagree, I'd be interested to receive enlightenment.
02-02-2008, 11:11
Mike Reed

Classifieds?

By the way, Filterlab, where is the 'classifieds' section? Or hasn't it started yet?
02-02-2008, 11:19
Filterlab

Quote:

Originally Posted by Mike Reed

...construct interconnect input sockets which are themselves hard-wired to the Elma? Thus effectively building a simplified passive control-less pre.?

Yes, on both the signal and ground paths. This essentially eliminates any crosstalk from components on other inputs via the ground. Extreme I know, but it could be one of those things for an 'audiophile with time on his hands' to do on a Sunday. :)

For me it's a little out there and whilst I understand the merits of disconnecting each component when it's not in use, I personally couldn't be bothered with the continued hassle of plugging and unplugging. However I actually only have two sources and a separate system for each - one being the two channel system (Mac, DAC, power amp, speakers), the other system being the AV side (PS3, AV amp, 5 speakers). These two systems don't meet anywhere and consequently there's no 'bleed' from the AV side to the 2 channel side.
02-02-2008, 11:21
Filterlab

Quote:

Originally Posted by Mike Reed

By the way, Filterlab, where is the 'classifieds' section? Or hasn't it started yet?

It's called (rather romantically) 'Private Exhibitions' and it's located in the main 'Hi-Fi, Studio and Trade' section. We've tried to keep the forum titles in keeping with 'art' so they take a little getting used to - although they are, of course, genius titles. :D

http://theartofsound.net/forum/forumdisplay.php?f=22
03-02-2008, 01:47
jimdgoulding

I run my leads direct into my tape inputs (one at a time). I read somewhere that doing this bypasses all the other stuff on my line stage. I don't know if this is universal. Perhaps VG and Mike can tell us more. What I hear doing this is less artifice, more organic, smooth sound.
03-02-2008, 08:56
Lowrider

Another solution is to use optical digital connections, when possible, thats how I got read of the hummm comming from the satellite antenna...
06-02-2008, 23:10
Vinyl Grinder

Quote:

Originally Posted by Chance66

bean there done it and its a myth. U might as well staple your testicles to the desk. if your sound is improved by this you need a new amp.

:rolleyes:Another negative view..it's not a myth..
06-02-2008, 23:19
Marco

Mmmm... Could it be the Swedish celibate in disguise, I wonder? :bog:

Marco.
06-02-2008, 23:40
Filterlab

Quote:

Originally Posted by Marco

Mmmm... Could it be the Swedish celibate in disguise, I wonder? :bog:

Marco.

No, too knowledgeable.
07-02-2008, 06:15
Lowrider

A brainless moron, why dont they just stay in their playground, Zero..., and leave us alone... :mad:
07-02-2008, 06:19
Lowrider

Another, this is a private message... :eek:

Quote:

Come to HiFi Talk where itz all talk and none of Marcos Bullshit!

$10 for all new signups for a limited period!
07-02-2008, 11:54
Marco

Hi Antonio,

Just ignore it. The matter is in hand.

Please read this:

http://theartofsound.net/forum/showt...=1313#post1313

Regards,
Marco.
25-04-2008, 14:55
Mike

Quote:

Originally Posted by Marco

If your preamp has most (or all) of its inputs used when your CDP, T/T, tuner, phono stage, etc, is plugged into it, have you ever tried disconnecting everything other than what's necessary for playing music at the time?

So if you're listening to, say, CD, disconnect the leads that are plugged into your other source inputs...

Doing so, in my experience, improves sound quality and gives a more natural, detailed, and 'focused' sound. Quite often, a lot of the stuff that's plugged into your preamp isn't used regularly so why not maximise the performance of the components that are? The improvement is subtle but in my opinion definitely worthwhile.

Marco.

This is another 'tweak' mentioned in some of Russ Andrews 'bumf' somewhere I think. :scratch:

I cant tell any difference on my amp, but then the inputs are relay switched and all inputs except the one in use are 'shorted' to ground anyway.
25-04-2008, 16:29
anthonyTD

Quote:

Originally Posted by Shian7

This is another 'tweak' mentioned in some of Russ Andrews 'bumf' somewhere I think. :scratch:

I cant tell any difference on my amp, but then the inputs are relay switched and all inputs except the one in use are 'shorted' to ground anyway.

mike,
it may make a diffrence because each piece of equipment connected to the pre-amp will have a diffrent earth potential, so even if the inputs not being used are grounded, the signal return of each component is still in the circuit.
thats only relivent mind you if all the signal returns rely on mains earth.
in the soul series they dont!
anthony...;)
25-04-2008, 18:59
Mike

Could be!.... but I couldn't hear it. :confused:
19-05-2009, 10:55
The Grand Wazoo

I've just stumbled on this thread but it interests me because of the experience I had with my headphone amp - a HFN/RR Headcase.

I once noticed that the hi-fi sounded a little quieter than usual & rather shut-in. I couldn't pin down the cause, pulled the whole system to pieces, tried replacing different components, checking phase - all sorts of stuff that couldn't possibly cause this.

Finally, I twigged that it was the volume pot on my headphone amp that was causing it. If it was left at anything other than zero setting, it had this effect - whether it was plugged into the mains or not. It was connected to the preamp via the tape out sockets.

Crap quality volume pot - changed it for a Sfernice & unplugged the Headcase from the system when it was out of use.

Moral - beware little used components with volume pots.
02-02-2010, 13:03
MartinT

I only have three inputs into my (Pass Labs) preamp - phono XLR, CD XLR and digital. All digital inputs are switched before the DAC. I can't detect any difference by unplugging other inputs and I'm pretty sure my preamp switches signal + earth, so total disconnection anyway.
02-02-2010, 16:42
Rare Bird

All you need is an handfull of RCA phono plugs , wire the signal to ground in the plug, plug em in the spare source input sockets...Don't do this for outputs tho...Remove any tape recorders from the Pre when not in use aswell.
02-02-2010, 17:39
DSJR

Quote:

Originally Posted by Marco

If your preamp has most (or all) of its inputs used when your CDP, T/T, tuner, phono stage, etc, is plugged into it, have you ever tried disconnecting everything other than what's necessary for playing music at the time?

So if you're listening to, say, CD, disconnect the leads that are plugged into your other source inputs...

Doing so, in my experience, improves sound quality and gives a more natural, detailed, and 'focused' sound. Quite often, a lot of the stuff that's plugged into your preamp isn't used regularly so why not maximise the performance of the components that are? The improvement is subtle but in my opinion definitely worthwhile.

Marco.

Yes I have and sometimes it does improve things. Even better is to use shorting plugs on the inputs not used and properly screened/shielded interconnects on the inputs you do use.

Some input selector switches also allow breakthrough across their connections and this of course muddies the noise floor..
02-02-2010, 17:41
Themis

Some preamplifiers disable unused inputs (other than the selected), no ? :scratch:
02-02-2010, 17:45
Rare Bird

So people think
02-02-2010, 22:15
CornishPasty

I've built a few preamps in my time and I always switch the return as well as the signal.

Many manufacturers bring everything back to a common or star point, signal return, psu ground, etc. I've never favoured this practice. I keep the signal and return together and completely seperate from any power supply grounding.

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