replacing 4558s in a Lake-People c76 DA-converter

[SSLtech]

Yes, my original wording was rather deliberate: "anyone who designed a great piece of gear completely by accident".

There's a big difference between an initial discovery and a finished design. :wink:

Many behaviours and properties are stumbled upon, but harnessing the property is part of the design.

I always maintained that the aphex has its place. I've been able to use it to integrate low-bandwidth source material into full-range, well-recorded program material. A treble boost won't help the two to match if there's no HF in the source; an equaliser just multiplies what's there, but it doesn't matter how much you multiply zero by, you still get zero. If you're struggling to dig up a bit of HF buried in the weeds, you're going to bring up a lot of noise along with it. The Aphex was handy for re-manufacturing HF harmonics from the high-midrange region, assuming that wasn;t buried in noise also... if it was, you had unsalvageable source.

The Aphex aural exciter was handy for solving this sort of problem: making brightness where there really wasn't any. A great solution, but if you dodn't have that problem, it was useless to you. I used to hate in the 1980's when producers would use it on already-too-bright brass!

Keiith

 

[smallbutfine]

As for the B*ringer comp*sers: the VCA chips vary a lot too. Each of mine has a different ones. But that's mostly due to the transition from DBX to THAT. Some inbetween ones are from µPC. But I don't think they make much of a difference. They're all slightly lower grade THAT2150 compatibles. I wouldn't expect an appreciable difference by upgrading to THAT 2180/2181.

I don't know if you're right with this because if it sounds crappy, every change for quality may be worth it... but i really don't know the B* composers design... what quality is the "crap in sound" (never heard one)?is it a rip off of some other more known design (like the Mack*y ripoffs??? Or a ****** up application note? They are really cheap so i am interested :grin: ?

(I really came to the audio line of diy because of beeing unhappy with my crappy Alesis 3630... and man, the good sounding devices made me dizzy with incredible high prices.
Now i'm SOOO happy i bought this one, because i never thought it would be possible to get such quality devices like the GroupDIY projects in my home racks...having modified, upgraded and begone to build new devices and repair mixers and stuff now...AMAZING, FASCINATING and GREATFUL rewarding feeling!
(Thanks A*lesis, B*ringer, E*tek and all the others for building crappy stuff like this, i would never be DIYing if you don't!
Don't think i'm an ol'e cheapy man, i spent enough money into making music and buying professional high end musical instruments in my life to buy a car and a house i think... :shock: )

The Aphex aural exciter was handy for solving this sort of problem: making brightness where there really wasn't any. A great solution, but if you dodn't have that problem, it was useless to you. I used to hate in the 1980's when producers would use it on already-too-bright brass!

That's funny! We made heavy rock in the 80's and early 90's and when we recorded an album the engineer of the studio takes a mysterious smile at the fine mix and proudly presented an aphex exciter c..."let's try out this one: a psychoacoustic effect" - Wow that sounded great and we heard of this expensive wonder devices already and heard - NOTHING to change... tried the next day again and verified we were not dizzy from the beer but really no incredible effect anyway. (We already had a good sound from the beginning with two excellent gibson guitars in kitty hawk and vox and "Generalfeld-"marshall tubes representing very different and fat sound styles complimented by my SKC Bogart bass with a lot of generic clear high end through a peavey mark VIII transistor...).
Our engineer said: "Well, and sometimes it just does...Nothing."
:grin: :guinness: :thumb:

Kind regards

Martin

 

[Rossi]

Yeah, I agree, there are instances where an exciter is just the right thing to use. I have an old cheapo B*ringer one for stuff like that. I haven't used it in years, though.

As for the B*ringer C*poser: there are various versions even within the same model number. I have an MDX2000 and three different MDX2100. I used those a lot when I was still using tape, but rarely need them these days. They're not that bad, better than the Al*sis 3630. That's at least what people tell me who own both. I modified one of my C*posers for feedback operation, and it sounds much cooler than feed forward. At the prices they're going these days, they're ideal for experiments. Don't get anything with "PRO" in the name; those are SMD, which is no fun modifying.

I still don't think it's worth swapping out the VCA chips. They're not that bad in the first place. Most people don't hear a difference between a 2150 and a 2180, and the 2159 is mostly like a 2150. To my knowledge it's a slightly lower grade 2150 (probably higher THD) for high volume manufacturers.

 

[smallbutfine]

Most people don't hear a difference between a 2150 and a 2180, and the 2159 is mostly like a 2150. To my knowledge it's a slightly lower grade 2150 (probably higher THD) for high volume manufacturers.

ehem, gyraf mentiond on his site that the 215x higher than 5 are "selected" ones... but can anyone say whatfor they are selected?
Yes, B*ringer used them all over, but can it really be that they are selected for BAD performance???Gyraf, can you drop a word?
Anyone with conn's to the chip business?

Greets

Martin

 

[bcarso]

[quote author="pstamler"][quote author="Rossi"]I heard the aphex exciter was invented by accident. Don't know if that counts as a great design, though.[/quote]

And the designer's story keeps changing. Sometimes he was building a Dynaco Mark III power amp and wired it up wrong, and sometimes it was a Dynaco PAS3 preamp. There's a bit of difference between those two designs.

Peace,
Paul[/quote]

And I interviewed with them years ago and the then chief engineer said it had been a Heathkit. But at that point they were deemphasizing the exciter product and trying to be taken more seriously for other equipment. :grin:

 

[CJ]

Aphex Exciter?

Motown. 1960.

Ask Bob O.

 

[hop.sing]

Ijust wrote Lake-People a mail about the 4558 at this place of the circuit. They are a small comany, they send the schematics with the manual, maybe they will share their ideas.

They kindly answered my question. The answer was in german, that is roughly what they said:
The 4558 works particular well in this application, because the one half of it is part of a filtercircuit, where it is even an advantage to have a slow opamp, and the other half of it is just volumecontrol, where it does not matter very much. And I am invited to swap chips to get a different sound, but current is limited because of the dc/dc conversion. Some chips, like the 5532 would use to much of it.
Any comments?
Thanks Tobias

 

[gyraf]

well, that sounds like a decent explanation - and certainly a nice company.. :thumb: