Pre-Amp Unnecessary?

chasm3940 · « **on:** 16 Mar 2006, 09:07 pm »

Question from a novice. I recently saw this comment in a review: "...some consider a pre-amplifier superfluous in this era of digital volume control..." What is this about? My meager knowlege of equipment is 20 to 30 years old. (I am in process of putting together a new, two channel system starting with Martin Logan Clarity hybrid electrostatic speakers. Am considering Innersound, Naim, NuForce amps. )

miklorsmith · « **Reply #1 on:** 16 Mar 2006, 09:14 pm »

You'll get different answers on this. But, if I was assembling the type of system you're looking at I would NEED a tubed preamp.

Preamps do more than just signal gain. A good one will fill out the flesh and meat of the music and greatly enhance the experience. I have done several informal comparisons within my system with a Modwright preamp in, then taken out with the system otherwise identical. I found dimension and tone to be far superior with the Modwright.

Some will say that signal purity will be compromised by the additional circuitry and interconnects. But, I calls 'em like I sees 'em.

audioferret · « **Reply #2 on:** 16 Mar 2006, 10:04 pm »

I have been trying to find people with experience with Tube preamps and class-d amps. What amps are you using with your modwright? I am thinking of this kind of setup.

PhilNYC · « **Reply #3 on:** 16 Mar 2006, 10:16 pm »

Quote from: audioferret

I have been trying to find people with experience with Tube preamps and class-d amps. What amps are you using with your modwright? I am thinking of this kind of setup.

FWIW, we've had a number of NY Audio Rave get-togethers that paired class D amps with tubed preamps...and for the most part, I think people really preferred the sound over using a solid state preamp. In our mix we've used preamps from Blue Circle, ModWright, BAT, and Tube Audio Design with amps from Bel Canto, NuForce, H2O, and a number of DIY amps based on ICEPower, UcD, etc.

samplesj · « **Reply #4 on:** 16 Mar 2006, 10:24 pm »

The problem with digital volume control is that at some point it will have to start throwing away real data/resolution. Often you willl see some sort of padding to the word length to allow for some amount of lossless reduction. For example the Squeezebox is able to use digital volume control safely at the lower attenation points (higher volume) because it pads the word size.

Some people argue that the data loss is really not significant because as the volume is lowered its harder to hear the losses, but in the end whether audible or not it is a corruption of the signal if that matters to you.

Now for the less on topic stuff, the modwright unit has gotten rave reviews, but it was just too much more than a set of S&B TX-102s. I like transformer based passives because they don't add anything to the signal, but don't have as many issues as resistive passives (pot in a box) or digital control at the source.

Just as a side note to AudioFerret you may also want to consider TVC + UcD also. There are a few people over on DIYAudio that have reported them to be a good combination. I've had some cheaper tube integrateds here and I much prefer the TVC.

Charles Calkins · « **Reply #5 on:** 16 Mar 2006, 10:26 pm »

audioferret:
I'm using an AVA T7ECR tubed preamp with CIAudio D-200 amps. No complaints here everything sounds real good.

Cheers
Charlie

miklorsmith · « **Reply #6 on:** 16 Mar 2006, 10:27 pm »

I was using the Modwright with a Clari-T. I did sell the Modwright in favor of a TacT, for all its functions. But, I also am going to a SET amp to try to recapture the rapture of the Moddie.

Any of Phil's recommendations are solid.

opnly bafld · « **Reply #7 on:** 16 Mar 2006, 10:30 pm »

chasm3940,
What will you be using as a source?

opnlybafld

GHM · « **Reply #8 on:** 16 Mar 2006, 10:49 pm »

Yeah I definitely prefer an active preamp over the passives. Especially a tubed preamp. I've tried several class D amplifiers or regular ones with a tubed preamp. It just fleshs out more tone from the music IMHO.

All the passives I've heard sound flat when compared to a good tubed preamp.
I just can't get away from the presence of a decent tubed preamp. Too my ears it is more musically enjoyable. I've yet to hear any SS component that could take the place of what tubes are known for. I like the control of SS..this is why I prefer to use them as amplifiers in a system and let the tubed preamp supply the tone and body to the music.

IMHO it's a compromise between two components to get the sound you want. You can't tweak a passive or SS preamp to your liking. ..What you hear is what you get. You can with a tubed preamp..just by changing tubes.

gongos · « **Reply #9 on:** 17 Mar 2006, 12:03 am »

My setup sounds better w/o a preamp.

konut · « **Reply #10 on:** 17 Mar 2006, 12:22 am »

I know I'm in the minority here but I haven't used a preamp in about 15 years. While I've never tried a tube preamp I'm sure, as evidenced by the previous posts, that many are happy with the effect. I've been using a Creek OBH-12 remote passive attenuator for about 10 years and couldn't be happier with it. Its been paired with various amps and speakers and always seems to get out of the way and let me hear the differences thereof. Limited to 3 inputs, its a challenge to get everything I want plugged into it but I've always found a way to connect all the sources that I wanted going. Except for the standard supplied remote being crap, I've never had a problem with it and now use a Harmony 688 that replicates all the functions of the original. Maybe I've been lucky, but I never experienced any loss of dynamics or flatness that some experience with passives. I keep my signal runs short and use low capacitance ICs and even with runs of 1.5 meters to the amps, which reside behind the speakers, I get no loss of highs or degradation in quality. As always YMMV.

bhobba · « **Reply #11 on:** 17 Mar 2006, 12:42 am »

Very interesting question. If you are starting out please be aware by a long way the greatest determinant of the sound you will get will be your speakers closely followed by the room. Well designed amps and preamps will have a much less affect. Some even claim none at all:
http://bruce.coppola.name/audio/wisdom.html
Especially
http://bruce.coppola.name/audio/Amp_Sound.pdf

Now I am not of the school that all amplifiers sound the same - but I believe the objective evidence is they do not have a drastic affect on most sound material.

To start out what I would recommend is a simple Panasonic DVD player feeding a Panasonic XR55 and spend the rest on the best speakers you can afford. Later you can upgrade to a better source such as a bolder cable modded SB3 and amp like the van alstine amps which look very good value and try the affect of preamps. In fact Wayne from Bolder cable speaks very highly of the sound of a modded SB feeding an XR55
http://www.audiocircle.com/index.php?topic=24689.msg236108#236108

The thing is to blind test the sound to make sure it is in fact better and the dosh is not wasted.

Thanks
Bill

Tweaker · « **Reply #12 on:** 17 Mar 2006, 12:59 am »

Have you had an active pre in your system to compare to? I used to run a passive (Mod Squad Line Drive) and when I auditioned a good active preamp I was sort of stunned at what I was missing, particularily, but not limited to, dynamics. Perhaps the Line Drive was not a good passive or the amp I was using at the time had an incompatible input impedence. I still have the Line Drive. I might have to reinsert it into the system and see what happens. I have a Behringer DEG2496 that has a switch to increase the output so it might work ok. Hmm. The other thing I didn't like about the Line Drive was the volume pot had to be dissasembled every few months and cleaned as it gets noisy. It also is not remote controlled...
Never mind.
Was the above post really intended for this thread?

chasm3940 · « **Reply #13 on:** 17 Mar 2006, 01:19 am »

OPNLY BFLD and others:
Source currently is an old Yamaha (CD30) CD player. Also, am currently using the pre-amp section of my old NAD3020 integrated. Both pieces to be retired as I work back upstream from the Martin Logans and whatever power amp I decide on (probably Innersound).

Bemopti123 · « **Reply #14 on:** 17 Mar 2006, 02:19 am »

Transformer based volume, especially with ultra high quality transformers might be the reference for me, in the future. If my finances would ever allow, I would like to make a head to head comparison between my First Sound preamp and the Silver Rock control from Audio Consulting. That would be a comparison to die for. Although some would state that passives rob dynamics from music, the Audio Consulting people claim that their component is the polar opposite of all those traditional passive stereotypes, lack of dynamics and other negatives. Maybe, this is a big maybe, if their claims are to be believed, then amplification nirvana can be reach with a pair of crossed fingers and lots of $$$.

opnly bafld · « **Reply #15 on:** 17 Mar 2006, 02:28 am »

If you plan on using a new CD player as a source you will likely need a preamp.
The pre can be either passive(no gain with most) or active(with gain)
Most CD players put out @ 2 volts with many amps this is enough to drive it to full output, but some amps will need more voltage to reach full output, hence the need for an active preamp.
Another consideration might be the need for a balance control, I found with some amps and some recordings the need to adjust for proper balance, most passive (all I'm familiar with) and some active preamps lack this.
Please take into account this is all just my opinion YMMV.

opnly bafld

bhobba · « **Reply #16 on:** 17 Mar 2006, 03:25 am »

Quote from: chasm3940

OPNLY BFLD and others:
Source currently is an old Yamaha (CD30) CD player. Also, am currently using the pre-amp section of my old NAD3020 integrated. Both pieces to be retired as I work back upstream from the Martin Logans and whatever power amp I decide on (probably Innersound).

Since you already own an amp then I think the path is obvious. Simply get your new speakers and connect it to your current amp. Get used to the sound then get some equipment on loan to see if it makes a difference. I would initially start with a modded SB fed directly into your amp and work from there. AVA components look good and they do have an offer of try before you buy:
http://www.avahifi.com/

Thanks
Bill

samplesj · « **Reply #17 on:** 17 Mar 2006, 01:37 pm »

Quote from: Bemopti123

Transformer based volume, especially with ultra high quality transformers might be the reference for me, in the future. If my finances would ever allow, I would like to make a head to head comparison between my First Sound preamp and the Silver Rock control from Audio Consulting.

Transformer control (TVC) can be had a lot cheaper than those Audio Consulting units. You can get a pair of S&B txs for less than 1/6 the price of the cheapest Silver Rock. Offhand I think the Sowters are even less than the S&Bs.

mcgsxr · « **Reply #18 on:** 17 Mar 2006, 01:52 pm »

I am feeding my modded SB3 directly into a gainclone, and then on to my speakers.

Love it!

JLM · « **Reply #19 on:** 18 Mar 2006, 12:19 pm »

chasm 3940,

Your referenced quote infers that the output voltage of typical CD players are adequate to drive most amplifiers directly and that digital sources don't need RIAA equalization that vinyl do.

Pre-amps provide volume control and usually source switching. Most modern audiophle abhor tone controls that are less commonly found in pre-amps. If you already have volume controls in a digitally based system, then no, you don't need a pre-amp.

Active pre-amps also provide impedance buffering, and boost signal strength, but honestly most systems don't require it. Passive pre-amps can't boost or buffer, but provide a purer signal path.

Like Mark above I use a modded Squeeze Box (that has volume controls) directly into amplification, but like GHM suggests would like to try a tube pre-amp/buffer for improved sound.