2. amps-preamps
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Why some preamps does not play music? Cold?

I mean technically/electronically wise, why some preamps while been very revealing and very good in reproduction of frequencies and extensions, are at the same time not engaging musically and emotionally and even boring? Are there a solutions to fix that (except for changing preamp)?
dvavc
georgehifi's avatar
georgehifi
10,312 posts
 

dvavc

A Quote from the master Nelson Pass

Nelson Pass,

We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.



All active preamps dvavc, have a colourations/distortion of their own, and all sound different to each other. None sound like the "mythical" "straight piece of wire".

If you want to hear what your source sounds like without these active preamp colouration/distortions you should try to use your source into your poweramp via a passive preamp, the closest to a "straight piece of wire" sound.

But for that to work it’s best the source output impedance should be low (1kohm/1000ohms or less) which most are. The passive pre should be a 10kohm passive, and the poweramp should be 33kohm or higher input impedance which most are. And interconnects from the passive pre to the poweramp should be 2mt or less and low capacitance (100pf per ft or less) which most good ones are.

This then will give you the most uncoloured, dynamic way of hearing your source, you may not like it, but that is the sound of what your source is without any active preamp colourations/distortions changing the sources sound.

If all parameters above meet the requirements try this. This is a $49 10kohm passive pre you can try, and even send back. And they have "B" stock as well.

http://schiit.com/products/sys

Cheers George

bombaywalla's avatar
bombaywalla
1,958 posts
 
If you want to hear what your source sounds like without these active preamp colouration/distortions you should try to use your source into your poweramp via a passive preamp, the closest to a "straight piece of wire" sound.
I agree that all active preamps are colored to some degree or the other but I’m sorry I don’t agree with you that a passive pre is the proverbial "straight piece of wire". Very few setups that I’ve heard sound better with a passive pre; most of them sounded way better with an active pre (colored tho’ it might have been).
There is one setup of a friend’s friend using a passive pre, Anthem power amp & small Magneplanar (not the 1.6 model, the one smaller than that, can’t remember the model #) that sounded oh-so-transparent. But it was simply superb for vocals, trios & small groups. Once you got some rock or blues or symphonic music going, everything just congested up. :(
My brother’s set-up used a MFA passive pre that was built personally by Billington himself & used the ref-grade xformers. Super sound for many years that it gave him service. Then one day he was dissatisfied w/ the sonics & installed an active pre - OMG! even better sonics & he has not looked back.......

atmasphere's avatar
atmasphere
11,841 posts
 
However, as it most apparent on complex, avangarde jazz pieces (Kith Jarett, Jan Garbarek, Chick Corea etc.) it looses musical connection (?) It does it on any kind of music, but on regular music it is less obvious, because it still have enough "melody (?)" left to connect sounds into music(?). When switched to any other, out of 5 preamps, (cold, SS or whatever) which BTW, have less of extensions, clarity etc.,, the music comes back. So, the correct word is probably musicality not emotional engagement?
Usually tubes have lower distortion (after all, they are quite linear). However, a lot depends on execution- and the tubes in the unit. You might have them tested for starters; a bad tube might do OK on simple material and might fall apart when things get complex.

Other brands might work better too.

Also there is the design of the line section itself- they are not all created equal and some are pretty bad- as George points out, they can be prone to colorations of their own (usually the distortions found in tube equipment are of the lower harmonics, which the ear converts to 'warmth'). But if there are design flaws all sorts of issues can crop up.

I would start by getting the tubes tested!
dvavc OP
81 posts
 
I tried different NIB tubes, both Sylvania though, while it did changed tonally, the issue complained about remained. I will try some other brand. However, it is 6sn7GTB therefore not to much choice to play with, unless try not GTB but that, as i understand, not recommended. Theoretically, are tubes in power supply might cause that?
Guys, thanks for your time and thoughts. 
knghifi
1,668 posts
 
Theoretically, are tubes in power supply might cause that?

It's very possible ... GZ34 family?
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