Help! My pv2600 is driving me insane.

This forum is for talking about all kinds of Peavey power amplifiers.
Post Reply
jcb3cx55
New Member
Posts: 9
Joined: Tue May 23, 2017 8:57 am

Help! My pv2600 is driving me insane.

Post by jcb3cx55 » Tue May 23, 2017 9:13 am

Hi I'm new to forum so please be gentle.

I have a pv2600 that I just got back off my drummer, who has been using it in his thrash metal band.

Whilst running it the other night in my garage I noticed only channel A power led was on. Checked the manual. This indicated it was in bridge mode (drummers band must have set this). And indeed it was in bridge. However I was getting output from both A and B channels. Although the channel B control had no effect.

How am I getting an output signal from channel B whilst in bridge?

Switched it back to stereo (this is how I want to run it). I now have both power LEDs on. But I have no output at all from channel B! And when rotating channel B knob up and down, it crackles through speakers (like a dirty pot crackle on guitar amp) and the SIG led flickers with the crackling?

Channel A sounds awesome though.

Is this amp screwed or does it sound like something mendable?

Look toward to your thoughts

Regards

User avatar
Enzo
Member
Posts: 9535
Joined: Fri Sep 12, 2008 10:24 pm
Location: Lansing, Michigan

Re: Help! My pv2600 is driving me insane.

Post by Enzo » Tue May 23, 2017 11:56 am

You HAVE to have output from both channels in bridge, bridging is using both channels for one output. The speakers are then connected to the two hot posts (red), one per channel. In bridge, the A channel inputs and controls serve both amps. The B stuff goes dead.

In stereo mode, both sides should work, you need to input a signal into each channel separately.

Clean that noisy volume control, and while at it spray some cleaner into the bridge switch.

jcb3cx55
New Member
Posts: 9
Joined: Tue May 23, 2017 8:57 am

Re: Help! My pv2600 is driving me insane.

Post by jcb3cx55 » Tue May 23, 2017 1:07 pm

Hi Enzo

I'm not using the output posts. Just speakon connectors. In bridge mode I'm still getting sound from channel b?

However, I want to run in stereo mode, which has a dead channel b output?

Could it possibly be dirty/faulty bridge switch not switching between two modes properly?

jcb3cx55
New Member
Posts: 9
Joined: Tue May 23, 2017 8:57 am

Re: Help! My pv2600 is driving me insane.

Post by jcb3cx55 » Tue May 23, 2017 1:16 pm

Hi enzo

Forgive me , but I think the Penny's dropped regarding this bridge stuff???!?

So using one input channel A, you can still run two speakers from both A and B simultaneously? I understood that the single bridge output should be used into one speaker?

Still doesn't explain dead channel b in stereo mode.

This is confusing.

jcb3cx55
New Member
Posts: 9
Joined: Tue May 23, 2017 8:57 am

Re: Help! My pv2600 is driving me insane.

Post by jcb3cx55 » Tue May 23, 2017 1:30 pm

Right, in stereo mode with input into A and B, I get no output from B. And a noisy B volume knob.

In bridge, using only input into A, both outputs work.

So to me, it appears the fault lies with channel B input not sending to channel B output??

Could a dirty volume control or dirty bridge switch cause any fault like this??

Please help.

User avatar
Enzo
Member
Posts: 9535
Joined: Fri Sep 12, 2008 10:24 pm
Location: Lansing, Michigan

Re: Help! My pv2600 is driving me insane.

Post by Enzo » Tue May 23, 2017 4:45 pm

Of course it could, that is why I suggested it. Even if it isn't the problem, you identified the control as noisy so it has to be serviced anyway. The switch routes the input signal, so if it gets dirty the signal can't pass through.

All the bridge speakon does is take the channel A positive to one terminal and the channel B positive to th other, so electrically exactly the same as the two red posts. Both channels are driving in bridge, but one channel is inverted so the signal is opposite polarity from the other.

In bridge you use a single speakon cord to the connector and connect it to a single LOAD, not necessarily a single speaker. As long as the total impedance is within spec, you can daisy chain more than one speaker on it.

jcb3cx55
New Member
Posts: 9
Joined: Tue May 23, 2017 8:57 am

Re: Help! My pv2600 is driving me insane.

Post by jcb3cx55 » Thu Jun 15, 2017 1:26 pm

hi Enzo

update on my broken pv2600. have just received it back from my wifes work collegue, who is an audio electronics engineer. he concluded that there is nothing wrong with the amp, he had output from both a and b and said i must have some dodgy leads.

however, after just plugging it it in my garage, i can only assume he is ignorant and had the amp set in bridge mode (again). i set it to stereo and using just one input and output lead to one speaker, had channel A kicking some tunes out. switched both the same leads to the channel b. and guess what, crackly channel b pot, no sound.

i then removed lid, sprayed cleaner into channel b pot and gave it a screw for a few minutes. i did notice a small amount of white corrosion leaking from b pot. whilst i was at it i gave channel A pot a spray too, and i noticed that channel A pot was a lot stiffer to turn compared to channel B pot? channel B pot was very loose, almost like it wasn't doing anything? gave the switches, jacks, xlrs and speakons a little spray in the back too just for good measure.

re ran the amp.....no different.

changing tactic slightly, i am now thinking of just running it in bridge mode, but am unsure of the implications when running speakers from A and B channels when in bridge.

i realize it will only be a mono input via channel A input. but what are the power output figures from each channel when in bridge mode, i will be running 1000w program each side at 4ohms.

i also realize there is a polarity phase issue when running speakers either side like this, but what exactly are the effects of such phasing and will it be noticeable when just playing recorded music through the amp. will the phasing cause an obvious problem?

look forward to your advise

regards

User avatar
Enzo
Member
Posts: 9535
Joined: Fri Sep 12, 2008 10:24 pm
Location: Lansing, Michigan

Re: Help! My pv2600 is driving me insane.

Post by Enzo » Thu Jun 15, 2017 1:51 pm

OK, just a hunch. Your average pot is held together by a few small metal tabs bend over to hold the back to the front - so to speak. ANy chance your pot has partially "sprung?" Are the little metal tabs lifted a bit so the parts of the pot are slightly loose? Also possible the pot is cracked or otherwise damaged.

jcb3cx55
New Member
Posts: 9
Joined: Tue May 23, 2017 8:57 am

Re: Help! My pv2600 is driving me insane.

Post by jcb3cx55 » Thu Jun 15, 2017 2:33 pm

OK Enzo. Will have another look at the pot. Would that be why it feels a bit 'loose'? I do have an old friend who is a retired electronics tech. He's mended my guitar amps, pedals, guitars and anything that has electricity flowing through it for years now. I'm sure he could find fault and repair it. However, if it needs new pot, are they a fairly standard part or would it be a peavey part. Bearing in mind we're in UK. Any part numbers for the pot?

What are your thoughts on the running in bridge query?

Regards

User avatar
Enzo
Member
Posts: 9535
Joined: Fri Sep 12, 2008 10:24 pm
Location: Lansing, Michigan

Re: Help! My pv2600 is driving me insane.

Post by Enzo » Thu Jun 15, 2017 5:56 pm

It COULD be, just one possibility among many.

If the pot is bad, the part number is on the schematic, PV either has them or not. Electrically, it is a simple pot, and anything you can make fit will work.

Part on the original model is 73900380, a 50k linear

Running amps in bridge is one tool in the tool kit, but I don't believe in it as a solution to a bad amp channel.

Dookie
Member
Posts: 1025
Joined: Fri Oct 10, 2008 5:09 pm
Location: Maine USA

Re: Help! My pv2600 is driving me insane.

Post by Dookie » Thu Jun 15, 2017 8:23 pm

jcb3cx55 wrote:hi Enzo

update on my broken pv2600. have just received it back from my wifes work collegue, who is an audio electronics engineer. he concluded that there is nothing wrong with the amp, he had output from both a and b and said i must have some dodgy leads.

however, after just plugging it it in my garage, i can only assume he is ignorant and had the amp set in bridge mode (again). i set it to stereo and using just one input and output lead to one speaker, had channel A kicking some tunes out. switched both the same leads to the channel b. and guess what, crackly channel b pot, no sound.

i then removed lid, sprayed cleaner into channel b pot and gave it a screw for a few minutes. i did notice a small amount of white corrosion leaking from b pot. whilst i was at it i gave channel A pot a spray too, and i noticed that channel A pot was a lot stiffer to turn compared to channel B pot? channel B pot was very loose, almost like it wasn't doing anything? gave the switches, jacks, xlrs and speakons a little spray in the back too just for good measure.

re ran the amp.....no different.

changing tactic slightly, i am now thinking of just running it in bridge mode, but am unsure of the implications when running speakers from A and B channels when in bridge.

i realize it will only be a mono input via channel A input. but what are the power output figures from each channel when in bridge mode, i will be running 1000w program each side at 4ohms.

i also realize there is a polarity phase issue when running speakers either side like this, but what exactly are the effects of such phasing and will it be noticeable when just playing recorded music through the amp. will the phasing cause an obvious problem?

look forward to your advise

regards
If you run in bridge mode then channel A will be the input as you know. But the outputs will be different. Channel A output will be normal. Channel B will be backward. RED binding post will be NEGATIVE. BLACK binding Post will be POSITIVE. The speakon outputs will be reversed on channel B as well. If the speakers running on channel A and those running on Channel B are close enough together there will be some cancelations. For sure in the bass range. If you correct this buy rewiring channel B's speaker wires then you could run it bridged as a mono amp.

Post Reply