TASCAM DR-100mkIII NEW Unreleased Recorder

[spyder9]

depends. if your output is balanced id think the xlrs would be the way to go.

also as far as  "quality" goes, that conversation is out the window when your minijack connection fritzes out during a recording

The 302 does also have an unbalanced output, but as you point out, the recorder's minijack is not a robust connection.

Do you ever put a preamp in front of your DR100mkiii?

Yup, I did.  I went TRS in, w/ a Shure FP24 out in front.  I used the XLR Line out on the FP24....

https://archive.org/details/deadandco2017-06-30.dr100.spyder9.flac16

https://archive.org/details/deadandco2017-07-01.dr100.spyder9.flac16

[dogmusic]

depends. if your output is balanced id think the xlrs would be the way to go.

also as far as  "quality" goes, that conversation is out the window when your minijack connection fritzes out during a recording

The 302 does also have an unbalanced output, but as you point out, the recorder's minijack is not a robust connection.

Do you ever put a preamp in front of your DR100mkiii?

Yup, I did.  I went TRS in, w/ a Shure FP24 out in front.  I used the XLR Line out on the FP24....

https://archive.org/details/deadandco2017-06-30.dr100.spyder9.flac16

https://archive.org/details/deadandco2017-07-01.dr100.spyder9.flac16

That sounds really good. (I've never heard their rendition of "Not Fade Away".) However it does seem a little undefined in the bass and drums. Is that what it was like live?

That's the problem I had when using the 302 in front of my DR100mkiii going XLR>TRS. When I monitored the material through the 302 headphone out, it was terrific. But the recording when played back off the DR100mkiii seemed undefined in the low end.

Now I wonder if that was because the line-in goes through the mic preamp, so in effect I was using two piggybacked preamps and it was leaving things muddy.

Thanks for posting those concerts!

[Gutbucket]

Here's the block diagram from the DR680 manual. Perhaps I'm reading it wrong. I don't know much about these things.

According to that DR-680 diagram the only difference between XLR and TRS input routing is the input jack itself.  Both XLR and TRS go through the same preamp circuit.  Preamp line/mic sensitivity switching is made to the circuit via the hardware switch.

If the trs line levels go through the preamps then why can't the gain be adjusted by using the gain knob? I'm not arguing the the point, just curious.

All depends on how they program it.  The TRS DET lines (TRS insert detection) of the Zoom trigger whatever logic they program to occur when a TRS plug is inserted into the input rather than an XLR plug.   I would seem to perform the same gain sensitivity switching role as the hardware switches on the DR-680, but may also do other things like disabling gain knob adjustment.


What is common to both recorders is that all signals pass through the same preamp circuitry.  This is how most all modern recorders work.  If it makes you feel better when using an external preamp, think of the recorder's preamp stage in low-gain mode as being an input-buffer stage.

[Gutbucket]

If you want to bypass the Tascam DR-100 mkii MkIII's mic preamps, then use the 3.5mm Line-In.  It's located on the top of the unit, labeled "Ext-In".

This is correct and confirmed by the diagram posted previously, which indicates signal into the 3.3mm mini-jack line-in of the DR-100mkIII is not routed through the OPA amplifier chip that signal from both the TRS & XLR inputs pass through.

So.. internal mic-pre is bypassable on the DR-100MK2 MK3 by using the 3.5mm line-in jack.  Internal mic-pre on the DR-680 is not bypassable.

[edited to correct Mk2 to Mk3]

[2nd edit]
You cannot bypass the input amplifiers.

According to the schematic, all analog inputs of the DR-100MK3 pass through OPA1652 amplifier chips.  The 3.5mm mini-jack [Ext-In] and internal mics passes through a seperate one than the XLR/TRS Line/Mic inputs which share another.

[jerryfreak]

i see some intermingling there

just to be clear youre saying that 3.5mm jack on BOTH mkII and mkIII bypasses preamp circuit, and line-in on both mkII and mkIII goes thru preamps

[dogmusic]

Here's the block diagram from the DR680 manual. Perhaps I'm reading it wrong. I don't know much about these things.

According to that DR-680 diagram the only difference between XLR and TRS input routing is the input jack itself.  Both XLR and TRS go through the same preamp circuit.  Preamp line/mic sensitivity switching is made to the circuit via the hardware switch.

It's not the difference between xlr and TRS inputs in this case (unlike the dr100mkiii) that caught my eye, but that the line-in path seems to go through a different preamp (the Line AMP) than the mic input on both input jacks, and that these separate paths are governed by the line/mic switch. To me it still looks like the line input does not go through the mic preamp. Otherwise, what is the difference between the "Line AMP" and the "Mic AMP"?

[Gutbucket]

i see some intermingling there

just to be clear youre saying that 3.5mm jack on BOTH mkII and mkIII bypasses preamp circuit, and line-in on both mkII and mkIII goes thru preamps

Oops, I meant Mk3 (now corrected in my post above), as recently posted by dogmusic on the preceding page of this thread.  That is the only schematic I've looked at other than the DR-680 diagram posted above.  I haven't looked at a DR-100Mk2 diagram.

Thanks for catching that.

[Gutbucket]

Here's the block diagram from the DR680 manual. Perhaps I'm reading it wrong. I don't know much about these things.

According to that DR-680 diagram the only difference between XLR and TRS input routing is the input jack itself.  Both XLR and TRS go through the same preamp circuit.  Preamp line/mic sensitivity switching is made to the circuit via the hardware switch.

It's not the difference between xlr and TRS inputs in this case (unlike the dr100mkiii) that caught my eye, but that the line-in path seems to go through a different preamp (the Line AMP) than the mic input on both input jacks, and that these separate paths are governed by the line/mic switch. To me it still looks like the line input does not go through the mic preamp. Otherwise, what is the difference between the "Line AMP" and the "Mic AMP"?

I'm a bit out of it today.. You are correct, the DR-680 diagram does show seperate line and mic preamp sections.   Both the TRS and XLR inputs feed either.

[jerryfreak]

so again, is this correct:

3.5mm jack on BOTH mkII and mkIII bypasses preamp circuit, and line-in on both mkII and mkIII goes thru preamps

[Gutbucket]

No.  I just went back to take a closer look at the schematic for the DR100MK3. All of the analog inputs pass through OPA1652 chip amps.  The XLR/TRS Line/Mic inputs share one. The 3.5mm mini-jack [Ext-In] and internal mics share another.  The input preamps cannot be bypassed by choosing an alternate input.

The chip shared by the Ext-In and internal mics is drawn much smaller on the schematic and is located after a switching array, making it easy to miss.

I've not seen the schematic for the DR100-MK2.

[dogmusic]

Here is part of the schematic (file size was too large for all of it) plus a block diagram for the DR100-MK2.

[Gutbucket]

In the MK2 only the XLR inputs are routed through a separate preamp chip(s).  ID of the chip is not specified on the schematic so not certain if it is different to Mk3.  What is different is that Line-in and internal mics are routed directly to the NJW1194  PGA (programmable gate array) without going through a separate preamp chip(s) first.  The PGA performs the buffer/amp duties for those inputs along with its other duties.  That isn't inherently bad, but generally reflects a lower performance spec than a seperate amp chip, otherwise there would be no reason to incur the cost of an additional preamp chip component.

EE types and DIY circuit folks familiar with these chips may be able to offer more specific insights into them.

[dogmusic]

Looking at the DR100mk2 block diagram, I was surprised to see that it has an analog limiter.

[heva]

Could anyone tell what the input levels [the rotary dials in the LCD] display?

Is it in dB or just some numbering?

[jerryfreak]

dB