I'm not sure that Michaelson Audio was ever anything other than a branding/badge engineering experiment for Musical Fidelity. The Odysseus was made in the same factory as the rest of their products and appeared to share the same component suppliers and construction methods.
At the time, MF were full of creative energy and prepared to have a go at almost anything. Reliability, safety and longevity appeared to be well down the list of priorities though which made sure that their dealers service departments were always kept busy. Best of the bunch was the B1, their entry level class AB integrated transistor amp which had next to nothing in the way of protection. Once the customer had shorted its speaker terminals and blown the output transistors it would just smoke its mains transformer until the fuse blew!
At the time, MF were full of creative energy and prepared to have a go at almost anything. Reliability, safety and longevity appeared to be well down the list of priorities though which made sure that their dealers service departments were always kept busy. Best of the bunch was the B1, their entry level class AB integrated transistor amp which had next to nothing in the way of protection. Once the customer had shorted its speaker terminals and blown the output transistors it would just smoke its mains transformer until the fuse blew!
I'm not suprised to hear they where made in the same factory; they even used the same blue paint for the decals... The build quality is pretty good on mine though with heavy castings and steel plate for the bodywork, solid brass controls, Alps volume and input selector and Rubycon/Elna capacitors splashed around. Nothing amazing but equal to some more expensive amps I've looked inside. Sound wise its difficult to knock the circuit design; it's not a million miles behind my £2000 Heybrook Signature pre/power on power and its got the same level of detail and transparency. It's also got just a touch of warmth to its presentation to betray the valves inside. It may be the best integrated amp I've heard? Mine seems to have lasted well too (crossed fingers) with no signs of repair despite being class A and running at a quoted 55 degrees Celcius (the casing gets very, very hot). It's definitely no B1 
It's possible many of the amps are like mine with poorer parts. I did find one forum where people were talking about problems with an Odysseus. I can't see you having any problems vinylengine. My initial problems were purely due to underated wattage resistors. The motorboating will be my fault. I haven't turned the amp on yet but I've got temporary parts in which should solve the issue. I'll be turning it on in a few hours so fingers crossed. I think the heat issues are not a major problem as long as the components are up to it. I think the power valves are actually pretty well seperated from the rest of the amp behind metal plates. I've not had a valve amp until this one and the sound was tremendous and possibly not even as good as it could be given that I have some poorer components which are easily upgradable. I did see photos of a Musical Fidelity transistor amp somewhere on this forum with a power resistor that looked like it had gone on fire the damage was so bad. The same scenario as on my amp but a lot worse. That amp was fixed but something was clearly not up to scratch in the first place.
The amp is now working. It's safe. No dodgy burning resistors or bad joints. Thanks for the info here. Otherwise, it might have taken me ages to realize about the inductors.
Since replacing those dodgy power resistors, fixing the bad joints and blown inductors, the amp has changed slightly. Before, it was loader but distorted slightly when turned really load (you couldn't turn it right up) but now the volume seems to make sense. No distortion at really load volume and the volume control doesn't turn the volume up so much. It adjusts more as how you'd expect.
I'm wondering about these Jamicon electrolytics. Would I notice any difference if I replaced them? There are 8 Jamicons at the cathodes. I do music production here so I actually have 24 bit 96 Khz audio coming from a top end computer soundcard. This sounds immense through the Odysseus but maybe minor differences between caps may have an effect. Any opinions here would be appreciated. The amp is in bit's so it's easy for me to do any upgrades now rather than later.
Since replacing those dodgy power resistors, fixing the bad joints and blown inductors, the amp has changed slightly. Before, it was loader but distorted slightly when turned really load (you couldn't turn it right up) but now the volume seems to make sense. No distortion at really load volume and the volume control doesn't turn the volume up so much. It adjusts more as how you'd expect.
I'm wondering about these Jamicon electrolytics. Would I notice any difference if I replaced them? There are 8 Jamicons at the cathodes. I do music production here so I actually have 24 bit 96 Khz audio coming from a top end computer soundcard. This sounds immense through the Odysseus but maybe minor differences between caps may have an effect. Any opinions here would be appreciated. The amp is in bit's so it's easy for me to do any upgrades now rather than later.
Congratulations on getting the amp up and running.
This really depends on how sensitive you are to small minor changes. I know people who claim to hear differences in things like fuses, power cord plugs and even different labels on the same brand of tubes. (production runs?) This is way beyond my sensitivities, and perhaps a blessing in disguise. This is something you will just have to try for yourself.
While I feel that Jamicon is a cheap brand of capacitor, they do work. And I've always believed that if something is working, don't bother fixing it. However if you'd like to replace them with a better make for prevention's sake, I guess now is the time. There's certainly plenty of electrolytic brands to choose from. Nichicon, Nippon, Black Gate, Sprague, Siemens, Mepco/Electra, Ero, Rifa, Mallory and many more that I can't think of.
Victor
This really depends on how sensitive you are to small minor changes. I know people who claim to hear differences in things like fuses, power cord plugs and even different labels on the same brand of tubes. (production runs?) This is way beyond my sensitivities, and perhaps a blessing in disguise. This is something you will just have to try for yourself.
While I feel that Jamicon is a cheap brand of capacitor, they do work. And I've always believed that if something is working, don't bother fixing it. However if you'd like to replace them with a better make for prevention's sake, I guess now is the time. There's certainly plenty of electrolytic brands to choose from. Nichicon, Nippon, Black Gate, Sprague, Siemens, Mepco/Electra, Ero, Rifa, Mallory and many more that I can't think of.
Victor
OK. I guess this is something I will just have to try. I might replace some of the Jamicons and see if there is any difference. It depends a lot on the rest of your gear. I'm testing the amp with an iPod at the moment but when I hook it up to my computer soundcard which is a pro production card then I hear detail that is way beyond the iPod or most stand alone CD players. Then it goes much further when I listen to my own recordings because I'm hearing them at 24 bit 96 Khz which is another leap above CD quality so it's possible components in the amp could make a slight difference that I can hear but my speakers are not top notch. Linn Keosas. However they seem to be pretty good with the valve amp. The screen grid inductors and cathode resistors are all to be replaced. The dodgy looking cathode resistors in the photos I posted are back in because they do actually work. I'll replace these parts first and take it from there.
Hi again.
I haven't changed any parts on the amp yet but some parts will be replaced. Dodgy resistors and screen grid inductors all to be replaced to something more like the original and possibly replace the electrolytics. Everything else seems OK. However I have a couple of questions before I start going through this amp in detail. Some of my repairs to get it working are only temporary fixes. There are a couple of other things to fix like a broken phono socket. I will need to pull the main PCB out again. I want this amp so that when I close it I won't be opening it again for years, if possible.
The power transformer makes a low humming sound. Is this normal with a transformer of this size? This does not get into the audio output except when at full volume, then you do hear a faint hum. However this is at volume that you would never turn to. I'm just slightly concerned about this hum and what may be causing it.
The other point is about electrolytic values. For most of the electrolytics I can get values as original. Some of the replaced electrolytics are slightly higher value. As far as I am aware this isn't a problem. However I have noticed the 6 big power electrolytics have been replaced with 560uf 250v when the originals in vinylengine's amp are 470uf 200v. I think mine were originally 470uf 220v judging from an invoice I have. I'm just wondering what values I should use. I can get 470uf 250v (or 200v) Vishay BC, Epcos, Cornell Dubilier or Panasonic electrolytics (Panasonic is actually what I have but 560uf - these caps may be OK but I won't know until I start stripping the amp down). These are the cap makes I can source in the UK at these higher values. What difference can it make upping uf or volts in these caps as has been done? What is more important - keeping uf or volts near original? Are there any problems associated with taking these values higher? For the other smaller electrolytic caps I can use just about any make, even Black Gates although very expensive.
Any advice appreciated. Thanks for helping.
I haven't changed any parts on the amp yet but some parts will be replaced. Dodgy resistors and screen grid inductors all to be replaced to something more like the original and possibly replace the electrolytics. Everything else seems OK. However I have a couple of questions before I start going through this amp in detail. Some of my repairs to get it working are only temporary fixes. There are a couple of other things to fix like a broken phono socket. I will need to pull the main PCB out again. I want this amp so that when I close it I won't be opening it again for years, if possible.
The power transformer makes a low humming sound. Is this normal with a transformer of this size? This does not get into the audio output except when at full volume, then you do hear a faint hum. However this is at volume that you would never turn to. I'm just slightly concerned about this hum and what may be causing it.
The other point is about electrolytic values. For most of the electrolytics I can get values as original. Some of the replaced electrolytics are slightly higher value. As far as I am aware this isn't a problem. However I have noticed the 6 big power electrolytics have been replaced with 560uf 250v when the originals in vinylengine's amp are 470uf 200v. I think mine were originally 470uf 220v judging from an invoice I have. I'm just wondering what values I should use. I can get 470uf 250v (or 200v) Vishay BC, Epcos, Cornell Dubilier or Panasonic electrolytics (Panasonic is actually what I have but 560uf - these caps may be OK but I won't know until I start stripping the amp down). These are the cap makes I can source in the UK at these higher values. What difference can it make upping uf or volts in these caps as has been done? What is more important - keeping uf or volts near original? Are there any problems associated with taking these values higher? For the other smaller electrolytic caps I can use just about any make, even Black Gates although very expensive.
Any advice appreciated. Thanks for helping.
Long time no post here.
The Odysseus has been sitting without even being in it's proper casing. No upgrades of caps, resistors, inductors etc which I actually bought to do these jobs. I simply never got around to it until today.
The amp has worked all this time without failing. So yes there are design flaws but not so bad it seems.
The Odysseus has been sitting without even being in it's proper casing. No upgrades of caps, resistors, inductors etc which I actually bought to do these jobs. I simply never got around to it until today.
The amp has worked all this time without failing. So yes there are design flaws but not so bad it seems.
could anyone upload again these photos with the michaelson odysseus or a schematic/service manual? thanks
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