Clearly your search skills are lacking. Calm down. Now read through this:-
http://www.diyaudio.com/forums/solid-state/166250-musical-fidelity-p150-owners-take-note.html
http://www.diyaudio.com/forums/solid-state/166250-musical-fidelity-p150-owners-take-note.html
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I had a very good business dinner last night with someone who is committed to design and on-shore manufacture of audio products with high long-term reliability. It was, to say the least, music to my ears.
As a contrast to some of the horror stories in the MF thread, the NAD 3020 I bought---a showroom sample from the long-defunct Paris Audio---finally lost one of two electrolytics in the auxiliary supply. Even with the capacitance down to essentially zero, there was a slight audible hum in the power amp output. Of course I replaced both of the two of them. But the bulk caps were fine. I looked at the ripple, for one thing, although I didn't note the operating voltage versus the ratings. I went ahead and bought replacement parts of the best quality I could.
That product is famous for being a careful tradeoff for economy. Some might suppose that a larger power transformer etc. would constitute an upgrade. But I think Edvardsen did an excellent job of spending money where it counted, and most anything one might do affecting the higher-power details (as opposed to the small-signal paths) would jeopardize the reliability. This was also Keith Johnson's opinion, who bought one from a friend as he hadn't time to repair his own amplifier and wanted to listen to music.
Someone in here had a rather low opinion of the product (didn't like the power amp topology and single-ended input stage and diode bias) and in particular complained of chemical reactivity of the epoxy used to secure the bulk caps to the PCB. In my inspection when doing the cap replacement, I saw no evidence of this.
But for safety I powered the thing down and will probably not use it to drive my AKG C1000 headphones anymore. Although I have never tested the short-circuit protection, there is no output relay to interrupt connections to the load in the event of some major fault.
As a contrast to some of the horror stories in the MF thread, the NAD 3020 I bought---a showroom sample from the long-defunct Paris Audio---finally lost one of two electrolytics in the auxiliary supply. Even with the capacitance down to essentially zero, there was a slight audible hum in the power amp output. Of course I replaced both of the two of them. But the bulk caps were fine. I looked at the ripple, for one thing, although I didn't note the operating voltage versus the ratings. I went ahead and bought replacement parts of the best quality I could.
That product is famous for being a careful tradeoff for economy. Some might suppose that a larger power transformer etc. would constitute an upgrade. But I think Edvardsen did an excellent job of spending money where it counted, and most anything one might do affecting the higher-power details (as opposed to the small-signal paths) would jeopardize the reliability. This was also Keith Johnson's opinion, who bought one from a friend as he hadn't time to repair his own amplifier and wanted to listen to music.
Someone in here had a rather low opinion of the product (didn't like the power amp topology and single-ended input stage and diode bias) and in particular complained of chemical reactivity of the epoxy used to secure the bulk caps to the PCB. In my inspection when doing the cap replacement, I saw no evidence of this.
But for safety I powered the thing down and will probably not use it to drive my AKG C1000 headphones anymore. Although I have never tested the short-circuit protection, there is no output relay to interrupt connections to the load in the event of some major fault.
Well I read the thread. First off everyone knows the A1 from the early 80s was thermally on the edge, but that was the time of the flat earth cult and people took that as a sign of superior sonics. Again from the 80s pushing caps to 10% above their voltage which is naughty and did carry on for some time. But the TdP designs were apparently good sounding.
Now Jez Arkless clearly had a gripe over the under-rating, but he cannot have been talking about the nuvistor as he had left MF in 1993 for the short lived Alchemist products. The nuvistor was launched in 1997. In fact pre 1993 there don't appear to have been any tube products. The tubalog was launched in 1993, but that was a DAC.
So I accept that they took good designs from a respected designer and underpackaged and cost reduced to the point of reduced reliability. As did many back in the 80s! But nothing that suggests pre-93 a pre-amp with a tube not in circuit. Shame he did not quote a product.
Please note I have never owned a MF product or met the boss. I have however basked in the glory of the de Paravacini beard once at a show, but they have hung on for over 30 years, which puts them in the elite group in the strange world of audio.
Now Jez Arkless clearly had a gripe over the under-rating, but he cannot have been talking about the nuvistor as he had left MF in 1993 for the short lived Alchemist products. The nuvistor was launched in 1997. In fact pre 1993 there don't appear to have been any tube products. The tubalog was launched in 1993, but that was a DAC.
So I accept that they took good designs from a respected designer and underpackaged and cost reduced to the point of reduced reliability. As did many back in the 80s! But nothing that suggests pre-93 a pre-amp with a tube not in circuit. Shame he did not quote a product.
Please note I have never owned a MF product or met the boss. I have however basked in the glory of the de Paravacini beard once at a show, but they have hung on for over 30 years, which puts them in the elite group in the strange world of audio.
MF was all-SS then, MA all-valve
(makes me wonder how many of the spacecraft designs under his own name Mr Michaelson managed to sell in those years)
(makes me wonder how many of the spacecraft designs under his own name Mr Michaelson managed to sell in those years)
Dunno, but he's a pretty good clarinet player. Have a couple of his recordings.
EDIT: M&A was 70s. MF came after M&A sank.
EDIT: M&A was 70s. MF came after M&A sank.
Michaelson Audio, the few models under that brand name were manufactured at Musical Fidelity.
(it's the Michaelson Audio gear Mr Arkless was referring to, parallel with the few years he was at MF, 1990+1991)
(it's the Michaelson Audio gear Mr Arkless was referring to, parallel with the few years he was at MF, 1990+1991)
Well, I got the 'nuvistor' and 'tube' thing mixed up - but I pretty much said I may have done so in an earlier thread.
Who knows, they may have cleaned their act up a bit.
However . . . about 5 years ago, I was in BIC in Tokyo on the 2nd or third flor where they had a pretty decent array of Japanese and assorted foreign gear when I noticed an MF integrated amp. I thought 'wow' a UK amplifier product and I reached for the volume control dial to adjust it . . . no kidding the knob came off in my hand.
Ok - I'll stop MF bashing and tell a good story about them 😉
A friend in Taiwan said to me about 4 years ago 'I've got this amp I bought in HK about 20 years ago. Its been in my trunk room for the last 10 - it doesn't work'. I offered to look at it - it was an MF A1. The series resistor in one of the rails had gone open circuit (both supply rail resistors were badly burnt from long term overload). I replaced it and have to say that A1 sounded fantastic . . . and that's what lead me to design and build the sx-Amp.
The A1 circuit sure is idiosyncratic (TdP design I believe) - but it works. - I advised my friend to put an AC cooling fan on the heatsink which he did and its still working
Who knows, they may have cleaned their act up a bit.
However . . . about 5 years ago, I was in BIC in Tokyo on the 2nd or third flor where they had a pretty decent array of Japanese and assorted foreign gear when I noticed an MF integrated amp. I thought 'wow' a UK amplifier product and I reached for the volume control dial to adjust it . . . no kidding the knob came off in my hand.
Ok - I'll stop MF bashing and tell a good story about them 😉
A friend in Taiwan said to me about 4 years ago 'I've got this amp I bought in HK about 20 years ago. Its been in my trunk room for the last 10 - it doesn't work'. I offered to look at it - it was an MF A1. The series resistor in one of the rails had gone open circuit (both supply rail resistors were badly burnt from long term overload). I replaced it and have to say that A1 sounded fantastic . . . and that's what lead me to design and build the sx-Amp.
The A1 circuit sure is idiosyncratic (TdP design I believe) - but it works. - I advised my friend to put an AC cooling fan on the heatsink which he did and its still working
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Ah, that at least makes sense from a timeline. Although there must be more to it than he says, but that was 25 years ago now!
And then this thread lost all relevance, fits the lounge, pretty sure this is what Aksa wanted when he invited to a discussion on the merits of feedback.
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I read through all that. You really think it was justified to claim nuvistors not in circuit based on this? You should be ashamed of yourself. You're doing exactly what you accuse "the industry" of doing. Thought you guys were only interested in facts...
Jez got carried away a little, so did Mr Russell.
Why make such a big deal out of it.
(Valve amps - do measurements tell it all? - Page 16)
For my entertainment, why did the concept of the Pioneer Exclusive M4/M5/M6 not survive beyond the '80s.
(output stages with local feedback only, and lots of class A current)
Why make such a big deal out of it.
(Valve amps - do measurements tell it all? - Page 16)
For my entertainment, why did the concept of the Pioneer Exclusive M4/M5/M6 not survive beyond the '80s.
(output stages with local feedback only, and lots of class A current)
Any thread goes entirely where those posting take it. If replies would rather have a rambling lounge chat about shock-horror industry gossip, then it's their ongoing off-topic posts that diminish the thread continuity. If you want a good thread about DIYaudio topics that can be followed to everyone's benefit, then it's the replies that should responsibly keep an eye on the topic, whatever diversions they might find amusing or interesting enough for all to share. I would think that's normal and more acceptable than constant reminders from the OP.
There have been some great, informative posts here by well respected members and there seems to be plenty of room for more. Keep 'em coming. 😎
I read through all that. You really think it was justified to claim nuvistors not in circuit based on this? You should be ashamed of yourself. You're doing exactly what you accuse "the industry" of doing. Thought you guys were only interested in facts...
I am only the messenger - so I don't see why your ailementary canal is in full swing over this. As I pointed out even before I did the 'heater +MF' search I may have gotten tube and nuvistor mixed up. And, I don't think Jez got carried away. The fact is these things took place.
We can only hope that they have cleaned their act up along any other companies that may be doing similar things.
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Why shouldn't I get worked up when what you've said is clearly complete bull**** and has the potential to put prospective buyers off that brand for no good reason. You're not a messenger, you're just making things up based on rumour and hearsay with the intention of showing your superiority over mere hifi enthusiasts (that like to listen to audio equipment and buy what sounds good to them so that they can enjoy their music) by implying that no one can actually hear any difference and it's all down to marketing.
Owedo,
I take exception to that.
So, are Jez, and the other guys I posted the link to making things up? Or is SY making it up about McIntosh?
If you or anyone else wants to by that product be my guest. If you read and accept half the drivel put out by the hi-fi press why would anything an ignoramus like me says be of any concern?
Clearly you have some other agenda going on. Don't make me part of it.
I take exception to that.
So, are Jez, and the other guys I posted the link to making things up? Or is SY making it up about McIntosh?
If you or anyone else wants to by that product be my guest. If you read and accept half the drivel put out by the hi-fi press why would anything an ignoramus like me says be of any concern?
Clearly you have some other agenda going on. Don't make me part of it.
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Since there has been no evidence offered to back up any of these claims, it's clearly you that's putting out drivel and has an agenda. How does your own medicine taste by the way? 😛