[Folsom]

I can't decide which to build...

Pass B1
Bottlehead Quickie
DODD Audio Buffer

I would love to power the second two with a switching power supply connected to my power conditioner... but if I'm not mistaken there is a reason you want to not do that? Either way I think as we've learned with say Squeezeboxes, cheapo switching power supplies sound good.

[JoshK]

Unless you know you need gain, you likely don't.

I think your list is good, except that you might consider the Aikido Cathode Follower circuit (tube based no gain buffer)...as an alternate.   The Pass would be my other top choice.

[Folsom]

I have zero desire for gain, but that said a tiny bit wouldn't hurt.

I just want to lower impedance so all my sources sound better. My phono preamp is the lowest at 330ohm but combined with my 10k stepped attenuator it goes up a lot. Other sources (1/8 for ipods, tuner, etc) are not so low...

[roscoeiii]

Yet to hear a passive that doesn't negatively impact dynamics and the "oomph" factor. But that said, I think that your goal to reduce impedance is a sound one.

Seems passives are tricky overall, and require careful equipment matching to perform optimally.

[Folsom]

The reason I want to get away from battery power is to not lose the umph. I got oogles of that and want to keep it.

[roscoeiii]

Makes sense. But to make sure you are getting maximum oomph, I suggest comparing active vs. passive options in your system if possible.

In my experience batteries and passive have similar effects in this regard. But if I were going to bet on a passive that does the least of this, I'd guess it is one that offers a low impedance signal to your amp.

[rodge827]

The reason I want to get away from battery power is to not lose the umph. I got oogles of that and want to keep it.

I had the Warp Speed Optocoupler as a pre and had oomph to spare.
Runs off a 12v sla battery with no gain.
I had it coupled to a low input (.25v) high gain ss amp with a Buffalo 32s dac.
Plenty of dynamics as well as micro details...very musical. 

[G Georgopoulos]

In my experience batteries and passive have similar effects in this regard.

I disagree,battery preamps are similar to active!

[Folsom]

Where do you get the warpspeed piece at? It seems to me like I could just replace my volume control and achieve my goals?

[jk@home]

I went from a CI passive to a Goldpoint passive plus Dodd buffer. Did wonders for my system, major improvement in resolution.  My power amp didn't need gain, just a low output impedance source to the amp (Aragon 8008), which has a low input impedance at 22k.  My Dodd unit is a condensed hot rodded version, I do the source selection upstream. Highly recommended. See Reply #1172

http://www.audiocircle.com/index.php?topic=79766.1160

[roscoeiii]

Where do you get the warpspeed piece at? It seems to me like I could just replace my volume control and achieve my goals?

There are massive threads on the Warpspeed. Many folks love it. But IIRC, it will not serve as a buffer that will lower the impedance in the way you suggested you wanted. I could be wrong.

[Folsom]

Hm well my volume control works pretty well; it has all dale resistors.

I just did a small mod to my system in the last hour and now I'm shocked. I hope a preamp couldn't be a downgrade!

I would like voices to be a little more textured and present (not bad already), and drums to be a bit more convincing. Piano sound like one is in the room already.

[Early B.]

I had the Warp Speed Optocoupler as a pre and had oomph to spare.
Plenty of dynamics as well as micro details...very musical.

Ditto. When I first hooked up my Warpspeed, I was astonished because it had the most oomph and dynamics I've ever heard in my system, and I've used active and passive preamps in the past.

[rodge827]

Where do you get the warpspeed piece at? It seems to me like I could just replace my volume control and achieve my goals?

Hi DoS,

Allan Flores is the guy who makes the Warp Speed Optocoupler.
He can be found on the DIY Audio.com site under the moniker "Blues" or contact him via email at: afdflores@msn.com.
He will be glad to discuss the Warp Speed with you and see if it will fit your needs.

 

[Folsom]

Well it certainly sounds intriguing. Still not sure about what preamp to back it though.

Thanks for the contact info. I found lots of information on it but the problem is there is so much information I wasn't sure where it originated from.

[TrungT]

This is not DIY but for those LDR fan want fully remote control LDR passive preamp.
http://www.tortugaaudio.com/

[clydethecat]

I can't decide which to build...

Pass B1

There's also a choice between the AC-coupled B1 using the boards from PassDIY, or the direct coupled "Mesmerize" B1 board from DIYAudio which includes on-board input switching and dual Salas regulators.

[Folsom]

The direct coupled one certain looks interesting.

[HT cOz]

Urish Dailey recently relesed his fully remote contolled LDR lighter note kit. I like that option with a Dodd buffer that can be switched into the path.

[rklein]

Yet to hear a passive that doesn't negatively impact dynamics and the "oomph" factor. But that said, I think that your goal to reduce impedance is a sound one.

I would have to mildly disagree with this comment.  I currently am using a Bent Audio TAP passive pre (Ted_b's unit) with my NCores and believe me when I say that I have dynamics in spades and yet the TAP has an incredible transparancy to it as well.  However, the TAP or the newer TAP-X should not be part of this discussion about inexpensive preamps!! 

I recently bought an Exasound E20 DSD capable DAC and was VERY impressed with the E20's volume control.

Regards,

Randy