Please help, I attempted to mod a TAmp and the fuse blew.

[Marsfrogie]

Hello. I just got done fiddling around with my TAmp in an attempt to mod it. When I plugged it in my power supply blipped yellow (load) and popped the 3A inline fuse. This is a Super TAmp.

Here is what I did.

Removed C1 C2 R1 R2 R3 R4

Bridged the place where R1 and R2 used to be.

Installed Solen 2.2 micro farad caps in place of the electrolytics.

Installed a 10000 micro farad cap where the power leads go into the board. (Could this cause the fuse to blow?)

Replaced C8 with a Panasonic FM 2200 micro farad cap

Replaced C10 with a 1000 micro farad Panasonic FM. I put the negative to the chip prong.

Removed L8 L9 L10 L11 and bridged the connections where they used to be.

Removed C25 and C26, Removed R20 and R22

Added 0.1 micro farad caps directly to the output leads. (I could not find a polarity on these so I guessed)

Added a 100 micro farad electrolytic panasonic FM cap to the back of the power connector coming into the box. Negative to negative, positive to positive.

Replaced the 470 micro farad caps that were on board.

Any ideas? Thanks for any help.

 

[Netlist]

I don't know the T-Amp but as a rule of thumb, reverting it to its original state and doing mods one by one is a better way to go.
A schematic would help too.

/Hugo

 

[audio1st]

I would think your problem is C10, shouldn't this be 1uF (+pos to chip pin 36)?

 

[Marsfrogie]

http://www.michael.mardis.com/sonic/start.html

That is a link to michael mardis's schematic.

C10 is originally 330 micro farad and is a power tank. Perhaps it is backwards. Can someone take a look at that schematic and tell me?

 

[Netlist]

If the fuse pops instantly, I'd go for a short circuit between VDD and ground somewhere. Check with Ohm meter.
A reversed electrolyte would explode after a few minutes and then perhaps pop the fuse.

/Hugo

 

[audio1st]

http://www.michael.mardis.com/sonic/start.html

That is a link to michael mardis's schematic.

C10 is originally 330 micro farad and is a power tank. Perhaps it is backwards. Can someone take a look at that schematic and tell me?

That link is to the basic T Amp and not the Super T..

See here...

 

[Marsfrogie]

Sorry I put up the wrong link. That is the schematic that I have been using.

 

[audio1st]

And is this C10?

 

[Marsfrogie]

Yes that is C10, but I have board version B so the stuff around it is slightly different. I put the plus side of the cap to the left side of that picture and the minus side to Cpump pin.

 

[audio1st]

It should be a 1uF ceramic...

 

[Marsfrogie]

Hmm, that's no good. Is the c10 that everyone is talking about on the power supply or something?

 

[audio1st]

C10 you are thinking of is on the original Non Super T Amp..That is replaced by the two 470uF caps( C9 & C36) on the Super....
C9 was the pump cap on the original board. See below...

 

[Marsfrogie]

Does it need this cap to operate? Are there any other values that can be used in it's place? Can I still wire a cap to one of the pins and then on to the +side of the original pad?

 

[audio1st]

It does need it and I think it must be 1uF. Sorry..

 

[Marsfrogie]

It's not a problem I'll go pick one up and put it in. Do you think that 10000 micro cap could be popping the fuse since it is a large load to initially charge it?

 

[audio1st]

Other people have used that size with good results and no fuse blowing.
Having said that I would try it without it first once you have replaced C10..
Good Luck..

 

[Marsfrogie]

One last question. I was only able to find a 1 microfarad tanatalum capacitor. Can I use this? I will put the plus side to the board and the minus side to the chip prong.

 

[audio1st]

For some reason Tripath say pos(+) to pin 36.
See pump pin 36 below.

 

[Marsfrogie]

Hmmm, that appears to be what I did. It still blows the fuse.

 

[audio1st]

Did you do anything to D8?