That was a great buy and it proves true that it can be cheaper to buy a used amp than a new transformer - if you have the skills to repair it economically.
So, the OP could buy a stock transformer from Farnell etc. but at £34, they're rather expensive for a cheap import. Maybe there's there's still that other alternative offer? https://uk.farnell.com/c/transforme...power-rating=120va&secondary-voltages=2-x-24v
So, the OP could buy a stock transformer from Farnell etc. but at £34, they're rather expensive for a cheap import. Maybe there's there's still that other alternative offer? https://uk.farnell.com/c/transforme...power-rating=120va&secondary-voltages=2-x-24v
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Apparently the OP is getting one for free (?)
But if isn't the case he can always try ebay.
He as been very quiet any update ?
But if isn't the case he can always try ebay.
He as been very quiet any update ?
I messaged the guy but he did say hes away. Im just waiting on him to message. I had a look at the transformer and to be honest its pretty expensive. I'm going to resolder the board tomorrow too.
Sorry im not always online. (i do read everything tho)
Sorry im not always online. (i do read everything tho)
Ebay special Cambridge Audio A1 mk1 serial AMxxxxx 0779 singing again.
Had a problem with my order (TIP3055/2955) so had to dive in my parts bin and found 3 matched set of 2SD1047/2SB817 and on the board they went.
Repair result 2 fuses + 2 sets of power transistors nothing else was damaged, not bad for £30 + postage (with bonus MM phono card installed)
Had a problem with my order (TIP3055/2955) so had to dive in my parts bin and found 3 matched set of 2SD1047/2SB817 and on the board they went.
Repair result 2 fuses + 2 sets of power transistors nothing else was damaged, not bad for £30 + postage (with bonus MM phono card installed)
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Have another question, can't find any info anywhere
Does someone know or have an idea about the idle current for this amp ?
I measured the good channel and it only had 3mV and the trimpot is almost maxed out.
Any suggestions are welcome amp is working fine just doesn't heat up had it running over 4 hours with volume at 11o'clock and was still stone cold.
Any updated on the original OP problem ?
Does someone know or have an idea about the idle current for this amp ?
I measured the good channel and it only had 3mV and the trimpot is almost maxed out.
Any suggestions are welcome amp is working fine just doesn't heat up had it running over 4 hours with volume at 11o'clock and was still stone cold.
Any updated on the original OP problem ?
Hi mjf and yes that correct, 3mV at emitter resistor with original transistors on the working channel.
So i thought i was getting a transformer but apparently its the full amp. Sorting that out and will go from there. Couldnt i just gut the main board out and switch them or can i not do that
Hi, yes you can use the board on your amp on the other one or the transformer from the other in yours it up to you but test before you do anything.
The guy said that he doesnt have the transformer so i asked for the boards since im not sure if any of the other components in my amp are shorted and then going to change the boards and buy a new transformer
Don't do that you going to get more problems
I'm 99% sure there is nothing else wrong with it just get the transformer 2x24Vac or 2x22Vac the first one is the original voltage
I'm 99% sure there is nothing else wrong with it just get the transformer 2x24Vac or 2x22Vac the first one is the original voltage
I don't know what the OP is thinking but the requirement here is for one working transformer. There's obviously no point in adding another amplifier with effectively the same problem. If it's a matter of not enough cash, cut your losses and get rid of the problem.
I enlarged the image you posted in message 96. This shows how messy the solder work looks close up. It is easily possible this is responsible for the apparent open primary winding of your transformer because of cold solder. You are going to have to clean this up in order to solder the new primary if that is necessary. My suggestion was you do that and remake the joints of which I have shown two.
You have given no indication that you have looked at into this. But you are going to have to do the first part regardless.
You might then remeasure the primary winding to see whether or not this restores continuity.
If you took the amplifier to a repair shop that is what they would do to establish whether or not there is a need to order a new transformer.
You have given no indication that you have looked at into this. But you are going to have to do the first part regardless.
You might then remeasure the primary winding to see whether or not this restores continuity.
If you took the amplifier to a repair shop that is what they would do to establish whether or not there is a need to order a new transformer.
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That's the reason I simply give up, simple problem with a simple solution but people like to complicate things for no reason.
Wish him good luck with his adventure but I'm out I don't have time or the will power to keep this thread going on and on.
Good luck
I have remade the 2 joints and nothing has changed so my next step is im getting the transformer.
The critical ones for testing the primary continuity are those identified by Mooly in post 17. It was not possible to enlarge the image to show all the dodgy solder joins in one frame. In post 98 to cover the entire field I suggested remaking the lot.
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I remade all the solders on the main board and there has been no change. I have ordered the new transformer just waiting for it to come now.
I ordered the transformer from farnell however they said its in back order and have to wait til December so was wondering if this one would work.
https://cpc.farnell.com/multicomp/m...eeldErjfyAlV2NGqL5C0sjiRP7CQ5XUMaAjoaEALw_wcB