collapse

Author Topic: Peavey Audition Plus  (Read 599 times)

psafloyd

  • Regular
  • **
  • Posts: 47
  • Chip Points: 0
    • View Profile
Peavey Audition Plus
« on: October 16, 2019, 12:22:33 PM »
The prelude
I have acquired one of these amps that has a particular problem. Having searched the site, I realise that others may have had a similar problem and I am hoping someone might recommend a sensible plan of attack.

The problem
The amp is in lovely nick, but on firing it up, there is a loud steady hum. This hum is not affected in any way by adjusting the volume or any of the controls, including the push button channel switch.

On reading previous posts, I checked if the speaker moved in one direction on start up and it does. So, I measured for DC at the speaker and this came out at 9.5V.

I haven't had it apart yet, as it only came in today, but am hoping for a plan of attack. But if there is DC at the speaker, this points to one of a number of potential causes, and I wondered if someone might suggest which to tackle?

I cannot find the Audition Plus anywhere as a schematic, so wonder if the difference was just branding. I have attached the Audition 20 schematic.

A whinge about the paucity of adult education

And if anyone is wondering why I haven't learned more since my first posts, I have been trying. I even tried to find a part time/evening course in electrical engineering or electronics and its a nightmare.

There are no electronics ones any more – I KNOW there used to be. As for the electrical engineering ones, they are either long vocational courses, or do little more than qualify the individual in PAT testing.

If anyone knows of any in the east London/south Essex areas, I'm all ears. Or a good correspondence course.

The thanks
Thanks in anticipation.     
« Last Edit: October 17, 2019, 02:58:20 PM by psafloyd »

DrGonz78

  • Legendary
  • ******
  • Posts: 554
  • Chip Points: 69
    • View Profile
Re: Peavey Audition Plus
« Reply #1 on: October 16, 2019, 03:43:19 PM »
Look inside the amp chassis and confirm if there is a 2030 type opamp power IC. Not sure how closely related your amp is to the schematic posted but we'll find out as we go. Start by confirming the 2030 and then we're off to the races.
“A person who never made a mistake never tried anything new.” -Albert Einstein

willpirkle

  • Chipper
  • *
  • Posts: 5
  • Chip Points: 0
    • View Profile
Re: Peavey Audition Plus
« Reply #2 on: October 16, 2019, 03:49:24 PM »
Agree with previous reply - if you are new to this, I'd definitely try to get the correct schematic as well. Peavey customer service (at least here in the states) is usually very generous with information and help. The last thing you want is to be second guessing the components, part numbers, etc...

Enzo

  • Legendary
  • ******
  • Posts: 1860
  • Chip Points: 193
    • View Profile
Re: Peavey Audition Plus
« Reply #3 on: October 16, 2019, 10:44:21 PM »
The Audition Plus is its own model.  You can get this or any other Peavey schematic from the factory:

customerservice@peavey.com

This amp, like many other small amps, uses a power amp IC to drive the speaker.  This  one is a TDA2040.  A TDA2050 would also work.  Those TDAs are no longer common, but an LM1875 should be a good substitute.

I point that out because it is almost certain your amplifier IC is bad.

One possibility to check first is a failed filter cap on one of the power supplies.  The two large-ish capacitors over near the fuse.  Any of them cracked free of the solder?

psafloyd

  • Regular
  • **
  • Posts: 47
  • Chip Points: 0
    • View Profile
Re: Peavey Audition Plus
« Reply #4 on: October 17, 2019, 09:53:47 AM »
Thanks, Enzo. When I get inside, I will be checking the filter caps, having been through some of these tasks in the past.

And thanks for confirming the difference. I spent a good time yesterday scouring for any indication it was a different model and I didn't find any.

I'll get back to you in the near future. Not this weekend, alas, due to the wife's brother being over from Geneva.   

psafloyd

  • Regular
  • **
  • Posts: 47
  • Chip Points: 0
    • View Profile
Re: Peavey Audition Plus
« Reply #5 on: October 17, 2019, 09:54:29 AM »
Look inside the amp chassis and confirm if there is a 2030 type opamp power IC. Not sure how closely related your amp is to the schematic posted but we'll find out as we go. Start by confirming the 2030 and then we're off to the races.

Thanks, I will be back soon, once I have the right schematic.


psafloyd

  • Regular
  • **
  • Posts: 47
  • Chip Points: 0
    • View Profile
Re: Peavey Audition Plus
« Reply #6 on: October 17, 2019, 09:55:00 AM »
Agree with previous reply - if you are new to this, I'd definitely try to get the correct schematic as well. Peavey customer service (at least here in the states) is usually very generous with information and help. The last thing you want is to be second guessing the components, part numbers, etc...

Will do. I'll be back.

Many thanks.

Enzo

  • Legendary
  • ******
  • Posts: 1860
  • Chip Points: 193
    • View Profile
Re: Peavey Audition Plus
« Reply #7 on: October 17, 2019, 01:18:22 PM »
I provided the right schematic, it is the link at the bottom of my previous post.

psafloyd

  • Regular
  • **
  • Posts: 47
  • Chip Points: 0
    • View Profile
Re: Peavey Audition Plus
« Reply #8 on: October 17, 2019, 03:00:27 PM »
Sorry, I didn't see that on the small screen I was using.

Have now got it myself. And I commend Peavey's customer support to everyone. Not only were they very prompt (half an hour and I had the pdf), but extremely nice and polite.

psafloyd

  • Regular
  • **
  • Posts: 47
  • Chip Points: 0
    • View Profile
Re: Peavey Audition Plus
« Reply #9 on: October 17, 2019, 03:24:56 PM »
I see there are TDA2040s and TDA2050s freely available on ebay from China. They're cheap as chips, but I'm sure I read that they are often copies and not of great quality.

I have seen TI LM1875s on Mouser, so it would seem to make sense buying from there if I find the filter caps are not the cause. After all, cheap is not good if they blow easily or don't work full stop.

The Audition Plus is its own model.  You can get this or any other Peavey schematic from the factory:

customerservice@peavey.com

This amp, like many other small amps, uses a power amp IC to drive the speaker.  This  one is a TDA2040.  A TDA2050 would also work.  Those TDAs are no longer common, but an LM1875 should be a good substitute.

I point that out because it is almost certain your amplifier IC is bad.

One possibility to check first is a failed filter cap on one of the power supplies.  The two large-ish capacitors over near the fuse.  Any of them cracked free of the solder?

 

* User Controls

 
 
Welcome, Guest. Please login or register.
Did you miss your activation email?

* Recent Posts

Ibanez TSA30 - buzzing by theaterguy
[November 11, 2019, 07:25:24 AM]


Intermittent loud crackle from Fender Deluxe 112 Plus by traxcontrols
[November 09, 2019, 01:23:37 PM]


So you need a preamp - here are your options by flester
[November 07, 2019, 05:03:55 PM]


Burned up cap by Den.
[November 07, 2019, 03:43:24 PM]


Acoustic 220 quieter volume than expected by DrGonz78
[November 07, 2019, 03:23:10 PM]

* Sponsors