[aktarus]

hello all,
I'm looking for a new preamp, now I've a Passive pre realised by Khozmo Audio, with a good quality ladder potentiometer. I'm very satisfied about it, but you know our hobby ... now I'd like to experiment an Active Pre, possibly a tube one.
Do you have some suggestion or experience to share with me?
thank you in advance
Best regards,
Fabio

[JLM]

What exactly are you after?  What's your budget?  IMO pre-amps are the place to add tubes (affects all sources, use cheaper tubes that last longer, avoids mixing too many different tube sounds by doing source/pre or pre/power tubes). 

Do you want typical tube colorations like warmth, bass bloat, or palpability?  Slow/syrupy and/or exaggerated sound can get old fast (many overdo it).  Or are you searching for more defined/solid imaging?  How about improved detail/dynamics?  OTOH some do tubes just to be one of the cool dudes.  Frankly I prefer to limit colorations/affects to the speakers (as every speaker has them) and keep everything else as neutral as possible.

BTW I recently owned a nice tube integrated (Prima Luna Dialogue Preminum Integrated) for 8 months and ran it against my original Channel Island Audio D-100's.  Yep, I liked it slightly better but: 1.) wasn't worth the extra investment; 2.) my speakers already have plenty of "sonic character"; and 3.) with the D-100's I can leave them on 24/7 without worries.

[CIAudio]

I've tried several tube preamps with D-200/500 MKII... my favorite of the bunch was the Rogue 99. It added some nice tube qualities without killing the bottom end and dynamics. It uses 6SN7's, which offer a lot of options for tube rolling.

[CSI]

Years ago I set up a system for my father in-law, a classical music buff. He has some really old but nice sounding B&W's that can be loose and boomy with the wrong gear. Since I had (and still have) such good luck with my very neutral D-100's (and love the way they control the bass) I put him into a pair of D-200's (original) and a ModWright preamp. He is now 94 and still listens to it on a daily basis. The combo works very well.

[aktarus]

Rogue 99 and ModWright seem to be very nice, My only concern is related the too high Gain of both: having a high sensibility Speaker (Klipsch Cornwall III, that have 104dB of Sensibility) with a such high Gain Preamplifier, my fear is to have some problem with the Potentiometer, having the habit to listen to music during the night and for this reason I like also to listen in a relaxing manner, but without loosing in dynamic, spatiality and harmonic richness ... So what do you think about my concern to use such preamp with high gain in conjunction with such high sensibility loudspeaker ???

Best Regards,
Fabio

[JLM]

You could try adding inline resistors or stepped attenuators (plugged directly into the amps).  High efficiency speakers like yours really don't need 200 wpc (unless you're deaf/soon to be deaf or play in an arena), can reveal system warts that less efficient speakers would gleefully pass right over, and as you say - make matching components harder. 

Are the D-200 MK2's still available in 26 or 32 dB of gain?  Hopefully they come from the factory so labeled.  I picked up my D-100 (originals) 2nd hand and without sending them back to Dusty.

BTW I've tried a passive pre and lost highs/dynamics with my 91 dB/w/m speakers.  Stepped attenuators worked much better, but obviously less convenient.

[aktarus]

With my Cornwall I've tried a lot of Amp (integrated, Pre+Final) but best solution is my actual

- Stepped Potentiometer by Khozmo Audio
- CI audio 200-MK2 (26db of Gain)

Really, trust me, the great woofers of the Cornwall are not so simple to be driven by few watts.
I'm happy with my Khozmo Potentiometer and with my (over boosted) Final, but I'd like to give a chance to tubes, that's all. 

[JimJ]

Rogue 99 and ModWright seem to be very nice, My only concern is related the too high Gain of both: having a high sensibility Speaker (Klipsch Cornwall III, that have 104dB of Sensibility) with a such high Gain Preamplifier, my fear is to have some problem with the Potentiometer, having the habit to listen to music during the night and for this reason I like also to listen in a relaxing manner, but without loosing in dynamic, spatiality and harmonic richness ... So what do you think about my concern to use such preamp with high gain in conjunction with such high sensibility loudspeaker ???

Best Regards,
Fabio

I owned a Rogue 66 Magnum for a little while with Klipsch Forte IIs. By far, the best-constructed preamp I've ever owned (even moreso than the Audible Illusions Modulus 3A, which wasn't a slouch in its own right). If there was a nuclear war, there would be cockroaches and Rogue Audio gear.

However, it had a static-y noise in both channels that never went away. I tried tube changes, seemingly gallons of Deoxit, nothing worked. It was just chronically noisy.

Replaced it with a dead-silent ARC SP9MKII, but I'd own a Rogue again if they sorted out the noise issues.

[jtsnead]

I have owned tube pre amps from Cary with 6ns7 tubes to Modwright with 5687 then a Dodd buffer with 6h30 tube, I liked the 6h30 the best for neutrality and not losing any dynamics and adding a little better soundstage at the time with my CLassD amp. Upgraded amps to Dsonic mono's, then changed to a Wyred 4 sound STP-SE, sound was better but I missed what the tubes added so I bought a AR LS 17SE which is fully balanced using 2 6h30 tubes and that is what I was looking for, dead quiet awesome imaging, bass, treble etc. I feel the 6ns7's are the closest to the 6h30 but with a little more tube warmth. Any other type tubes are more of the tube sound and also can be noisier. The 6h30 is a great tube for long term use and readily available in new forms that perform as good as the NOS variety, again in my opinion.

[Quiet Earth]

With high efficiency speakers such as Klipsch Cornwall you can have as many watts as you like but the gain of the power amplifier should be low. 26dB is probably too much gain for a Cornwall. A good example of a low gain power amplifier with a decent amount of wattage is the Quicksilver Horn Mono. 

When you put a 10 dB pad in front of a high gain amp, you still have a high gain amp but now it has a pad in front of it. Yes, the preamp noise is attenuated by 10 dB but any self noise of the power amp is not. More importantly than that, rarely does a pad have a friendly output impedance to the input of the power amplifier. That is why the sound becomes lifeless and boring when you pad an active preamp.

Gain staging. It's not easy for the high efficiency crowd in the modern world. (High efficiency meaning speakers greater than 96dB/1W/1m)  If you want an active tube linestage you are probably going to have to ditch the high gain amp. (Ask me how I know....  )

[aktarus]

So, if I understand right, you are suggesting me to change my loved Final (CIAUDIO D-200mk2) for a lower gain Final, and stay with a passive preamp

[CIAudio]

Tubes inherently have high gain. In a system with highly efficient loudspeakers, the gain of a preamp is unwanted. The combination of a passive and D-200's should work great.

If you wish to add tube coloration somewhere, you could try a tube buffer but I've never heard one I like (although I've heard good things about the Dodd).

If you decide to buy a tube preamp, I can lower the D-200 gain to around 20dB by adjusting the input stage feedback (not a pad/divider network).

[aktarus]

I'm in Italy... Too expensive operation for -6dB operation, how much will cost such operation? In terms of money and time?
More, it seems that doddaudio has some problems: no site, no info, nothing than some (very good) reviews ... Mmmmm.

[aktarus]

What do you think about the EasternElectric MiniMax BBA as a passive pre with buffer stage?

[CIAudio]

I'm in Italy... Too expensive operation for -6dB operation, how much will cost such operation? In terms of money and time?
More, it seems that doddaudio has some problems: no site, no info, nothing than some (very good) reviews ... Mmmmm.

Sadly, Gary Dodd recently passed away, so I don't know the state of the company.

[CIAudio]

What do you think about the EasternElectric MiniMax BBA as a passive pre with buffer stage?

I have never heard one... but worth a try if you can find one locally.

[aktarus]

Some experience of somone having D-200 mk2 and an high efficency loudspeaker?
My actual decision is to try the minimax buffer preamp, but to stay with D-200 mk2

[jk@home]

Don't own the CI amps, but I've tried four different tube buffers over the years with my VDA-2 DAC, and the iFI iTube that I am currently using has been the only one I felt actually improved the system with no downside. Pretty much saved me from wanting to buy a new tubed DAC any time soon.

[Quiet Earth]

So, if I understand right, you are suggesting me to change my loved Final (CIAUDIO D-200mk2) for a lower gain Final, and stay with a passive preamp

No. I am saying that your amplifier and speaker are probably too efficient to add a tube preamp. You would have loud music with the volume control just barely up. And it might sound a little congested, pinched, or fatiguing in the long run. (Too much gain.) But there is really only one way to know. Can you borrow one? (A tube preamp.)

If you like your amplifier with your speakers you should probably keep it the way it is.

If you want to change the flavor of your passive pre you could look into a passive transformer volume control, a buffered passive, or some other type of passive volume control.

If you want to add tubes to the mix, how about a tube DAC or tube phono stage?

[kernelbob]

Try a Tortuga passive preamp.  They use light dependent resistors for volume control.  There are no switches or potentiometers in the signal path.  I'm using a balanced version which lists for around $1800 and sounds superior to $10k and higher preamps (I previously used an ARC REF3).  I suggest opting for the optional higher grade copper wiring.  That's only a $50 option.

This is the first and only passive preamp I've heard that has all the bass power and slam that I previously only heard from actives.  Very clean, yet palpable sound with all the soundstage width and depth you could want.  They use a software controlled self calibration system so attenuation levels and balance stay spot-on.

Check out the Tortuga website at www.tortugaaudio.com.  I have no affiliation with the company other than being a very satisfied customer.

Regards,
Robert