Role of preamp?

[crackaddict]

Hi,

It's been a while since I've been here. A year ago I wrapped up my first project:

- Reduction + Integration
- Stereomour + Impedance kit
- Crack + Speedball
- all into Blumenstein fullrange 5" Mako standmounts

This weekend's special on the BeePree looks really good, and the amp looks interesting. But... I don't know where a preamp fits into the system.

Is this something I can add to my setup before the Steremour, to get more volume out of my system? Or is this something I should buy with e.g. Paramounts and just build a completely new setup...?

Thanks for any advice before the sale ends!

Derek

 

[mkane]

  I have the Quickie ahead of a Stereomour and I believe it add 10 decibels of gain. The BeePre is 8.something dB of gain so yes, you get more volume.

 

[crackaddict]

Thanks. Is that the primary benefit/use of a preamp in this kind of setup, or are there other reasons to introduce one related to e.g. improvement of sound quality? I would imagine it's really for additional amplification and perhaps convenience of input selection?

Regards,
Derek

 

[Grainger49]

I find that there are greater dynamics with an active preamp in the system.  The bass seems to be fuller and more extended. Of course YMMV.

 

[Chris]

Yep, adding a Bee Pre to your stereomour would bee the ultimate incarnation of the stereomour's capabilities within its design parameters IMO... and my opinion is not humble    haha  just kiddin

 

[crackaddict]

OK, this sounds interesting indeed. I thought the phono preamp was all that was really needed, but in terms of sound quality and output volume, this may be the thing for me. And it would presumably integrate well with Paramounts if I replace the Steremour one day.

Will have to look at the layout of my setup (both in terms of wiring, inputs/outputs, as well as my physical space) and figure out if now's the time to add to it.

Thanks!
Derek

 

[Grainger49]

Derek,

Do realize that the preamp will not increase your power output.  What it does is makes you reach it faster.  If you are short of power it won't help.

 

[crackaddict]

Hmmmmm, not sure I get that. Thinking of my guitar amps, I would have likened this to a preamp stage there. Doesn't every stage of amplification feed the next, for higher output at the end? Or are you saying the Stereomour outputs its max wattage when dimed regardless of what goes in?

Thanks,
Derek

 

[Grainger49]

Gain is not power.  But the gain of the preamp will deliver the voltage needed to get your amp to full power faster, or at a lower volume setting than without the preamp.

 

[Chris]

And yes, if someday, you are thinking of diving into the Paramount pool, you are already half way there with a BeePre....

 

[Paul Joppa]

Grainger said it correctly, but this is such a widespread confusion that I will add my two cents.

As you turn the gain up with the volume control, the power output increases in proportion - until the power stage runs out of steam. Extra gain is like a wooden block duct-taped to your car's accelerator - it does not increase the engine's power, you just don't have to push the accelerator down as far to get there. It's only helpful if you have short legs... :^)

Adding gain is only useful if you can turn the control all the way up and still not drive the output stage up to its maximum power capability. You can identify the maximum capability by listening for overload distortion - be aware that SETs overload very gently, unlike high-feedback solid state amps which make really horrible noises when overloaded. If it still sounds clean at the max volume control setting, AND you want more loudness, then some added gain would help. There is no easy way to tell how much more loudness you could get before the overload distortion became noticeable.

The real function of a preamp is to provide source switching and a volume control. Stereomour includes those functions so in most cases you don't need a preamp. In fact, we also sell the Submissive which has only those functions (no gain).

(As Grainger noted, some people like the more subtle change in the sound character when a preamp stage is added. I'm just saying that is a subtle change.)

You can read a lot more in my white paper, posted at http://bottlehead.com/signals-noise-and-signal-to-noise-ratio/ - or from Bottlehead.com choose more then community then Signals, Noise and Signal-to-noise Ratio.

 

[crackaddict]

Thanks, everyone. This is super helpful! Paul, I'll seek out your white paper. Good tip.

I passed on the BeePre for now, which probably makes sense until I go the Paramount path. At that point I'll have three new projects to undertake! But I'll listen to what I've got for a little while before walking away from it.

Derek

 

[denti alligator]

I really like the sound of using a Quickie with my SEX, which technically doesn't need a pre-amp. But curiously I can't use the Quickie to control the volume, because if I set the SEX at high volume, using it as a power amp, the microphonics from the Quickie are too loud. So I set the Quickie at about 80%, and use the SEX to control volume. This sounds best. Paul, can you explain why this would be the case?

 

[Paul Joppa]

Sam, the answer is buried in the above-mentioned white paper.

But try this:

With the Quickie at 80%, set the SEX for the loudest level you are likely to actually use, and leave it there.

Then use the Quickie level control to adjust.