[lcrim]

I have a bedroom system that includes a Decware Select amp.  It can be used as an integrated as it has a volume pot around back.  I have been running this system w/ a preamp for a while for a couple of reasons.  Partly it was to get enough gain to run an analog front end comfortably and partly it was to have the additional outputs for a line level output to a sub.
Yesterday I took the preamp out of the circuit and learned a few things.  I have a rotary switchbox that has six inputs for the single output to allow numerous sources.  After swapping the speaker leads around because there was no longer a preamp inverting absolute phase, it seems that I don't really need the additional gain.  First I  realized that the new phono section (Jolida  JD-9) even with a LOMC has more than enough gain all by itself.  The digital sources @ 2 volts can drive the amp to full output w/o any additional gain.  Other than losing the use of the sub until I can get some Y adapters there really is no downside.
The sound is less colored and sounds cleaner and maybe I'll hate it in a week but for now I am enchanted.  Granted I now run the risk of more burn "tatoos" from the Select as you have to reach around back to get to the gain knob but it does sound better.
I think that simpler is better.  Dynamics are scaled down somehow but musicality has improved as distortion is reduced.  Detail retrieval at lower volume settings is terrific. 

[PaulFolbrecht]

Larry,

It generally takes a very expensive preamp to sound better than no preamp.

If possible, use high (speaker) level inputs to your sub.  It always sounds so much better - better coherency.  You'll also save your source the burden of driving the sub as well.

[JLM]

Isn't this exactly what Steve Deckert says of his amps?  (Read his pre-amp papers.)

BTW simplier IS better.  (Owner of single driver speakers, chip based monoblocks, single source, and no pre-amp system.)

Every time I think about adding a tube pre-amp (to improve imaging, depth of sound stage, and tube magic) I run across another account like this that makes me a bit more content to stay with what I've got.

[Bob Reynolds]

I also use a Decware amp (in my office system) with a NHT PVC so that I can biamp with a powered sub. IMO, taking the bass load off the amp more than compensates for any issues wrought by even an inexpensive preamp.

[lcrim]

The sub really doesn't add to the amp load as it is a powered sub.   Some time ago I tried speaker level ouputs w/ that sub and it apparently changed the load that the amp was seeing, unlike most SET amps the Decware thrive on low rather than high impedance.
My tastes may have evolved but listening w/o a sub hasn't made me miss it.  The speakers are Parker 95 MKII's, a nice match for the Select because of their low impedance, and are rated to 55 Hz. That's not very low but like the guy said, everything sounds more coherent so I may not mess w/ it.

[mcgsxr]

Those speakers look very interesting, I have not heard of them before - nice use of wide range drivers, thoughtfully augmented by the tweeter.

Nice catch Larry, glad the synergy is working out well too!

[seraph321]

I built my latest system on the idea of the simplicity of a modded squeezebox connected directly to my amp. No need for a preamp because the SB has a digital volume control. Well, it's good, but now I'm about to add a Modwright SWL 9.0. I'm convinced that I'm getting extremely accurate playback, and it's plenty loud enough, but it's just not drawing me in like it should. I've heard the Gallo ref3s sound so much more alive than this, and it's always when there are tubes in the chain. The best I've heard them sound was with a tube integrated, but I'm thinking the modwright will help a lot. Plus, I'll finally be able to hook up other sources when/if I want to.

[Bob Reynolds]

The sub really doesn't add to the amp load as it is a powered sub.   

You're right - the sub does not add to the amp's load. But, if you're not high-passing the main speakers then you are sending a full range signal to the Decware amp which does add to the amp's load. One of the advantages of a powered sub is biamping with its amp. I use a little M&K BMC Mini for that purpose with my Zen amp.

[Paul_Bui]

Isn't this exactly what Steve Deckert says of his amps?  (Read his pre-amp papers.)

BTW simplier IS better.  (Owner of single driver speakers, chip based monoblocks, single source, and no pre-amp system.)

Every time I think about adding a tube pre-amp (to improve imaging, depth of sound stage, and tube magic) I run across another account like this that makes me a bit more content to stay with what I've got.

Hi Jeff,

I used to agree.  Whether it's true (the simpler the better) or not I guess is depending on how good the tube preamp is.  Please see my response to seraph321 below.

[Paul_Bui]

I built my latest system on the idea of the simplicity of a modded squeezebox connected directly to my amp. No need for a preamp because the SB has a digital volume control. Well, it's good, but now I'm about to add a Modwright SWL 9.0. I'm convinced that I'm getting extremely accurate playback, and it's plenty loud enough, but it's just not drawing me in like it should. I've heard the Gallo ref3s sound so much more alive than this, and it's always when there are tubes in the chain. The best I've heard them sound was with a tube integrated, but I'm thinking the modwright will help a lot. Plus, I'll finally be able to hook up other sources when/if I want to.

Can't agree more.  Although I am not a ModWright SWL 9.0's owner, I know Dan Wright back when he modded my Sony 9000ES.  In addition, the rave reviews from many reviews including Srajan whose ears I trust.  Congratulations!  Please let us know how crazy you are about it once the preamp lands on your doorstep. 

Like you, I intended to stay minimalist using a modded SB2 connected directly to a Patek SE.  No need for a stinking tube preamp which seems to color the sound, but where's music gone?  I didn't want to hear what Srajan said, "A good tube preamp like the ModWright or MiniMax is 'the hammer' with the Patek and what I think truly makes it perform like a $10,000 amplifier of any persuasion. That's what I'd recommend - a good but not silly-money tube pre." , but here I am, ending up owning a SinglePower MPX3 Special Edition double-functioning as a headphone amp and a preamp.  How right he is!  My buddy Gymane (GHM) must receive credit for talking me into this.     

Since the SP MPX3 arrival a couple weeks ago, music has come back in my room.  Violin masterpieces played by the legendary Arthur Grumiaux have never sounded this sweet.  Overall, music takes on a substantially more solidified foundation accompanied by a richer meatier midrange and extended yet silky smooth highs.  Organ tracks suddenly became more realistic, not only due to the above mentioned solid bass but also the magic airy ambience of the surrounding hall that has been missing without the preamp.

What I describe so far is about the unit used as a tube preamp with stock tubes.  Used as a headphone amp which is the major reason for its existence, the MPX3 SE is worth an entire separate topic, whose narrative would be off topic here.

[PaulFolbrecht]

Guys,

I am at or near the end of an 18+ month amp-trying oddysey.  Amp and preamp, that is.  I went through it all and tried just about it all, except for class A solid-state.  High-power solid state, push-pull tube, class D (NuForce and Bel Canto, but not CI), and tube SET.

I found that with anything BUT a tube power amp - especially a SET - a tubed pre was indeed "necessary" to get proper soundstaging, decays, and harmonic density.  That is, I needed that pre *except* with a good SET.

This is what drew me to the endpoint of single-ended triode amps with a passive, transformer-based linestage.  Believe me, I DO have soundstaging, tonal density, and a very quiet and dynamic system as well.

I cannot say for certain or unequivically that this is the "best" setup, but it allows me the *simplicity* of no active preamp without *any* of the drawbacks to that, as far as my ears are concerned.  When I realized this, I decided I'd rather have amps that need nothing added to them* then those that do.

Paul

* I can't say for sure whether a (tubed) pre "adds" or just "keeps alive what NO pre would have lost.

P.S. The Red Wine 30 counts as a tube amp.  I think Vinnie rubs tubes on them before shipping or perhaps grinds tubes and spreads the dust on them.  Something of that nature.

[PaulFolbrecht]

Oh yeah I happen to have a ModWright 9SE for sale on Audiogon. :-}  No doubt, it with a number of switching amps is a very nice combination.

[Paul_Bui]

Guys,

I am at or near the end of an 18+ month amp-trying oddysey.  Amp and preamp, that is.  I went through it all and tried just about it all, except for class A solid-state.  High-power solid state, push-pull tube, class D (NuForce and Bel Canto, but not CI), and tube SET.

I found that with anything BUT a tube power amp - especially a SET - a tubed pre was indeed "necessary" to get proper soundstaging, decays, and harmonic density.  That is, I needed that pre *except* with a good SET.

This is what drew me to the endpoint of single-ended triode amps with a passive, transformer-based linestage.  Believe me, I DO have soundstaging, tonal density, and a very quiet and dynamic system as well.

I cannot say for certain or unequivically that this is the "best" setup, but it allows me the *simplicity* of no active preamp without *any* of the drawbacks to that, as far as my ears are concerned.  When I realized this, I decided I'd rather have amps that need nothing added to them* then those that do.

Paul

* I can't say for sure whether a (tubed) pre "adds" or just "keeps alive what NO pre would have lost.

P.S. The Red Wine 30 counts as a tube amp.  I think Vinnie rubs tubes on them before shipping or perhaps grinds tubes and spreads the dust on them.  Something of that nature.

Yours is an excellent case of good sound without complication.  Everything being equal (musicality, satisfactory playback quality), the simpler the better indeed.  I guess I was forced to go the tube-pre route in order to find the synergy of components already existing in my setup.

[lcrim]

Last week I posted about passive transformer volume control preamps asking about the Django from diyhifisupply.com.  There was suggestion to try out the TVC from Promitheus Audio in Malaysia.  I couldn't pass it up @ $340.  I want to try it out in both systems both with the Decware and the Eastern Electric Minimax.  I like what the EE preamp does with its companion piece but you don't know until you try different combinations.  In any event I now have more preamps than good sense.

[PaulFolbrecht]

The EE unit is a wonderful preamp.

[andyr]

If possible, use high (speaker) level inputs to your sub.  It always sounds so much better - better coherency.  You'll also save your source the burden of driving the sub as well.

Hi Paul,

Could you possibly explain the above statements of yours?  (BTW when you say "sub", I assume you mean a powered sub?    )  I'm in the process of building up a powered sub kit so this is timely information.

Why does using speaker-level inputs to a sub make it more coherent?   

Why is it good to "save your source (preamp) the burden of driving the sub as well"?   

Thanks and regards,

Andy

[PaulFolbrecht]

Hi Andy,

Yes, I was talking about powered subs.

Most subs have both low (line-level) and high (speaker-level) inputs.  The latter tend to sound better - the sub is getting the same signal as your main speakers.  Even though you're running this from your amp, it's no power drain on the amp - it's just using the signal to drive its internal amp.  It may be just related to phase (and thus could be adjusted out), but as I said, the low-level inputs usually sound a bit disconnected from the music, many find.

As for driving the sub via low-level, I was talking about the *no preamp* case ("source" here means the digital source, specifically *not* a preamp).  If you have an active preamp, no sweat at all - any such unit certainly has the current reserves to drive two ouputs, including long interconnects.  With a passive linestage or no linestage at all, it's a different story.  Some people will do this (2 amps, long ICs) with TVCs, which of course convert extra gain (voltage) to current and thus have better drive capabilities than resistor-based passives, but again a resistor passive or source-direct is different.

The problem is that dynamics can suffer because the source must provide all current needed to drive the amp(s).  With a Y-connector off the source, driving two amps, one of them probably with long ICs, I think dynamics are bound to suffer - probably seriously - as the current-delivery capabilities of almost any source is going to be seriously taxed.

So, if you're using a resistor-based passive, or source-direct, really try to avoid driving two amps (such as a sub) and long ICs as well.  This is the common wisdom.  I have found it to hold true with passive (resistor) linestages.

[Bob Reynolds]

Andy,

You may find this article of interest: http://www.mkprofessional.com/bass_mgmt.htm

As Paul stated, many subs have both line-level and speaker-level connections. M&K recently started supporting speaker-level connections in their consumer products for additional flexibility, but it is not their preferred method of connection.

The comment "The latter tend to sound better - the sub is getting the same signal as your main speakers." really does not make any sense. If there is such a thing as the "character" of the main amplifier, then what about the "character" of the amp in the sub? Doesn't that goof things up?

When an active external xover (bass management controller) is used between the preamp and amp, you have the greatest chance of obtaining a seamless integration of the sub with your main speakers. The other advantages of using a BMC is that you are now biamping with the sub which will lessen distortion of the main amps and main speakers. It's really a win-win.

Just my $0.02.

-- Bob

[PaulFolbrecht]

The comment "The latter tend to sound better - the sub is getting the same signal as your main speakers." really does not make any sense. If there is such a thing as the "character" of the main amplifier, then what about the "character" of the amp in the sub? Doesn't that goof things up?

Sure it does, Bob, you just missed the point.  This is what REL recommends and, I believe, Velodyne as well (I'll check the manual for my Velodyne sub tho it may not be in there).  REL's website has a paper regarding the benefits of using high-level inputs.  Here's an excerpt:

"High-level connection, using the enclosed cable with the Neutrik Speakon connector,
is always the first choice. By connecting to the amplifier’s speaker outputs the sonic
signature of the entire amplification chain is folded into the signal for the sub, thereby
keeping timing and timbre cues consistent. In other words, the signal sent to the REL
is exactly the same signal sent to the speakers, allowing for seamless integration. This
connection can be made without affecting the performance of the amplifier because
the sub’s amplifier input impedance is 100,000 ohms. This scheme also avoids adding
any detrimental effects by not interposing any additional electronics into the
amplification chain."

You are correct (of course) that the signal is still then amplified by the sub's amp.  But the signal it's using is still going to be closer in phase to what the main speakers are driven off of.

Who knows more about subs than REL?  Are they a bunch of idiots?

[Bob Reynolds]

Paul,

I realize that's the approach REL uses and one of the reasons I did not buy a REL sub. Vandersteen does the same and as much respect as I have for Richard, I've never bought the speaker level connection argument. Richard does try to regain one of the advantages of using line level connections by passively high-passing the main amps/speakers in such a way to flatten the response of the entire speaker system.

In the audiophile community there seems to be a fear of putting anything additional into the signal chain, so from a marketing perspective the REL approach has merit. Since that's not a concern of mine, I chose the advantages of line level connections + BMC.