Access to the Lab is now improved ...

So instead of walking across a series of stepping stones embedded in mud, we now have some proper decking outside the lab. It is huge. Well done, Kris - it really does look spectacular. After this, the next steps will be some tidying up at the bottom, and the rockery / wild garden / pond .. looking forward to some post lock-down family gatherings here.

Fixed the Cambridge P500

Another one off the list of things to sort out .. turned out to be one of the darlington output transistors. They have integrated emitter resistors, and one had gone from 0.22 ohm to something in the hundreds of ohms, so it got replaced. While I was there I checked all the caps (no problems) and I replaced all of the heat sink compound, as there was pretty much none on the transistor I changed. Actually I changed both on that channel to make sure I had a matching pair. Applied power, and success! Sound in both.

There's quite a lot of discussion on t'Internet about the bias current, but I found in the spec for the trannys themselves that they recommend 40mA. So I put some meters on, looking for 17.6mV across the two 0.22 ohm resistors. They seemed to want to settle at 20.4mV which is close enough.

This is a budget amp, so I wasn't expecting too much, but the heatsink is a bit pissy and it feels cheap. The whole amp is not worth saving, really but it might do for a bench amp at a push. At least it is now off my bench so I can move on down the list of things to be repaired.

Changing HDD to SSD in an iMac

For a friend; I volunteered to change the hard disk to an ssd in a 2012 iMac. Well, doesn't sound too difficult, does it? I mean, how difficult can it be?

First, there is the getting in to the thing in the first place. It involved delicate prying of the screen away from the back, using guitar picks and a scalpel (very, very gently) to cut through the glue. It fought back, so I did what most people do and went to Youtube for guidance. The main thing seemed to be get it warm with a hair dryer. So, being a very hot May Day, I left the thing out in the sun for three hours to get nice and toasty inside and out.

This got me to the point where the scalpel and guitar picks started to work, and a suction cup gently pulling the front eventually got it to give way ..

So the next step is to fit the SSD in the hole where the old HD was. Now, the old HDD looks like this:

.. and the new one is too small. 

So it's off to Amazon to order up a converter. The first one wasn't the right style to fit into an iMac despite all of the promises on the web site, so I had to have another go. I also ordered up the sticky strips designed to work in an iMac to put the thing back together again. 

All done .. restoring from a Time Machine backup, only took 12 hours for 2TB of data. That has to be quite fast, but clearly benefiting from the fusion drive it was coming from as well. 

Look, Heidi - I have 27 Inches Of Loveliness in the Lab! - if only temporarily ...