This. I would see what the resistance of the loop of speakers measures.
Small 2 channel audio amplifier connection
- Thread starter OilStained
- Start date
Yes I did. I used a DMM, the resistance was in RMS. I don’t believe i gained anything significant by this alone.
This statement doesn't make sense. Resistance is a DC measurement, RMS is AC. You would simply put the DMM in the lowest ohm setting and read the resistance. If the resistance reads higher than the lowest ohm setting will measure, you have a 70/100 system and you need a PA amp. If the resistance reads lower than 4 ohms you will eventually damage the amplifier.
The previous amp was placed in a "bridged" output state. The manual for the previous amp was very underwhelming and didn't provide if bridging was capable. The previous amp was also rated to a minimum of 4 ohms. When bridging an amplifier, the resistance or load the output section sees is halved. So if the speaker(s) were presenting a 4 ohm resistive load to the amplifier running in a bridged mode, the amp would "see" a 2 ohm load. That is below its rated capabilities & it would run hot & eventually fail.
My mistake. I will make the measurement and reply back.
Measurement started at 34, then settled at 33.8.
Ok. 34ohms of resistance is quite high. I can also see why the previous amp was damaged being bridged into a 34 ohm load.
Being bridged will cut the impedance the amp sees in half. So it’ll effectively see a 17 ohm load. Your previous amp was rated to produce 8w x 2ch at 8ohms. So 16w total at 8 ohms. Half of that at 16 ohms. With a total summed output of only 8w divided by however many speakers you have Wired into your business area, it’ll be pretty easy to clip the signal. Normally a clipped signal will damage speakers before an amplifier but continuous clipping can also damage output stage of the amplifier.
You might want to take a look at how your speakers are wired. Are they individual 4, 8, 16 ohm speakers wired in series, parallel or series-parallel configuration.
It’s best to know what you have so you can properly match equipment for the best performance & reliability.
OVERKILL
$100 Site Donor 2021
The Pyle PFA300 is apparently rated at 90W but they don't say at what impedance, they just give a range of 2-8 ohms. If we assume it's 90W @ 2ohms, that's 45W at 4ohms and 22.5W at 8ohms, a bit more than 16W, but not much, lol. Based on those numbers, he'd have 11.25W to play with, which I agree, it's pretty easy to clip the signal with and given that this is a pretty low rent piece of equipment, that doesn't bode well for longevity, though for $50, it's also possible that it just hit its anticipated lifespan.
Amp is also listed as "Class T", which is just a switched Class D amp, I assume a Tripath knock-off. Would be interesting to see inside it now that the OP has taken it out of service, I'm guessing it's pretty bare bones inside.
I had searched that amp & had found an old manual that stated 9w rms x 2 @ 10% THD. That's what I based my response off of. When going to the Pyle website there's only the single page generic manual with ratings as you state:
I'll browse around to see if I can remember where I dug up that old pdf manual. But yes, it's as you say for equipment on the reliability/price point scale.
So it was the replacement amp that I had found to have the really low rating (in an incomprehensible fashion).
Here's the manual of the replacement:
https://pyleaudio.com/Manuals/PDA29BU.pdf
Power Rating:
OVERKILL
$100 Site Donor 2021
Oh wow, those are disappointing specs, lol
OVERKILL
$100 Site Donor 2021
Yeah, that's exactly what I expected. It's about 1/4 as complicated as the 2-channel amp I built for micro electronics class in Grade 11, which was 20W RMS per channel at 8ohms, but Class B.
You can see the distinct lack of anything designed for heat removal there. Even given its status as Class D, that's not a recipe for longevity.