MACKIE PPM608 repair

[kaboom]

Re: MACKIE PPM608 repair

Not so fast.

Depending on the DC voltage rails to the amplifier section, it is very possible that it is well capable of 500 watts.

Conversion from the 120vac line down to the DC voltages can be pretty efficient with SMPS, and since the rating is probably for a 4ohm load, it is quite possible to be a valid spec.

That said, Mackie is one of the more reputable companies. They aren't prone to exaggerating the power out.

BUT, P.A. gear is usually rated to peak output, not RMS (as hi-fi gear is) so it is also possible that is the peak power rating...

Yep, it is peak output rating:

From the spec sheet, RMS rating at 4 ohms is 250w @ 1% THD, 300w @ 3% THD and 8 ohms 160w @ 1% THD and 180w @ 3% THD

Here's the link to the specs:

http://mackie.com/sites/default/file.../PPM608_SS.pdf

So the 160w AC input consumption is within the range of possibility.

The digital cinema amp line I use for screening rooms is also very efficient and for the AC input, pounds out a lot of power per AC input watt.

IIRC, the "listed" power consumption is for a 1/4-1/3 rated-power-output with either pink or white noise. Somewhere, I have a Mackie PDF that explains this. It also explains that if one ran the same amp into a dummy load at full output power (sine wave test) and then measured consumption from the AC line, to expect input VA to exceed rated output power.

I found this rather odd, since it basically allows giving a nameplate rating lower than its actual consumption.

PWM amplifiers (so-called "class D" or "tripath") are essentially an SMPS whose output varies at an audio rate. Full switching amps, the ones with an SMPS feeding that PWM power section are quite efficient- on the order of 85-90+% overall, AC line to output terminals.

Imagine if a computer had a line-frequency transformer and linear regulators- they'd make a Prescott look tame.

[momaka]

Re: MACKIE PPM608 repair

Not so fast.

Depending on the DC voltage rails to the amplifier section, it is very possible that it is well capable of 500 watts.

Conversion from the 120vac line down to the DC voltages can be pretty efficient with SMPS, and since the rating is probably for a 4ohm load, it is quite possible to be a valid spec.

Right.
But that's not what budm was talking about.

The problem is the rating for the power consumption - according to the manual, it is 160 Watts. It doesn't say maximum, but you can bet that this is what it most likely is. I mean, if it's not maximum, then what is it really? Just a random number?? To make sense, it has to be a maximum. And not just that, but maximum continuous power rating.

Let's assume the power consumption of the unit is 160 Watts maximum RMS and the amplifier has a class D output stage with a generous 95% efficiency. Even with this, you will see, at best, 152 Watts RMS TOTAL output power. Doesn't matter if you do all 152 Watts into a single channel or 76 Watts into two channels - the total power output is capped by the maximum power consumption of the unit. In other words, you can't have more power going out of the unit than what is coming in, which I am sure you understand very well too.

Thus, either the stated power consumption rating in the manual is wrong, or the RMS output power ratings are BS. The fact that the power consumption is not stated as a maximum and that the unit is advertised as having the capability to output 2x 500 Watts peak just screams of a cheap amplifier (much like those no-name eBay Ni-MH rechargeable AA batteries that claim to have 3000+ mAh capacity).

[Agent24]

Re: MACKIE PPM608 repair

PWM amplifiers (so-called "class D" or "tripath") are essentially an SMPS whose output varies at an audio rate.

Isn't Tripath just a brand name of a certain Class-D IC family?

[budm]

Re: MACKIE PPM608 repair

Not so fast.

Depending on the DC voltage rails to the amplifier section, it is very possible that it is well capable of 500 watts.

Conversion from the 120vac line down to the DC voltages can be pretty efficient with SMPS, and since the rating is probably for a 4ohm load, it is quite possible to be a valid spec.

That said, Mackie is one of the more reputable companies. They aren't prone to exaggerating the power out.

BUT, P.A. gear is usually rated to peak output, not RMS (as hi-fi gear is) so it is also possible that is the peak power rating...

Yep, it is peak output rating:

From the spec sheet, RMS rating at 4 ohms is 250w @ 1% THD, 300w @ 3% THD and 8 ohms 160w @ 1% THD and 180w @ 3% THD

Here's the link to the specs:

http://mackie.com/sites/default/file.../PPM608_SS.pdf

So the 160w AC input consumption is within the range of possibility.

The digital cinema amp line I use for screening rooms is also very efficient and for the AC input, pounds out a lot of power per AC input watt.

250W RMS per channel, so 500W total output for both channels driven while consuming a lot less input power, it is BS. So the power conversion is better than 100%, sure!

[budm]

Re: MACKIE PPM608 repair

US site: 160W
SPEC FROM UK site: 680W
I guess MACKIE could not get away with the lies in EURO.

[beezerboy]

Re: MACKIE PPM608 repair

a friend of mine has one of these and it quit working. I told him I'd take a look. my electricity is pretty good & I've built tube amps from scratch & done antique radio repair. BUT... how do you get the case of this rascal apart? the top, back, and bottom are all one formed piece... the 2 side caps fit over the edges of the case and I don't see any way to remove them. these also have the carry handles as part of their structure. I've searched the net and there isn't much out there on this amp. I got the available downloads that were in this post, plus the operators HB from Mackie.

[R_J]

Re: MACKIE PPM608 repair

There should be 6 screws (3 on each side) holding the front panel to the case.

[beezerboy]

Re: MACKIE PPM608 repair

... and 8 more top & bottom. and 2mm hex heads. maybe mine is different. anyway, thanks. I got it apart. I had a bad power connector to the PC board & bodged it enough to do some preliminary testing. I have 335 VDC out of the rectifier. the fans don't turn on but I don't have the amp control board connected. the ribbon connectors are pretty short

[Geeeetarzan]

Re: MACKIE PPM608 repair

Hi Folks, I've got a Mackie PPM 1012 mixer/amp that i got dead, no lights. Fuse is internal and is not blown. Power supply seems to be the same as in this thread so i didn't start another one. Should I? The power supply powers up without popping the fuse, no smoke no smells.No components seem obviously smoked or swollen. I'm a tube amp guy so i'm fine with high voltages knowing this one isnt that high, and have a decent fluke meter. With no schematic i'm not necessarily in my element. With a schematic and voltages i could chase. Anyone have the schematic? Or is anyone familiar with specific quirks on this one? I was told it was running at the end of a long extension cord outside and died of its own accord. No drops/spills. I'll upload some pics. - Thanks

[Geeeetarzan]

Re: MACKIE PPM608 repair

pics

[Geeeetarzan]

Re: MACKIE PPM608 repair

found the Mackie 608 schematics, and while the power supply for the PPM1012 is very similar, its not the same. Must be the same PCB, just some differences.

[Armada]

Re: MACKIE PPM608 repair

Hi my friends. I need your help with this power supply...

After the replacement of a sorted D24 and some electrolytic capacitors with optical problems the power supply don't turning on. Also I don't have any ticking or something else... I have check all Mosfet and diodes and they are OK.

I measured the power voltage when I turn it on and in the drain of Q1 and everything is OK. But in the drain of Q2 started from 150 Volts and dropping to zero 0 after few seconds.

I can't understand what is going wrong... Please could you give me an advise or help to find the solution?

Thank you all of you.

No ticking No any voltages in the 2nd part of power supply.

Mackie PPM608