changing out 5532 to 2604 ok....UPDATED!!

[Flatpicker]

[quote author="Svart"]...just took a look at digikey... wow that would become insanely expensive...[/quote]Yep. $5 a pop. But just using them on the output, for example, would cost a total of $15 - much cheaper than a decent output transformer.

Haven't looked at your circuit, but I'd say it'd be acceptable to do this for the input and output. I think Buzz Audio uses this method.

 

[Flatpicker]

BTW, I'll be going down this road in a week or two. I'm building a Jensen/API type pre with an input transformer and options to use either a servo, bi-polar caps, 30uFs of metal films, or transformers for output coupling/dc nulling. Lots of testing to do...

 

[Svart]

thanks butta, I got some lm837s and mc3309(?)s that i need to try. these are really for the EQ circuit.

 

[Rochey]

i think i've said this before, apologies if I have... It's a quick FYI i guess.

For those of you with any interest... take a look at which opamps TI uses on it's 118dB DAC (PCM4104) EVM and PCM1792 EVM...

Wait, it's easier if I tell you - we used NE5532's on them - because whilst they are a little power hungry, we found that we got cleaner performance from them than just about any of the newer opamps TI/BB has released. When we used TI NE5532, we could get the clean signal all the way to the 131dB DAC of the PCM1792 in mono mode.

With such a clean op-amp, I guess the only reason to switch it out would be 'flavour' -- right?

PRR, MCS -- i'm waiting for your posts :thumb:

 

[gyraf]

Thanks Rochey,

I always suspected that NE5534/32 were better than their hifi-buff reputation..

Jakob E.

 

[StephenGiles]

:grin: :grin: :grin: :grin: :grin:

 

[Rochey]

ho ho ho...

come on then, get it all out in the open :roll:

 

[Svart]

updated again..

however again I find that the caps have more to do with sound than the OPamps do. I took my master channels and buss channels and went to work. I socketed all opamps in the audio path and proceeded to change out parts until i liked the sound. I came up with this scheme:

channel strips: opa2604 in all areas where 5532s and tl082s were.

master and busses: opa2134s for summing amps and output drivers (was 5532, tl082). AND i changed out multiple TL084s with opa404s(very expensive.. but thanks to TI for samples!)

I'll continue the recapping portion of this in the other thread that i had started over caps.. but here's a quick rundown...

replaced all coupling caps with pana FC caps of the next size up.. 47uf went to 100, 100 went to 200 and so on(really because i was running out of certain sizes.. :green: ) I DID NOT like the sound of them WITHOUT bypassing with polypropylene .1UF once I bypassed them the sound opened up and became what I expected!

Here is another tidbit from my work on this matter... I noticed that the pres had lowpass caps after the phantom blockers which were promptly taken out. during this process i noticed that the impedence of the input was set at 3.3k with resistors to ground right after the phantom blockers too. I changed this to 600ohm and immediately my mics started sounding better! I don't have to EQ as much and the actual sound is clearer and more natural.

more on this later... :thumb:

 

[Gus]

Do the FCs have a forming voltage that you bypassed?

 

[Svart]

hmm.. the spec sheets don't show and to be honest I didn't take that into account.

 

[microx]

Yep, dont knock the 5532 just because it's been arround for a while. I swapped out 4558's with 5532's with great success, got rid of the "gritty" sound, more headroom and less noise. Tried 2604's instead of 5532's and they were no better except for a tiny drop in noise level-and they are cheap!
But as has been said MANY times, work on the power supply and your labours will be rewarded.
Steve

 

[Svart]

the Powersupply is a switcher, based on my calculations is running at 60% of it's rating which is 5 amps on the +-17v rails.

I DO like the 5532, however I was looking for something with a slight drop in noise and some coloration, along with the *slight* gain in headroom.

in all I liked the sound of the 2604 in the channel strips, very open with slightly less high end fuzz. in the busses i liked the 2134s for their coloration, which is even less of this high end fuzzy hiss which is much more apparent when summing many channels together. I just HAD to get rid of the tl084s in the audio chain, they are OK usually but if i had already changed everything else out and I have some samples to try i might as well right? :green: so i stuck some of TI's very expensive opa404s in their places. I DO notice a much better image quality to the audio all together.

so that said, I'm glad i did change the 5532s out but not because i was looking for something *better*, just something more suited to the sound of the circuit and console as a whole.

just stick sockets where the ICs were so you change them back.

:thumb:

 

[Svart]

wow.. how come i'm ALWAYS the last person to post in the threads i'm interested in..

i guess i'll have to change my signature to ~THREAD KILLER~

:sad:

as for this thread.. i've decided to just go nutz and replace everything with an opa637.. :green: actually i'm going to get a few of those dual dip-to-single dip adapters so i can try two opa637s instead of a single opa2134/opa2604 in the summing areas of the console. i got a few of these ICs sitting around begging to show me the true future of audio..

CHIPS!


:green:

now lets see how many people flame me....

 

[Flatpicker]

[quote author="Svart"]wow.. how come i'm ALWAYS the last person to post in the threads i'm interested in...[/quote]Because you're the one doing all the experimenting!

We are still reading, btw. :wink:

 

[Svart]

:green:

I'm just trying to put down everything I do on here so that others can comment or critique, learn something, get ideas of their own or just laugh at me. :thumb:

:guinness:

seriously, has anyone had any experience with the opa627/637?