# Blown Soundstream, worth saving?



## Lance_S (Feb 11, 2009)

Hey guys,

Wanted your opinion on this amp. Hooked it up to what I was told was speaker terminals. Found out it was a 12 v hot. Didn't run it long but two of the 4 channels are out. I don't know if what I am seeing on the board is from heat or condensation that is now rusting (amp is 25 years old).

It's a good little amp and would like to fix it if possible. But it might be a paper weight at this point.

Thanks,

Lance


----------



## Sleeves (Oct 22, 2010)

Silly question, but did you check the 5amp fuses? I'm not familiar with this model, but it looks like the outputs are individually fused and maybe you got lucky and they popped before damage was done.

If not it's not usually economically feasible to have that small of an amp repaired unless you have someone local to do it or you are just really sentimentally attached to your classic equipment.


----------



## Lance_S (Feb 11, 2009)

Yeah, It's the first thing i did. The fuses did pop and I replaced them. The ones that are in are new. My concern was where the points meet the board. they look corroded to me, it's the brown stuff loaded up where the wires and circuits connect to the board. maybe that's normal, haven't seen that on other amp guts.

Thanks,

Lance


----------



## [email protected] (Jun 12, 2008)

DOes the stuff on the board look like rust, solid color? Or is it kinda see through?


----------



## Lance_S (Feb 11, 2009)

take a look at the pics attached, they do a better job of explaining it. the connections to the board look like they are covered with a brown, crusty substance. I don't know what it is. Someone with more board experience will know what it is though. 

The reality is that what I am seeing may have nothing to do with the problem I am having. It may be something totally different. 

L


----------



## ChrisB (Jul 3, 2008)

Looks like flux to me.


----------



## Timelessr1 (Feb 12, 2010)

Have you actually tried to hook it up correctly after the first incorrect install? How do you know the amp is not working? Which soundstream model is that? D- series?


----------



## Lance_S (Feb 11, 2009)

No it's A or AB, I am not sure. It's an MX140 (soundstream). I have hooked it up. When I do the side that isn't giving output get warm, quick. No output though.


----------



## Lance_S (Feb 11, 2009)

ChrisB said:


> Looks like flux to me.


What's flux? You can scratch it off with your finger if you try. It's a build up of some kind.


----------



## Chaos (Oct 27, 2005)

Try talking to this guy about it - he works on SS amps, even designed some of them: 

DIYMA.com - View Profile: ace956


----------



## Lance_S (Feb 11, 2009)

Thanks Chaos, will do.


----------



## [email protected] (Jun 12, 2008)

ChrisB said:


> Looks like flux to me.


Thats why I asked above if its kinda clearish


----------



## [email protected] (Jun 12, 2008)

Lance_S said:


> What's flux? You can scratch it off with your finger if you try. It's a build up of some kind.


Flux is in solder, if its not in there you have to add it manually when soldering. I would think back then when that amp was made they didnt have rosin core solder. Its not your problem and its nothing to worry about.


----------



## Lance_S (Feb 11, 2009)

Thanks Beats.

It's pretty much all over the board so I thought that it might not be the problem. The side that functions has as much as the side that doesn't so that was my guess but I am not an electrician and most of whats under the hood is all greek to me.

The problem with this type of amp is that it probably has a street value of what $50 to $70 bucks? If I have it seen by a pro, they usually charge $35.00 just to look at it. Then, depending on fix time, which is $50.00/hour plus parts, I could just go buy a another one.

Problem is, I have owned this amp for about 25 years, I would love to see it come to life again.


----------



## wheelieking71 (Dec 20, 2006)

yes, that is definately just flux on the board. hard to tell from your pics, but i see no evidence of a major meltdown. that should be an easy fix. look up daveds50 in vegas. he could hook right right up for a very fair price (if he has the time)


----------



## Lance_S (Feb 11, 2009)

I will shoot him a PM, thanks for the advice.

L


----------



## Lance_S (Feb 11, 2009)

I shot him a PM, no member found. Was it spelled correctly? Thanks.


----------



## 9mmmac (Dec 14, 2010)

Oh boy... Why am I suggesting everybody take their amps apart? Anyway, the SS's have the output transistors sandwiched between the board and the heatsink. CAREFULLY unscrew the hex head screws and the little black ones by the speaker and power terminals. Carefully lift the board away from the heatsink. Flip it over and look at everything. Your nose is also a big help here! BTW, in the second pic, I see something fishy. Look at the induction coil (???) which is the black donut with wire wrapped around it. Look closely at the 9 o'clock position. THAT looks like a burnt trace maybe- see how it's kinda 3D-ish? What's on the other side?


----------



## FartinInTheTub (May 25, 2010)

It's sad that the amp is broken... Those MC140 Soundstreams were good little 4 channels. 35x4 makes a very clean sounding improvement over stock.


----------



## Lance_S (Feb 11, 2009)

cajunner said:


> how much are you wanting to put into this amp?
> 
> are you willing to buy a cheap multimeter (or have one) and say, 20 bucks in parts and shipping for the parts needed?
> 
> ...


I have a nice multimeter, I just dont' know how to use it. Actually there is some truth in that but I am a quick study so yes, I would be willing to go through the steps and replace what is needed it someone would walk me through it.


----------



## Lance_S (Feb 11, 2009)

9mmmac said:


> Oh boy... Why am I suggesting everybody take their amps apart? Anyway, the SS's have the output transistors sandwiched between the board and the heatsink. CAREFULLY unscrew the hex head screws and the little black ones by the speaker and power terminals. Carefully lift the board away from the heatsink. Flip it over and look at everything. Your nose is also a big help here! BTW, in the second pic, I see something fishy. Look at the induction coil (???) which is the black donut with wire wrapped around it. Look closely at the 9 o'clock position. THAT looks like a burnt trace maybe- see how it's kinda 3D-ish? What's on the other side?


I will take it apart this afternoon, Carefully! I will take a look at teh induction coil, maybe get a closeup pic and post for your review. I will review the backside and get back on the board this afternoon. 

Thanks guys for all the help. I appreciate all the advice and wilingness to help a newb who has an emotional attachment to an old amp.

Lance


----------



## Lance_S (Feb 11, 2009)

FartinInTheTub said:


> It's sad that the amp is broken... Those MC140 Soundstreams were good little 4 channels. 35x4 makes a very clean sounding improvement over stock.


Yeah, it is a great little amp. Bridged it will make 70w x 2 and that was back when everything was based on 12V so bridged it should be in the 90w range. I was planning on having it run my tweets when my RK6's come in from Massive Audio (DAT). The mids will be driven by an old RF Power 300 Mosfet in 2 channel (maybe 200 x 2). I don't know if the SS will keep up with the RF but I would like to try vs. just running the RF passive. I would like to run the fronts active.


Thanks,

L


----------



## Lance_S (Feb 11, 2009)

K,

Here are some new pics of the back side of the board. Everything looks (too the newb eye) and smells fine. No obvious burn marks or jumps. nothing out of the ordinary but hopefully those with more trained eyes might see something. I have added some fresh pics of the front as well.

Thanks,

Lance


----------



## 9mmmac (Dec 14, 2010)

Hmmmmm. In this new series of pics, I'm suspicious of one particular transistor. It's the 3rd from the left. The right leg looks "bad". What's it look like to you? And ALL of the fuses are good? Well, I'd send it in to be repaired. It might seem a little wimpy, just by reading the specs... but I think you'll be quite satisfied with it once it gets working again. BTW, don't test it unless you put it back together- those transistors will overheat and die quickly without the big-azz heatsink they're bolted to. Good luck! Let us know how it works out for you!


----------



## Lance_S (Feb 11, 2009)

No, it's just the pic. The legs are clean. I put it back together today and bench tested it. Channel "A" is not seeing any signal, no LED power light for that side. So no output on either the left, right or mono wiring. Channel "B" works fine. The little LED between the rca's lights up and I get output.

I double checked all of the fuses, they are all fine. So nothing smells burnt. All the legs look fine. No heat jumping or scaring of any kind. I am out of ideas. I was hoping to open it up and see the obvious answer but without a walk through on testing it with an ohm or load tester of some sort to pinpoint the problem I am out of luck.

I thought about having it fixed to use as a tweeter amp. In 2 channel mode it makes 70 to 90w / channel. My frustration is that it might be a $2.00 part that needs fixing.

L


----------



## 9mmmac (Dec 14, 2010)

Well, pretty much everybody agrees it's a good amp worth saving/fixing. Perhaps it's something in the preamp stage and the power transistors just don't have anything to work with. Do the RCA's seem tight?


----------



## Lance_S (Feb 11, 2009)

Yup, they seem tight. When I hook up the rcas the LED for the channel B lights up, just not on channel A. Who would you send it to?


----------



## 9mmmac (Dec 14, 2010)

Two people come immediately to mind:

You can send it back to it's creator, Wade Stewart. He's here as ace956, or [email protected] Good guy, good prices but a little slow and booked up pretty well. Get in touch with him anyway, he might have a spot on his bench.

These guys are more expensive, but turnaround wil be quicker:
Just Repairs -- Audio Car Amplifier Orion Soundstream Xtant HiFonics & Many More Amp Repair
Call them first to discuss, and ask for a pre-approval code if you want. You'll need it for the submission paperwork. 

Good luck, and let us know how it works out! Others may have other contacts, but we all would like to hear your experience with whomever, be it good or bad.


----------



## Lance_S (Feb 11, 2009)

cool thanks.


----------



## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Might be worth it to take it apart again and clean the board real good, contact cleaner, IPA, Acetone, even brake cleaner can clean the board in a jiffy... 

A little work with a few Q tips and all the legs of everything will be nice and clean, no possible "cross talk" it also lessons the chance of a chunk of metal that you might not see, from being trapped...


----------



## Lance_S (Feb 11, 2009)

Aaron,

Thanks, will give it a try.


----------

