How good is that DIY-stuff really ?

[MartyMart]

Just cause you are buying a "store bought" or "factory built" piece of gear, does not mean there will be no errors! I know they can be found...everywhere!

My 2 cents  

Cheers!
Jeff

You're right Jeff, I've seen some HORRIBLE "fixes" inside some VERY expensive gear !!!
And sometimes soldering that looks like a monkey did it blindfold  !!!

MM.

 

[gswan]

Wich schem are you talking 'bout Gswan? links?
thanks.

Here's one:
http://www.waltzingbear.com/Schematics/Urei/Urei_1176LN_series_F_page_2.htm
See the component across the ratio switch marked UA4706.

 

[okgb]

Not sure how many schematics have " purposeful " errors
to throw people off
but then again there's the Chinese
who don't need a reason [ oh yeah it's cheapness ]
and it's not like these errors equal charactor

 

[3nity]

Really huh?
I always noticed that but since no one asked that question i said why i would bother myself.
So what you think that is? if i read you first post you said trimmer?
Thanks.

 

[[silent:arts]]

there is a lot of great sounding DIY gear around.
not all, but most are based on some "classic" schematics.

for me it doesn't matter if they sound the same, as far as they sound good.
I don't like exactly looking "clones" either.

for example, the D-LA2A follows exactly the original schematic.
does it sound exactly like an original unit?
I don't know, I didn't compare and it doesn't matter for me. since it is dual / stereo nobody can do a lookalike replica anyway  ;D
but since it was inspired / follows the schematic of the original it has the name LA2A in it.

analags D-AOC: great story: inspired & follows the LA2A topology. but with a new name. 8)
won't sound the same, and (due to the other name) nobody tried to do an LA2A lookalike replica. good thing.

analags poorman is the same, not following the schematic but the topology. nobody ever claimed it sounds (or should look like) the original. and the name ever was poorman 660 / 670, not anything with FAIRCHILD.

okgb:
at least some old german schematics (Neumann / Telefunken) have "purposeful" errors, for sure.

 

[DerEber]

Which one do for example? I fear from getting fooled by wrong shematics.
;D

 

[MartyMart]

okgb:
at least some old german schematics (Neumann / Telefunken) have "purposeful" errors, for sure.

Yup - seen a few of those !!

MM.

 

[1954U1]

for me it doesn't matter if they sound the same, as far as they sound good.
I don't like exactly looking "clones" either.

+1 !

Thanks to this great forum I've learned exactly that,
and most important thing of all, I'm learning how to obtain the sounds I like, also slightly modding the projects here, instead to go crazy trying to understand which vintage gear [or clone] commercially available has these sounds.

 

[s2udio]

I fear from getting fooled by wrong shematics.
;D

Yup nothing worse than a bad shematic......they just nag,nag,nag................ ;D
:
sorry DerEber....could'nt resist !!!

 

[Svart]

Wich schem are you talking 'bout Gswan? links?
thanks.

Here's one:
http://www.waltzingbear.com/Schematics/Urei/Urei_1176LN_series_F_page_2.htm
See the component across the ratio switch marked UA4706.

That was a real part.  The UA4706 I believe is the UREI part number for a trimmer/resistor for calibrating the unit to a different spec.  I don't think it's a red herring as the unit works fine without it.

 

[gswan]

That's correct.
It probably refers to a production test procedure which determines the value. Its job is to trim the threshold to a calibrated value, so that units coming off the production line all behave in roughly the same manner. It won't change the sound quality, just the threshold of compression. I've used it in all of my clone units first by using a trimmer and then setting the resistor value to match the desired setting.

 

[JohnRoberts]

FWIW, I have seen tons of mistakes in those "Ideas for Design" magazine schematics.  I really doubt they make mistake on purpose. More likely some graphic artist at the magazine that wouldn't know a cathode from an anode if his life depended on it.

If you can't understand a schematic, it may not be your fault. The schematic may be wrong..  I expect schematics from manufacturer's app notes to be more accurate, and publishing on the web makes it easier to revisit and make corrections.

JR

 

[jsteiger]

Like with everything else in life, it's not always about the mistake itself, but how it's handled afterward. Did we make a reasonable correction/adjustment or did we just say fuggit? Did we learn from our error???

FWIW, I had a piece of equipment that I bought on eBay. Turns out it was from our very own Nielsk. He was great about the problem although he never knew about it and it was definitely not his fault. Anyhow, I discover a MAJOR flaw in a PCB from one of the top pro audio manufactures out there. After numerous emails to said manufacturer, I finally got "oh yeah, one of the engineers remembers there was a problem on the Rev A boards". This problem was not fixable by cutting traces and adding jumpers. The board would have been destroyed in trying to do this. I told them that. They said nothing. A good reputable company would have said, "send us that old PCB and well send ya a new current one". They did jack shit about the problem. These things were so efed up they should have never left the factory. The boards were actually 100% unusable under certain situations.

This is the kind crap that does not happen here. Sure there will be problems. When they are found they are brought out into the open. Sometimes, numerous forum members have numerous different fixes. Everyone learns something (or more!) and we move on, enjoying our DIY gear!

I think overall, the projects 'round here are better than store bought...for many reasons!

Cheers, Jeff

 

[gswan]

Sounds a bit like the open-source software argument, particularly where encryption in involved.

 

[SNG]

if there are bad schematics around is it not an good idea to make a kind of library or thread with the schematics that works and has maybe been tested...???

 

[Ptownkid]

Design error: There's one particular clone on here with a glaring error on the schematic that has a major affect on the way the unit sounds. I found this out when comparing my original unit to a "clone" that I was working on (using the same schematic), that didn't sound quite right. Being the anal perfectionist that I am, I proceeded to rip one of my original units apart to figure out what the difference was. It ended up being a simple thing that was easy to overlook, but a major error on a VERY popular project here that prevents it from EVER being a faithful reproduction of the original unit.

Well, I'd REALLY like to know what we're talking about here...PM me the answer if you want to keep it from being right out in the open. You had to know saying something like this would create curiosity...

 

[warpie]

at least tell us if the project starts with 'gs' and ends with 'sl'  ;D

 

[smallbutfine]

OK, now it has my attention...'glaring error' sounds just too meaningful. I guess no pcb producer here should be too p*ssed about publishing of a fault. After all we are just humans and make errors. And everyone overlooks the obvious sometimes, is sometimes maybe too lazy to fix something immediately and forgets it totally after some time and similar things...

 

[okgb]

I dunno , my gpultec has never sounded right [ good ] and i don't
have an original to compare it with , so it sits, a waste of money

If it's time to move forward with a new design , if it's just a mod
doesn't seem too bad ?

Not a personal secret, just potentially "bad for business" for individuals that use this forum to sell their products. I chose to omit names to avoid the "not so polite" PM's that I sometimes get from these individuals.


but as mentioned you had to know it would get people's attention
did you expect the individual to out thenselves ?
or as we sometimes get a spanking , that everyone should pay more
attention [ & research ] to whatever they build ?

or why not host a site with correct schematics for people to find ?

 

[drpat]

You guys are relentless...  I'm definitely not gonna open up that can of worms again. Sorry if you missed all of the action the first time around...