Passive pre amps

organ

The last conversation I had with several Polkies was about passive pre's and the synergy needed to get them to perform with great dynamics and both frequency extremes.

Last night I decided to try out my ASL autoformer passive into my current set up. My AZ Amp-2 are extremely sensitive at their inputs. The slightest amount of noise (from upstream components) that won't show up with other amps can clearly be heard on the AZ. Also, could be that the entire signal path in the amp is less than 4" or 2.5" (can't remember exactly).
My dealer kept telling me that a passive is the most ideal for the AZ, but I guess I was having too much of a blast with another active pre and haven't really played with the passive in a while. Makes perfect sense. That combo provides the most simple and shortest signal path. I was worried my RT1000's wouldn't be sensitive enough, but OMG!!!:eek: This combo is absolutely stunning. Sounds like the soundstage got pushed back several more feet, no loss in dynamics or HF and LF. Background became noticably darker. Images are more stable and there is an increase in smoothness or "flow" of the music. The images are also larger now, in fact, quite big compared to running my active. Any hint of harshness that was present before has been completely eliminated. Hearing those tri-laminate tweeters do their thing is something I've never grown tired of since I got into Polk 11 years ago.

Man, when the synergy is right with a passive pre, it's quite a trip! So who else in here use a passive?

nikolas812

Interesting.



I keep hearing about the exact same things you experienced with a passive pre. I'll have to try one down the road for sure.







Nik

Face

Glad to hear one worked out for you.

Early B.

organ wrote: »

Man, when the synergy is right with a passive pre, it's quite a trip! So who else in here use a passive?

I do. There's no need for a bunch of extra electronics in the signal path.



BTW -- God parties with a passive pre.

strider

I've been running a passive buffer pre for about 6 months or so. I enjoy it.

organ

Cool. Glad to hear others are enjoying their passives as well.

Nikolas,
Definitely give them a try. YOu can always re-sell if you don't like it and used ones can be had at good prices.

Early,
That's true. With my actives, thhe sound is more 'electronic', hard to describe, but that's the only word I can think of to decribe the difference.

reeltrouble1

sounds great, this hobby always holds suprises.

RT1

organ

So true lol.

rubin

Congrat's to your improvement

zingo

I really enjoyed my B1 when I had it. It's pretty cool being able to pop the hood on your pre and tracing the signal path with your finger in just a few seconds. I have a feeling that I'll miss the B1 once I move away from my PC rig, but then I'll probably just build another one...

rubin

Which will provide more satisfactory/musical results, a passive,a ss,or a tube pre?Just curious.I know it's all about synergy,so then would active preamps, ss or tube, colour the sound compared to a passive?

zingo

That question has close to a thousand answers and at least that many hours worth of discussion...

rubin

zingo wrote: »

That question has close to a thousand answers and at least that many hours worth of discussion...

I'm all ears, and ready to learn. Ok then, how about passive vs tube pre?

venomclan

I am dying to try a Placette.

Early B.

venomclan wrote: »

I am dying to try a Placette.

Yeah, Placette is the truth.

organ

Rubin,
Like Zingo said, it's hard to say. For me, the passive has been a hit or miss kind of thing. When it's working out great in a given system, the sound is really something. When the synergy is not right, it can sound slow with less dynamics and a cut off at both frequency extremes can occur.
For me, I prefer the passive when it's working out great. It has a more natural sound to it. But that's just IMO.

Early B.

organ wrote: »

Rubin,
Like Zingo said, it's hard to say. For me, the passive has been a hit or miss kind of thing. When it's working out great in a given system, the sound is really something. When the synergy is not right, it can sound slow with less dynamics and a cut off at both frequency extremes can occur.

I think part of the problem is that the use of a passive requires doing some homework, and audiophiles are a lazy bunch of ****. It ain't plug & play like solid state. For instance, you gotta pay close attention to the specs of your interconnects. A passive can help you learn, in part, how synergy is created.

Many people who tried a passive simply popped it into a system that wasn't appropriate for it, then proclaim that passives lack dynamics. To make the issue more complex is the fact that there are a variety of different passive designs. A particular passive pre may sound great on one system, but not on another one. Or change the cables and it sucks. Or have a weak source and the passive gets blamed for it.

Another issue is when the passive is doing a fantastic job -- too good, in fact -- and the passive gets blamed because it reveals the flaws in the system where the real culprit could be anything connected to it.

organ

I learned all that the hard way by being lazy lol.

Early B.

organ wrote: »

I learned all that the hard way by being lazy lol.

Me, too.

strider

Early B. wrote: »

Another issue is when the passive is doing a fantastic job -- too good, in fact -- and the passive gets blamed because it reveals the flaws in the system where the real culprit could be anything connected to it.

That's the issue I ran into right off the bat. I couldn't stand to listen to my turntable after I started running my passive. Previously I could't get enough of it. Changed a couple small things with it and it become more listenable; right now I'm stuck with it as my CDP is being repaired.

Face

To add to what Early B. said, a high voltage source helps with passive preamps. My DacMagic puts out 2.1v(IIRC) and drives my McIntosh MC-7270 with ease.

Another issue that people may run into are impedance mismatches. Some research on their component's input and output impedances is needed beforehand. The only way around that is to install a buffer style preamp like the Pass B1. Interconnect length should also be kept as short as possible.

That being said, I really enjoy my Goldpoint SA-4HT and Pass B1's. The Goldpoint is stepped attenuator, allows 4 sources, and has HT Bypass. I use it in my Tannoy HT/2 channel rig. The Pass I move around in my other rigs. One other thing about the B1 is that is has a few caps in the signal path, so you fine tune the sound of your rig by swapping in different caps. But if you're looking for the ultimate in transparency, you should check out a stepped attenuator or transformer based passive.

strider

Face wrote: »

That being said, I really enjoy my Goldpoint SA-4HT and Pass B1's. The Goldpoint is stepped attenuator, allows 4 sources, and has HT Bypass. I use it in my Tannoy HT/2 channel rig. The Pass I move around in my other rigs. One other thing about the B1 is that is has a few caps in the signal path, so you fine tune the sound of your rig by swapping in different caps. But if you're looking for the ultimate in transparency, you should check out a stepped attenuator or transformer based passive.

So your Goldpoint's even more transparent then the B1? Wow.

The stepped attenuators are the volume pots with a solder connection for every step? Kinda looks like a radial engine on a WWII airplane?

zingo

Yup. It's a whole bunch of resistors all soldered around a knob so that each step with the knob is an exact, repeatable value, unlike the wiper on a pot.

zingo

After liking the B1, a Goldpoint is definitly my next try for preamps.

Systems

strider wrote: »

The stepped attenuators are the volume pots with a solder connection for every step?

They are multi pole switches not pots.

Another advantage besides having just a single resitor in the signal path is the exact match between the two channels.Even high quality pots can have as much as a 10-20% disparity between it's two sections and can vary depending on the pots position.



While I liked the transparity it provides I have found that the purely passive approach to be lacking some life and dynamic drive.

Systems

Face wrote: »

I enjoy my Goldpoint SA-4HT

Those look like quality constructed units.I would like to get one and incorporate a good buffer stage(B1?) into the chassis.

Face

GV#27 wrote: »

Those look like quality constructed units.I would like to get one and incorporate a good buffer stage(B1?) into the chassis.

I believe someone has already. I thought about doing the same.

strider wrote: »

So your Goldpoint's even more transparent then the B1? Wow.

The stepped attenuators are the volume pots with a solder connection for every step? Kinda looks like a radial engine on a WWII airplane?

A few fellow Polkies and I had an odd experience with a stepped attenuator today. The attenuator has more plentiful bass than an Parasound preamp.

Serendipity

Face wrote: »

A few fellow Polkies and I had an odd experience with a stepped attenuator today. The attenuator has more plentiful bass than an Parasound preamp.

That was interesting. The passive pre had a lot more bass than the Parasound.

organ

Face,
Awesome pre amp. I wonder how resistance based pre's compare to transformer/autoformer units? There's another design for me to try.
Regarding the bass, yeah, with my current set up, I get more bass from my passive than active as well.

MillerLiteScott

Face wrote: »

I believe someone has already. I thought about doing the same.



A few fellow Polkies and I had an odd experience with a stepped attenuator today. The attenuator has more plentiful bass than an Parasound preamp.

Mike,

Which pre is that? Or did you build that one?

Scott

Face

It's an older Goldpoint stepped attenuator in a custom case.