Topic: GP DMIC-20 content

[leegeddy]

first thing you may want to do when the UPS man drops off a brand spanking new Graham-Patten DMIC-20 (48kHz version) is to.........

1. open the damn thing up and locate the Analog Devices SSM-2017 mic preamp IC.

2. replace them with the BurrBrown INA-217 mic preamp IC.

3. see how fast you can melt the AD SSM-2017 with a butane lighter.
sorry, no photos.

4. plug in a custom Canare BNC>Coax s/pdif cable

5. think of ways to bug ToddR for tips on Gain Pot mod.

6. feel bummed because i don't have another show coming up until end of December.

marc

Just for the record, the Todd R that does the gain mods on the DMic20 is not me -- different Todd R from the DC area.  I'm pretty sure he's on this board, but I don't know his handle.

Marc -- good to hear you've tried out the INA217s instead of the SSM2017s.  I always felt the MV100 and DMic20 that uses them were a bit harsh in the high end.  Did you ever notice this and do you think the INA217 replacement smoothes out the high end at all?

todd;
ahhh seee. thanks for the clarification.

as for the INA217 vs. the SSM2017, i immediately noticed the clarity and the lower noise floor in my recordings.  perhaps the clarity was due to the smoothness in the highs, but i didn't pick up on the "smoothness" aspect of it immediately.  i just lumped the sonic difference as "clarity". 

what op amp is a good replacment for the OP275?  the slew rate on the OP275 is not too high.

thank you for much of the inspiration to my DIY bug
marc

[blu666z]

I really have no clue what I'm talknig about so telll me to shut up if I say something stupid but...

Does it matter which direction resistors are oriented?  ie.  Is there there a definte input and output side?

If you look at the resistors below the longer chip in the middle of the photo, starting at the blue thing counting toward the outside, the third resistors on each side are turned opposite of each other.  All the rest seem to be oriented the same.  Again, tell me if I'm way off.

-Kevin

[Todd R]

Resistor orientation does not matter.

[F.O.Bean]

and all the pretty colors on the resistors just tell their size/handling capacity

[Swampy]

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!

[Brian]

ICmod DMIC-20 ?

[Brian]

oh and +t's all around for the great thread BTW.  lots of great info here

[leegeddy]

oh and +t's all around for the great thread BTW.  lots of great info here

indeed, +t all around for a great discussion.

i've listed mine as: BurrBrown mod GP DMIC-20......

both my Beyerdynamics have been modded as well and i simply refer them as "BurrBrown mod....."

marc

[Chuck]

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!

Alex:

Can you report any noticable difference in the sound of your DMIC-20 with the mod?

[Swampy]

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!

Alex:

Can you report any noticable difference in the sound of your DMIC-20 with the mod?

I haven't taped a show in the last six hours I'll definitely let everyone know after Hookah on Saturday.

[F.O.Bean]

excellent alex

[Simp-Dawg]

i got my chips, but i still think there's a problem with my dmic20...in fact i'm pulling it off the auction block.  i'm only getting around 5v or so on the xlr's, not the full 48v i need...

[dr.ph0b]

i got my chips, but i still think there's a problem with my dmic20...in fact i'm pulling it off the auction block.  i'm only getting around 5v or so on the xlr's, not the full 48v i need...

sounds like your phantom power maybe horked?

[Simp-Dawg]

yeah i'm pretty sure that's the problem right there...i should test it with an external phantom supply to be sure the levels are hot enough with the proper voltage....

[wbrisette]

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