Peavey pvx p15 low output

[nosaj]

I've got 2 Peavey pvx p15 powered speakers. I have the schematics but they don't really say what I should see at the power amp. I'm gonna set it up with a sig gen an a dummy load tomorrow But Peavey doesn't list a signal test.
The power supply voltages at the power supply are good.

nosaj

[The Dude]

What are the symptoms? (no sound, distortion, etc...)

[nosaj]

Passes sound but it's not very loud. I'll get a measurement on output. .
what would an appropriate voltage of a 1k sinewave to inject directly into the power Amp?
both speakers same symttom.
Thanks nosaj

[The Dude]

I'd first check speakers. You could have speakers with shifted gaps. I couldn't tell you amp input level without seeing a schematic. If speakers check good, just bring up the signal generator slowly and see what you get.

[g1]

That one has a mic input? Shouldn't take much at the 1/4" in. Maybe 50 to 100mV ?

[The Dude]

^^^^^^ That. I thought you were talking about going directly into the amp circuit on the other side of the mixer.

[nosaj]

I was talking about injection at the poweramp. Yo divide n conquer if issue was pre or post.
nos as j

[x-pro]

I think, to get 230W (+/-38...39V) output power at the low channel output at 8 ohms speaker impedance, 1V RMS should be applied directly to the chip input.
The heatsink on the chip is a must!

[Helmholtz]

I think, to get 230W (+/-38...39V) output power at the low channel output at 8 ohms speaker impedance, ...

From +/- 38V I calculate a sine power output of 90W into 8 Ohm?

[x-pro]

Incorporating the load into the bridge. The data from this?

[Helmholtz]

Thanks, I missed the bridge mode.
Then theoretical output would be 360W.
But supply voltages will sag and limit available output.

[g1]

But supply voltages will sag and limit available output.

They (datasheet) spec 150W per ch. at +/-35V, so I think 300W would be reasonable at sag.

[x-pro]

A simple calculation from the datasheet.
420W(8) - sin. 58V(RMS) gain 36dB - 63.1; (58V / 63,1)=0,92V

[nosaj]

Could i not just inject signal at connector on the preamp: hdr8sh pin 5 and pin 7 to go into the power amp?
nosaj

[The Dude]

Yes. Note that the pre has a low pass out for the woofer and a high pass out for the horn driver. Be careful not to run too much full range signal on the HP out (pin 7). Horn drivers don't like low frequency. BTW: are both the horn and woofer low volume, or just one or the other?