DIY preamp options.

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I have a pair of Paradigm active 20s and for those who don't know they are active, bi-amped, speakers. My current preamp is a H/K dolby prologic with tuner. My goal is to take a DIY preamp stage and replace the H/K preamp stage. This allows me to keep the tuner and remote, etc. My problem is which one to build. I am leaning towards the balance Zen line stage, since the Paradigms have balanced inputs. Does anyone have any suggestions for a superior preamp? I would even consider a tube pre. How much money are we talking to build a balanced Zen?

On a side note, is the Basslist still in existance? It has been about a year since I last subscribed.


The sound is incredible.
I have never heard anything better.
Anything using opamps can´t reach it.
I first used a preamp that was a design from elektor magazine. It was a 2 stage line amp with one stage buffer and one stage amp. It used in each stage a ne5534. Typical for a normal preamp. Most comercial ones use them 2.
I used some "op" some "tl" everything you can imagine. Some of these opamp cost very expensive. When I reached the preamp to a very good level, I read the Pass article of the balanced line stage. I was shocked because it was so simple.
It cost cheap too. When I made it and first listened to it, my first reaction was to throw my old preamp away. haha !
Yeah I was pissed I spent so much time with opamps and money to mention. With half the money I made an excelent preamp. It was the first time I listened to a voice singing and I could actually hear the air. Funny feeling !
The parts I got from here and there. I was in Greece then so some store ordered them from Germany I think.
But it doesnt matter you can find the parts anywhere.
Hmm What to do?

I've completed phase one of my audio projects. (2ways and a sub) Now it is time for phase 2 the pre amp. I started collecting parts for an op amp pre amp and active crossover. Your comments about the line stage interest me however I have not seen schematics for non op amp active filters. I wonder if it would be worth building the line stage only to pass it through an op amp filter? Any Thoughts or has anyone seen plans for active filters that don't use op amps?

Although I've not tried it, you could probably make a filter with either a single BJT or JFET. For the JFET, bias the source with an matched JFET operating at IDSS. Then use the JFET as a unity gain buffer in a Sallen-Key topology.

Alternatively a BJT in a common emitter configuration may work well for the MFB (multiple feedback, but would take careful biasing.
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