New member looking for light

[Dorian 10]

Hi, thanks for letting me join the site. Here is the story: a friend gave me a rack of amps, while most of them where not really in great condition, there was a PT2400 in there. I finally had time to get my hand on it. I gave it a due clean and did some random testing. While some people told me it was a really complicated amp and a really "busy" chassis, I can definitely say that it's well engineered and not overcomplicated to disassembled. However, I'm looking for some guidelines to trouble shoot and attempt to fix it. I did look the manual but doesn't explain in details. Is there a topic related to this? Thank you very much for your help. 

 

[3M_Audio 880]

Hello Dorian and welcome. Carver amps are significantly different in design than what most of us would consider as a 'normal' amp, so that's likely where you heard about it being complicated.

 

What sort of issues is the amp having? You might also try some searches here in the forums to find previous posted info that may help you.

 

 

[wrf 3,829]

Welcome @Dorian.  The PT2400 is a beast.

 

Many of the Carver amplifiers share their basic principals of operation.  Service manuals for them often go into great detail on their design.  Reading the service manuals for the M-400, M-1.5 and the PM-1.5 will provide an excellent foundation for understanding the PT2400.  It's obviously different from those amps, but the basic idea of a triac controlled power supply and multi rail amplifier are the same.

 

Also keep in mind that the PT2400 is virtually identical to the TFM-75.  They have different input circuits and are likely voiced differently, but share many common circuits and components.

 

And as @3M_Audio said, what symptoms of your amp?  What kind of test equipment do you have? And most important, what kind of background do you have?  The PT2400 is not the place to be learning the principals of electronics.

[Zenith4me 1,386]

Welcome to TCS!

[Dennis47 854]

Welcome @Dorian!

Nice amp!! 

[jeffs 2,603]

7 hours ago, wrf said:

The PT2400 is not the place to be learning the principals of electronics.

I would agree. It's probably the worst amp to start your Carver repair journey.

One bright spot is that the amps are mostly completely independent channels, including power. If one channel works, you have a reasonable reference.

 

It's not a commonly discussed amp so I would not think there are any threads regarding repair.  I fixed a PT1800 a long time ago ... have stayed away from these amps since.

The PC boards are dual sided. For me, this significantly adds to the repair challenge.

[Cring08 149]

Welcome!

[Dorian 10]

Thank you for your warm welcome. I know this isn't the easiest amp to start with but it's here and I have nothing to lose since it cost me nothing appart from my time. But I see this as an opportunity to learn even if it's a fail, at least I tried. I located in New Zealand, so there isn't any carver specialist around. I got a multimeter, a signal generator, an oscilloscope and a soldering iron. I also got a friend who design electronic board and keen to explain me or help when I'm in a jam. I checked the service manual but only found how to adjust the bias and also that the amp work by "individual block" (like Jeffs mentioned). I'm mostly looking for informations on how to test those stages (power supply, input board, amp board...). The amp has been cleaned deeply, I visually inspected and didn't see anything suspect appart from some circuit rust on the fan side of the amp board. Channel 1 turn on but the clip light is fixed red (no input connected). And the second channel doesn't turn on, I'm suspecting the black capacitors on the power supply board as I tested the big blue one and they seems fine. If you have any repair thread regarding the Tfm-75 please let me know. Thank you again for your input.

[Kurt 1,390]

Welcome to the Carver Site!

[Dorian 10]

On 10/24/2023 at 12:14 AM, wrf said:

Welcome @Dorian.  The PT2400 is a beast.

 

Many of the Carver amplifiers share their basic principals of operation.  Service manuals for them often go into great detail on their design.  Reading the service manuals for the M-400, M-1.5 and the PM-1.5 will provide an excellent foundation for understanding the PT2400.  It's obviously different from those amps, but the basic idea of a triac controlled power supply and multi rail amplifier are the same.

 

Also keep in mind that the PT2400 is virtually identical to the TFM-75.  They have different input circuits and are likely voiced differently, but share many common circuits and components.

 

And as @3M_Audio said, what symptoms of your amp?  What kind of test equipment do you have? And most important, what kind of background do you have?  The PT2400 is not the place to be learning the principals of electronics.

Thank you for your warm welcome. I know this isn't the easiest amp to start with but it's here and I have nothing to lose since it cost me nothing appart from my time. But I see this as an opportunity to learn even if it's a fail, at least I tried. I'm located in New Zealand (230V), so there isn't any carver specialist around. I got a multimeter, a signal generator, an oscilloscope and a soldering iron. I also got a friend who design electronic board and keen to explain me or help when I'm in a jam. I checked the service manual but only found how to adjust the bias and also that the amp work by "individual block" (like Jeffs mentioned). I'm mostly looking for informations on how to test those stages (power supply, input board, amp board...). The amp has been cleaned deeply, I visually inspected and didn't see anything suspect appart from some circuit rust on the fan side of the amp board. Channel 1 turn on but the clip light is fixed red (no input connected). And the second channel doesn't turn on. If you have any repair thread regarding the Tfm-75 please let me know. Thank you again for your input.