Trouble after speedball and output cap installation

[sten]

The initial crack build went smoothly, but things headed South after installing the output caps and speedball upgrade.  In hindsight I wish I had done these steps one at a time.

The caps are non-polarized Daytons (DMPC-100 100uF 250V) which were attached to 6U / 7U and 9U / 10U respectively.  It didn't seem like there was a whole lot to go wrong with this part.

I took my time with the speedball construction ensuring the correct components were oriented correctly and installed in the right location.  I looked closely at the solder joints and everything checked out fine.  I think you can see in the following picture that half the LED's are lit up and half aren't (with the exception of the nine pin socket).

Speedball

Output Caps

From what I gather the next step would be to remove/desolder the leads to the boards and reheat all the joints adding a bit of solder.  Any advice on how to proceed troubleshooting this would be greatly appreciated.

Thanks,
Sten

 

[Doc B]

Look at the small metal can transistors and verify that you have 2N2222As on the big PC board and 2N2907s on the small PC boards.

 

[sten]

Thanks for the reply Doc.  That's almost certainly what I did as I didn't differentiate between the two types.

Since the leads are so short I'm thinking I may want to replace instead of re-use.  

2N2907        NTE159M
2N2222A      NTE123A

Would these NTE equivalents be OK?

Edit - The more I read about these NTE replacements the more concerned I'm becoming with their quality.

I will contact Eileen for replacements.

 

[JC]

At one time, both of those were on the wall at Radio Shack; those types have been used for many a year.

Of course, you will pay a premium for the convenience, if they have them.

 

[sten]

Thanks for the tip JC.  I checked the shack and they had some plastic ones which probably would have worked.

Doc you were spot on.  I had reversed the transistors but was fortunately able to reuse the existing ones without too much trouble.

Got everything switched around; passed the voltage checks and I'm in audio heaven now.  This amp is the bees knees and sounds truly amazing on my 650's.

This was my first foray with DIY and I went through the full gamut of emotions during the course of the build.  The profound sense of accomplishment in the end is a good sign this won't be my last Bottlehead project.

 

[JC]

Yup, different manufacturers use different packages over the decades, but a 2N2222 is a 2N2222.

Good for you that you were able to re-use your existing ones!  BTW, I don't think you were the first to make this particular misstep, not by a long shot.  It is a very easy one to make.

 

[Doc B]

Doc you were spot on.  I had reversed the transistors but was fortunately able to reuse the existing ones without too much trouble.

The thing that gives this away is how only one LED in the pair was lit.