recommend full featured preamps?

For dirt cheap and better than many thousand dollar preamps, a good Dynaco Pas 3 is still hard to beat.

Roger Modgeski of Music Reference/RAM Labs is working on a tube preamp in the $1,000 range that uses tone controls. He was looking to design controls that overcame the problems of tone controls and the sonic damage they do. I think they may actually be available now. I don't know if he succeeded or not, but I do know he is one heck of a good audio engineer. I'm sure he would be happy to talk to you about. I think it is part of his SET series of components.

"I think their impedence curve does dip down to almost 3 ohms at one point."

That's probably a red flag with most any tube amp.

What is the amps rated output in 8, 4 and 2 ohms? If it does not double each time or come close, that could well account for the poor bass response.

My speakers are Infinity Prelude PF-R, which are highly efficient - but I think their impedence curve does dip down to almost 3 ohms at one point. The Baron is not like other tube amps, its output is more dependent on the speakers' imp. curve., but seems to work ok (it is very adjustable). The Preludes do have switches for adjusting the bass output, but they just make it boomy - the wrong curve for my needs, I guess. I do have a rug in front of the speakers, but more work on early reflections is probably a good idea. TV monitor is between them, unfortunately, but speakers are forward enough to avoid 1st reflections from tv's edges. Thanks to everyone for all the thought and suggestions.

Have you considered 'tuning' your room?
I know what it is like to be space/layout constrained, but just maybe, a few small adjustments would help.
Something for first reflection....a dense wool tapestry like I use or some carpet directly in front of the speakers.
Extra points scored for good imagination here.

Just may help!

Lloydc,

What are the speakers in your system?

Often, the problem you describe with bass at low levels can be due to a mismatch between amp and speakers, especially with tube amps and lower efficiency speakers that have a more complex load to handle.

For example, I'd love to have your amplification but I have yet to discover a tube amp that could drive my fussy Ohm 5's properly (believe me, I'm still looking but am not hopeful).

I replaced a 360w/ch SS Carver m4.0t with a 100 w/ch Musical Fidelity A3CR for exactly the same reason, poor bass at lower to moderate volumes. The Carver actually went louder and sounded great doing it.

If this is the case with you, then tone controls might help compensate but better matching of amp and speakers could correct the problem and negate the need. It did in my case. I don't think I've touched the tone controls on my Carver preamp since.

Tandberg, from the early to mid-80s. As sweet a sound as you'll ever hear and very well-built...Great phono sections, too!

-RW-

I GAVE AWAY a NAD1700 tuner/preamp.
It had too many features to list, but the tone controls
were triple turnover for bass+treble.
Decent phono section, too.

I bought it in about '87 and I think it had a few more years in it.

That's a good pre-amp to start with.

Any idea why the tone controls are needed?

Can't you do some tube rolling with that model to tweak the sound?

Thanks for the suggestions. I'm currently using an AR LS-15 preamp, Mesa Baron amp, EAR 834P phone pre. I have a backup pre, a DB Sytems 2B with excellent tone contols, which was very good in its day, and generally considered better than anything by Carver, but it is a high-feedback ss design, not equal to the AR/EAR. I was hoping for something I could potentially afford that wouldn't be too much of a step down. I have tried various preamps and devices over the years, always been disappointed at the electronic "veil" all forms of eq introduce, not least of which are phase issues, so I am aware of the downside of tone controls. In theory, flexibility could more than make up for it. I will (save up and) look into Mac and Accuphase. The points above about the Mac's flexibility are pretty persuasive.

Also, the low cost for the Carver used today is a big plus. It provides lots of features but sounds VERY GOOD even without them. Over time, you may find ways to tweak your system using it that results in not needing the flexibility in the pre-amp anymore. Then you might look at moving up to something even better, though I truly believe the C-6 is nothing to sneeze at in regards to sound quality.

I'm almost to that point myself. If I can find a SS amp or hybrid with sound that is more like the tube emulation outputs on the Carver than the SS, and I can use my DBX without issue when needed, I think I am golden. I haven't quite decided what that is yet though, so for teh time being, my Carver is still the man.

Undertow,

The Carver holography circuit is what I thought you might be referring to.

It has nothing to do with compression or dynamic range. If your system lacks transparency, think of it as a magic "transparency" button.

technically, it reduces crosstalk between channels. I suppose crosstalk would be considered a form of noise and that circuit then a form of switchable noise reduction.

Wouldn't surprise me if many other newer amps that sound inherently transparent do something similar internally to achieve it. The most unique thing about the Carver is the circuit can be switched in or out as needed. That is the flexibility aspect of it. And yes, it does work exactly as advertised. The tradeoff is a small change in the timbre of the sound, particularly in the mid-range.

I used to use the holography circuit but then realized there were other ways to coax more transparency out of my system that I pursued (power conditioning, interconnects, setc.). Now I do not use it much. But it was nice to have around back when I needed it.

The features I still find most useful on the Carver today are the two switchable circuits for separate signal processors. I use 1 for a dbx range expander that still comes in handy with dynamic range-challenged recordings.

Also, the tone tilt feature I mentioned can be useful to provide flexibility in adjusting tone/timbre in ways not possible with conventional tone controls.

There is an absolute phase shift circuit that can help with the low end if needed, depending mostly on room acoustics.

The blend control can also be useful. It provides the ability to continuously increase or decrease channel separation all the way from mono to greater than normal.

I find I use these features very infrequently these days (the separate DBX the most because many recordings just have the dynamics sucked out of them before they even hit your system) but they have been invaluable tools to help me get my system tuned in better over the years when needed.

Mapman,
I remember now its called the "Holography" circuit... Its pretty nice for those compressed recordings...
I was not really knocking the carver as it is for the price its not bad, you can find some of the Mcintosh pres for 500 to 700 with all the features from the late 80's early 90's same era that are a bit better for a couple hundred was all I was illustrating.

As for the Behringer its okay, but really a cheap piece that is a pain to work with for most people, too many gadgets and features that have nothing to do with straight 2 channel full range speaker useage, and results will vary with much time needed to sometimes get dialed in or be effective correctly.. And then buying one used for 150 or 200 bucks might as well go with a mcintosh, its a better unit period in my opinion, well built, and eliminates all the EXTRA cables and conversions from XLR to RCA using a unit from the Pro audio realm...

Carver pre-amps like the c-6 have a lot of unique features that you may or may not find useful. I'm sure Mac does as well, but I am reasonably certain that each has a different set. So it is not an apples and apples comparison if you are looking for particular types of flexibility. You need to do the research and determine, if that is the way you want to go.

A separate digital equalizer device like the BEhringer suggested by Vegasears will cost more as well but could prove to be most effective, at leat for digital sources if not analogue, if needed.

Loudness is one of the more useless features on the Carver as it is with most preamps. I've never used it. There are many other unique features you will not find elsewhere that I have used to very good effect from time to time. There is greater flexibility in adjusting the tone controls using a tilt feature in combination with the actual tone level controls that you will not find elsewhere and I have found to be quite effective in getting levels set just right when needed without a separate equalizer.

There is nothing on the Carver that deals with "natural noise" that I am aware of, though I'm not sure exactly what that means.

You might find a Carver in good operating condition for $300. You won't find a Mac most likely in that range. If the cost is not a concern, get a Mac if that is what you prefer. A Carver c-6 pre sold for $900 almost 20 years ago, so it was never "cheap"...it is a very respectable unit. It has held its value pretty well over time I would say.

I been very satisfied with mine for almost that long. The only piece I own that I've held onto for longer is the Linn Axis turntable.

Stick with the mcintosh.. Not even close to carver, carver is okay for 300 bucks used, but sometimes no remote, and the loudness turned on sounds like you are hitting a plastic garbage can in the garage... They have that goofy other mode I forget the name it adds some nice effect, some natural noise thing or something.. Harmonic something or other...

Anyway most of your Preamps with Bass only knob is just a 100 hz boost.. But with a mcintosh pre you get the 5 band eq, which the bass range knobs start at 30 hz which is very low and very nice to get that just slight bump in the room loading feel like a subwoofer, and then you can kick up the 80 hz as well, and the 120 hz range in the mid bass etc...

And Mcintosh has the variable loudness knob, so you can choose how much db in loudness you want to add, not just an on full blast loudness or off button. And the mcintosh sounds more full and warm in the SS realm nearly tube. And resale value in most cases is better you would barely loose anything if you decide to move on again.

Vegasears,

Yes, that Behringer unit could be just what the doctor ordered with a good but less flexible pre-amp. Good call!

another angle

http://www.proaudio.com/product_info.php?manufacturers_id=72&products_id=2198

"The addition of tone controls in your system will only compromise fidelity."

I would agree with the audio purest perspective that use of tone controls are better avoided, if possible, but sometimes it isn't for whatever reason and the advantages of adjustable settings and options can far outweigh the disadvantages compared to the alternatives.

If pre-amp flexibility is critical to your application, a properly functioning second hand Carver pre can likely do the trick without breaking the bank.

Would need more details about your system and setup to suggest how you might avoid this, if possible.

the accuphase line of pre-amps is one of the most intensive ive seen with bass, treble, balance (left and right), some models even have db gains. mono switch, loudness compensation switch as well as other nice goodies.
And they also sound great!

The addition of tone controls in your system will only compromise fidelity.

Best I could tell you is pick up a used Carver pre-amp. These can be had for not much, are very good and have lots of flexibility features if needed. Get one like the C-6 in my system that has separate pre-amp outputs voiced to sound more like a tube pre-amp than SS, if you have leanings towards tubes.