Pre-amp Questions

[chessman]

I think (but please someone tell me if I am wrong) that a pre-amp has (1) a line stage, (2) a power stage, (3) sometimes a phono stage, and (4) a volume control. I assume that a built in DAC is resident in the line stage.

I have an external DAC feeding an Emotiva DMC-1 pre-amp/processor. I had been considering buying a separate two channel pre-amp with a HT bypass in an effort to improve the two channel experience. But then I realized (1) I have a fancy DAC and (2) I do not need a phono stage, so would buying a separate two channel pre-amp just be buying an expensive powered volume control?

[Cujobob]

A pre-amp doesn't necessarily have a phono stage. A high-end preamp will amplify the signal from your source (depending on the unit, the amount of gain varies...phono needs much more gain) and provide a proper impedence for your power amplifier. What it will do is introduce less distortion than a poor pre-amp, provide better volume tracking, and you can get some tubey goodness.

I find a good tubed pre adds depth to the image and makes things more realistic.

[chessman]

Thanks, Cujo. So maybe a tube linestage would be an upgrade. I have considered an Emotiva USP-1 (cheap and nice features), but feared a lack of musical pizazz. I considered a McIntosh tube pre-amp, but started to fear I would just be burning money for a volume control.

Anyone have a suggestion? I use a sub in two channel and would need a HT bypass.

[Cujobob]

Integrating a subwoofer is often the big difficulty. The Emotiva stuff offers value and will better most cheap receivers, but the feature-set is the only reason to purchase one IMO.

For under a grand, I'd go used and get one of these: Mapletree Line 2A/Ultra 4A, SAS labs 10A (I think thats the model), a DIY Aikido...also heard good things about the Promitheus Audio gear (they have both active and passive). I'm sure there are other good options, as well. At more than a grand, the Dodd Ref. Pre is great.

Getting a remote will cost you, unfortunately. Ask someone else on how to configure the sub into there.

[Jason]

The Maple Tree nor Dodd has a HT pass through. But if you have the budget for the Dodd, I'd contact him to see about putting in a pass through....never know.

My pre has a pass through (Rogue Perseus)...I've been reasonably happy with it, but it's my first tubed pre (and dedicated pre) so I don't have much of a frame of reference.

[Cujobob]

A new Mapletree can have one installed free of charge, but it takes up two input slots (out of a possible four).

If memory serves, the Dodd ref pre comes with HT bypass standard.

[Jason]

A new Mapletree can have one installed free of charge, but it takes up two input slots (out of a possible four).

If memory serves, the Dodd ref pre comes with HT bypass standard.

did not know that...cool

[dvenardos]

What is the input impedance of your amp? You could also go with a passive preamp.
CI audio is supposed to have good passive preamps. I have their DAC, but not either of their preamps.

http://www.ciaudio.com/

I haven't heard one but the lightspeed attenuators get rave reviews.

To implement a HT bypass you just need an input that bypasses the volume pot.

[chessman]

The input impedance is 20k ohms.

[dvenardos]

You would probably want to go with a passive pre with 10K or 20K impedance. I expect to have my goldpoint 10K passive pre completed this week, you can also get them completed with whatever impedance you want.

http://www.goldpt.com/sa2.html

The input impedance is 20k ohms.

[Cujobob]

There are many options for passive attenuators...the best are EVS Ultimate Attenuators (they created the design), though there's VERY little difference...I also have another brand, but can't recall the name...they were a cheaper alternative I got to try them out. If you don't have volume control elsewhere in your system, it can be a PITA, in my opinion.