[doctorcilantro]

Not sure if this is gonna happen, but I'm looking for someone willing to solder some RCAs on to a cable for me, and mod my EMU1212M for recording benefit only (opamp replacement). Please PM if interested.

cheers,
DC

 

[Gruber]

Quote:

Originally Posted by ijan /img/forum/go_quote.gif As requested, these are not modded pic, a trace i did. Input decoupling (or as most ppl say output decoupling caps) are caps crossed with the green X. Also, output N-D-FET was removed on my card since it was damaged and could not find any replacement for a 2N4392 SOT-23. I removed all four of them and are werking better than it was before, no side effects observed. BTW, its PIA to desolder the caps, if ur that lazy, might as well short the caps from the under planar without removing them. im planning to mod in on protoboard, 4xOPA637BP that i haf so much lying around.

Hi,
I just found this thread
Ijan, did you have to make any links after removal of these 4 2n4392 FET, i fitted a few cap mods, and headphone lead with socket which got trodden on(unbeknownst to me) and bent pins together now card wont output any sound, only buzz and harddrive interference,VR1 5v reg seems ok, opamps replaced,still same prob. also i think digital board is not outputting s/pdiff, software loads ok without objection L/R Any ideas for testing card?

 

[Crassus]

Did I understand correctly that in the image posted by Pozitron, the large caps (4) marked with red can be removed entirely (or just the legs soldered together with jumper wire?).

Any risks involving this? My 1212M is connected to a >3k€ amp so I would rather not risk blowing the balanced inputs...

 

[Crassus]

Ok, I took out the soldering iron and shorted the capacitors. The reward? Clearer treble, definately worth doing.

Anyone removed the muting components (small black smd components near the jacks)?

 

[whitelabrat]

I'm thinking about simply bypassing the 47uF coupling caps with 0.022uF metallized polyester film caps instead of removing them. If I'm not mistaken the input resistance of the opamp is around 50k ohms so this should do nicely. Am I mistaken? I'd also like to try an AD45048 (AD8397) opamp. It's super fast, but the JRC is already fast so I may get away with it.

If I do anything with the power caps, I won't replace anything. Just add uF with some Nichicon KZ or ES's.

Any thoughs on my strategy?

 

[whitelabrat]

Mods done. Result: Wow.

Simply bypassing the coupling caps with the 0.022uF did the trick. The best ten cents I've spent on audio. Next the AD45048 was a significant improvement too. I read that it's a cranky opamp, but I just plopped 'em in and they work as-is.

Otherwise I replaced one 100uF cap with an Elna Similic II cause I had one, and I bypassed the 1000uF with a 0.47uF film cap.

The whole mod cost me about a dollar.

 

[Goit]

deleted.

 

[FayeForever]

Great, bump to catch more attention

 

[Zaubertuba]

Great thread, guys! It looks like bypassing the coupling caps is a no-brainer. Otherwise, I have a couple questions:

1.) I already gained a huge improvement from my 1212m just by upgrading my computer PSU to a cleaner Seasonic unit. Do you think I would still garner any additional improvements by upgrading the filtering/supply caps? What if I can't afford Blackgates? Would Elna/Panasonic/Nichicon caps still be good options in this regard?

2.) Quote:

Originally Posted by whitelabrat Otherwise I replaced one 100uF cap with an Elna Similic II cause I had one....

Which one did you replace, and with what value?

3.) How do you think the LM4562 or the LME49720 would do in this application? It seems the HA versions (military spec. metal can versions) would excel if they're not too cranky...and of course you'd have to be creative with wiring them in.

 

[whitelabrat]

I'll see if I can take a photo if I can find my camera.

I don't think Blackgates are worth it. *dodge rotten tomato*.

I like Nichicon's for price point. Need better performance? Bypassing with a cheap film cap will address any high frequency short comings of an electrolytic. If you can use a 0.1uF film cap instead, go with it. You can probably use a COG ceramic cap too if desparate.

The best situation is no caps in the signal, but I was concerned about DC coupling, so I kept them in.

I just took a gamble with the opamps I chose. I got 'em free so I used them. I'd go with opa637's if I had money to burn. Can't say they'll be stable though.

 

[sonci]

I have used the LM4562, but I must say theres not such a big difference with the stock sound, Its strange that this card gets better when the capacitors are replaced, more than the opamps, or maybe because its opamps are pretty decent,
I have replaced the capacitors on the analog and digital card, with Blackgate ST and FK, I think its worth (just for the beauty of the BG), and you have a deeper sound.

@whitelabrat, Have you removed the mutting transistors?

What do you mean by".. concerned about DC coupling"

 

[whitelabrat]

I have a tendency to ruin solid state things so the less I do the better. I ruined a Super DAC Pro 707 withing 24hrs of purchase.

The purpose of the cap between the DAC and the opamp are to decouple from any DC current that may happen between the two. You only want AC which is the audio signal. The downside of this is that the capacitor effects the audio signal.

If there is any DC offset it could cause problems for some power amplifiers. I don't have any good test equipment other than a multimeter, and I have a tendency to ruin things. I just assume the E-mu folk had a good reason for putting them there.

If you really want to go for maximum improvement, skip electrolytic altogether and go film caps instead for lower values. For power supply caps electrolytic are fine, but I'd suggest that more is better rather than sporting brand names. For example, I would choose 10,000uF v25 from a cheap Xicon cap over a 1,000uF v25 Elna if the costs were the same.

I'm not knocking Blackgate. I'm listening to some right now.

Decoupling capacitor - Wikipedia, the free encyclopedia

 

[sonci]

Thanks

So, you havent touched the mutting transistors, which protect the card against shortcuts during start up and shut down? Do they affect SQ?

 

[Zaubertuba]

Quote:

Originally Posted by whitelabrat /img/forum/go_quote.gif I don't think Blackgates are worth it. *dodge rotten tomato*... ...I like Nichicon's for price point. Need better performance? Bypassing with a cheap film cap will address any high frequency short comings of an electrolytic. If you can use a 0.1uF film cap instead, go with it. You can probably use a COG ceramic cap too if desparate.

I don't want to discount the Blackgates, but it's really not in the financial cards right now. I happen to have two 1,000uf Nichicons sitting around (one 50v and one 35v), and they're readily available (I think I actually got these ones at ratshack).

I really need to figure out how caps effect sound quality. I used some poly caps to decouple my opamps on my balanced a47 and lost all the highs. Bypassed them with cheap .5uF ceramic caps and the thing sounds bloody euphoric (I mean, really good).

Quote:

...I'd also like to try an AD45048 (AD8397) opamp. It's super fast, but the JRC is already fast so I may get away with it...

Looking at the spec sheets for both of these, it looks like they're designed with different purposes--are you saying they're really the same chip inside?

Quote:

I just took a gamble with the opamps I chose. I got 'em free so I used them. I'd go with opa637's if I had money to burn. Can't say they'll be stable though.

Based on your experience, I'm more likely to go with the AD45048 (AD8397?). Hate to risk blowing up my E-Mu. I'm probably as prone to break things as easily as you are. I actually have less knowledge, so that likelihood is probably even greater.

Quote:

Originally Posted by sonci /img/forum/go_quote.gif I have used the LM4562, but I must say theres not such a big difference with the stock sound, Its strange that this card gets better when the capacitors are replaced, more than the opamps, or maybe because its opamps are pretty decent...

Hmm, maybe I'll just try getting 4562's in my a47, then, and see what the AD45048's sound like on my 1212m. Perhaps a good demonstration that a chip that's good in one application may not really be all that great in another.

 

[Booda]

[QUOTE=Iron_Dreamer;811033]Hey all, despite the risk of having this card die one me as the last one did, I have already gone ahead with the full pallet of mods, including full blackgate treatment to the relevant portions of the digital and analog boards, and replacing the stock JRC 2068 opamps with LT1364's, biased into class-A and decoupled with 0.01uF Polypropelene caps, which I also added to be decouple the voltage input rails of the CS4398 DAC chip.

Pictures are from Edwood's Kodak DC290, which I resurrected with a firmware upgrade:

Digital card front: (there is another 50V 470uF cap not shown, on the back of the card near the transformer in the upper left)

Analog card front:

another:

and the back:

It only has about 72 hours total of burn-in time on the whole mods package so far (more on the stock card), so my impressions might still change over time especially considering that I put the supposedly highly burn-in sensitive N-series caps in as the output coupling caps.

However, the main gains over the stock card (as far as I can tell, without having another one to compare head-to-head) are in the soundstaging/imaging, speed/slam, treble extension, background blackness, and detail.

The soundstage is much more 3-D and precise than I recall it being stock, every little sound has it's place, and they are tied down to that spot very tightly. The soundstage is also much taller than before. I think these changes are mainly due to the blackgates, since I installed them first, and very quickly noticed the new soundstage. They also seemed to increase the detail a bit.

Replacing the opamps and putting in the new decoupling caps for the DAC are responsible for most, if not all the rest of the changes. First trying the card out with my POS Aiwa cans to make sure nothing was wrong, I could instantly tell the card had been transformed, and my hypothesis could not have been more true as I switched to the CD3000.

The first thing I noticed was the lightning-quick dynamics, which are unlike anything I've heard, making drums and cymbals hit with eye blinking impact, and greatly enhancing the sense of attack in other instruments, especially piano. The bass is also a bit more powerful because of this (and not as lean as the stock card either, though not as heavy as the bypassed RME or my old modded DI/O), punchy is the best way to describe this bass.

Treble extension/clarity has also increased dramatically. Combined with the lightning-quick attack, the treble is so fast and tight is is quite amazing to me, I have never really heard treble like this before. It reminds me of the first time I listened to my modded DI/O, after only having used M-Audio cards before, and going "holy ****!!! So this is what real bass sounds like," except of course on the modded EMU I have that reaction to the treble.

Detail and separation across the board have also been increased, as I am noticing new sounds or instruments in songs that I had never really gotten out of the mix before, or understanding lyrics I had previously thought to be unintelligible.

The amazing near-silent background, even at full amp volume, of the stock EMU also grew better with the mods, to the point where only a faint sound is heard with the Gilmore cranked using the uber-sensitive CD3K's. Listening-wise it helps the instrument separation most.

Total parts cost for what I did was about $140, not too bad considering the great increase in SQ realized. At least I think this should hold me off from wanting an external DAC for quite some time (at least until the LA meet

) I wonder how much better an internal soundcard (without an external DAC) could possibly be...[/QUOTE]

Well done. I have checked to your CD library on sales. I am very interesting on some. Could you PM me your update lists?

thank you.