Do I really need a preamp?


I am considering another preamp to go with my CJ 2200. Am thinking about a CJ pre to go with it. However since my main source for listening is a cd player which has variable output, why do I need a good preamp. I have an Adcom GTP 450 tuner/preamp which will do the job for radio, tapes, etc. That said, how can I run cd and pre into the amp? As always, your help is appreciated.
128x128artemus_5
Welborne Labs informs me that their steps are 2 db, which I think are unfortunately large. Every commercial stepped attenuator I know of uses steps that large, presumably to be able to fit in with a wide range of power amps and sources. But each system needs only a small part of the huge range of attenuation allowed--literally from zero to infinite--and I would strongly recommend (1) getting a kit, so you can choose your own step size, which I'd make 1 db, (2) find out how much attenuation your system needs by rigging up a crude fixed attenuation network with female RCA connectors and resistors, no chassis needed, and (3) get your own resistors (which could be interspersed with some of the ones supplied with the kit). Don't know how to work out their values? The basic equation: attenuation = 20 log Rs/(Rs + Rg), where Rs is the series resistor and Rg is the resistor to ground.
my experience has been that an excellent (tubed?) preamp basically levels the playing field when considering any cd player up to $3k (or more?) my $500 nad 5-disc *changer* is competitive w/the likes of the $3k audio resolution cd-50/55, & $1800 alchemist cd player. added benefits of a great pre are realized w/winyl & tuna as well. get an excellent pre, and a cheapie cd-player, & wait until there is tons-o-software for the winner of the next-generation format what/when ever it's decided.

ymmv, doug

ps - perhaps a decent cd-player run straight-in to a great toob-amp mite take the edge off the digital...

OK boys and girls, you,ve made a believer out of me. Actually I thought I knew the answer already but wanted to check with others before making a final descision. I had tried both ways but a faulty cable had caused some intermintent problems that were hard to track down. I have decided to go for the Conrad Johnson PFR pre. My wife is so impressed with the CJ MF2200 that she has almost given me the green light. Life is good!
I had a Wadia 850 running straight to a BAT VK60 amp. It was awesome...until I tried a BAT vk50se preamp. For the money, the Wadia direct couldn't be touched. But, the BAT preamp too was a huge upgrade. IMHO, a preamp is a must when funds allow it...
hello artimus i am not an audiophile yet,but i hope my 2cents helps i too have an adcom pre(565) It has been sitting un pluged for 3 years.keep trying to put it back into the systum for audio,565 just removes detail&life fromthe music.am using a denon 1520 direct into adcom454.the denon has a varible out,staight out,andoptic out ,would alow hookup to more than one power amp.
tried agolden sep in system,bb king& organ ,wonderful.santana,ihad to look at lable to see who it was.
Try the Mod Squad Line Drive. It's called a passive preamp but it's really a quality-switching device. It gives all the versatility of a preamp but without the gain/color. They can be found on the used market for $100. to $150.
I don't recommend using the variable output of a CD player. I tried this with my $2,000 Sony ES player. The sound did not congeal well, the image being tall & illdefined & the sound somewhat transistory & harsh. When I connect the fixed outputs through my tube preamp, the sound is much more coherent, clean & focused. Using a passive control unit might be a different story, although I wonder if some of the same problems may still be present. A number of authorities believe running passive creates other problems.
I run my Resolution Audio (variable) outputs directly into
my amp. This works very well. (my Sony ES also does the trick) If you want to add another layer of grunge buy a preamp (with it you will also need anothe pair of cables)
In the end you should trust you ears, as I do mine.
Absolutely, preamps are Essential, Hearts of a Fine system Try RSA, Ray Samuels Audio Tube Line Stage PreAmp, Simply Out of this World,
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I run my cd player with variable output directly into my SET amp. I love the sound, am very happy, not tempted to put a pre-amp in the path. As the previous poster noted, if you do that and have other sources, you gotta keep switching the interconnects (or else just buy a rotary switchbox). I am really cheap so I just switch the cables!!
Well, I've tried wading in from both sides of the pond and think that some good points have been made here both pro and con. If you are running directly into a tube amp, you might get very good results via the variable output. You already have tubes to soften the digital nasties, and many tube amps have high input inpedance, which lends itself to such an application. It would certainly be the cheapest avenue, and possibly the best sounding. In other words you have nothing to lose by trying it out. First hook up the direct variable connection from the CD player to the amp inputs (keep the level low to start), and see how you like the resulting sound quality. The problem, as I see it, is that you will have to disconnect the CD player when you want to use another source. So, what that effectively brings you back to is the compromise of adding a passive preamp to gain volume control and switching for all sources -- in which case you might as well use the more direct fixed output on the CD player into the passive preamp as someone else has already suggested. And yes, that can limit dynamic impact somewhat. But heck, if you like the direct variable input enough (which may add an active output stage internally), then it might be worth disconnecting and reconnecting the player to facilitate the use of all your other sources. As with most comparisons, your ears should aid you in your final decision.
I second the opinion of Themusicshop, and have looked at the Welborne Labs kit (or assembled) unit he recommends. If you can do a kit, I'd ask Welborne how big the steps are, and negociate about getting different resistors for the kit, so as to make them no larger than 1 db, if they are larger than 1 db. (Typically they're about 2 db in the middle of the range.) If you arrange to have the control go down from 0 db in 1 db steps, you still have 23 db attenuation, which should be plenty for a CD player and halfway typical amp and speakers. You could get info from your manufacturers on how much attenuation you'd be likely to need. Reviewers almost always hate the variable output connection, and I presume with good reason. But if the output stage itself is decent, I disagree that an active preamp is needed for anything.
Although off topic a bit, in my opinion anything that you add will color the sound. It just depends if you like the way the end result sounds. I find it that way for interconnects speaker cable, digital cable, power cords, amp, preamp, changing tubes, etc. Some are more transparent; some sound better, all color to varying degrees.
I played around with the variable connection out of the Levisnon 39 and passive preamps. To really get the max out of your speakers (especially if they are dynamic speakers) you will always need a good active preamp for the dynamics and soundstage. Also, good power cords like the maganan reference and whale elite add to it. That's a whole other forum discussion. There are no short cuts at this level in hi-end audio.
You don't have to have a pre-amp with a variable output digital system. Alot of people think it's best not to add another layer of curcuit into the chain. I have done it both ways and tend to like what a pre-amp adds to the sound. I realize I'm adding something and in the best systems that's bad, but in the systems I can afford I feel it sounds better with a pre-amp. I use a tube pre with a solid state amp, I think the tube adds some warmth and sounds less digitial. I would suggest trying a pre-amp for a week-end if possible and switching back and forth. As far as hooking up both I don't know the right way, I can imagin some set-up but I will leave that one to others. J.D.
You should check out a passive unit, it will add almost nothing to the sound but will add the source switching you need. Check out the kit from http://www.welbornelabs.com
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