Topic: GP DMIC-20 content

[Todd R]

Hey, so thanks for the suggestion Marc, I just did the mod (if you can call it that, it was so easy!) What do you guys think I should list the DMIC as now on the txt fles? somthing mod DMIC-20? Help. THANKS!

I'm not sure this really qualifies as a mod, at least not the extent that it needs to be noted in lineage. To me this is like listing cables, it's not something that really matters in the end. Since exchanging the chips really only helps lower the noise floor and doesn't change the sound quality, I don't see where it helps, but that's just me.

Wayne

I don't think I agree with you here.  All chips -- esp op amps -- have their own signature on sound.  (BTW, the SSM2017 and INA217 are basically glorified op amps, op amps plus some auxilliary transistors to round out a "preamp on a chip" all put together in one piece of silicon.)  You can't really say all that is happening is that you are lowering the noise floor.  By changing out the gain chip the signal goes through, you will change the signature sound of the preamp. 

I'm pretty sure all Doug Oade does with making the modSBM1 is to change out the op amps.  At least, that is the change that is responsible for the majority of the mod that results in a different sound for the SBM1.  With the w-mod and p-mod UA5's he changes the op amps and replaces some of the capicitors in the signal path.  Bottom line though, most of what we already label with "mod" status is the result of changing out a few components in the signal path.  This may only be reflected in the published "specs" as a lower noise floor (or perhaps a faster slew rate or something of the like), but changing the components in the signal path does change the sound in a more basic way than just lowering the noise floor.  I'm sure lots of people will comment on how the sound of the stock SBM1 differs from the Oade mod SBM1.  (Ok Makers Marc, time to jump in and help me out here.)

I've always heard a harshness in the high end with all the preamps that use the SSM2017 chip -- the DMic20, the MV100, and the PSP3.  I'm interested to hear whether changing the SSM2017 to an INA217 alleviates this harshness.

[Tim]

maybe it would make the psp3 worth that hefty price tag

[F.O.Bean]

so has anyone actually tried out their mod-dmic20's??

[wbrisette]

I don't think I agree with you here.  All chips -- esp op amps -- have their own signature on sound.  (BTW, the SSM2017 and INA217 are basically glorified op amps, op amps plus some auxilliary transistors to round out a "preamp on a chip" all put together in one piece of silicon.)  You can't really say all that is happening is that you are lowering the noise floor.  By changing out the gain chip the signal goes through, you will change the signature sound of the preamp. 

In theory I agree with you, but unless there is some improvement, or changed sound it's a moot point. Again I liken it to when people list cables. If you're Eric Johnson and you can tell the polarity of a wire (he claims he can), then maybe cables make a difference, but most of the time it's a waste.

I'll eat my words if the change makes a world of difference. (hmmmm, yummy).

BTW, has anybody thought about putting in the THAT 1510 chip? While not shipping yet, it looks like it might be better than the BurrBrown.

Wayne

[wbrisette]

Folks should check out:
http://recording.org/users/kev/kdmp.htm
http://recording.org/users/kev/kdmp.htm

Looks like somebody has already done some A/B testing.

Wayne

[F.O.Bean]

only vocals tho, whos gonna be the first to a/b some live environment stuff

[(((KB)))]

^ I know this is waaayyy old, but did it work for anyone?

-K

[Kyle]

^ I know this is waaayyy old, but did it work for anyone?

-K

did you mod yours?

[(((KB)))]

^ I know this is waaayyy old, but did it work for anyone?

-K

did you mod yours?

No, not yet.

Checked into it w/ an engineer friend of mine and he said to do it because the BurrBrown IC's have better specs. It's not going to make it a V2 or anything, but should have better results that the stock IC's.

For a "second opinion", I asked Richard (PoorlyConditioned) about this upgrade. He said he did this upgrade with "THAT Semiconductor" IC's instead of the BurrBrowns. He said that he didn't really do enough tests to know if it improves or not, but thinks the stock setup is quite good, anyway.

I'm told that the "THAT" IC's (1500's???) are better than the BurrBrowns, but you have to purchase them... $2 something and a min order of 50 so, I settled for the free BurrBrowns. I ordered free samples following the information in this thread. Planning on doing the swap this week since I'm rolling for MMW/SCO in Philly on Saturday.  Whether or not you hear the difference is another story... depends on playback system to really hear a difference I would assume. Planning on doing a quick A-B test w/ a test tone generator or something when I get them...replace only the left channel and leave the right alone to do the test, then install the other after. It will be intersting to hear if there's a difference.

-Kevin

[(((KB)))]

^ I know this is waaayyy old, but did it work for anyone?

-K

did you mod yours?

Did the upgrade test today... (re-recorded a random show dual mono w/ the upgraded L channel and the stock R channel)... I can say for certain that it didn't degrade the quality. Seems to have made it slightly better... tough to hear it on my playback system. I need some good cans to really tell for sure. Going to pass the test file on to my friend that has audio analysis software, so he'll be able to tell me for sure.

-Kevin

[F.O.Bean]

i always liked my dmic-20 stock, butw anted to try the mods before i sold it

i would be more interested in the gain pot mod than anything

[(((KB)))]

i always liked my dmic-20 stock, butw anted to try the mods before i sold it

i would be more interested in the gain pot mod than anything

One of my pre's has that trim pot mod done to it, but it's sooo sensitive... I'm afraid to really use it. I like the just plain dip switches actually, much easier to keep the channels even.

Tossed around the idea of having the dipswitches taken out and replace w/ potted potentiometers, but I don't think Nick Z. wants to do it since he said it was a pain in the ass... oh well.

I'm pretty satisfied w/ the the IC test I did, so I decided to do the BurrBrown upgrade to both pre's I have. The faster chip seemed to pass through more detail overall and make the highend a little less harsh.

-K

[tubehead]

got a chance to listen to bird's INA217 version in a blind A/B, it pretty much followed my hunch, the stock ICs sound a bit harsh on the top end, the 217 is smoother in general but especially on the high end, definitley worth the $10 or whatever you have to put into it....

those dmics seem to be plenty moddable, it should be possible to make an adapter board and cobble in an INA103, the same part used in the V2/V3. i'm not a big fan of GP in general, after tearing one of those things down (and seeing the HORRIBLE gain pot mod that who-the-fuck-ever put into it) it seems most of it is pretty consumer-ish or prosumer/broadcast quality. no drooling over the part selection etc. the adc is a crystal semi which doesn't wow me either...i'm about to get an ad20 (with an AKM adc, my favorite!) and mod the hell out of it...anybody know what's in those>??

[poorlyconditioned]

got a chance to listen to bird's INA217 version in a blind A/B, it pretty much followed my hunch, the stock ICs sound a bit harsh on the top end, the 217 is smoother in general but especially on the high end, definitley worth the $10 or whatever you have to put into it....

those dmics seem to be plenty moddable, it should be possible to make an adapter board and cobble in an INA103, the same part used in the V2/V3. i'm not a big fan of GP in general, after tearing one of those things down (and seeing the HORRIBLE gain pot mod that who-the-fuck-ever put into it) it seems most of it is pretty consumer-ish or prosumer/broadcast quality. no drooling over the part selection etc. the adc is a crystal semi which doesn't wow me either...i'm about to get an ad20 (with an AKM adc, my favorite!) and mod the hell out of it...anybody know what's in those>??

The front end of the AD20 isn't very nice IMO.  It has a differential transistor pair, then into a standard opamp, either MC33079 or INA something.  Normally this would be OK, but I don't think the transistor front end is very well done.  It *does* have low noise, but my opinion is that it sounds "flat", lacking detail.  I would stick with the DMIC20, since it has +/-12V in there, and you could put in practically any front end you want.

  Richard

[(((KB)))]

Rolled (w/ the BurrBrown DMIC-20) for Blues traveler last night at a local venue where I frequently record. I def. think the recording sounded better with the upgrade.   

Much thanks to all who made posts on this thread.

-K