Shane Frencham Posted January 5, 2020 Share Posted January 5, 2020 Hi there, I have recently purchased a McIntosh MA252 integrated amplifier from the classifieds here at StereoNet. I am having an issue in that one of the speakers is not producing any sound. But you can hear a very quiet hum when I put my ear close to the non working speaker. I have tried changing to a different turntable, and also connected a CD player. The same issue arises each time. I have tried swapped the speaker connections, but the speaker that worked and speaker that didn't work simply swapped around. I wanted to see if there are any StereoNet members close to me that may possibly come and visit me and have a good look and see if they can diagnose the issue. I could also pack the amp up and bring it to you. I am more than happy to negotiate a price for your help. I also wanted to make it clear that the gentleman I bought the amp off has been nothing but helpful and would have sorted this out for me, but he is in Melbourne and i'm in Adelaide. I am off work this week, if anyone local can help it would be greatly appreciated thankyou. Shane Frencham Link to comment Share on other sites More sharing options...
blakey72 Posted January 5, 2020 Share Posted January 5, 2020 That's not good news mate. So you've swapped speakers and inputs to test that it's the amplifier channel that isn't working then? Tried different inputs on the amp too (cd and phono)? Link to comment Share on other sites More sharing options...
5L15 Posted January 5, 2020 Share Posted January 5, 2020 I just googled the amp, if it’s the same one I’m looking at? Have you checked the tubes for damage?(possibly got dropped in transit). Link to comment Share on other sites More sharing options...
Tony M Posted January 5, 2020 Share Posted January 5, 2020 (edited) Like all the other locals, I'd be happy to help if I could. But, your experimentation so far seems to have clearly established that one channel of the amp isn't working. Possibly (hopefully) it's just a faulty tube and swapping the tubes L to R should confirm or negate this. If it doesn't, you need a competent tech to have a look inside - maybe as simple as a connection coming loose in transit. I'd suggest discussing options with the seller before getting someone to look inside though as it's obviously quite a valuable bit of equipment. Is it still covered by a tranferrable warranty? I think Vision Living at Goodwood are McIntosh dealers and might be able to help. I've found them good to deal with. Good luck - it looks like a lovely amp and the situation must be intensely frustrating. Edited January 5, 2020 by Tony M 2 Link to comment Share on other sites More sharing options...
Shane Frencham Posted January 5, 2020 Author Share Posted January 5, 2020 Quote That's not good news mate. So you've swapped speakers and inputs to test that it's the amplifier channel that isn't working then? Tried different inputs on the amp too (cd and phono)? Yep mate, I tried swapping the speaker inputs, I tried the phono input with two seperate turntables, and tried the cd player in both inputs. Quote I just googled the amp, if it’s the same one I’m looking at? Have you checked the tubes for damage?(possibly got dropped in transit). This is my first tube amp, but from what I can gather everything is ok. The tubes are lighting up green, and from the research i've done I believe the tubes go yellow when there is an issue. I don't think it's a transit issue as they were packed perfectly in their original packaging and looked very snug in their foam. Link to comment Share on other sites More sharing options...
Shane Frencham Posted January 5, 2020 Author Share Posted January 5, 2020 Quote But, your experimentation so far seems to have clearly established that one channel of the amp isn't working. Possibly (hopefully) it's just a faulty tube and swapping the tubes L to R should confirm or negate this. Thanks Tony, I didn't think of that. I'll try that tonight when the kids are put to bed. And thanks for letting me know about Vision Living, that may be my next port of call. Link to comment Share on other sites More sharing options...
hammer193 Posted January 6, 2020 Share Posted January 6, 2020 Do you get this sorted ? Link to comment Share on other sites More sharing options...
agisthos Posted January 7, 2020 Share Posted January 7, 2020 Use Challenge Hifi on Prospect road. The owners brother is an experienced tech with all amplifier types. Link to comment Share on other sites More sharing options...
darthlaker Posted January 7, 2020 Share Posted January 7, 2020 Call Bruno Kasum of Kasum Audio. He is your man. Very experienced tech. Phone: 0430 329 347 @Cello Sweet. 1 Link to comment Share on other sites More sharing options...
rantan Posted January 8, 2020 Share Posted January 8, 2020 11 hours ago, agisthos said: Use Challenge Hifi on Prospect road. The owners brother is an experienced tech with all amplifier types. The last time I was in Challenge , Steve told me that his brother has retired from tech work. Link to comment Share on other sites More sharing options...
Grumpy Posted January 8, 2020 Share Posted January 8, 2020 On 01/05/2020 at 5:54 PM, evilhomer74 said: Yep mate, I tried swapping the speaker inputs, I tried the phono input with two seperate turntables, and tried the cd player in both inputs. This is my first tube amp, but from what I can gather everything is ok. The tubes are lighting up green, and from the research i've done I believe the tubes go yellow when there is an issue. I don't think it's a transit issue as they were packed perfectly in their original packaging and looked very snug in their foam. I assume you tried different rca cables when you connected the other equipement ? ( cd player and other tt ) Link to comment Share on other sites More sharing options...
Shane Frencham Posted January 9, 2020 Author Share Posted January 9, 2020 Hi there all, thankyou so much for your replies and help. I swapped the tubes around from each channel. The first tube i pulled out, on the non working side, was very loose and barely in the socket. I am pretty sure this was the first tube I inserted when I was setting it up, and not ever owning a tube amp before I reckon I was very careful and too scared to push it in too hard. So I swapped all of the tubes around holding my microfibre cloth, and carefully pushed them in with a little more force. I now have a fully functional McIntosh amp! I feel a little stupid. The loosest tube must have been in far enough to light it green, but not in far enough to make the channel work. Thankyou so much to everyone who replied to me and helped, this is such a brilliant community thankyou so much. Also a massive thankyou to George who sold me the amp, thankyou for not giving up on me and my average knowledge, and thanks so much for all of your advice mate. I may be in contact soon for some more advice if that's ok. Now i'll move on to my next step...... upgrading the average speaker cable. I'll be keeping a close eye on the classifieds. Shane 8 Link to comment Share on other sites More sharing options...
HypnoToad Posted January 9, 2020 Share Posted January 9, 2020 1 hour ago, evilhomer74 said: I was very careful and too scared to push it in too hard. This applies to the first time for a lot of things. Link to comment Share on other sites More sharing options...
agisthos Posted January 10, 2020 Share Posted January 10, 2020 On 08/01/2020 at 11:33 AM, rantan said: The last time I was in Challenge , Steve told me that his brother has retired from tech work. It was bound to happen, last time I used him he seemed to be about 70 years old. Who in Adelaide do we use now? I have been using the guy from Adept electronics on Main North Road for general work. He does do high end audio apparently. In fact one time I went in there and sitting on the front desk was an ME850 and ME14 combo. I said thanks for that, Ill take this lot now.... Link to comment Share on other sites More sharing options...
rantan Posted January 10, 2020 Share Posted January 10, 2020 1 hour ago, agisthos said: Who in Adelaide do we use now? You should make contact with @skies2clear. Not only is he a great tech, but also a true gentleman and all round good guy. 1 Link to comment Share on other sites More sharing options...
howze Posted January 12, 2020 Share Posted January 12, 2020 On 09/01/2020 at 2:36 PM, evilhomer74 said: Hi there all, thankyou so much for your replies and help. I swapped the tubes around from each channel. The first tube i pulled out, on the non working side, was very loose and barely in the socket. I am pretty sure this was the first tube I inserted when I was setting it up, and not ever owning a tube amp before I reckon I was very careful and too scared to push it in too hard. So I swapped all of the tubes around holding my microfibre cloth, and carefully pushed them in with a little more force. I now have a fully functional McIntosh amp! I feel a little stupid. The loosest tube must have been in far enough to light it green, but not in far enough to make the channel work. Thankyou so much to everyone who replied to me and helped, this is such a brilliant community thankyou so much. Also a massive thankyou to George who sold me the amp, thankyou for not giving up on me and my average knowledge, and thanks so much for all of your advice mate. I may be in contact soon for some more advice if that's ok. Now i'll move on to my next step...... upgrading the average speaker cable. I'll be keeping a close eye on the classifieds. Shane Not owning a tube amp I'm sure I would have done the same, glad to see the culprit was just a loose connection after all. Link to comment Share on other sites More sharing options...
Peter-E Posted January 15, 2020 Share Posted January 15, 2020 On 05/01/2020 at 5:11 PM, 5L15 said: I just googled the amp, if it’s the same one I’m looking at? Have you checked the tubes for damage?(possibly got dropped in transit). the old techo tap. Make sure they are seated properly Link to comment Share on other sites More sharing options...
Peter-E Posted January 15, 2020 Share Posted January 15, 2020 (edited) On 09/01/2020 at 2:36 PM, evilhomer74 said: Hi there all, thankyou so much for your replies and help. I swapped the tubes around from each channel. The first tube i pulled out, on the non working side, was very loose and barely in the socket. I am pretty sure this was the first tube I inserted when I was setting it up, and not ever owning a tube amp before I reckon I was very careful and too scared to push it in too hard. So I swapped all of the tubes around holding my microfibre cloth, and carefully pushed them in with a little more force. I now have a fully functional McIntosh amp! I feel a little stupid. The loosest tube must have been in far enough to light it green, but not in far enough to make the channel work. Thankyou so much to everyone who replied to me and helped, this is such a brilliant community thankyou so much. Also a massive thankyou to George who sold me the amp, thankyou for not giving up on me and my average knowledge, and thanks so much for all of your advice mate. I may be in contact soon for some more advice if that's ok. Now i'll move on to my next step...... upgrading the average speaker cable. I'll be keeping a close eye on the classifieds. Shane Is the Green lighting via LED? I've not seen a tube light Green before. the glow is normally from the heater element and usually orange as per heating an element. I also expect that was likely the problem. the heater was not getting the current to heat. no heat not work. A simple test for a dead tube is to check if it's warm. Edited January 15, 2020 by Peter-E Link to comment Share on other sites More sharing options...
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