Kit 34 at it again

[Greg.]

Yep, and also return to the original fuse value. Once all is well, you can increase the fuse value if you wish. Interestingly when some of us did this in our kits from the same era, we found the sound to be different and some considered it better!

[jiten]

Thank you Bob and Greg.
Will try and follow instructions to the letter. Any idea how high a voltage to expect without the load? Just so I can compare with the expected voltages. Is it a percentage value above the voltage in the specs?
Bob, if you get the chance, I would do the death road but even better is to cycle in Bhutan where the views of the Himalayas as you go around every hairpin bend (about one every 200 yards) are stunning. The country has only one road, 10 ft wide running east west and traffic generally is at about 20 mph because of the terrain.
Thank you for your help.
Jiten.

[jiten]

Dear All,
An update on the transformer. The new one arrived on Monday and apart from the grey and purple wires being rather thinner than the original, everything seems OK.
I removed the old transformer and think have identified the problem. On the primary side, the yellow green earth wire and the brown wire were both trapped between the transformer and chassis.
As a result both wires are flattened over about an inch or so and I suspect that with the heat and pressure over time the insulation has simply broken down. Therefore the transformer may well be OK.
Anyway installing the new one and had to do it a couple of times to make sure no wires were caught.
Will solder everything in place tomorrow and see what happens.
Best wishes, Jiten.

[John Caswell]

Hi Jiten,
Thats good and bad news.
However when fitting the new one, initially leave all the wires long, until you are absolutely sure all is OK, then at least you will have a new transformer to sell if you wish.

John

[jiten]

Dear All,
Have fitted the new transformer and back to good music. Thank you all for your help and advice.
The old transformer is probably in good working order as long as the squashed two wires are spliced out. I will be happy to give it away after a month or so to make sure the new one beds in.
If anyone is interested in having it, please let me know.
Kind regards, Jiten.

[Shane]

Hi Jiten, if you really are giving away the old transformer, I would be a very grateful recipient! Happy to cover postage costs, of course! Let me know when you're ready.

[jiten]

Dear Shane, I think John Caswell was interested in looking at it to find the cause for its failure but I think that has been established.
At the moment the new one has significant hum. It is not from the casing or fixing to the amplifier as that is firm.
I will be in touch. Kind regards,
Jiten.

[Shane]

Don't worry if you have other plans for it!

[jiten]

Dear All,
Been away so no posts. The new transformer still has a hum which is audible for about 5 ft from the amp. It is not in the sound which is fine and quiet. I can alter the hum slightly by pressing on the transformer cover. Any suggestions on how I can eliminate it?
I used the original washers and bushes when I fitted the new transformer. If I need to use new ones, any help on what to get and where from? They would need to be heat resistant as the transformer does get hot ( within reason).
Thank you as always.
Jiten.

[Phil Y]

Hi Jiten,

Noisy transformers seem to be quite common these days. I found mounting the transformer of my amp on rubber grommets did the trick. It is now only audible from quite close up rather than from seated as it was to start with. Originally the transformer was vibrating the amp chassis and through that, the shelf it was sat on, using it like a big sound board. If you can safely, lift the amp up while switched on. If the noise gets less this may point to the same problem as mine. If you do end up doing this remember to fit an earth to one of the mounting bolts.

Phil.