Pre Amps, line transformers & old microphones????

[retrorelix]

Hi,

I've been fiddling around with music and home recording here and there for the better part of 3 decades. I recently decided to get a little more serious and have been trying to get my "Sanford & son" studio together. Over the years i've aquirred some vintage gear & mic's that I've just started getting around to experimenting with like an EV-666 "mic of the beast" and some astatic harp mics etc... and intend to expand my vintage mic collection, these old mic's are new to me... I want to start using them either through a mic'd amp, direct through the mixer to the recorder or just straight into the recorder... As I'm sure you know old mics don't always have standard 1/4" or balanced 3-pin plugs, so I got some adapters... only to find most of the mics don't seem to work or have a very weak signal... some may very well need to be fixed and others might just be crappy mics or could be I just don't know what I'm doing when it comes to these antiques... I mostly get them cheap from garage sales or free from people that are are getting rid of stuff. I did eventually get the EV666 (a good mic) to work at a low volume without the line transformer after trying differnt cords and jiggling the plug and cleaning the pins... and after locating the proper line transformer it was much louder but still a little low in volume with some noise/buzzing when turned up.

My main question here is...I've never used or needed a stand alone pre-amp that i know of... I've gone through things before the recorder that are amplifiers of sorts like some little old radio shack amps made for enhanceing video sound... but I'm fuzzy on the whole concept of a pre amp, what are they good for... do I really need one? aren't they usually built in to recorders? I gather they may be used like a power booster for a turntable that doesn't have one built in or leveling sound from different sources??? ... most info I find on the web is for 1 or 2 jacks going direct to a computer or with a guitar for amp modeling which I don't care to do... I'm already using all vintage analog equipment and only aspire to record low-fi garage punk, delta blues and experimental noise without overprocessing...I don't want to sound like Bon jovi, Phil Collins or Boston, I just want to record some raw sounding stuff with vintage gear. If needed can I use my Marantz tube reciever/amp or something I might already have like a tube screamer pedal or keep an eye out for something old made for other applications for a Pre-amp? like the old Mcintosh MC60 amp I turned down from a moving job and let go into the dumpster (dooh!!!)... i have alot of other stuff just not a device that is specifically called a pre-amp which it seems are pretty pricey especially a vintage one which i woold prefer.

Second question... do alot of old 50's era mics absolutly need a line transformer or should they work by just plugging the into an amp/recorder/mixer... and/or will a pre amp do the same thing as a line transformer? I never have... and probably never will, have a head for numbers and technical specs... I have a grasp on most things I need to know... I have tried to learn about watts, ohms, impedance etc. but it just confuses and bores me. I'd like to think I'm not a total moron... I actually went to school for audio and video and worked as an assistant in some recording studios, TV staitions and and other A/V related jobs... I have pretty good common sense that usually serves me well... but remebering numbers is just something that escapes me like reading music they teach you when your learning but I don't use it or like it and they don't usually use vintage or home studio gear for any of the stuff in school or in the field.

lastly... By not knowing this technical stuff am I at risk say if I use the wrong impedience mic hi-z, low-z or whatever??? can I potentially damge my equipment. I recently blew a record channel on my Revox A-77 (that one I did save from the dumpster) I don't recall what I had going into it when this happened... I was useing a tascam 424 MKI for a mixer and may have been running it into my stereo for monitoring possibly with a loop-back somewhere, maybe trying squeeze 1 more track or something? The Revox is almost 40 years old and was probably never serviced so this may have just been a coincidence? so I recently purchased a Pioneer rt-707, a Tascam 238 8-Track, and an AKai 4 track cassete deck all of which I've yet to use.

Before I do... Any non-technical mumbo jumbo and insight or a point in the right direction into pre-amps and their uses in an analog home studio or live environment, when they are needed, ways around them and/or cheap substitutes... and a general understaning how to make old mics work properly without blowing up my decks would be greatly appreciated.

Rob

 

[phaqu]

A pre amp boosts the signal of your mic to a usable level. The signal coming off the mic is usually too low to put down on tape, so it needs to be amplified or "pre-amp ed". If you have a mixer, it will almost always have preamps built into it, and most likely be good enough for what you want to do. As for the marantz as an amp, I used to use the tape out to go to my cassette. If the mic is a low impedence you would need a line transformer to go into it,since a stereo reciever will not accept an xlr 3 pin input, like what should be on the ev mic. As for the vintage pres, forget about it. Their value is really high and most people know it. Unless you have the rest of the propper equipment, you would just be wasting your money.
As for the old mics, it depends on how theyre wired. (this may help http://homepages.tcp.co.uk/~sowter/2preline.htm )
To put it simply, a balanced signal (usually low impedence) is used for noise ( electronic interferance) redution that builds up on the line going to the pre or the recorder.
And a 40 year old recorder is probably prone to some kind of malfuntion, Hell.... my ADATS took a shit on me at 3 or 4 years.
Anyway,there are a lot of cheap pres on the market now. You should be able to find one for under a hundred bucks ( if not cheaper).

 

[SteveMac]

so I recently purchased a Pioneer rt-707, a Tascam 238 8-Track, and an AKai 4 track cassete deck all of which I've yet to use.


Rob

Let me know how the 707 works out. I just had an rt 701 that I could have picked up locally snagged from under my nose on ebay.. I hate when that happens! I'd like to get one of those for writing songs on.

 

[Dr ZEE]

As for the vintage pres, forget about it.... Unless you have the rest of the propper equipment, you would just be wasting your money.

What "propper equipment"? Like?

/respects

 

[Dr ZEE]

Rob, I'll try to respond on some of your lines... in general terms.
...as your question(s) is pretty much general... (????)

what are they good for...

preamps(?)
To alter/control the signal when sending signal from device A (or stage/block A inside a device/system) to device B (or stage/block B inside a device/system)
Also, the desire to do so may be driven either by technical demand (so the device or the system works properly as specified) , either by experimentation to achieve a special effect (effect, being applied to the signal).
As I see it: in reality, technical demand and an effect are always tied together, however an effect often gets loose and so acts as the only reasoning on its own, which is good for the art and is good for preamp-builders and for the market

...do I really need one?

It depends. If you face a situation (situations), when you need or want to alter/control the signal when sending signal from device A (or stage/block A inside a device/system) to device B (or stage/block B inside a device/system), then you may need one (or few of them).

I have tried to learn about watts, ohms, impedance etc. but it just confuses and bores me. I'd like to think I'm not a total moron...

same here and it seems to never change

By not knowing this technical stuff am I at risk say if I use the wrong impedience mic hi-z, low-z or whatever??? can I potentially damge my equipment.

If you are experimenting with equipment (especially with vintage equipment) you always are at risk even if you DO know technical stuff, but if you don't know technical stuff, then you are at risk, plus you don't know that you are at risk, or maybe you do know that you are at risk, but don't know what risk you are at. I'd say it is not a good thing, especially when it comes to risk of taking 250V(or so)DC discharge from your pinky finger through your heart to your toe. Blowing up a speaker or a recording channel is nothing, really

**************
Practically (for your microphones/preamps experiments), not to say that you may ever need anything like this, but, you may want to take a look at these (bunch of devices have been bilt for various situations): Here are some (just something I've found on one page... you can search google to find out more details about those devices... you may need one if it does what you want in a specific situation). Those things are just a transformer (s), few leads, in/out connectors, few electrical componets ...(that's if you look inside of them ) You can bild your own devices from junk or from new parts.... (if you are into diy.), or buy htem, they aren't really cheap ... well, it depends on how you look at it and your wallet size...

/respects

 

[littlesongs]

"like the old Mcintosh MC60 amp I turned down from a moving job and let go into the dumpster (dooh!!!).."

(that would have paid more than the moving job even as a paperweight...)

a quick and dirty look at the cream of vintage preamps and how things relate can be found on this well worn page...

http://www.mercenary.com/readguidtovi.html

these days -- if you include all the reissues, knockoffs and audio places going under -- you do have alot of options when it comes to finding mic pres... modules from classic recorders have their own flavor and if i had my druthers, i would love a couple of racks that simply held four channels apiece of several different classic models... ampex 350/351 most obviously, but also the scully 280 and even the venerable ampex 440 line would make for interesting combinations... one could also get into even more obscure brands and lines that had great sound, but poor transports or little parts support... there's been a price spike, so i know most folks go this route to cheat on the sounds going into and out of these infernal little memory boxes...

 

[SteveMac]

Great article Littlesongs. Thanks for putting it up.

 

[Dr ZEE]

At some point, other people in the audio community asked these pioneers to build equipment for their studios. The world of professional recording equipment manufacturing was born.

... and so was the world of manufacturing of professionals.... and all the smoke and mirrors that come with it.

If you want to write a "sort of guide to vintage gear" , then why not to just write about the vintage gear from the point of collected by you experience and gathered by you knowldge such as: what it (the gear) is made of, how it is designed/constructed etc.., and what it does and how it does it(objectively to the extand of possibility to be objective and subjectivelly as well), while leaving all the price/market values, popularity, legendarity, analogies with vintage musical instruments and such crap out of it and while not goings cheaply on yourself wasting your own time and the reader's time pointing out again and again how bad and unacceptable for "professionals" are "some other cheaper gear" from "some other manufacturers" B.S. etc.... then it could be (maybe...) a REAL great article...
*********

well, Steve! ... I'm not really trying to say a thing here...as always (or as never) ..heh heh A Good read is a good read... after all. One man's trash is another man's treasure.
But, just as a note, I'd say (imho): real good read comes from people who just do something and write about what THEY DO (or have done) ...no more no less than that: Got nothing to Sell (And by "sell" I do not mean literally selling goods/services for cash, I am talking about the salesman attitude - "my product (be it a screwdriver, a "scientific" theory or a political view) - IS the only thing you ever need and the only thing you should trust") - nor Got anything to Trash. The style is different, the attitude is different, and you (as a reader) waste less or no time. For example: Like This Guy ... it's just something from top of my head ..from the bookmarks list I happen to have.... again, it's just my view... - that's mho, you know

/respects

 

[SteveMac]

OKay, Mike. When you talk about his bashing other methods, that type of thing I tend to just look past until I've had some experience with that particular thing myself Because it's normal to hear someone go on that what they find of value is the only true thing and what they find of non value is not. I don't see anything wrong with someone having an opinion of what they think is lame. But he IS writing about his own experience with the gear. I appreciate the article because it goes back , and basically names the originators. And I would like to try some of that stuff out, DAmn it!

 

[Dr ZEE]

I don't see anything wrong with someone having an opinion of what they think is lame.

me neither. never. imho, 90% of 'talks' is all about 'opinions'.
Again, it's about attitude, style and presentation of "your opinion". If it was titled something like: "Rant on my cloudy life in the jungle of legendary vintage gear"... then it's all cool with me... because his "article" exactly what it is.

he IS writing about his own experience with the gear.

Yes he does.
*********

The world leader in cost and performance is the exalted Fairchild 670. Testing for this 2-channel, 70-pound mutha was performed in Les Paul's living room. Serial numbers 1-6 were production prototypes and sound slightly better than the subsequent production models. Those subsequent production models (fetching more than $20,000 these days) must be heard to be believed! It's like adding the in-your-face fatness you have always craved with the thickest, most controlled bottom you have ever experienced, and with a high end that just shimmers and dances to your delight. When I don't have one around, I go to Georgetown Masters in Nashville to have Denny Purcell master my record. Besides being one of the finest mastering engineers on the planet, he has his "Fairchildren" (a pair of 660s, the mono version of the 670) that always make my recordings sound like I almost have a clue

...that's just a cut.... but the whole 'story' is pretty much like that...or worse:

Olympic console number two was also built for Olympic. It can be heard on the Rolling Stones' Let It Bleed and Beggars Banquet, and a copy of the desk was made for the Stones' mobile truck for the recording of Exile on Main Street. Folklore says that Chris Blackwell of Island Records wanted his artists to record in his studios, but they didn't want to because he didn't have one of these cool Helios desks. Chris set up Mr. Swettenham with his own company and ordered the first five units. Mercenary purchased two of the Island desks for a client a couple of years ago, but they weren't quite as cool as the original "Stones" desks, in my humble opinion. Helios modules are still available in loose form and are well worth investigating for the serious audio professional.

...now, that's a real good rant from a real serious professional. Heh heh heh
The question is: Fletecher, who (in your mind) are you writing your "guide" for? For a "serious professional"? Ah... I see, now. I've got it. I suppose, a typical "serious professional" of today is the right person to be guided by "your giude": "WOW! Rolling Stones' ! ...WOW! Chris Blackwell! ..wow wowo wow... in-your-face fatness!!!!!!...wow wow wow wow...," ...
...I mean -
Now, Steve, c'mon now. This is fun to read. Yes, it is, if you have time to kill. I can see how it can be 'appreciated' too. I'm not arguing that.
My point is: Is it informative per say? Is it a guide? If it is, then: Guide to where? HERE?
Yeah, well, that "guide" may be is a "a quick and dirty look at the cream (cream?????!!! arghhhhhhh) of vintage preamps". Does this "guide" show "how things relate"? Relate what to what?
Fletcher himself needs to listen WELL to that "sound bite" on that page. And why do you need a such "sound bite" to begin with? For fun? Well... and fun that was. That's all I can tell

..ahhhh,
/respects

 

[SteveMac]

me neither. never. imho, 90% of 'talks' is all about 'opinions'.
Again, it's about attitude, style and presentation of "your opinion". If it was titled something like: "Rant on my cloudy life in the jungle of legendary vintage gear"... then it's all cool with me... because his "article" exactly what it is.


Yes he does.
*********

...that's just a cut.... but the whole 'story' is pretty much like that...or worse:

...now, that's a real good rant from a real serious professional. Heh heh heh
The question is: Fletecher, who (in your mind) are you writing your "guide" for? For a "serious professional"? Ah... I see, now. I've got it. I suppose, a typical "serious professional" of today is the right person to be guided by "your giude": "WOW! Rolling Stones' ! ...WOW! Chris Blackwell! ..wow wowo wow... in-your-face fatness!!!!!!...wow wow wow wow...," ...
...I mean -
Now, Steve, c'mon now. This is fun to read. Yes, it is, if you have time to kill. I can see how it can be 'appreciated' too. I'm not arguing that.
My point is: Is it informative per say? Is it a guide? If it is, then: Guide to where? HERE?
Yeah, well, that "guide" may be is a "a quick and dirty look at the cream (cream?????!!! arghhhhhhh) of vintage preamps". Does this "guide" show "how things relate"? Relate what to what?
Fletcher himself needs to listen WELL to that "sound bite" on that page. And why do you need a such "sound bite" to begin with? For fun? Well... and fun that was. That's all I can tell

..ahhhh,
/respects

If he had gotten into the gizzards and mechanics of each unit I would have

1) been bored
2) would have no idea what he was talking about
3) never would have read the article (or saved it for that matter).

Now, when he says "the thickest and most controlled low end" and "top that shimmers" I think I know what he's talking about. Those type of things are impossible to explain but he takes a stab at it. He also says that his time is "limited" meaning, for the article. Naming off the prices is just another way of saying how sought after these rare and vintage pieces are. That's what antique collectors, per say, do. He also says, "not all expensive, new gear is good alot of it is crap" which, for me , rings a bell,.........riing a ling a ling .............. time for recess.

 

[Dr ZEE]

Now, Steve, before I "respond" ..heh heh ... I just want to tell you that I perfectly understand what you are saying and all that... and not really arguing with you over something... becuse there's nothing really here to argue about ...
but I'm just going to respond to what you say... not to pick on your words...but rather to simply try to point out the way I see things... sort of

If he had gotten into the gizzards and mechanics of each unit I would have

1) been bored

That would strictly depend on the way it is written and presented... of course if you do not give a crap about what the gear really are, but all you want to hear(read) what somebody thinks about them in the form of dad's stories about good ol'days... then of course, no hope there... lol

2) would have no idea what he was talking about

That is likely in the case, when/if the writer has no idea what he was talking(writing) about.

3) never would have read the article (or saved it for that matter).

ahhhh, I kind of don't believe so... simply because I don't belive that you only read (or save for that matter) entertainment material. But how am I supposed to know for sure. I may be wrong...

Now, when he says "the thickest and most controlled low end" and "top that shimmers" I think I know what he's talking about.

You may think so, of course, but really ...and I MEAN REALLY this IS the situation when you REALLY have no idea what he is talking about, because there's no way to know what he is talking about.

Those type of things are impossible to explain but he takes a stab at it.

That is true. And so the "stab" it is ... not a "guide".

He also says that his time is "limited" meaning, for the article.

Yeah, for the article the time is limited, but not for "Rolling Stones".... Stones here, Stones there.... there's always time for stones, you know

Naming off the prices is just another way of saying how sought after these rare and vintage pieces are. That's what antique collectors, per say, do.

Ahhh, cut it out, Steve. When you see prices all over the article... you may be almost sure, that this is NOT a guide. Prices, names, rock-stars and such have nothing to do with what this article pretends to be. Also, I have to say, that the article is perfect for the MIX magazine. MIX-mag is all about things, that have nothing to do with what the MIX-mag pretends to be.

He also says, "not all expensive, new gear is good alot of it is crap"

Now, that "IS" and eye-opener! Isn't it? ...heh heh heh ... what a brilliant point! Steve, like you don't know it already. It's just like everything in this world.
Also, said who? Based on what? "Engineering experience?" Or what? Ahhh, how could I forget? -!OPINIONS! - that's the key word! , which is fine with me.
I wonder if there are any of new expansive crappy sh*tty B.S. gear on the mercenary.com's list for you to purchase? You'd guess not? Right? ...
-Right.
*********
Now it's ................... time for recess


anyhow....

 

[SteveMac]

Now, Steve, before I "respond" ..heh heh ... I just want to tell you that I perfectly understand what you are saying and all that... and not really arguing with you over something... becuse there's nothing really here to argue about ...
but I'm just going to respond to what you say... not to pick on your words...but rather to simply try to point out the way I see things... sort of

Right, it's like us arguing if it's raining because it's raining here but not in NY.

I have to say this. You ARE pretty thorough when looking things over. I never even noticed that the web site had things for sale or it was owned by the author. I just basically read the article. ........ but wait....

..what's this... http://mixonline.com/mag/audio_mark_knopfler/

Now, were were you saying everybody in "mix" should be discredited?


I actually know nothing about Mix or Fletcher, but I do have one of Marks most recent albums, "shangrila" and I say it's a great record, gosh darn it!

 

[retrorelix]

Ok, still soaking this all in but I think I'm starting to get a better grasp on the whole thing... I appreciate the input from you all and did enjoy the mercenary article that was right up my ally and have bookmarked it for future reference... still a little confused because there are so many differently configured things that are called "preamps" I'm not sure where to start... I have always been pretty happy with the sound I get from my revox a77 which has a Hi-mic/lo-mic switch so I suppose I could use that as a preamp. From what can tell there isn't much difference between a pre-amp and any other kind of amp? If I am understanding this right the old pre-amps that people like les Paul, Sam Phillips, Rudy Van Gelder etc. used/built were more or less just a nessecary source to power the microphones they fed into their recorders useing their expertise & technology at hand of the day... and what most musicians/home audio enthusiest now commonly refer to as a pre amp is a little box that usually attempts to simulate that old tube sound? So short of spending a whole bunch of money.... running a mic through some kind of tube amp (bigger tubes... bigger sound?) and into a line input on a mixer/recorder might result in something closer to the desired effect? or would that be too many power sources?

I will probably break down and get a little pre-amp box just to see what it does...I'm looking at the ART StudioV3 Tube Mp?... I've since rewired one of my astatic mic's with a standard 1/4" plug and ditched the screw on adapter and it works perfectly fine now... I also realized The buzz I was getting from the EV-666 mic only happens when I am touching it and thogh I could use a little decibal boost...the volume is an acceptable level.This mic also has a screw on plug adapter probably made for unbalanced signals but is an XLR mic with a unique D shaped 3 pin plug at the mic end... so I should probably rewire the other end with a regular xlr or balanced 1/4" plug and I should be good.

 

[jpmorris]

... and what most musicians/home audio enthusiest now commonly refer to as a pre amp is a little box that usually attempts to simulate that old tube sound?

It would seem that way. I really did just buy mine to act as a phantom power supply. It does contain a valve, but it's starved-plate design, which is not good. It's giving the valve something idiotic like 9v.. a proper design should use at least 100v, and preferably more like 240v.

I will probably break down and get a little pre-amp box just to see what it does...I'm looking at the ART StudioV3 Tube Mp?

It looks like a more advanced version of the one I have. It won't give you a proper valve sound if that's what you're looking for. On the other hand, if you just want it to drive a phantom-powered mic without having to use the 48v supply on the mixer, it will probably do a good job.

 

[Dr ZEE]

Now, were were you saying everybody in "mix" should be discredited? it!

Heh heh. I would not be there or here (or where ever I was not) as a one who'd say that everybody in the MIX (meaning , on the pages of that publication) should be discredited. Faces, names and events are all over the magazine. All kind of names, events and faces are "masterfully" crafted into an ornament for a user to get that "feeling" of being involved into a mystic circle of "professional audio and music production", - the "circle", which is like a imaginary dream garden in a collective farm - we build it and we nurse it for us to belive that we are there, while we are HERE .
That's the best way I can put it....
Mark IS the MAN when it comes to being a guitarist, an artist. I love the attitude he carries nowdays as well.
As for his studio, - it's cool. Did he really build it? .. hmmmm, I don't know. Maybe. Do you know for sure? I have no idea.
Going through the list of gear of a rock-star - that's a typical thing in the MIX-mag.... enjoy your exhibition ...heh heh
Mark is great musician and an artist (one of my Fav...., btw). Was not he a rock-star - he would not be having a chance to get his face posted on the pages of MIX-mag, whether or not Mark built his studio as he did (or did he? ... or did he not?... if not, then who did? us - the fans? I don't know, Steve, help me out )

Knopfler concludes, “A quality studio will save you time and irritation afterward — sitting in a mastering facility trying to compensate for room and recording shortcomings. People should use good studios when they possibly can. For so many projects and from so many standpoints, it's the best way to do it.”

MIX-mag crew-team guys know what they are doing, Steve The bottom line is: buy the products (building "quality" studios facilities services included!) you've seen on our pages or go to the studio, the owner of which bought the products you've seen on our pages. If you do so, then you are OUR MEMBER!, then You are our true "Brother in Arms"
********
100% of Village Youths - To Collective Farm!!!

/respects

 

[SteveMac]

Heh heh. I would not be there or here (or where ever I was not) as a one who'd say that everybody in the MIX (meaning , on the pages of that publication) should be discredited. Faces, names and events are all over the magazine. All kind of names, events and faces are "masterfully" crafted into an ornament for a user to get that "feeling" of being involved into a mystic circle of "professional audio and music production", - the "circle", which is like a imaginary dream garden in a collective farm - we build it and we nurse it for us to belive that we are there, while we are HERE .
That's the best way I can put it....


/respects

I know exactly what you're saying. That in fact could make a good modern statement if you could somehow paint actual pictures of "that imaginary place". It's an illusion but I don't know if its done on purpose with a that goal in mind. It might just be in the "neatness" of the media. Everything is neat and tidy and has it's little place. The craft creates the illusion.

 

[Dr ZEE]

Rob, imho... from technical point mics/mic preamps is a pretty borring puzzle. However, I can imagine how some people can enjoy it. I've found a page you may want to look at (at RANE site): LINK
From the point of practical experimentations with various mics and mic preams - it's an adventure with limitless possibilities and nuances all mixed with undefined objectives and subjective evaluations of the results, and so you never know what you may get. If you add vintage gear, which often employs customazations and/or modifications... then you really get on the edge of it.
Also learning basics (here are some , as example place to find some info) of "survival" is a good move, imho, but in reality, there are no clear "how to(s)"... you are on your own, sort of speak.
********

....mercenary article that was right up my ally and have bookmarked it for future reference

still a little confused because there are so many differently configured things that are called "preamps" I'm not sure where to start...

In that case, I can tell you one thing for sure: - NOT at Mercenary Audio

/respects

 

[Dr ZEE]

.... I don't know if its done on purpose with a that goal in mind.

Yeah. Good point.. or question?
What is(was) the "original purpose"? I don't know. There's no way to know... I think,,, nor needed to be known, as I see it.
When seeking for an answer to a specific question, The important thing to remember is, that Form and Content are not the same things. In respect to an individual's desier (a need) an attractive Form may be tied with misleading (or irrelevant) content, while the real solution(s) may be hidden under an unattractive form. Also, regardless of intentions (or "original goals"), any content provider faces the choice, followed by craftsmanship of a form. Sometimes content-form junction is being intentionally manipulated, sometimes it is being unintentionally neglected. Maybe, That's what makes the world of information confusing and exciting at the same time....

 

[Dr ZEE]

Rob, (and Steve! ) I've come across a nicely put page you may want to go through and maybe save... ????
link: All About Pads (by Rick Chinn)
(and there are more things to look at at the main page of the site: http://www.uneeda-audio.com
... also, it's not exactly entertaining type ... but, damn useful