Discrete Dip 8 Opamp

[JohnRoberts]

Our meat computers are very unreliable, and short term sound memory is superior to long term sound memory.  Perhaps you are trying to work around the short term memory, and/or hearing adaption.

Music is complex and our brains generally ignore most of what we hear and focus on little parts of the whole at a time. Judging anything by ear is imo very difficult, but that in effect is the work of studio mixing/production...

Hardware design is so much easier.

JR

 

[strangeandbouncy]

HI John,



  agreed, judging anything by ear is very difficult, yet it is how I earn my meagre living. Just try it. It is very revealing. Th efurther I go into a mix, the harder it becomes  to make any changes. I call this factor the *cochlea burn*. That is why I do the same again the other way round.


     SO much easier than Hardware Design . . .  


    KIndest regards,


       ANdyP

 

[living sounds]

How much DC do you get with these op amps? I put modern op amps in my console and got rid of all the DC filtering caps. Also, are these small enough to fit two side by side on a single-to double DIP adapter?

 

[abechap024]

How much DC do you get with these op amps? I put modern op amps in my console and got rid of all the DC filtering caps. Also, are these small enough to fit two side by side on a single-to double DIP adapter?

Hello,
DC on the output depends on how much time you want to spend matching and selecting parts to trim DC out. Matching the input transistors will help keep DC to a minimum, also the resistor labeled "3k-5k" will let you adjust DC offset. The ones that I've made for my console so far and measured the DC offset is reasonably small (<10mv) and thats with me not really matching the input transistors to an extreme extent and just putting in a 3.9k resistor on the trim. What you would expect to see
All in all, in my experience Electrolytic caps don't sound too bad if they have some DC offset keeping them biased.

"Problem"  : with new opamps is they have practically no DC offset therefore all the coupling caps become quite useless and un-biased and un-happy.

I haven't tried the double dip adapter, but it is a thought. It depends on what adapter you use. It certainly is possible. What one do you have in mind?



On another note, I ran some files through using the NE5534 and the Discrete opamps and also the OPA227. There are differences. I will get around to posting files, but I want to run some more tests. I want to do a whole mix with ICs on the mix buses and then using that exact same mix, fader positions everything except the discrete opamps on the mix buses print another.

Tanks!

 

[living sounds]

Thanks! I use the double dip adapter from Brown Dog, since I haven't found a substitute for this one (yet).

The thing with DC and electrolytics I don't get though. Yes, electrolytic (and also tantalum) caps sound better when biased, but I thought this was more about DC in the double digit volt range, and not just a few 100 mV...

But I really like the clarity I get with zero caps in the signal path, and <10mV DC doesn't matter anyway (IMO), so it's cool.

 

[gemini86]

10mV doesn't matter, but when it's amplified further down the chain, say 40dB, that's voltage gain of 100, so 10mV becomes 1 volt and so on... you say you removed all the DC blocking caps, so that could get hairy.

 

[JohnRoberts]

As long as you don't have a DC300 for a power amp, all you will be bothered by is pot scratch and switch clicks.

Fader gain stages with 10dB (3x gain) and bus amps with noise gain of N+1 (and DC gain if DC coupled) may benefit from trims. 

JR

 

[abechap024]

(i guess we can't delete posts with this new skin? Well I'll re edit when I have something worth sharing, I'm waiting for the storm to pass so I can plug all my crap back in..)

 

[abechap024]

Build Manual for these:

www.acsoundstudio.com/manuals/BUILD_MANUAL_A_OPTIMIZED.pdf

Thanks!

Abe

 

[illacov]

Bump for clips!

I want to order a pair to mod a 2 buss EQ  ;D

Peace
Illumination

 

[Balijon]

Hello,

reading through the whole discussion I see two items:
1)  A great initiative from Abe to create new easy 'plug-in' options for existing equipment with a new engine. Great concept!
2)  A discussion comparable to a car-forum....
Clearly all cars have 4 wheels, an engine etc.. All drive 100km/hour but clearly the experience is not the same.
Surely we can fit a V12 in a Beetle, does it make it a better car? Depends where you are driving, on a drag-strip it will!
Although technical excellent cars are being produced today, why do so many people like certain classic cars? Not because they are technical superior if measure them, but because they feel good and have something extra. The something extra is the magic, this is not measured by how fast they accelerate (slew-rate) or brake, but it is character consisting of a collection of many small things that interact well.
Character is all about: dare to be different and creating a statement.

I think consoles are instruments and we are painting pictures with it. So we can start a pissing contest about the best paint, cloth and pencils. In the end it is the picture that counts.

And yes, I like the big V8's and V12's. Are they the most economic? No, but it only hurts when you fill-up at the gas-station..

Abe, thank you for providing us a new Lego block.

grT

 

[abechap024]

Thanks for your kind words. And yes I agree with whats been said here...on both sides!! Its what is "wrong" with these opamps that make them sound so "right".

I think the main discussion point here, is maybe something more transparent might be better on places like the mix bus amps...

The more I listen to more I realize its a give and take, You can have clean and pristine, but on the flip side of that same coin is "sterile, weak and lifeless".

BUT

You can have strong, juicy and vibrant sound but that doesn't come for free either, it can end up sounding "fuzzy, undefined, and hazy".

It really depends on the program material and the context...

I redid my consoles bus amps, and finding I really do like the sound, but it does have a tendency to maybe ever so slightly (sometimes a good thing, sometimes not) smooth things together.

So I'm still experimenting. I really like having this color in may arsenal though, very useable and very pleasing BUT possibly too much for certain things. I'm thinking I'll have the best of both worlds eventually, and have some ultra clean, and some colored buses.

I guess this doesn't came as a real surprise though, if we had one circuit that sounded great on everything, I imagine we would all just be building that..

thanks all!

 

[snaper]

Clean your PMBox Abe please

 

[salomonander]

any chance to still get some of these boards? or is there something similar out there?

 

[ChrioN]

Anyone still having these files?

 

[psb_87]

Shame this thread is dead, and Abe's website is no longer online... This is just the thing I am looking for to upgrade my board