Topic: Tascam DR-70D 4-channel audio recorder (Part 3)

[Ozpeter]

(The above is derived from my experience working for electronics production company).
(Please excuse my English, it isn't my first language).

Very informative and well written post, actually!    Thanks!

[2manyrocks]

I wouldn't ride that horse too far because there's a substantial amount of knowledge being given away on GS every day by people in business.  The JW mod is no secret because he posted it.  It's also no secret that the opamps and capacitors are the common subjects of the mod.  Since it is already known the opamps and the capacitors are the subjects of the mod, it's not big step to disclose which ones are being used or at least give some more specific indication of what the mod consists of. 

So far as adding $22.92 to the production cost of the DR70d, we have seen a price swing of $299 to $179 since it was released about October of 2014.  Tascam apparently has some room here to have used higher grade components, and then they would have had an even better product. 

But as priced now, it's $300 MSRP plus $150 for the mod.  That's $450 instead of the $325 or $350 it could have been direct from the factory before discounts--possibly $205 to $225. 

Joshua-G's writing is excellent, BTW.
     

[dogmusic]

Re: playing DR70D files in the DR680:

With its latest firmware Version 1.30, the DR680 can now play DR70D files as multi-track files.

But you have to rename the DR70D files on your computer (as explained in the DR680 Manual Addendum that comes with the Firmware).

Then you must do a REBUILD on the Project folder when you insert the card in the 680.

It's not quick, but it does allow control of playback of DR70D 4-track recordings without using a DAW.

[Joshua_G]

It's good that you don't see me blush…

[H₂O]

FWIW - To correct an earlier allusion I mentioned that the D70 is based off the hs-p82 - after reviewing the p82 schematics, the p82 has discrete transistor based Pre-Amp coupled to AD8599 opamp

[gormenghast]

^my aerco mp-2 was not covered in "glue"...  but nbox+ was.

I was about to respond with the same. 

[morst]

Agreed.  I don't think JW really gave a crap about such an inexpensive unit.  He is not currently doing the mods anyway as he has too much going on with his core business which, I assume, is a lot more lucrative.

I'd figure that Busman will add a line to his website about his DR-70D mod, and then we'll find out slightly more about the details.

Hey Picklemic, are you handy with a small screwdriver?? 

[noahbickart]

My Bussman modded unit arrived today. I haven't had a chance to use it yet, but I can probably take some pictures of the insides after the kids go to bed.

[Cheesecadet]

Please do take pics of opampsnif possible. Pickle mic is recuperating from Jazzfest

[morst]

Please do take pics of opamps if possible. Pickle mic is recuperating from Jazzfest

YEAH, YOU RIGHT!

[2manyrocks]

Pictures?

Is it possible to record m/s using two inputs on the 70d and use the other two inputs for spot mics at the same time?

[voltronic]

Pictures?

Is it possible to record m/s using two inputs on the 70d and use the other two inputs for spot mics at the same time?

Yes.  Go to the MIC menu option, and then you have options for MS MODE 1/2 and MS MODE 3/4.  For each of those stereo pairs, you can choose from OFF, REC, or MONI.

[voltronic]

Updated the FAQ today with an "Other Technical Info" section which lists the specific chips used, as far as I was able to find.  I'm not sure if it's worth really adding a section on "Mods" until Jim Williams or Busman is making them more widely available.  There's also now a link to the FAQ in my signature because I just found out I could do that... 

Thanks to Cheesecadet: http://taperssection.com/index.php?topic=172109.msg2133142#msg2133142

And to Jim Williams: https://www.gearslutz.com/board/remote-possibilities-acoustic-music-location-recording/960891-new-very-compact-4ch-recorder-tascam-2.html#post10842631

Also, I mistakenly stated earlier in this thread that I thought I heard about the 70D using the same opamps as the DR-680.  I now found where I was getting that from, and my memory was off - it's supposedly the HS-P82 that uses the NE552 opamps.
http://taperssection.com/index.php?topic=171565.msg2125629#msg2125629

[H₂O]

FWIW - To correct an earlier allusion I mentioned that the D70 is based off the hs-p82 - after reviewing the p82 schematics, the p82 has discrete transistor based Pre-Amp coupled to AD8599 opamp

The hs-p82 does not use the ne552 op amps - instead it uses a discrete transistor network in front of AD8599 op-amps

[voltronic]

FWIW - To correct an earlier allusion I mentioned that the D70 is based off the hs-p82 - after reviewing the p82 schematics, the p82 has discrete transistor based Pre-Amp coupled to AD8599 opamp

The hs-p82 does not use the ne552 op amps - instead it uses a discrete transistor network in front of AD8599 op-amps

Whoops - I missed that comment earlier.  Thanks for clarifying that.  Clearly, Tascam must be using "HDDA" as marketing, and it doesn't describe any particular circuit or chip.