Confusing question about voltage conversion

[SteveM]

Using this chart http://www.sengpielaudio.com/calculator-db-volt.htm I discovered the -10 conversion for setting up Tascam decks (316mv) is in Dbv's compared to the -8 in Teac decks (308mv) is in DBu's. So I'm trying to figure out what 6+ is on the Teac deck because it's not specified in voltages but I'm not sure whether to use DBu's or DBv's. Can anybody shed any lilght on as to why they would used different measures? I'm not exactly sure what the difference is between the two.

 

[Dr ZEE]

First of all, question, why do you care?

...what the difference is between the two.

No difference. Same things, but with different "zero" pick. You can pick your own for your own "brand" (or your own line of gear ), say, you pick 1.788 RMS (to honor Massachusetts' Ratification of the Constitution) and/or because you like 5V P-P as a nice solid number and make your own "code-name" for students to wonder , something like dBStvM, and then let the "calculation" roll
Also, It's not physics but rather is an annoying bad math game.
To know what ever +/-X dBwhatEver "is" in Volts on any gear you'd need to know what the maker of that gear "picked" as "standard". If you don't have that bit of info, then there's no way to know. What's on paper in the manual for the sx machine in that regard. ??? Any note'info there at all?
IMO, this whole Festival of dBweees is a monstrosity, that did not have to be, it should never escape from telephone-makes para-scientists' island labs , but it is here and is well and "audio-engineers" just can't get enough of it.

 

[SteveM]

First of all, question, why do you care?


No difference. Same things, but with different "zero" pick.

That's what I wasn't sure about. I didn't know if they kept on one scale or not. Makes sense now.

Also got the A3340 manual and it seems to be pretty much the same thing. I bought a PDF on line. Looks pretty crappy. Last time I do that But it's enough to make out what I need.

 

[Beck]

Using this chart http://www.sengpielaudio.com/calculator-db-volt.htm I discovered the -10 conversion for setting up Tascam decks (316mv) is in Dbv's compared to the -8 in Teac decks (308mv) is in DBu's. So I'm trying to figure out what 6+ is on the Teac deck because it's not specified in voltages but I'm not sure whether to use DBu's or DBv's. Can anybody shed any lilght on as to why they would used different measures? I'm not exactly sure what the difference is between the two.

Hey Steve,

Are you trying to set this up for tape operating level, hence your reference to 6+ (+6)? Just wondering because the nominal operating level of your machine and the gauss level for tape are two different things.

Just checking…

 

[SteveM]

Hey Steve,

Are you trying to set this up for tape operating level, hence your reference to 6+ (+6)? Just wondering because the nominal operating level of your machine and the gauss level for tape are two different things.

Just checking…

Thanks for asking Tim. No, actually for output. The manual for the a3340s said to set up the output to +6 with the output controls turned fully clockwise. Then you turn them back to 0, and that's where you leave the knobs. But I got the A3340 manual and it was altogether different. Still uses DBu, but makes sense now. It gets even more confusing when they're calling for 400khz at -18dbs on the oscillator and all I've got is -10 , but... too much math.

 

[Dr ZEE]

... said to set up the output to +6 with the output controls turned fully clockwise.

+6 - that is on that damn TEAC speacial test-set when you play that damn TEAC test tape (or on some other cool AC meter with dB scale in the style of 0.775V RMS-is-Zero with damn 10K resistor across output). Is this what your are doing exactly ...??? heh heh
If not, then my guess you are playing some tape (????) What meter do you use?
I am just trying to figure out what exactly you are up to
*************
"Then you turn them back to 0..." (again, in their case it's 0.775 RMS), again - that's on your test AC-meter.
They call it "specified output" ...sort of starting point before you pursue the rest of screwy-tweaking.

Seriously, Steve, what are you practically trying to achive. No jokes .

 

[SteveM]

+6 - that is on that damn TEAC speacial test-set when you play that damn TEAC test tape (or on some other cool AC meter with dB scale in the style of 0.775V RMS-is-Zero with damn 10K resistor across output). Is this what your are doing exactly ...??? heh heh
If not, then my guess you are playing some tape (????) What meter do you use?
I am just trying to figure out what exactly you are up to
*************
"Then you turn them back to 0..." (again, in their case it's 0.775 RMS), again - that's on your test AC-meter.
They call it "specified output" ...sort of starting point before you pursue the rest of screwy-tweaking.

Seriously, Steve, what are you practically trying to achive. No jokes .

No "archiving" Mike. The channels weren't even, output and input wise. I like them to be equal and uniform when I'm recording. And now they are.

Now I need some of those big 10.5" reels. Where can I get the good Quantegy tape? 406 or 407?

 

[Dr ZEE]

Where can I get the good Quantegy tape? 406 or 407?

Nowhere.! , that's where. Where else ?
Maybe try calling Q-guys, ask if they may find couple of reels left on dusty shelf: http://www.quantegy-online.com/info.html
or you can eBay all night long.

No "archiving" Mike.

Grrrrrrrrrrrr! , "r" was not the one that I've unjustly mistreated. It was damn "e".

You are ignoring my questions, Steve ..heh heh , which is , and I shall not be pulling the tooth, since you are happy with them being uniformed and equal .

 

[SteveM]

Nowhere.! , that's where. Where else ?
Maybe try calling Q-guys, ask if they may find couple of reels left on dusty shelf: http://www.quantegy-online.com/info.html
or you can eBay all night long.

Well, that stinks. I haven't looked around much lately.

Grrrrrrrrrrrr! , "r" was not the one that I've unjustly mistreated. It was damn "e".

I didn't even notice. You need to get one of these nifty spell checkers like I have and have it on all the time.

You are ignoring my questions, Steve ..heh heh , which is , and I shall not be pulling the tooth, since you are happy with them being uniformed and equal .

I guess I'm ignoring because of:
a) I don't know what the question is.
b) I don't know WHAT I'm doing.

All I was doing was wanting to set it up to according to spec to see if I could get rid of a few of the quirks. And it did. The brake tension was WAY too tight and imbalanced and stretched the hell out of my calibration tape. The volume levels between normal and simulsync were far different and also amongst individual channels input and out. Channels didn't erase fully. I've got all this pretty much worked out now. I love this deck. Even the extra step with the toggle switch doesn't bother me as much now. This was definitely a project that was worth the effort.

 

[Dr ZEE]

I don't know what the question is.

uh, something like: ...my guess you are playing some tape (????) What meter do you use?

I don't know WHAT I'm doing.

Yes you do, you just keep it secret heh heh

I was asking just to know what exactly (actually) you are doing and with what equipment, because it's nice to know what IS The Game .

If you get that feeling of "I don't know WHAT I'm doing", then try to simplify the procedure in your mind or on paper , something like in the form of block diagram, so you know where you are, where's their goalkeeper, what's the ball and what's the referee's head sort of speak .
See the attached pic.
You see, you can "Play The System" to your own desire or to your own "standard" (within the limits of the system of course). You sure can match (make uniformed ) the systems within the "multi-system" - muti-track machine that is. etc.
If you wish to tweak your system so it corresponds (or "perfectly" complies) with an established and "universally accepted" remote system (a standrad), then it (the task) gets more demanding. Then you have to follow the exact procedure as described by the maker of that system and you have to use the Test Signal Source and the Test Meter (Measuring Device/Monitor) which themselves comply with a "remote system's" standard. Actually a standardized Test Meter can evaluate (or say verify) the Signal Source and if the source is adjustable, then it can be "standardized" right there on the spot, however it does not apply to the situation, where a pre-recorded tape is The damn Source.
Some people refer to those "Sources" and "Measuring Devices" as "Trusty"...heh heh
Compliance grants The Trust, that is , and Don't we all see how it "works" all around us

A side thought: If your system seeks no direct / indirect interaction with other (remote) system(s) (Systems that were/are being Played by others, that is ), then it's free as a bird

Blah blah blah
here's the pic

 

[SteveM]

uh, something like: ...my guess you are playing some tape (????) What meter do you use?


Yes you do, you just keep it secret heh heh

I was asking just to know what exactly (actually) you are doing and with what equipment, because it's nice to know what IS The Game .

If you get that feeling of "I don't know WHAT I'm doing", then try to simplify the procedure in your mind or on paper , something like in the form of block diagram, so you know where you are, where's their goalkeeper, what's the ball and what's the referee's head sort of speak .
See the attached pic.
You see, you can "Play The System" to your own desire or to your own "standard" (within the limits of the system of course). You sure can match (make uniformed ) the systems within the "multi-system" - muti-track machine that is. etc.
If you wish to tweak your system so it corresponds (or "perfectly" complies) with an established and "universally accepted" remote system (a standrad), then it (the task) gets more demanding. Then you have to follow the exact procedure as described by the maker of that system and you have to use the Test Signal Source and the Test Meter (Measuring Device/Monitor) which themselves comply with a "remote system's" standard. Actually a standardized Test Meter can evaluate (or say verify) the Signal Source and if the source is adjustable, then it can be "standardized" right there on the spot, however it does not apply to the situation, where a pre-recorded tape is The damn Source.
Some people refer to those "Sources" and "Measuring Devices" as "Trusty"...heh heh
Compliance grants The Trust, that is , and Don't we all see how it "works" all around us

A side thought: If your system seeks no direct / indirect interaction with other (remote) system(s) (Systems that were/are being Played by others, that is ), then it's free as a bird

Blah blah blah
here's the pic

Mike, you have the advantage of being able to make those calls because you're much more familiar with the inner workings of these things than I am. But I know what you're saying. To me though, if it isn't near where it's design to be then in my mind the system or a link in it may be weak. I don't have have that freedom to roam in my imagination. I'm in chains. You know what I'm saying?