I have a Halfler P230 amp. Even at very low volume, my speakers sound like they have bass breakup. I tried other speakers, and they do the same thing.
I checked the large power caps (10000uf 75 volts) with a VTOM. Infinite resistance. If indeed the caps are bad, would that cause this problem??? How doe the amp even work if these caps are bad?
I checked the large power caps (10000uf 75 volts) with a VTOM. Infinite resistance. If indeed the caps are bad, would that cause this problem??? How doe the amp even work if these caps are bad?
If you don't have a capacitor tester ,when first connected ( making sure there is no standing voltage in the capacitor ) the meter needle should swing to the right ( low ohms ) then swing back to high resistance .
Time for some ownership TLC...
What does the DC offset read?
Old amps, with old caps, need replacement. Cannot be reasonably measured...
too many will test as good = ARE NOT! Like a 20 year old tire,
with 1/2 it's tread, brittle, cracked, cross-linked and
simply not safe to drive on... but "measures fine"
So many of the P230s (I own 2) have been abused and overheated in night clubs and in DJ racks... heat is a component/capacitor killer. The P230s have a wretched front end PCB [mess] to offer XLR/balanced input options, which KILL THE SOUND quality, and need be removed, its wiring cleaned up.
Their are multiple caveats to consider in the P230. I believe it was factory built only... it would be a complicated build... Fortunately, their are not (kit builder) solder issues... but should have it's solder work / connections checked, it has twice as many as a 200/220.
These P230 amps are a foundation for a really good amp ~ when rebuilt ~
What does the DC offset read?
Old amps, with old caps, need replacement. Cannot be reasonably measured...
too many will test as good = ARE NOT! Like a 20 year old tire,
with 1/2 it's tread, brittle, cracked, cross-linked and
simply not safe to drive on... but "measures fine"
So many of the P230s (I own 2) have been abused and overheated in night clubs and in DJ racks... heat is a component/capacitor killer. The P230s have a wretched front end PCB [mess] to offer XLR/balanced input options, which KILL THE SOUND quality, and need be removed, its wiring cleaned up.
Their are multiple caveats to consider in the P230. I believe it was factory built only... it would be a complicated build... Fortunately, their are not (kit builder) solder issues... but should have it's solder work / connections checked, it has twice as many as a 200/220.
These P230 amps are a foundation for a really good amp ~ when rebuilt ~
Reply
I don't know what DC offset is or how to measure it. My question is: If the caps are bad, would the effect be distortion in bass, even at low levels?? I thought it was my speakers. But I tried other speakers and they do the same thing.
I don't know what DC offset is or how to measure it. My question is: If the caps are bad, would the effect be distortion in bass, even at low levels?? I thought it was my speakers. But I tried other speakers and they do the same thing.
DC offset is any DC voltage appearing across the speaker terminals. Typically it should under about -/+ 50 millivolts. The closer to zero the better. Measure with no music playing.
Just put your meter on a low DC voltage range and check across the terminals.
Just put your meter on a low DC voltage range and check across the terminals.
Thanks Mooly!!!
*I don't plug ~ anything ~ vintage up to my system / speakers
~ without testing first ~
*I don't plug ~ anything ~ vintage up to my system / speakers
~ without testing first ~
Good advice 🙂 and I guess that should lead into a question to the OP.
Has the amp a hidden history or was it working OK and just 'failed' in use?
Is it both channels affected?
And:
Hard to see they could cause this tbh. If they were almost open circuit then I would expect you to be getting lots of hum and noise coming through.
Has the amp a hidden history or was it working OK and just 'failed' in use?
Is it both channels affected?
And:
Hard to see they could cause this tbh. If they were almost open circuit then I would expect you to be getting lots of hum and noise coming through.