#Hifonics amp wont turn oun free
Find many great new & used options and get the best deals for Audiopipe APMN2075 1000 Watts Mini Amplifier at the best online prices at eBay! Free shipping for many products! Taramps DS 800x4 Amplifier 2 Ohm 800 Watt RMS 4 Channel Amp New. Audiopipe APCLE1004 Amplifier 1000 Watt 4 Channel. If the thump is still there, I'd change the first filter cap in the power supply at the plates of the power tubes.Audiopipe 1000 watt 4 channel amp manual. Then fire it up and see if the thump is gone. If there's voltage, you replace the coupling caps, but I'd also check the cathode bias resistor, bypass cap if present across that resistor, all the resistors on the grid and screens of the power tubes, etc. So, if you open it up, take it off standby, and meter for voltage on pin 2, you can determine whether the coupling caps are leaking. The volume drop would occur after the tubes have been stressed to the point that they start to redplate/draw excessive current.Īssuming that this amp is the usual cathode biased dual el-84 18 watt style, there should be 0 volts on pin 2 of the EL84's. What you could also be experiencing is a leaky signal coupling cap into the power tubes, which would then cause an extremely high bias, increased heat, etc. Ok, yes I initially meant the power supply filter caps. Problem with heat related of course is every time I turn it off I need to wait again to see if fixed, and even then am never 100% sure I got the problem. IF it does, I'm thinking I ought to try the rectifier tube first.Ģ) I'm wondering, given the smell of burned electrics I noticed, if I ought to open it up and visually inspect the components for burn marks, smells, etc.ģ) After #1, if that doesn't fix it, I think I will still keep the new rectifier tube in, and then trade out preamp tubes (there are only three) one at a time. Let it heat up for a while, play it pretty high volume, and see if either it thumps, or that "unwanted tremelo" comes back. The plan so far.ġ) I think I ought to start it up, and recreate if I can, or create the problem. It was getting late last night, I thought I ought to wait until I'm fresh to troubleshoot any more. So.gentlemen, put your wagers down! Which component do you think it is? SO I play, goosing the input a little, trying to let it warm up, and then though the thumping never comes back, there is now a sort of irregular "tremelo" effect, volume loss, comes back, etc. Everything else the same as when I had the problem. So at this point, new output tubes in place. Both "looked ok" (I know.doesn't mean much) so I installed new matched pair in there.
There was significant brown (heat) marks on the middle of one, and a little on the other.
Took out the 5U4 rectifier tube, reseated (put back in). Also usually the amp is quiet, now it was shooshing way more than usual. No thumping anymore, but it was now cooled down a good deal. Took it home.Īt home: briefly tried to power up. At that point I turned the amp off and called it a night. Here is the interesting part, I set all knobs (volume, EQ, master vol, gain) to 0.still thumping. The thump was regular, probably around 80 bpm (guessing, it was lilke a heartbeat thump).Īlso, first thing I did was unplug the input to the amp (guitar input) (still had pedals in the effects loop though). Also, later realized I had smelled some kind of burning smell before it happened, looked down at my new pedal on the pedalboard and briefly wondered if it was that, then got distracted.until later when I heard the thump. Retubed about six months ago.Īt rehearsal last night, I suddenly hear "" regular sound, now that I think of it sounds kinda like when you go to standy but not totally.
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