[PaulFolbrecht]

Need some advice here.  Am considering a used pair of Opera monoblocks that are 230V (Asia).  I can get a converter/transformer to run them on 120V here, of course, but I have two concerns:

1) Freq. difference: will 60 vs. 50 Hz (as in Asia) have any negative effect??  Overheating?  Anything else?

2) Sonic degradation due to the power supply.  If I had, say, a 3000W transformer (the blocks draw 150W each) I think I should be good power-wise.  But this is another oppurtunity for noise, etc.  But, that's why we run good PCs...

Would really appreciate advice on this from someone knowledgable Thanks.

[PaulFolbrecht]

Anybody... ?

[Occam]

Need some advice here.  Am considering a used pair of Opera monoblocks that are 230V (Asia).  I can get a converter/transformer to run them on 120V here, of course, but I have two concerns:

1) Freq. difference: will 60 vs. 50 Hz (as in Asia) have any negative effect??  Overheating?  Anything else?

2) Sonic degradation due to the power supply.  If I had, say, a 3000W transformer (the blocks draw 150W each) I think I should be good power-wise.  But this is another oppurtunity for noise, etc.  But, that' ...

1) Running a power transformer specified for 50hz on 60h is not problematic, as the demands on the transformer is less. Conversely, a transformer specified to 60hz operation could be undersized for 50hz operation.

2) A properly configured voltage changer (autotransformer) is not going to introduce mains noise. A properly configured and sized transformer (either with a shield between primary and secondary and or split/multiple bobbins) will provide line conditioning. Something like a Signal DU-3 would do the trick -
http://www.belfuse.com/Data/DBObject/pgs28_29.pdf
And while your at it you should configure it for balanced power for additional noise reductiion benefits.

But it would be far easier to examine the connections of the power transformer's primary and hopefully find it has two winding for the primary that are simply connected in series for 220vac operation, and could be rewired in parallel for 110vac mains power. Much simpler overall...

If you live in the NYC area, I can lend you a DU-3 to try.

[PaulFolbrecht]

Thanks a lot, but mostly I'm wondering if the amps themselves could be harmed by 60Hz AC.  I've been told the higher freq could cause higher heat, or perhaps some problems with caps.  I haven't the EE knowledge to know if this is true or not.

These are Consonance Cyber 845 monoblocks, FWIW.

[ctviggen]

I don't see how the frequency would affect the capacitors.  As for extra heat from 10Hz (60 instead of 50), I can't see how that would happen, and if it did happen, you'd have to be cranking your system.  Assuming that the heat increase is related only to frequency, that would be a 20 percent increase in heat.  However, in reality, the increase in heat isn't nearly as much, as you're converting AC to DC and using the DC in the AMP.  After the transformer, you have some diodes and caps and then on to the amp stages.  The effect of frequency on the diodes and caps is going to be minimal.  I defer to Paul on the effect of frequency on the transformer.

Also, you could run 230V over to the amps and then you wouldn't have to worry about putting another transformer in front of the amps.  You could also use Paul's rewiring trick, but running 230V would mean that you wouldn't have to rewire anything inside the amp (but you would have to run wire to the amp, which isn't hard if you have good access to your fuse box).

[PaulFolbrecht]

Well, I passed on these amps.  Too many unknowns.

[G.Michael]

I had a 230V, 50 Hz CD player I powered with an isolation transformer (120 V in, 230 V out), with good results.  The 60 Hz wasn't an issue.

FWIW, I no longer have the player, but I do have the tranformer.  It's a monster, weights upwards of 35 lb and is very quiet... so if you change your mind about the amps, I have the transformer that would easily power them.