[Lisa]

I have a Headsave Classic and I use it with a Mascot PSU. that is rated 24V, 500mA.
Now I want to try the Classic in another room and I've got two PSUs from battery chargers and I want to try them and see if one of them sound good enough to use. (I don't want to carry the Mascot back and forth, it's too much of a hassle as it's nicely tucked away behind furnature, so it takes to much effort to unplug. Let alone lugging it around all the time.)
So I thought I'd try the Classic with inferior PSU and see if it's better than my MINT on plainview that I use now in the other room.

The specs of these PSUs are
12V, 1000mA (which messures 16.77V without load)
and
12V, 1500mA (messures 12.12V)

So I figure the voltage won't hurt or kill my amp. But how about the current? Is 1500mA too much or will the amp just use what it needs and the PSU will only give out what it's been asked to deliver?

P.S.
The Classic uses three OPA627s op-amps. Is 12V too low and will it damage anything or just not sound good or anything?

P.P.S.
I didn't know where to post this, amp or DIY section. I choose amp because the only thing I'm doing myself is plugging in the PSU. But if mods think it fits better in DIY please move the thread.

 

[jefemeister]

The amp will only draw the amount of current it needs. There's really nothing wrong with being able to provide more. In fact, it will probably provide more "headroom" ie, more current on demand more quickly. This is the same principle of amp wattage. Most speaker amps don't supply more than 5 watts or so on a continous basis but the wattage headroom allows for ultra-quick transients where a lot of current has to be delivered quickly. I can't offer any specific advice on the Headsave.

 

[Lisa]

Thanks!
If I understand correct than what you're saying is that I won't hurt my amp when I try these PSUs with my amp?

 

[PinkFloyd]

Quote:

Originally Posted by Lisa Thanks! If I understand correct than what you're saying is that I won't hurt my amp when I try these PSUs with my amp?

It won't hurt your amp Lisa, don't worry.

 

[Andrea]

Hi Lisa.

Don't worry about the current of the power supply. Any risk in this regard would only come from a too low current, which isn't your case.
A higher current means just a lesser effort of the power supply in satisfying the amp's needs.

Regarding the voltage, if lower it won't hurt your little amp any way either, though I'd surely prefer the one measuring the higher voltage without load.

What I'd pay attention to, instead, is whether the power supply is supposed to be regulated or not. Is the Mascot PSU regulated ?
If it's not, the amp has to have some 'voltage stabilizer' built in.
In this case, there's no possible way those p. supplies could be a 'technically' wrong match.
Otherwise, was a regulated supply required, you should prefer a properly regulated one -- still nothing prevents experimenting.
Should it sound good, then it would be fine nonetheless.


Ah, the old memories.

 

[Alick]

It's worth pointing out that the 1000mA supply looks like it might be unregulated as it has a fairly high no-load reading. It certainly won't hurt in this application as the original supply is 24V, but if the amp had required a 12V regulated supply, it might not be wise to try an unregulated one.

In general though, the more current a supply is capable of providing the better, as long as the voltages are compatible (and it's not an X-Can V2!

). It hopefully goes without saying that you should only replace an AC supply with an AC supply and a DC supply with a DC supply of compatible connector polarity...

EDIT: I took so long typing this that Andrea beat me to it ...

 

[Andrea]

Quote:

Originally Posted by Alick I took so long typing this that Andrea beat me to it ...

he he he

(it took long to me too, they beat even me to it

)

 

[Lisa]

Thanks all!
I've tried both shortly after Pinky said that my amp wouldn't die on me and it didn't!

I think they both aren't linear regulated though. I got the idea that the voltage of the 1000mA is higher than the other one because the LED was a bit brighter. And the 1500mA says switching mode.
From my brief listening both of them didn't give any nasty side effects. No obvious humms or hissses.

I think I'll ask Norm if switching modes PSUs can harm the amp before I start using one of them regularly.

 

[Lisa]

Quote:

Originally Posted by Andrea Hi Lisa. Is the Mascot PSU regulated ?

Yes it is.
Quote:

If it's not, the amp has to have some 'voltage stabilizer' built in. Otherwise, was a regulated supply required, you should prefer a properly regulated one -- still nothing prevents experimenting. Should it sound good, then it would be fine nonetheless.

Does that mean that even when there isn't a voltage stabilizer built in that it still can't hurt the amp?
Because all I am concerned about is not doing the amp any damage. If it doesn't work out I'll just use my MINT like I did before. I just want to know what's possible.

 

[Andrea]

Yes, Lisa, you can still safely use the unregulated P. S., especially since you say it produces no obvious humms or hissses or such.
That's a proof.

Anyway, knowing that the one is 'switching mode', it's likely better to use the other, the 1000mA one (since the first is likely not designed for audio applications - not that the particular typology be wrong itself for this use).

 

[Daroid]

In this case it wouldn't hurt your amp. Unregulated supplies is just not very safe using if you don't know the unloaded voltage output which varies from model to model. The unregulated supply is merely a multiplicator, which multiplies the input voltage with a factor. Since you know the unloaded voltage output it's fine. Beware of voltage fluctuations though.

Quote:

P.S. The Classic uses three OPA627s op-amps. Is 12V too low and will it damage anything or just not sound good or anything?

4.5V to 18V is fine. Lower than 4.5V will most likely increase distortion to mediocre levels and above 18V will harm it/destroy it.

 

[Lisa]

Quote:

Originally Posted by Andrea Anyway, knowing that the one is 'switching mode', it's likely better to use the other, the 1000mA one (since the first is likely not designed for audio applications - not that the particular typology be wrong itself for this use).

They're both not designed for audio. Both are designed for a battery charger.

But as long as I'm not using the charger I can use the PSU for something else, right?

The only problem that I've encountered with the 1000mA one is that the plug sometimes makes bad contact when the amp is moved. Than the amp stops working (duh! no power) Can this harm the amp if it happens often?

 

[Lisa]

Quote:

Originally Posted by Daroid 4.5V to 18V is fine. Lower than 4.5V will most likely increase distortion to mediocre levels and above 18V will harm it/destroy it.

Do you mean unregulated or all sorts of PSUs? Because the 24V Mascot works fine.

 

[Andrea]

Quote:

Originally Posted by Lisa They're both not designed for audio. Both are designed for a battery charger.

Naturally

, but the point is that a 'traditional' power supply with the right specifications can be considered 'universal', while with a 'switching mode' it's a different matter.

As for the bad contact of the plug, well, let me think... No, actually it won't harm the amp because we're dealing with low, DC voltage and low current, thus with no relevant 'impulsive' phenomena. Wow, this is talking serious

.
But you could try cleaning the plug with alcohol, to fix this.

 

[Andrea]

Quote:

Originally Posted by Lisa Do you mean unregulated or all sorts of PSUs?

He must have meant unregulated PSUs.
In fact, 18V unregulated will result in about 24V measured.