I'm sorry to read that your initial enthusiasm is bashed by this issue. I'm pretty sure that it is not as complicated to fix as it seems.
Unplugging the Faston connectors is rather simple (as long as you put some kind of labels on each of them (plus photos), then it's rather easy to take the board out and replace/add what has to be replaced/soldered (not much on this board and access is rather simple).
Then plug the connectors back, and normally, all should be ok. Since you've already turned it on and that nothing burnt or ceased to work (is it right?), my guess is that this is the only part of the amp that needs to be reworked. Beside, this amp normally needs no particular fix (except sometimes in its life some caps replacing).
So, except if you're fed up with it, and that the seller is ready for a full refund, I'd keep it and do the work (which doesn't seem much at first view). And you could ask for a partial refund (at least for the components you would have to buy, it won't be more than a few euros)...
That's my thoughts, but you choose. Maybe more knowledgeable guys would have a different view?
(If it's not too much asking, how much did you pay for it? - no obligation to answer, just to know)
Good day
Unplugging the Faston connectors is rather simple (as long as you put some kind of labels on each of them (plus photos), then it's rather easy to take the board out and replace/add what has to be replaced/soldered (not much on this board and access is rather simple).
Then plug the connectors back, and normally, all should be ok. Since you've already turned it on and that nothing burnt or ceased to work (is it right?), my guess is that this is the only part of the amp that needs to be reworked. Beside, this amp normally needs no particular fix (except sometimes in its life some caps replacing).
So, except if you're fed up with it, and that the seller is ready for a full refund, I'd keep it and do the work (which doesn't seem much at first view). And you could ask for a partial refund (at least for the components you would have to buy, it won't be more than a few euros)...
That's my thoughts, but you choose. Maybe more knowledgeable guys would have a different view?
(If it's not too much asking, how much did you pay for it? - no obligation to answer, just to know)
Good day
Well, frustration comes from my communication with the seller that was somewhat complex during the last week. Since the very beginning I asked him if the item was in original status and if any maintenance work had been performed. He repeatedly reassured me that it was in perfect, untouched status and that it was original in all its parts. Now I discover this stuff and, by the way, he doesn't want to accept the return affirming that I modified the item.
I bought it on Catawiki and payed it about 1500€ including shipment and fees.
I bought it on Catawiki and payed it about 1500€ including shipment and fees.
Hi,
For the whole picture, originally I was looking for a 27.5 then I stepped into this ML9 and liked it a lot for the way it is built
Gaetano, your seller is not fair... How possibly could you modify it that way!
But the price paid seems on par for a "normal" ML-9 amp.
Well, for sure a 27.5 is a nice amp, as @GKTAUDIO suggests. But not the same price tag as well. The ML-9 is fairly nice amp (I own one
) and it's a real ML from the Colangelo time.
Well now I guess we can consider you're stuck with it, but not all news are bad. To repair what's visible (2 caps, 1 diode and 1 resistor, plus the Rifas while you're here, I insist on this) it's quite simple. Just getting this board out and you're not far of the success. Then, do you think you can manage this with possible distant help?
Or - slightly more complicated but perfectly doable - take the board out and send it to one of us who will take the soldering part in charge. I did it for mine, why not just for the pleasure of it. Just have to pay for the parts, it's a quick and easy job, if no bad surprise from the burnt part.
That's my 2 cents, have a nice evening and don't be frustrated (while I understand you can be). We'll find a solution!
But the price paid seems on par for a "normal" ML-9 amp.
Well, for sure a 27.5 is a nice amp, as @GKTAUDIO suggests. But not the same price tag as well. The ML-9 is fairly nice amp (I own one
) and it's a real ML from the Colangelo time.Well now I guess we can consider you're stuck with it, but not all news are bad. To repair what's visible (2 caps, 1 diode and 1 resistor, plus the Rifas while you're here, I insist on this) it's quite simple. Just getting this board out and you're not far of the success. Then, do you think you can manage this with possible distant help?
Or - slightly more complicated but perfectly doable - take the board out and send it to one of us who will take the soldering part in charge. I did it for mine, why not just for the pleasure of it. Just have to pay for the parts, it's a quick and easy job, if no bad surprise from the burnt part.
That's my 2 cents, have a nice evening and don't be frustrated (while I understand you can be). We'll find a solution!
Hi @perelman ,
yes, definitely not a fair seller. Anyway I have opened a complain procedure on Catawiki and I expect to have it solved in a couple of weeks.
Afterwards, if I will still have the ML9, will surely go for repairing. I am not very expert at soldering but definitely I can try, it doesn't scare me, especially if I know that I will have such a nice support like the one I found here. Thank you for being so gentle and ready to help, I will keep the "remote" fix as fallback chance in case I feel a bit overwhelmed.
Besides this, for sure I will need some help on choosing the components and where to buy them, I'm sure you have the right suggestion on this too.
Thanks for the kind words, I feel confident that the ML9 can be fixed, after all.
There is just one more evidence that puzzles me a bit, the difference between the temperature of the right channel dissipator and the left channel one. On the right I measure about 55C, on the left 48C, do you have an idea on the possible causes?
Have a nice day
Gaetano
yes, definitely not a fair seller. Anyway I have opened a complain procedure on Catawiki and I expect to have it solved in a couple of weeks.
Afterwards, if I will still have the ML9, will surely go for repairing. I am not very expert at soldering but definitely I can try, it doesn't scare me, especially if I know that I will have such a nice support like the one I found here. Thank you for being so gentle and ready to help, I will keep the "remote" fix as fallback chance in case I feel a bit overwhelmed.
Besides this, for sure I will need some help on choosing the components and where to buy them, I'm sure you have the right suggestion on this too.
Thanks for the kind words, I feel confident that the ML9 can be fixed, after all.
There is just one more evidence that puzzles me a bit, the difference between the temperature of the right channel dissipator and the left channel one. On the right I measure about 55C, on the left 48C, do you have an idea on the possible causes?
Have a nice day
Gaetano
1) yes you'll get support here
2) easy to find the components, I can make a list of the obvious parts and the place where to buy them safely (genuine parts not like on eBay or fake places). Just FYI, it should be under 10€ or near, shipping to add.
3) about the difference with the temperatures, it could be the bias of each channel to balance (turning up on down the little screw on the yellow trimmer (variable resistor) on the amp board (middle position around). Maybe they are unbalanced. We'll see that later, don't touch it now, no need. I doubt that one of the transistor has failed.
keep up!
2) easy to find the components, I can make a list of the obvious parts and the place where to buy them safely (genuine parts not like on eBay or fake places). Just FYI, it should be under 10€ or near, shipping to add.
3) about the difference with the temperatures, it could be the bias of each channel to balance (turning up on down the little screw on the yellow trimmer (variable resistor) on the amp board (middle position around). Maybe they are unbalanced. We'll see that later, don't touch it now, no need. I doubt that one of the transistor has failed.
keep up!
the parts:
capacitors, resistor, security caps,
the diode I'll need to read more precisely too get the same.
I think it should be all necessary...
capacitors, resistor, security caps,
the diode I'll need to read more precisely too get the same.
I think it should be all necessary...
Here you'll read an old post where you'll find someone who had the same symptoms of different temperatures in his ml-9. Bias balancing. Just to reassure.
try this one. Good one too. I'll have a look on mine, I certainly not bought 875...Looks like that the Vishay caps have minimum purchase lot of 875 items
Or this one. 16V but even better.
Quality is important always, but no need in that place to spend fortunes on "audiophile" caps. Just has to be axial, and there are not as many as radial with those values. But you'll find, no worry.
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Hi,
some news on this topic. Last night I spent a couple of hours in a lab owned by a technician who is specialized in maintenance and repair of professional audio equipment. I've been knowing him for quite a few years and I use to take his opinion in high account. We opened the amp together, he examined the power board and told me that the capacitors and diode are missing since the birth. He is 101% convinced that they were not removed after being there, they just have never been there. This sounded suprising to me but it is actually possible that there are multiple revisions of the board.
Maybe it is interesting to see if my serial number is far from the one of @perelman , do you think it makes any sense?
some news on this topic. Last night I spent a couple of hours in a lab owned by a technician who is specialized in maintenance and repair of professional audio equipment. I've been knowing him for quite a few years and I use to take his opinion in high account. We opened the amp together, he examined the power board and told me that the capacitors and diode are missing since the birth. He is 101% convinced that they were not removed after being there, they just have never been there. This sounded suprising to me but it is actually possible that there are multiple revisions of the board.
Maybe it is interesting to see if my serial number is far from the one of @perelman , do you think it makes any sense?
It is of course possible that various board versions exist.
But mounting a resistor like a drunken sailor would do is highly unlikely for a company like Mark Levinson.
You could ask John Curl, the designer of the ML-2 and maybe even the ML-9.
He is a member on this forum and can be easily found.
Hans
But mounting a resistor like a drunken sailor would do is highly unlikely for a company like Mark Levinson.
You could ask John Curl, the designer of the ML-2 and maybe even the ML-9.
He is a member on this forum and can be easily found.
Hans
I totally agree with @Hans Polak. Diode and cap may be absent of the board from start, but the resistor is not concerned and it’s implantation as it is cannot be ML-validated, for sure.