Problem with das musikding SHO clone

[poppyman]

Hello,

I've built a few of the "hardone" kits sold by das musikding.

I always thought they were simple and sounded really great especially on valve amps.

Unfortunately, I built one for a friend who explained that the boost was frying after being on for a few minutes in a row (like 10 mn).
So After replacing the BS 170 transistor about 5 times and building a spare one and lending him my own hardone boost and ending up with the same results, I realized that the transistor was overheating dramatically and obviously very quickly.

Did any one experience that before with the musikding SHO? Is it a problem that SHO clones have? Are they meant to be used for a short time only?

I found a picture on the internet of a guy who epoxyed tiny aluminium plate to BS170 transistors to use them as diy "heatsink" ,would it work for that?

Is it something I did wrong? Or is there a simple way to prevent transistors to overheat?

Thank in advance.

Hardone schematic: http://diy.musikding.de/images/stories/hardone/hardoneschalt.pdf

[deadastronaut]

you could always try a vero version....nice and small, and quick to knock up...

ive never built one, so i have no experience of the 'heating' etc...

http://www.diystompboxes.com/smfforum/index.php?topic=91399.0

renegadrian's stuff is good ok!...

[poppyman]

thanks so much for the really quick reply and the link!
I'll try to give a go soon.

I still wish I could fix the boosters I built or, at least, understand what's wrong about them.

[PRR]

If R4 is 5.1K as shown, the transistor can't get hot.

If C3 is installed backward, it WILL get hot. Likewise C2.

[Scruffie]

If R4 is 5.1K as shown, the transistor can't get hot.

If it's used under the expected operating conditions though, yeah?

You say you got the same results when you leant him yours... do you mean he got the same results or you got it with his equipment? Is it possible how he's powering/using it is causing an issue.

Did they work fine for you with your equipment before?

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[poppyman]

Thank you for the advice.

It always worked with my rig (which is a bit similar to my friend's: lots of pedals, 20w valve combo, different guitars including the same he owns: a danelectro with high output pickups).

This morning, I just double checked my soldering and the orientation of the caps, and everything looks fine.
I also left the boost on, maxed out , for 20 minutes and the transistor didn't even get warm.

I  asked him to plug an adapter (one spot) just for the boost and keep it out of the chain but it didn't change the result : the boost transistor got damaged after a prac.

There's must be something wrong with his rig  :/