Using Yamaha HS8 active monitors with vintage Yamaha Preamplifier

[boteto]

Hello,

I have a pair of Yamaha HS8 active monitors which I want to use them with a vintage Yamaha Preamplifier. I don't want to risk and damage the speakers so here a my concerns:

The Preamplifier output voltage is rated at 0.5V and the speakers specification says input sensitivity -10 dbu which converts to 0.250V.
Will the Preamplifier output voltage be enough to supply good signal to the speakers. Theoretically it should be enough but I want to be on the safe side.
Thank you!

 

[AnalogSteph]

Together with the input level control on the HS8, you should have plenty of leeway - maybe start at the 12 o'clock position (+4 dB) and see where that gets you. Most preamps can dish out a lot more than nominal output anyway if need be (they rarely run anything less than +/- 12..15 V internally, so up to 6-9 Vrms is entirely feasible if you get them enough input).

Just make sure you don't get yourself into any trouble with ground loops. If the preamp is already grounded by some source device (say, via PC --> USB DAC with no galvanic isolation), you may want to make some #17 or #18 cables as per RaneNote 110. If it's entirely floating thus far, connect RCA output ground to cable shield as well. Also, a more refined version of such a cable with better balance can be made if you know the preamp's output impedance (I imagine the service manual would be available at HiFiEngine and the like).

 

[LTig]

I agree with @AnalogSteph. Vintage preamps are specced with relatievely low output voltage but that was at a time where all analog sources (tuner, tape) also had low output voltages. This changed in the 1980's with the CD player where the standard output voltage was 2V, and that led to a higher ouput voltage of the preamp when using the same volume setting. As long as your preamp does not distort with digital sources (CDP, DAC, ...) you should be fine.

• Start with the minimum input level of the HS8.
• Play the source with the lowest output.
• Slowly increase the volume of your preamp until the sound is as loud as you'll ever might need, but stop at about 3:00 o'clock (just to have a little reserve if a recording is very quiet).
• If it is not loud enough at 3::00 o'clock increase the input level of the HS8 accordingly.

 

[multichannel_guy]

Together with the input level control on the HS8, you should have plenty of leeway - maybe start at the 12 o'clock position (+4 dB) and see where that gets you. Most preamps can dish out a lot more than nominal output anyway if need be (they rarely run anything less than +/- 12..15 V internally, so up to 6-9 Vrms is entirely feasible if you get them enough input).

Just make sure you don't get yourself into any trouble with ground loops. If the preamp is already grounded by some source device (say, via PC --> USB DAC with no galvanic isolation), you may want to make some #17 or #18 cables as per RaneNote 110. If it's entirely floating thus far, connect RCA output ground to cable shield as well. Also, a more refined version of such a cable with better balance can be made if you know the preamp's output impedance (I imagine the service manual would be available at HiFiEngine and the like).

As far as more modern preamps go, what Schiit preamp would you suggest with the HS8?

 

[40th Anniversary]

As far as more modern preamps go, what Schiit preamp would you suggest with the HS8?

I use an RME ADI-2 DAC FS as my main pre; and I have used the Schitt Midgard (no remote) with my HS8s and it sounded fine.
A dedicated preamp like the Kara should work fine; and will probably perform better than the Midgard.