RFT PP100 transistors vs DEI 2879s

[BlackCowboy]

I finally got the pp100s installed in the 2x8. It worked great for about two weeks and now the power is going from 150 swinging to 900 to 50 swinging to 500 or so. It will work right for a little while and then cut the output in half. The box does about 1200 with 15 watts drive, but I was running it light. Reflect is very low. One of the resistors burned up coming off one of the transistors. I replaced the resistor and it is still doing it. Do you think one of the transistors is bad or do you think there is another problem? I was thinking either a bad cap or a bad transistor. Guess these pp100s may be crap.

 

[BlackCowboy]

A local bought a 6 pill tnt from xforce and had similar results. He bought replacement pp100s from xforce and still isn't happy. He runs it at 500 watts pep because he's afraid of blowing it again.

I wasn't there when it blew and didn't repair it so I don't know anymore than what he's said. He's a friend so I told him I would fix it if he bought a matched set of Toshibas instead of the Chinese pills. He went the cheaper route.

There is another local guy building amps with the HG transistors. They seem to be holding up for him. I've thought about buying a pair of them to test, maybe one day. I have a new xforce 2 pill I won on their forum. I should stress test it and put in some HG pills when it blows.

Where did you get the pp100

 

[9C1Driver]

The pp100 finals were sold by X-Force on their web site. Once the supply of Toshiba finals ran dry and/or was too expensive they had these made for them exclusively. The pp100 was a replacement for the 2879 and the pp60 replaced the 2290 final. Not sure who they had make them. Here is a link.

http://www.xforceamps.com/category/Transistors-67

 

[543_Dallas]

Where did you get the pp100

The owner of the amp bought them from xforce. I wouldn't try ordering any. I think their website is still up and they are out of business.

 

[OldTech03]

There are all kinds of reasons why most of what is thought to be true in this post is simply not. I'm not trying to start a fight but the truth is simple and it's not likely Xforce had these PP100's built to there specs as that investment by a company already in the RED most likely didn't happen as the tooling up costs for that adventure would be extremely expensive. I headed up a department at a company that had to change tooling when new equipment was developed and the tooling costs for even a change in plastic cabinet parts were around $25,000 per platter not to mention the other upfront costs and that was 25 years ago it takes a long time to recover those costs and at least 500 amplifiers at a 10% net profit margin would be sold and barely breakeven point.
Next, since none of us can see what is going on with this 2x8 I'm wondering is this an xforce that was built with PP100's or was it a 2sc2879 Toshiba built with real Toshibas and not knockoffs? This is important because knockoffs which include the PP100's would need different cap values and possibly different transformer wind ratios on the inputs than the Toshibas to work without issues and at least give them a chance.

If I'm wrong about any of this please set me straight Like the President said I know I have made mistakes but on purpose, LOL.

 

[9C1Driver]

Ok let me rephrase the way I said it. X-Force found some place in China, Japan, Malaysia that already made this part under a different name. They made a deal where they would purchase so many a year and this company would stamp "pp100" on them. This way X-Force could claim they are special and great yada yada yada. I would not be surprised if they are the same finals as the current HG2879 with pp100 stamped on them. I agree with 543 Dallas, don't try to order any just get the HG versions of what you need.

 

[dave457]

I believe bbi did a recent vid showing that the hg's and the pp's are different inside

 

[bevis]

I believe bbi did a recent vid showing that the hg's and the pp's are different inside

That BBI video actually showed that the HG2879 and the PP100 were near identical inside.
The DEI's were dramatically different.

 

[bevis]

That BBI video actually showed that the HG2879 and the PP100 were near identical inside.
The DEI's were dramatically different.

Exactly this !