Knif audio

[Jonte Knif]

Thanks for all this info. And especially for the positive comments

I'll share my views:

What kind of strain relief would you like to see there? The wire tied to PCB perhaps? I'm open to creative suggestions. That shielded cable runs 15cm from point a to point b.

Consider the force that is produced, let's say, at 10G acceleration into a piece of wire, in this case 1,5 grams producing a "force" of 15 grams. This is about the maximum stress there is ever going to be. The CNC-machined alu chassis will start to disintegrate long before the wire loosens. I can tell you, the wires barely move if the unit is handled in any "normal way". Talking about stress is, can I use this word, absurd. But hey, there is always room for improvement, so, thanks anyway.
For all other wiring than shielded balanced cabling I use teflon insulated silver/copper wire. Many of you know the stuff. Its mechanical properties are superb and when inserted into a turret and soldered you know its going to be there for a while. Unfortunately in those pictures you can not yet see my current turret type.

I was very surprised to read that some people prefer connectors above solder turrets. The best connector is no connector. I don't use solder turrets for ease of assembly. BS. After building some real gear with solder only, you feel in your shoulders the cost of not using handy connectors.

And finishing a huge passive mastering EQ last week I feel like finding somebody else to do the job for me, and fast

It is not a coincidence that well made guitar amps use turret boards. And they DO get to see the road. I really wish I could use turret board based construction, but there are some pretty substantial problems. Lundahl trannies, relays and regulators for example. Also the amount of work would be prohibitive. Take a look at the price of DW F gear, perhaps at least some of it comes from the labor required, because it ain't coming from Tele804S tubes.

I wish I could also use 3,2mm boards, but many of those bloody modern components have pins hardly long enough for that 2mm board. Using thicker board is not a cost issue, you got it right there.

C3m or C3g, that is the question... Those of you who understand something about tube amp design probably know it, others have to guess

There are some serious safety issues on some pro audio gear, so it is good that you keep your eyes open. I just opened a certain "boutique" compressor which had safety ground wire soldered to XLR-housing lug, which was screwed to the off the shelf steel chassis with self tapping screw only. Whether this would pass CE-tests or not, I'm not sure, but I doubt. I was kind of shocked. Fortunately not electrically.

China stuff is another interesting issue. Or "hand made in the USA" China stuff. Most of it ok, but not everything.

It's going to take a while until my gear is widely available, but so far I'm pleased to see it replacing brands starting with T and M in local studios and mastering facilities. Ecstatic Electric has my pre amp for sale (I decided to start with the "easiest product"), test it if you happen to live in the neighborhood.

I wish USA gets its economy running a bit more smoothly (with the help of a new president, perhaps? ) so that the price of my gear compared to US-made stuff will be more competitive. (Take a look at the Euro/USD rates during a couple of years.) At the moment the situation is really a bit on the edge. Hard to export but still possible (easy) to beat the competition locally.

And last:
I really would like to thank you all for contributing to this forum. There are a couple of guys here who really know their circuits. On the other hand there are, of course, always the guys who "know". But I guess that comes and goes with age (I have to wait for it myself...) I have not participated in the discussions because writing in English is a bit tedious for me and I also have other things to do, but I visit the forum every now and then.

-Jonte

 

[Viitalahde]

Welcome!

It's great to see gear hailing from Finland, and that someone has the interest and energy to start some sort of a product line. I know I don't.. And that's because I'm not an engineer type of a person, more like a "try it and see what happens" type. Maybe that's why some of my gear looks like swiss cheese inside, full of holes from previous experiments.

How about the amorphous core Lundahls? I'm having interest in ordering a few for a MS matrix for start, maybe also for a vari-mu idea I have cooking in my brain.

 

[Jonte Knif]

Terve Jaakko,

I don't personally have ears good enough for listening to very detailed stuff so I've passed the idea of AM cores to my customers but I have been reluctant to persuade anyone to take them because the difference can be small... But I have one idea waiting to be tried. At some point, without further explanations I'm going to put AM-core trannie to one channel of a two channel unit, preferably the pre. The owner will then be asked to listen to the channels (of course not knowing which one is which and what has been changed) and decide if there is a difference and which channel he/she prefers. After that I can blackmail more money for the AM-cores from the unfortunate victim, OR take the AM core out to be forgotten in the collection of "not so great ideas".
According to Per Lundahl the AM-core has more discrete states, but he has no definitive objective explanation for the sound and doesn't, as an honest engineer, try to invent one either. Certainly not a case for my AP-rig distortion measurements. I guess the difference is something to be believed or not _before_ somebody does blind AB-test or the difference is so big as to be laughed at. Could be?
If some of you are interested in physics, check out how amorphous iron alloys are manufactured. The poor crystals trying to take form as the alloy cools are literally frozen before they can form. Any material with that kind of mystical manufacturing proses has to sound good, doesn't it?
Anyway, I tend to dedicate my time to engineering and "visioning" rather than playing with esoteric stuff. Only after I am confident that my gear has reached the best possible sound with "normal" (errhhh...apart from EF804S and the mystical Siemens tubes) components I can sincerely start to build an audiophile guru aura of my own. But that requires hairier face and I don't seem to posses genes for that.
Was this the brewery forum? I'm getting too technical perhaps?
So, about brewing...Does anyone have access to Carmeliet Trippel

-Jonte

 

[ruairioflaherty]

[quote author="Jonte Knif"]
So, about brewing...Does anyone have access to Carmeliet Trippel

-Jonte[/quote]

Now we're talking!! Trippel Carmelite is my very favourite beer. I discovered it in a great Belgian bar on my first trip to Amsterdam and drank it religiously (groan) every time I returned. It is hard to find in Ireland.

Welcome to the forum, it's great to have another manufacturer of premium analog gear in the house. Hopefully in my mastering work I will be able try your gear at some point in the future.

Cheers,
Ruairi

 

[audiox]

Hello Jonte
You probably know that that equipment that you manufacture must fulfill several EU directives. Most important are the Low voltage directive and EMC directives (emission and immunity). Practically there are two alternatives. 1. Do all the required tests in a test house which can be very expensive (up to 10000 euros). 2. Do nothing which makes your products illegal. I guess your company is quite small, so I am interested to hear how you have solved this problem. A friend of mine is planning to start manufacturing audio gear but these test are the main reason he hasn't started yet. Maybe you (as an existing small manufacturer) can give some advice.

 

[Jonte Knif]

Hi Audiox!


The Directives are a pain. When I first time went to read them in a company here which published them in Finnish also, the guy who handed me the pile of paper said: Have fun. In a sarcastic way.

Two reasons:
Because of television fires (amongst other things, of course) the directive has gotten quite strict. Ridiculously strict in some cases.

The directive is essentially written by test personnel to test personnel. This man said that he has been translating the papers a lot, and seemed to sincerely think there is some room for improvement in respect to the readability. So, your friend is going to have some quality time also, or pay big money for consulting engineers in addition to the tests.

Any how:

This is a very delicate issue. Know what you are doing.
You don't have to use a test house. You can give a "declaration of conformity" Some of the tests required are pretty much impossible to do in a small workshop, but many manufacturers do it anyhow and give that piece of paper.

For example this "safety earth at XLR lug" -issue I mentioned was found in a compressor for which the manufacturer had given the declaration. It is to be seen on their web site and in the manual.

The thing is that you should be able to put substantial amount of current through the safety E to the chassis with a very small resistance and measure it. I really, really doubt they did the test and it is the most important one. They even didn't use common sense. OK then. What can be done? Use common sense. And use it with care, these are not things to be messed with. Over engineer if you are not sure. For example my safety grounding goes like this:

From the Euro connector with thick and short wire with Abiko-connectors to a M4 screw attached to the aluminum back plate with lock washers and a lot of force. From that point on the current flows pretty easily in 4-10mm thick aluminum plates to the whole chassis

I build all my gear to the double insulated standard. So actually I'm following the standard for non-safety grounded equipment too. Over engineering, but I've seen it in other equipment too.

Fire:

When using non-standard components like high end caps you can perhaps not so easily get the UL-test results from manufacturers. I remember having problems with Orange Drops long time ago. If you can not show that every component over 1 cubic cm fulfills the required UL-classification you HAVE TO LET the test lab to burn every single f****g piece to test. There is no way you can say "come on guys, this cap is aluminum and polypropylene in a ceramic housing and I've tried to burn it, it impossible to set on fire with a butane torch" At this point I miss the common sense on their side and get a bit mad.
But such is the law.

Rohs (lead free etc):

This is pretty easy. Component manufacturers have to take it seriously because it is illegal to sell NEW non rohs stuff. BUT can I show that EF804S is ok? Of course not. Can I sell an EF804S? Yes. But not IN an equipment!!! There is never going to be an inspector knocking on my door and asking for reports for NOS tubes. But if you really want to be strict you practically have to sell the equipment without the tubes, and then sell the tubes as "spare parts" (you can sell old non-rohs components, but not whole gear with those components installed.) I know of no manufacturers who would have gone this far into total ridiculousness.

I feel that the Rohs is an important standard because consumer electronics end up to the hands of Chinese and African workers working with open fire
to "recycle" million tons of 3-year old computers. But now that we are talking about high end gear you should probably find your own level of strictness according to your conscience. And if using leaded solder consider your own health too.

EMC

This is totally and entirely impossible to measure by one self. You have to have an anechoic chamber (for EM-radiation of course).
In transformer coupled linear tube gear with statical shields everywhere the directive will not be a problem. I don't know what kind of equipment your friend is going to manufacture, but if he is not hard core engineer he perhaps should have the test made. Here it happens to be possible to get done with modest cost in local university of applied sciences.

Ask these question from at least 10 different engineers and manufacturers and you'll get surprisingly different replies. Actually the EMC standard tests give different results in different labs said one EMC engineer to me.

In any case your friend should consult engineers in the test lab to see if he is on the right track, and if he is able to follow the standard further without help. In this way he perhaps can avoid the cost of the tests and still be sure that the gear is OK.

Disclaimer: Everything I said could be just an opinion

I wish this was of some help.

 

[lofi]

please accept my thanks for your frank and informative replies. i am only sorry that i will not be financially able to buy your gear for a while, but in the mean time best of wishes for the near and long term future

:sam: :sam: :guinness:

Iain

i would have written this in Finnish but english is also my second language, my first being Gobbledygoop :grin: so hats off to you !!

 

[audiox]

If I understood right your choise has been not to test?

I guess that makes sense because you have to sell quite many units to cover testing costs (like 10 000 euros). And it is a small probability that some authority gets interested in your products and wants to see the test reports. Right?

 

[[silent:arts]]

you don't have to do the tests, you have to sign you will exist the test

 

[rob_gould]

Very informative - thanks :thumb:

 

[audiox]

[quote author="[silent:arts]"]you have to sign you will exist the test[/quote]

I don't understand what this sentence means. Please explain.

 

[[silent:arts]]

mhm, english is not my language :green:

what I mean:
you give your signature stating your equipment will pass all the tests.
this doesn't mean you have done the tests.

 

[audiox]

What are the worst possible consequences if it turns out that your product doesn't meet say immunity tests. I mean that it is not dangerous and works fine in normal operating environment but fails that specific test.

Is it possible that some authority wants to see the test results? And if you don't have them, what happens? Some penalty? Have to take the products back? Is Knif Audio taking a risk by not doing the tests but still signing the declaration of conformity?

This is interesting because most small manufacturers don't do the tests. I am sure of that. If you manufacture one or two units in a year you simply can't pay 10000 euros for some test.

 

[lofi]

the tests are worse case scenario rather than ordinary / expected use. If you sign that your products are safe and in the worse case somebody dies from useage you will get charged with corporate manslaughter at the least.

Make sure you know your product will pass the tests, and when your positive it will, sign the paper to state it is

Iain

 

[audiox]

As I said I am not talking about low voltage directive but EMC directives which are the most difficult to meet.

I mean the case that the product works fine in normal operating environment (with mobile phones etc) but fails the immunity test. So it is not dangerous and it does not emit any interference.

 

[Crusty2]

I talked to my uncle this weekend about my concerns with the flying wire, and he goes with Dshay's take on it, that the shielding constitutes a mechanical bond and that it's perfectly fine as-is and compliant. He said that even if it were a twisted pair, that the other wire would be considered a mechanical bond. He also told me that I need to read more than one book on the subject before posting my opinions :? Oh well, discussions are good, right?...

Jonte, are you going to the AES show in October?

 

[Jonte Knif]

Hi

I had a long discussion with this EMC-engineer, and he, of duty, said that don't worry too much about EMC if your equipment is encased in metal and going to be used in a studio where EMC disturbances are unlikely. But anyway, use common sense.
1) use a nice mains filter
2) use ferrite beads or coils all over
3) keep the circuit "slow" enough and avoid high frequency distortion and rectification effects. According to the engineer the nastiest test for this kind of equipment is probably the one in which a modulated RF signal is fed to the circuit. Any nonlinearities will then produce sum and difference tones which can be in the audio range and pass any output filters easily. In Finland this is called "the Russian radio" phenomenon. I wonder how guitar amps pass this test!!! Really.
Mobile phone is actually, in a very crude way, quite fine test. The problem is that you never know the transmitting power. And the frequency range is not quite the same as in the EMC test. If you get the zippatizappati-sound from your equipment when you talk to your handy two meters from it, you got a problem: You get angry customers

Any how, all this boils down to the very fact that the directive certainly requires immunity to such signals which are never going to be present in a good studio. Do you REALLY get high level radio signals to a line level input?

About the declaration of conformity:

If you just sign the paper and don't do any tests you are on a shaky ground. You just can not "know" everything for sure. I suggest at least:

Get a Variac and some kind of an adapter for all fuses to be connected to a multimeter. It is not that trivial to fulfill the requirements of fuses blowing at 2,1 times the rated current at 10% mains undervoltage in all possible fault conditions. I had to use a NTC-resistor in mains to limit the inrush current to be able to use fuses small enough. And if some fuse doesn't blow, you have to wait for some time (was it six hours?) and see if something else happens, starts to burn for example This six hours would cost a fortune in an official lab.

The tests here in Finland used to be such that in the process the equipment would be totally destroyed because of the severity of the abuse. I've now been told that they have got a bit more respect for equipment which is obviously not meant to be treated like a vacuum cleaner and which cost a lot. I understand the responsibility of the test lab, and that is the last place where one can ignore the standards!

Thanks for Crusty2. I appreciate.

I can not come to AES, I'm sorry.

Time for a Laphroaigh

-Jonte

 

[Kid Squid]

Interesting stuff ,Chaps,
Good reading.

Time for a Laphroaigh

Cheers :thumb:

Steve

 

[jensenmann]

Laphroaig
You got taste, bro´

:thumb:

 

[Kid Squid]

jensenmann Posted: Fri Aug 29, 2008 8:18 am Post subject:

--------------------------------------------------------------------------------

Laphroaig
You got taste, bro´

And a wicked bad head to go with it :wink:

Worth it though :grin:

Steve