Amplifier matching advice

[Alby0521]

Hello

I own a Beepre since 2 years now and I use it with a stereo mouse II. Love the combo.

I got an opportunity to get a yamamoto a08 (45 tunes) and I was wandering if the Beepre would be a good match.
Here the specs of the amp:
SPECIFICATIONS:

Tubes: 45, 80, 717A
Output Power: 2 + 2 Watt at 8 Ohms
Frequency range: 23-30kHz
Input impedance: 200kOhms
Size: 40cm(W) x 29,4cm (D) x 20,4(H)
Weight: 14.3kg
Mains Voltage: 230V is standard. On special order, 100V or 150V is possible.


Thanks in advance for any advice.

Best

AB

[Paul Birkeland]

What is the gain of the amplifier and how sensitive are your speakers? 

[Alby0521]

Hi

The speakers are 105 dB (klipschorn).
For the amplifier gain I can’t find that figure anywhere.

Any suggestion on that?

Best

AB

[Alby0521]

I actually found it.

Supposed to be 18db gain.

Best

AB

[Paul Birkeland]

I would plan to use some -12dB inline attenuators at the inputs of the amplifiers. 

[Alby0521]

Hi

Do you think it would be too much gain without the attenuators?
I have the volume control upgrade in the Beepre.

Best

AB

[Paul Birkeland]

With 105dB sensitive speakers (assuming they are 8 ohms), then you need about 3V out of the amplifier to drive your speakers to very loud levels.  Your average digital source will have about 2V of output, as will many phono preamps.

If you have a BeePre with 8.3dB of gain and an amp with 18dB of gain, you're going to end up with the BeePre level controls turned almost all the way down much of the time.  The amplifier will also amplify the noisefloor of the BeePre significantly and there will be very little signal coming out of the preamp relative to the noisefloor. 

Using the inline attenuators will resolve these issues nicely.  If you should end up with less sensitive speakers down the road, you wouldn't need them any longer.

[Alby0521]

Thank you very much!

Understood.

Best

AB

[Alby0521]

Hi Paul

Before I buy the attenuators plugs, I have a pre amp which is basically a volume control: https://www.schiit.com/products/saga-2

Would this work the same way if I go from the Beepre to it then to the amp?

Best

AB

[Paul Birkeland]

In terms of the basic concept, yes, but you'll want a few inches of cable between it and your amplifier (hence the advantage of the plug in attenuators).

[Alby0521]

Hi Paul

Would you still advice -12 plug attenuators if the amp had 15 dB gain? Or you would go lower?

If I use the volume control pre amp, when you talk about few inches output cables do you mean 30- 40 inches or 5-10?

Thanks in advance.

Best

AB

[Paul Birkeland]

Yes, the -12dB attenuators would be a good idea.  By inches, I mean less than a foot.

-PB

[Alby0521]

Understood.

So in this case, would you also recommend the inline attenuators for my Stereomour 2 also fed by the Beepre?

Best

AB

[Paul Birkeland]

If your Stereomour has the stock level controls or the BeeQuiet, you can just use those instead.