Stereo 2:100 Power Amp - Burnt socket on PCB

[mkcreel]

Hello,
My 2:100 power amp will not power up and from what I've found when I opened her up, I shouldn't try to power her up until she's repaired. I've posted a link to several pics, but just in case you are unable to see them, I'll try to describe it for you. If you are facing the 2:100 from the front, the problem area is to the far left. There is a bundle of wires in a plastic socket that plugs into a socket on the PCB. One end of the socket is burnt to a crisp! It appears the last 2 rows furthest from the front of the amp are toast.

I'm not sure what caused this? Maybe a load was placed on a channel with no speaker or load box attached? Maybe a power surge, though I doubt that because no other equipment is damaged, and I use a power conditioner.

I'm not sure if this amp is repairable? I would rather avoid a $75-$150 bill for someone to tell me this amp is not repairable. Has anyone seen this before with this amp? Any info is greatly appreciated.

Thank you

https://plus.google.com/113102188781099682541/posts/WC128Eesb1G

 

[ando]

Certainly repairable. If they can't replace the socket with a new one, they might choose to just permanently solder the wires in place. It doesn't look that bad to me. A decent amp tech will sort that out no problem. You won't know how much it will cost unless you submit it for appraisal though - so you might as well accept that you'll be paying that fee.

 

[vick1000]

Hate to speculate, but the cause may be those E34Ls, they draw more current than EL34s, and that many together are going to draw a HELL of a lot more current.

 

[mkcreel]

I appreciate the feedback guys. I sent these pics to an excellent amp repair guy I know, and he seems to think it was from the "heaters". I've heard that term used, but I'm not familiar with the concepts behind it. I did not know placing EL-34's in all 8 power tube slots could cause an issue. I've not heard that as a possibility, but doesn't mean it's not true. Does that mean 6L6's are more efficient and less taxing on the power amp? If that be the case, then off with their heads, bring in the 6L6's! I don't really need this much power amp, but you what they say, "it's nice to have that extra power to use if you want to scoot on around, it's no problem!" Lol

 

[vick1000]

I appreciate the feedback guys. I sent these pics to an excellent amp repair guy I know, and he seems to think it was from the "heaters". I've heard that term used, but I'm not familiar with the concepts behind it. I did not know placing EL-34's in all 8 power tube slots could cause an issue. I've not heard that as a possibility, but doesn't mean it's not true. Does that mean 6L6's are more efficient and less taxing on the power amp? If that be the case, then off with their heads, bring in the 6L6's! I don't really need this much power amp, but you what they say, "it's nice to have that extra power to use if you want to scoot on around, it's no problem!" Lol

Those are not EL34s, at least not all of them. Look at the screen print on the tubes, they say "JJ E34L", the "L" is after the "34", that is a different tube, and draws more heater current. That's probably what caused the fire, and chances are the screen grid resistors are blown as well, and maybe even some other power side related parts.

 

[shreddinater]

Certainly repairable. If they can't replace the socket with a new one, they might choose to just permanently solder the wires in place. It doesn't look that bad to me. A decent amp tech will sort that out no problem. You won't know how much it will cost unless you submit it for appraisal though - so you might as well accept that you'll be paying that fee.

Same thing happened to my 2:Ninety. I just cut of the melted part of the plug, cleaned up the pins and soldered the wires back on to the pins. All working again but I would love to know what caused the meltdown and if its a design fault.

 

[mkcreel]

I got this amp repaired by a qualified technician. He tells me this is a long standing issue with this 2:One Hundred amp , and it's actually a design flaw. The plastic plugin to the PCB is not sufficient to handle the amount of current flowing thru it. The tech removed half the plug and soldered the power connection straight to the PCB. It appears to be working well now. It's for sale if anyone is interested, I have it posted on eBay.