[AmpDesigner333]

We are looking at 36V (as opposed to 30V) for our lower power supply voltage.  You get more power while retaining the benefit of lower voltage on the super quiet backround noise level.  This results in a 50% power output increase: 75W into 8Ω and 150W into 4Ω.

Here are the power levels for the various supply voltages into 8Ω and 4Ω:
    30V: 50W / 100W
    36V: 75W / 150W
    48V: 125W / 250W
    60V: 200W / 400W

Any thoughts?

Thanks for reading our board.

-Tommy O

[OzarkTom]

If 36v sounds the same as 30, that will be great. The 30v gave me super quiet backround noise levels as you mentioned, 50 watts is more than enough for me. I don't need 36v.

[AmpDesigner333]

If 36v sounds the same as 30, that will be great. The 30v gave me super quiet backround noise levels as you mentioned, 50 watts is more than enough for me. I don't need 36v.

We will be having listening tests next week.  Bench measurements as well.  My prediction is that the 36V supply will sound identical at low levels.  When pushed hard, probably stronger.  Thanks, Tom.

[jseipp]

I've found all of your predictions to be spot on with my equipment.  If the 36V power supplies offer more power while maintaining the magic, then that can't be a bad thing, and will likely make them an easier sell to someone hesitant about power restrictions. 

Like Tom, I feel no need to change mine.  But, I will hopefully be running another pair of high efficiency speakers in the near future, and will want to talk with you about trading into another pair of supplies that fit....

[AmpDesigner333]

I've found all of your predictions to be spot on with my equipment.  If the 36V power supplies offer more power while maintaining the magic, then that can't be a bad thing, and will likely make them an easier sell to someone hesitant about power restrictions. 

Like Tom, I feel no need to change mine.  But, I will hopefully be running another pair of high efficiency speakers in the near future, and will want to talk with you about trading into another pair of supplies that fit....

Thanks for your kind post.  The Maraschino circuit likes low voltage because the noise level drops a bit while retaining speed and control.  The 50% boost in power essentially adds headroom that benefits the listener even at low levels where one might think they aren't "using it".  It's also just right for many mid-efficiency speakers.  For example, my little B&Ws just love 30V for delicate, detailed music, but rocking out is more satisfying with 48V, especially with DUAL 48V power supplies, which was our first available configuration, and the one used in the first several professional reviews.  For big, inefficient, power hungry speakers, like the larger Mags, nothing beats dual 60V 1kW supplies!

[jseipp]

What you say makes perfect sense -- I look forward to reading about your measurements and especially your listening tests.

[G Georgopoulos]

Thanks for your kind post.  The Maraschino circuit likes low voltage because the noise level drops a bit while retaining speed and control. 

i dont know,you mean higher ps voltage have more noise,due to what?

[AmpDesigner333]

i dont know,you mean higher ps voltage have more noise,due to what?

Georgopoulos,

Please answer this post first:
http://www.audiocircle.com/index.php?topic=143217.msg1529885#msg1529885

Thanks (:

-Tommy O

[G Georgopoulos]

Georgopoulos,

Please answer this post first:
http://www.audiocircle.com/index.php?topic=143217.msg1529885#msg1529885

Thanks (:

-Tommy O

tom i just did with an explaination,can you please explain why high voltage ps's have more noise?
i dont pick on you mate,it's the nature of the forum,opinions explanations etc...

[AmpDesigner333]

tom i just did with an explaination,can you please explain why high voltage ps's have more noise?
i dont pick on you mate,it's the nature of the forum,opinions explanations etc...

The simple version: With a given amount of noise (a.k.a. voltage error), and a gain stage where the power supply voltage is the gain factor, the voltage of the supply is directly proportional to the amplification of the noise.  However, the modulator's control loop can only correct external noise and has a noise factor of it's own. As the "reference" moves, the modulator compensates for the error, but not "its own internal error" (which is quite low).  So, raising the loop gain (supply voltage times the modulator gain), the added gain amplifies the portion of the noise that remains.  Control theory covers this. The part that is unique with the Maraschino is that the modulator itself has an extremely low noise floor.  This means that added gain (6dB from 30V to 60V) doesn't cause the same increase in output noise.  It's all math.  Thanks again.