Search found 6868 matches

by Enzo
Tue Jul 20, 2021 10:03 am
Forum: Bass Amplifiers
Topic: Max 115 not working
Replies: 1
Views: 25

Re: Max 115 not working

Blown main fuse? And work from there
by Enzo
Fri Jul 16, 2021 8:10 pm
Forum: Keyboard Amplifiers
Topic: KB300 mechanical vibration (buzz buzz)
Replies: 4
Views: 53

Re: KB300 mechanical vibration (buzz buzz)

Just my personal opinion, but I hate to hear every trouble blamed on "crappy design". They made tens of thousands of these amps, and they made many more thousands of other amps of the era on the same production equipment and made of the same materials and techniques, and designed by the same tams. A...
by Enzo
Fri Jul 16, 2021 11:53 am
Forum: Power Amplifiers
Topic: Peavey Classic 60/60 Bias Mod
Replies: 2
Views: 60

Re: Peavey Classic 60/60 Bias Mod

I have actully done it, but t isn't simple. The amp has two independent power amps. If you want the bias supply adjustable, that isn't so hard, but if you want to adjust the two channels separately, you will have to duplicate the bias supply circuit. Also othere will be traces needing to be cut and ...
by Enzo
Thu Jul 15, 2021 5:59 pm
Forum: Speakers/Enclosures
Topic: Hisys 4 XT Specs need
Replies: 6
Views: 181

Re: Hisys 4 XT Specs need

1505 is the model, the 8 means 8 ohms. ( It also comes in a 4 ohm, which would be 1505-4.)
by Enzo
Thu Jul 15, 2021 5:52 pm
Forum: Keyboard Amplifiers
Topic: KB300 mechanical vibration (buzz buzz)
Replies: 4
Views: 53

Re: KB300 mechanical vibration (buzz buzz)

Also try disconecting the horns, a cracked piezo tweeter can buzz.
by Enzo
Thu Jul 15, 2021 5:51 pm
Forum: Keyboard Amplifiers
Topic: KB300 mechanical vibration (buzz buzz)
Replies: 4
Views: 53

Re: KB300 mechanical vibration (buzz buzz)

Have I ever encountered an amp that buzzed? Of course. SO many things can buzz. Pop the grille off. Does it still buzz? Grilles are often a buzzer. Turn it off and listen close. Ball up your fist and whack the cab on top, on the sides, on the front or rear. Do you hear any kind of rattle or noise wh...
by Enzo
Wed Jul 14, 2021 11:40 am
Forum: Mixers
Topic: Peavey 5300 no sound output.
Replies: 5
Views: 90

Re: Peavey 5300 no sound output.

Fair enough. However I referred to power amp chips, not power supply chips. You can see inside, I can't, but are the two power amps the IC type rather than individual power transistors? The two 15v supplies would be for the preamp (mixer section) The power amps run on some higher voltage. Are there ...
by Enzo
Wed Jul 14, 2021 1:16 am
Forum: Mixers
Topic: Peavey 5300 no sound output.
Replies: 5
Views: 90

Re: Peavey 5300 no sound output.

Make sure MUTE button is not pressed. The speaker outputs have separate amps, so it seems unlikely both have the exact same bad transistors. Lower right corner is MAIN MIX out jack. RUn a cord from there to some other amp - any kind of amp - and see if sound results. I have no idea what is inside th...
by Enzo
Wed Jul 14, 2021 1:02 am
Forum: Guitar Amplifiers
Topic: 6505+ Has low output
Replies: 10
Views: 156

Re: 6505+ Has low output

Great!!!


But for future reference, a signal will not get far through a circuit with power off. We trace a signal in an active circuit.
by Enzo
Tue Jul 13, 2021 11:12 am
Forum: Guitar Amplifiers
Topic: 6505+ Has low output
Replies: 10
Views: 156

Re: 6505+ Has low output

If the two speaker jacks work the same, then I would rule out the switching contacts in the one jack.

SO then apply a steady signal to the FX return and trace it through the return stage and into the phase inverter stage. Use either a scope or a "signal tracer".
by Enzo
Mon Jul 12, 2021 3:47 pm
Forum: Guitar Amplifiers
Topic: 6505+ Has low output
Replies: 10
Views: 156

Re: 6505+ Has low output

OK, so issue is in power amp. Just a hunch, plug the speaker into the other speaker jack. I don't care if the 4 ohms or 8 ohms will be "wrong". it won't hurt it. See if it helps.
by Enzo
Sat Jul 10, 2021 12:10 am
Forum: Speakers/Enclosures
Topic: Hisys 4 XT Specs need
Replies: 6
Views: 181

Re: Hisys 4 XT Specs need

Hmmm, I didn't realize I did that.

I can find that the Hisys uses the 22XT horn driver

Your panel does say Black Widow equipped. I don't know which ones, but I'd bet they are the same as in the SP.
by Enzo
Fri Jul 09, 2021 8:21 pm
Forum: Guitar Amplifiers
Topic: 6505+ Has low output
Replies: 10
Views: 156

Re: 6505+ Has low output

KNown quirks? It is just an amp like a thousand others. We just troubleshoot the problem. I doubt the power tubes are at fault. Plug a cord from FX send to FX return, any help? Plug the guitar into the FX return, is that still low output? (None of the preamp controls will work this way) And beyond t...
by Enzo
Thu Jul 08, 2021 10:04 pm
Forum: Speakers/Enclosures
Topic: Hisys 4 XT Specs need
Replies: 6
Views: 181

Re: Hisys 4 XT Specs need

https://assets.peavey.com/literature/ma ... 302170.pdf

There is the spec sheet, looks like it has 15" Black Widow woofers and a 22XT horn driver. Specifically 1505-8KADT
by Enzo
Thu Jul 08, 2021 3:39 pm
Forum: Guitar Amplifiers
Topic: 5150 Peavey Head only works when a 1/4 jack inserted in footswitch input
Replies: 2
Views: 66

Re: 5150 Peavey Head only works when a 1/4 jack inserted in footswitch input

Plug a spare cord from FX send to FX return. ANy help? MY suspect is that the FX loop is turned off by your plugging into the FS jack. That bypasses the jacks. Normally the FX loop is always on, and if the jacks are funny, you lose signal.