[shellylh]

Well, I guess I should feel lucky that my old Extreme died a gentle death (the same amp as moonboy). But now I am a little paranoid. Should we be worried about other tube amps with big caps in them that are sold by DIYers or small businesses whose products are not tested/approved by the FCC or some other agency? Specifically, I have a Woo Audio WA5-LE. I assume that there are some big caps in that PS/AMP. There are lots of pictures of the WA5 insides that are running around head-fi and they *look* well built. I assume that the amp is properly built and safe but I really have no way of knowing this. I just assumed that if it were not, someone would have said something. Of course, this is what I thought about the Extreme I owned before the SP amps started dying.

So, should I open up the WA5-LE and take pics or should I not worry. Sorry for being so paranoid (and taking the thread off course a bit), but I get worried easily - especially after owning a SP amp.

 

[Skylab]

Tube amps have been in use for almost a century. I don't think there is reason to extrapolate beyond this one problem. I'd say don't worry about your Woo - just enjoy it. Everything I have ever seen or read about Woo amps seems very, very sound.

 

[mrarroyo]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif Tube amps have been in use for almost a century. I don't think there is reason to extrapolate beyond this one problem. I'd say don't worry about your Woo - just enjoy it. Everything I have ever seen or read about Woo amps seems very, very sound.

I would concur w/ your assesment. Besides I am not aware of any similar problems reported w/ Woo amps.

 

[mrarroyo]

Quote:

Originally Posted by kevin gilmore /img/forum/go_quote.gif The 8 amp bridge has 4 wires. A plus wire, a minus wire, and 2 ac wires. So the plus wire goes to either of the 2 anode connections pointing to the inside of the chassis, the minus wire goes to either of the 2 cathode connections at the outer edge of the chassis and the AC wires, one goes to the front junction of the 2 diodes, and the other goes to the back junction of the 2 diodes. like this

You are going to kill me w/ my newbie comment. In the diagram you show a third row of four holes to the left of the original 8 holes. Does this third row represent hidden holes under the board that would only be seen if the board is remove and you are able to see the other side? Thanks.

 

[Pars]

Kevin can correct me if I am wrong, but I believe he was trying to show the middle row as being the pins coming off the bridge package. Necessary so that you could see how the bridge is wired into the existing diode holes.

 

[spritzer]

The Woo amps are very well made by people that know what they are doing so no need to worry there.

 

[shellylh]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif The Woo amps are very well made by people that know what they are doing so no need to worry there.

This is what I thought but it is good to have some confirmation.

 

[mrarroyo]

Quote:

Originally Posted by Pars /img/forum/go_quote.gif Kevin can correct me if I am wrong, but I believe he was trying to show the middle row as being the pins coming off the bridge package. Necessary so that you could see how the bridge is wired into the existing diode holes.

Thanks.

 

[BrianS]

My MPX3 uses 3 6CG7 tubes. The caps are shorter than the transformer shell. I think it gets warm to the touch but not hot. This is one of the first generation MPX3's. I may open it up later to see inside.

 

[mrarroyo]

Quote:

Originally Posted by Pricklely Peete /img/forum/go_quote.gif Have a look here. DIOTEC ELECTRONICS CORPORATION MANUFACTURES TVS DIODES FOR PoE SURGE PROTECTION,SOFT RECOVERY HIGH SPEED LEAD MOUNT/TAB MOUNT/BUTTON DIODES AND RECTIFIERS, PRESS FIT DIODES, DIODE CELLS, AND MORE Maybe Dr Gilmore can suggest a good alternative from the many models these guys produce. Peete.

Hi, any idea where I can source the 8 amp bridge? Also which model? Thanks.

 

[mrarroyo]

FWIW I may have found another 8 amp bridge diode, hopefully someone here will be able to chime in to see if it will work or not.

http://www.allelectronics.com/make-a...IFIER/-/1.html

http://www.allelectronics.com/make-a...5A-800V/1.html

 

[mrarroyo]

My Singlepower MPX3 Slam SE had three areas that needed attention. Two of them were critical and the third not so if I refrain from using 6BL7-GT tubes (2) as the output tubes. Even if I were to use them the demise of the power transformer (currently a Hammonds 372BX) was not considered to be an imminent one since the total draw would be 3.3 amps and the 372BX can supply 3 amps. Nonetheless here is a picture of the power transformer.

According to the cursory review/evaluation of the pictures I posted at Head-Fi Dr. Gilmore indicated I needed to install bleeder resistors on the two large power caps. Here is a picture of the installed resistors across the poles of the power caps.

The second area that needed immediate attention was the 4 diodes, which were overheating and scorching the board. Here is a picture of the as found condition followed by a picture with them removed.

I exchanged a few PM and post with Dr. Gilmore and he recommended a couple of alternatives. Of these I chose FDS16DT diodes and chose to purchase heat sinks for them. Enclosed is a picture of them installed.

The amp is up and running w/ no smoke coming out of neither it nor are there any strange noises coming out of the headphones, thus I consider the work a success. Cheers and thanks to Dr. Gilmore for his patience and technical expertise.

 

[immtbiker]

Miguel, I think that is fantastic that with the help of Kevin, you were able to take an amp that you love that had issues, and reconfigure it into a safe, properly spec'd new unit.

Enjoy your "new" toy, dude.

Another potential hand grenade bites the dust!

 

[shellylh]

Miguel: Congrats on the successful refurbishing of the amp (now safe and sound).

 

[mrarroyo]

Thanks guys and gals, I hope it provides many more hours of listening pleasure.