21-10-2015, 03:38 PM
(21-10-2015, 08:22 AM)ppppenguin Wrote: Trevor is right from an appearance and workmanship point of view. He is also right to say that for some caps the physical layout and cable routing can be critical too. But in many cases any suitably rated cap will do the job, even if the result looks ugly. For example an audio coupling cap should never rely on critical layout.
These large Wima capacitors are pretty hard to miss. I've now come to quite like them. They were never intended for valve radio work at all but there are ways and means. One system is to solder copper wire to the pins and sleeve the wire. This makes it a bit safer. If the copper wire is the right thickness there will be a rigid, solid span where you connect. In most cases you don't need long lengths.
On the HMV, I had to experiment with flexible wire instead which was also rigid enough for support. There are some leads that are longer than the norm although a far few of the original caps had longish leads as well. I would only remove 3 of the old caps at a time because it would be really easy to get mixed up. That would be fatal as the HMV is very awkward to trace.
The Wimas are pretty affordable and easily picked up at a local Maplins branch. Most are rated at high voltages.
In terms of audio quality they're impressive. On the G.E.C. the audio quality is terrific so long as there is some grounding of the earth wire.
I think they're also very robust with soldering heat. I do try and use a heat sink but find the Wimas take a bit of stress.
They look a bit "loud" and that's why it's not everyone's cup of tea.
