[nanahachi]

**I am sure this has been addressed before, so please link me up if this is a blatant repost**

I am sick, and just want to listen to some tunes at work to make the day go by more quickly.

However, I am getting lots of distortion from my Supermacro V3. Yes, the batteries may be drained, thus it would make sense why I am getting static. However, I plugged in my recently-received Coby AC adapter and plugged it into the SM. Still, I am getting the distortion.

I will try charging the batteries tonight at home, but is there anything I can do while here at work?

The amp does not power on with only the AC adapter plugged in, without batteries. (I'm new to the adapter, and have yet to read up on its functionality. bad me.)

thanks for any tips/links/etc

 

[StevieDvd]

Quote:

Originally Posted by nanahachi I am sick, and just want to listen to some tunes at work to make the day go by more quickly. However, I am getting lots of distortion from my Supermacro V3. Yes, the batteries may be drained, thus it would make sense why I am getting static. However, I plugged in my recently-received Coby AC adapter and plugged it into the SM. Still, I am getting the distortion. I will try charging the batteries tonight at home, but is there anything I can do while here at work? The amp does not power on with only the AC adapter plugged in, without batteries. (I'm new to the adapter, and have yet to read up on its functionality. bad me.) thanks for any tips/links/etc

The distortion is most likely due to low power, had it with mine once. It should run on psu power only as that's the way Xin recommends trying opamp swapping with circuit boards out of the case. Again I've done that so as standard battery power is definitely optional.

The psu socket is a little tricky, you may find that the tip is slightly flat on one side so it makes a connection despite the case screw being in the way.

My guess is that the tip is not going in far enough, check to see if the case screw is interfering or not.

Hope this helps get you going..

Steve

 

[nanahachi]

thanks for that info Steve!!

i will chalk this one up to being sick, fear of fiddling with the Coby, and stupidity.

I just tried fiddling around with the AC adapter, and raised the voltage from 1.5 to 7.5v. all of a sudden, the light on the SM lit up.

real quick, does anyone know the recommended voltage for the SM?
**ANSWER:
"When using the Coby CA11, set it to 12V" -- Xin
http://www.fixup.net/talk/topic.asp?...04&whichpage=2

boy I feel stupid. being sick does that to me I guess.
again, thanks for the help!

 

[Spektrograf]

As you've discovered, your PSU was set at the wrong voltage. I'd guess that that somehow affects the charging circuit as well. Here's the recommended settings for the Coby PSU:

9V
positive tip/negative ring (switch down)
(make sure it's set to your wall voltage, as well... 100-120V AC for the US)

Xin has said that you can set it as high as 12V, but 9V is recommended, though I don't know the rationale.

edit: 100-120V for countries like the US

 

[nanahachi]

aaah, i meant to ask about the polarity. thanks for mentioning that and the rec. voltage of 9v.

However, when I try 9V, I am getting distortion, so I'm going to leave it at 12v. I need to check which opamp i have, I think.

 

[MarcusH]

Quote:

Originally Posted by Spektrograf Xin has said that you can set it as high as 12V, but 9V is recommended, though I don't know the rationale.

I guess the rationale is to prevent you from harming your amp. The coby ac adapter isn't regulated - so the actual voltage (and current) may vary. IIRC Xin chose the coby because it's relatively stable, AFAIK the supermacro shouldn't be charged/used with a voltage above 15V so you should be on the safe side when using 9V (I guess the 12V setting isn't dangerous after all).
Remember, when you try to measure the actual power output using a multimeter be prepared to measure a lower voltage/current and that the actual output will be higher once you've plugged your supermacro in (due to the added "load"). So when you want to use a 3rd party adapter you may get a voltage well below 15V but once you add the supermacro it may exceed the safe voltage range. That's how I understand it - maybe I'm wrong *g*.

Marcus

 

[Chri5peed]

I think I'm falling in love with my Supermacro!

When you've taken it apart for opamp rolling and power it up, doesn't that mean PCBs are live?

 

[YngwieJMalmsteen]

Just make sure it doesn't get too hot nanachi.

 

[nanahachi]

ah, thanks for the warning.

so far, it is as cool as ever. I will be sure to monitor it though. The batteries arent in the case atm, but i will be doubly sure that when it is charging, that it doesnt start cooking.

 

[labrat]

Deleted.

 

[StevieDvd]

I ran mine on 12v with the coby but replaced it with a better UK psu, still on 12v though. That's the unregulated voltage so it's nearer to 15v which the SM3 copes with fine.


Stev

 

[Chri5peed]

Steve maybe you can help me?

I'm looking for a UK PSU for my SM3. Finding unregulated ones is proving very hard.

Also battery-wise when they die do you loose sound in a few minutes or does it get progressively worse over a longer time?

 

[nanahachi]

another update

When plugging in the Coby today, on the underside, I noticed that it was set for 220V and not 100/110 as it should have been. When I plugged it into the outlet, and then tried to lower the voltage from 12v to 9v, 9v sounded just fine, with no distortion.

Steve, I too am curious what PSU you upgraded to, though I doubt that I will do so.

 

[StevieDvd]

Quote:

Originally Posted by Chri5peed Steve maybe you can help me? I'm looking for a UK PSU for my SM3. Finding unregulated ones is proving very hard. Also battery-wise when they die do you loose sound in a few minutes or does it get progressively worse over a longer time?

I got a Uniross make from my local market (good guy been there years) for about £6. Snipped the end off the Coby one before I binned it, making sure I had the tip soldered the right way of course. I'll check the model number tonight at home. Got it as it was UK wallwart (no adapter needed) and better build/finish than the Coby

I would have thought regulated were harder to find, there's always Maplins who do both kinds.

Battery low tends to distort and can affect the switches. I thought I had a problem with the switches (bad distortion and one channel only) which was just low batteries as I was using a power hungry set of opamps.

Steve

 

[StevieDvd]

Quote:

Originally Posted by nanahachi another update When plugging in the Coby today, on the underside, I noticed that it was set for 220V and not 100/110 as it should have been. When I plugged it into the outlet, and then tried to lower the voltage from 12v to 9v, 9v sounded just fine, with no distortion. Steve, I too am curious what PSU you upgraded to, though I doubt that I will do so.

Xin sets the Coby to the safest setting by default - as we UK'ers use 220v putting one set at 110v has a more drastic effect that a US user plugging it in to a 110v socket. Especially as we have to use an adaptor to convert the Coby - which is why I changed to a UK model.

12v setting charges up the batteries better but the amp will run OK on the 9v setting.

Not sure my psu is of any interest as it's a UK one

A 15v regulated would work but as the SM3 has it's own built it regulation the cheaper unregulated ones are more economic. The main reason Xin does not mention this is in case people use a 15v unregulated one in error as that's likely to way over 17v and in possible damage territory.


Steve