pan60
02-09-2010, 09:55 PM
AML Audio Maintenance Limited
The 5003D Pre-Amp
Interview / Review with Colin
Jan. 12, 2010
Pan60: Hi, Colin :)~ ...Let's chat a bit!
Tell us a bit about yourself. I always like to start here.
Where are you from? Where do you live?
Colin: The answer is one and the same; Manchester. I was born here and have lived here my whole life. That doesn?t mean I love it here. I just don?t think that I am he kind of person who likes change.
I went to primary school very locally, and then secondary school in a town called Oldham (about 5 miles away). After that it was University in Manchester. This city just cannot seem to shake me off !!
Pan60: What is your favorite food, ( I have to ask that based on our last chat ), as well as favorite drink?
Colin: I wish that you had asked me what I don?t like to eat as that would be a significantly easier question to answer (Rhubarb and Celery. How can anybody think that these are OK to eat? They are just plant stalks. You wouldn?t eat the stalk of a tomato plant, would you? [Ooops! I slipped into a small rant, there... sorry]).
My criteria for food is usually based around ease of consumption. I have always been a ?big eater? (comes from the old fashioned ?you won?t get desert if you don?t clear your plate?). I usually like to have Indian, Chinese, traditional British (stewed meat and overcooked vegetables) and, of course, a full English breakfast.
To narrow it down to a ?favorite?? Boy, that is tough. Too tough, in fact. I must abstain from your line of questioning and call upon my ?right against self-incrimination? (5th amendment).
My favorite drink? That?s easy. Tea. I drink enough tea, so that when I die, they will need to close a PG Tips factory. If you mean Alcoholic beverage, then that is Bacardi/Diet Coke/no ice/lime wedge. or red wine. I like Guiness, as well, but it goes down too easily.
Pan60: Tell us something about your hobbies.
Colin: I recall when filling out job applications and my CV, there would be a gaping great space for ?hobbies and Interests.? I would sit there for hours trying to think of some interesting hobby to put down, such as ?scuba diving? or ?white water rafting? or ?saving endangered species? or ?climbing the 6 great peaks for charity.? I even considered putting ?skiing down a pink run? at one point. Sadly, these would all have been an exaggeration of the truth. Maybe I am one of life?s ?hobby-less? people. Of course, I ?do stuff,? but I wouldn?t really describe them as hobbies.
I guess that if you press me for an answer, I would probably say ?DIY.? I do enjoy building, woodwork, plumbing... stuff like that. Although, currently, I don?t get the chance to do these things.
I am a bit of a workaholic (I know you won?t allow me to say that the AML is my hobby), and when I am not working, I spend hours entertaining my 3-year-old boy. The only time left is spent asleep and eating.
Pan60: What is you favorite car, motorcycle, boat, or even plane?
Colin: I have no fascination for motorcycles (though I am sure you will try to convert me). I?ve never ridden one. Boats don?t float my boat either (I am sure there is some grammatical rule broken by that sentence). And planes? Well, as long as they land the correct way up, I?m easy.
Cars. I would say that I like cars that are a bit like me, i.e. built for comfort rather than speed. If I were a lotto winner, I would probably go for a Bentley Continental.
Pan60: You know I am going for the conversion as to the motorcycles: )~
I am more into the vintage stuff then anything. I get more out of working on them then riding, these days. I am also into old cool bicycles, as well.
Are you a musician, mix engineer, producer? How did you get interested in electronics, and how did this lead you to the audio industry?
Colin: I can play the guitar a little (used to play in a punk band). But, to describe myself as a musician would be an insult to anyone who ever picked up an instrument. I have never been at the sharp end of a mixing console either. I could use one easily, but the result would sound like **** (reader enter your own expletive here).
Pan60: Give us some background in your experience in the audio electronics world?
Colin: Let?s go in reverse chronological order (this way if the reader is bored they can skip to the next paragraph having missed nothing). Audio Maintenance Limited was initially set up to provide spare parts and support for all the AMEK products after we closed down the AMEK factory. When AMEK was still ?alive? I was the Service Manager - responsible for the service and spares departments for the whole of AMEK worldwide. (I enjoyed that job... had some very good staff).
Prior to being the Service Manager, I was a Project Manager for AMEK. I arrived at AMEK from AMS-Neve. where I was a service engineer for the Capricorn Digital mixing console. A thankless task which involved spending most of my time overseas making modifications to DSP cards, because it had been shipped out the factory before it was really finalized as a design.
Although, I foolishly once suggested an improvement to the design of the touch sense circuitry for the control surface and ended up spending several weeks at Lucasfilm changing 6500 surface mount resistors (note to younger readers ? don?t make suggestions which you haven?t thought through.).
Most of the service work on Capricorn just involves fixing stuff that was designed wrong or built wrong. I can count on one hand the number of occasions when I actually went out to a genuine fault?.
Before that I worked in high voltage engineering (and I don?t mean valves. I mean 400kV stuff, but not for very long, really. It just didn?t suit me. Before that, I was teaching electronics.
Pan60: Tell me your thoughts on discreet verses IC. I am always hearing discreet is better, as well. But, some engineers feel that IC is better. What do you think? There is no right or wrong answer. I feel they both have their merits. I just like to pick the brains of you guys ( and gals ) that design great gear: )~
Colin: It is really a question of ?horses for courses.?
As I see it, IC op-amps are an engineering compromise at the silicon level. For example, a circuit which has both PNP and NPN transistors is undesirable in terms of its efficient use of the silicon wafer and complexity of manufacture. If the circuit were all NPN (or PNP) it would be easier to manufacture, and hence cheaper. So, commercial (cheap) op-amps are usually all NPN (or PNP). Now, you should take that with a pinch of salt because I cannot remember where or when I came to that opinion, and it could be complete nonsense (I am not a silicon designer by any stretch of even the most vivid imagination).
Certain parameters like slew rate and noise voltage may be simply unobtainable using discrete devices due to their physical limitations.
Equally, there may be many commonly used circuit implementations which are simply impractical using discrete devices. Very high Q filters, for example. Of course, it could be done discretely, but you would end up with hundreds of transistors.
Pan60: You pretty much run A.M.L. yourself, is that correct? Do you ever just close the doors and say, the heck with it, I'm a going fishin??
Colin: I essentially ?run? AML but have a lot of help from a couple of other people. I have a person who does PCB assembly and some repair work and someone doing accounts. but they are not employees of AML they are sub-contract labour.. I do everything else. answer the phone . reply to emails. process the orders. PCB layout designs .. make the brews!
It would be nice to just go ?fishin?. unfortunately this is physically a lot easier than mentally. When you are so intimately involved with a business it is just not possible to switch off like that (maybe some lucky people can. but not me). So, in essence I don?t ?run? AML. AML ?runs? me. and it tries its hardest to ?run? me 25 hours a day.
Pan60: Often. when I speak with an engineer, or just gear freaks as a whole, I find, inevitably, it is the company the can run their lives. So, sometimes, we need to take a break and just go fishin?! : )~
What made you want to get into the 500 format?
Colin: It is purely a market driven decision. Ooh! Look at that big bandwagon! There?s space on it for AML!
It also has much to do with the lack of safety certification (which is a CE requirement) as the safety aspects all fall in the lap of the lunchbox manufacturer. I?ll get to this later in the interview in more detail.
Pan60: I see you have some nice discreet op-amps in your pre, as well as some nice transformers. Is the op-amp a specific design after a particular model or is this your own design?
Colin: Generally ?op-amp? refers to differential devices (with huge open loop gain, very high input impedance, zero output impedance, enormous bandwidth, etc.). The gain stages of the 5003d mic amp are single-ended Class A and are a modified version of a design that came from a well known text. Really nothing special about the electronics design at all. Obviously it has a few tricks up its sleeve to make it sound the way it does. But, these have to do with the implementation rather than topology.
The 5003D Pre-Amp
Interview / Review with Colin
Jan. 12, 2010
Pan60: Hi, Colin :)~ ...Let's chat a bit!
Tell us a bit about yourself. I always like to start here.
Where are you from? Where do you live?
Colin: The answer is one and the same; Manchester. I was born here and have lived here my whole life. That doesn?t mean I love it here. I just don?t think that I am he kind of person who likes change.
I went to primary school very locally, and then secondary school in a town called Oldham (about 5 miles away). After that it was University in Manchester. This city just cannot seem to shake me off !!
Pan60: What is your favorite food, ( I have to ask that based on our last chat ), as well as favorite drink?
Colin: I wish that you had asked me what I don?t like to eat as that would be a significantly easier question to answer (Rhubarb and Celery. How can anybody think that these are OK to eat? They are just plant stalks. You wouldn?t eat the stalk of a tomato plant, would you? [Ooops! I slipped into a small rant, there... sorry]).
My criteria for food is usually based around ease of consumption. I have always been a ?big eater? (comes from the old fashioned ?you won?t get desert if you don?t clear your plate?). I usually like to have Indian, Chinese, traditional British (stewed meat and overcooked vegetables) and, of course, a full English breakfast.
To narrow it down to a ?favorite?? Boy, that is tough. Too tough, in fact. I must abstain from your line of questioning and call upon my ?right against self-incrimination? (5th amendment).
My favorite drink? That?s easy. Tea. I drink enough tea, so that when I die, they will need to close a PG Tips factory. If you mean Alcoholic beverage, then that is Bacardi/Diet Coke/no ice/lime wedge. or red wine. I like Guiness, as well, but it goes down too easily.
Pan60: Tell us something about your hobbies.
Colin: I recall when filling out job applications and my CV, there would be a gaping great space for ?hobbies and Interests.? I would sit there for hours trying to think of some interesting hobby to put down, such as ?scuba diving? or ?white water rafting? or ?saving endangered species? or ?climbing the 6 great peaks for charity.? I even considered putting ?skiing down a pink run? at one point. Sadly, these would all have been an exaggeration of the truth. Maybe I am one of life?s ?hobby-less? people. Of course, I ?do stuff,? but I wouldn?t really describe them as hobbies.
I guess that if you press me for an answer, I would probably say ?DIY.? I do enjoy building, woodwork, plumbing... stuff like that. Although, currently, I don?t get the chance to do these things.
I am a bit of a workaholic (I know you won?t allow me to say that the AML is my hobby), and when I am not working, I spend hours entertaining my 3-year-old boy. The only time left is spent asleep and eating.
Pan60: What is you favorite car, motorcycle, boat, or even plane?
Colin: I have no fascination for motorcycles (though I am sure you will try to convert me). I?ve never ridden one. Boats don?t float my boat either (I am sure there is some grammatical rule broken by that sentence). And planes? Well, as long as they land the correct way up, I?m easy.
Cars. I would say that I like cars that are a bit like me, i.e. built for comfort rather than speed. If I were a lotto winner, I would probably go for a Bentley Continental.
Pan60: You know I am going for the conversion as to the motorcycles: )~
I am more into the vintage stuff then anything. I get more out of working on them then riding, these days. I am also into old cool bicycles, as well.
Are you a musician, mix engineer, producer? How did you get interested in electronics, and how did this lead you to the audio industry?
Colin: I can play the guitar a little (used to play in a punk band). But, to describe myself as a musician would be an insult to anyone who ever picked up an instrument. I have never been at the sharp end of a mixing console either. I could use one easily, but the result would sound like **** (reader enter your own expletive here).
Pan60: Give us some background in your experience in the audio electronics world?
Colin: Let?s go in reverse chronological order (this way if the reader is bored they can skip to the next paragraph having missed nothing). Audio Maintenance Limited was initially set up to provide spare parts and support for all the AMEK products after we closed down the AMEK factory. When AMEK was still ?alive? I was the Service Manager - responsible for the service and spares departments for the whole of AMEK worldwide. (I enjoyed that job... had some very good staff).
Prior to being the Service Manager, I was a Project Manager for AMEK. I arrived at AMEK from AMS-Neve. where I was a service engineer for the Capricorn Digital mixing console. A thankless task which involved spending most of my time overseas making modifications to DSP cards, because it had been shipped out the factory before it was really finalized as a design.
Although, I foolishly once suggested an improvement to the design of the touch sense circuitry for the control surface and ended up spending several weeks at Lucasfilm changing 6500 surface mount resistors (note to younger readers ? don?t make suggestions which you haven?t thought through.).
Most of the service work on Capricorn just involves fixing stuff that was designed wrong or built wrong. I can count on one hand the number of occasions when I actually went out to a genuine fault?.
Before that I worked in high voltage engineering (and I don?t mean valves. I mean 400kV stuff, but not for very long, really. It just didn?t suit me. Before that, I was teaching electronics.
Pan60: Tell me your thoughts on discreet verses IC. I am always hearing discreet is better, as well. But, some engineers feel that IC is better. What do you think? There is no right or wrong answer. I feel they both have their merits. I just like to pick the brains of you guys ( and gals ) that design great gear: )~
Colin: It is really a question of ?horses for courses.?
As I see it, IC op-amps are an engineering compromise at the silicon level. For example, a circuit which has both PNP and NPN transistors is undesirable in terms of its efficient use of the silicon wafer and complexity of manufacture. If the circuit were all NPN (or PNP) it would be easier to manufacture, and hence cheaper. So, commercial (cheap) op-amps are usually all NPN (or PNP). Now, you should take that with a pinch of salt because I cannot remember where or when I came to that opinion, and it could be complete nonsense (I am not a silicon designer by any stretch of even the most vivid imagination).
Certain parameters like slew rate and noise voltage may be simply unobtainable using discrete devices due to their physical limitations.
Equally, there may be many commonly used circuit implementations which are simply impractical using discrete devices. Very high Q filters, for example. Of course, it could be done discretely, but you would end up with hundreds of transistors.
Pan60: You pretty much run A.M.L. yourself, is that correct? Do you ever just close the doors and say, the heck with it, I'm a going fishin??
Colin: I essentially ?run? AML but have a lot of help from a couple of other people. I have a person who does PCB assembly and some repair work and someone doing accounts. but they are not employees of AML they are sub-contract labour.. I do everything else. answer the phone . reply to emails. process the orders. PCB layout designs .. make the brews!
It would be nice to just go ?fishin?. unfortunately this is physically a lot easier than mentally. When you are so intimately involved with a business it is just not possible to switch off like that (maybe some lucky people can. but not me). So, in essence I don?t ?run? AML. AML ?runs? me. and it tries its hardest to ?run? me 25 hours a day.
Pan60: Often. when I speak with an engineer, or just gear freaks as a whole, I find, inevitably, it is the company the can run their lives. So, sometimes, we need to take a break and just go fishin?! : )~
What made you want to get into the 500 format?
Colin: It is purely a market driven decision. Ooh! Look at that big bandwagon! There?s space on it for AML!
It also has much to do with the lack of safety certification (which is a CE requirement) as the safety aspects all fall in the lap of the lunchbox manufacturer. I?ll get to this later in the interview in more detail.
Pan60: I see you have some nice discreet op-amps in your pre, as well as some nice transformers. Is the op-amp a specific design after a particular model or is this your own design?
Colin: Generally ?op-amp? refers to differential devices (with huge open loop gain, very high input impedance, zero output impedance, enormous bandwidth, etc.). The gain stages of the 5003d mic amp are single-ended Class A and are a modified version of a design that came from a well known text. Really nothing special about the electronics design at all. Obviously it has a few tricks up its sleeve to make it sound the way it does. But, these have to do with the implementation rather than topology.