Category Archives: Pinout

Problems of Assigning Channels Based on Color alone

The need for 8p8c to 8p8c connectivity is of the utmost importance.
Second to is the “field breakouts”.  The colour plays a huge part.
I’ve been noticing more and more breakout tails entering the market, so it needs addressing.  We cannot use the 25 pair or TIA colour codes to determine the channels.
For the field, I would expect a simple visual inspection to influence deployment decisions.  Looking at the solid colours to determine the channel order.  Below is an image that has been the result of many conversations.  An observation I’d like to present:  If you look at RJ45 connectors the solid colours are visible. The order of the solid colour should dictate the channel order. Pair three in both cases is split around pair 2.  Pins of multiples of 2 are considered “Hot”.  QTP-B is based on the TIA-B wiring scheme. 
This is where a lot of QTP development started.  How to terminate this twisted 3M ribbon cable to an RJ45 Jack.  Since it would not fit and CAT cable is everywhere…

QTP DB25 Pin out standards

I had an integrator call today asking what the compatible pin outs of the QTP-DB25 adapters were .

QTP-DB25M and QTP-DB25M use the Tascam DB25 Pinout.
Channels 1-4 terminate to one RJ45 and 5-8 to the other. 

QTP-DB25F - Face 3:4Screenshot 2015-05-05 14.25.00QTP-DB25F - Face 3:4

If you are using AES in and out the pin out is identical.
CH 1-4 are IN 1-4  and CH 5-8 are OUTPUT 5-8 Tascam1

The Third Compatible pin out is the Yamaha AES pin out.  The QTP-DB25Y is only available in a male DB25 connector.  The IN the first RJ45 and OUT the second.

All the RJ 45 connectors terminate to the TIA -B standard and use the following pair and polarity designation
Screen Shot 2015-03-14 at 10.10.47 AM

April Fools are paying 4 times the price.

QTP – DB25

QTP-DB25M               Male
QTP-DB25M - Face 3:4
QTP-DB25M+             Male + Shield
QTP-DB25F                 Female
QTP-DB25F - Face 3:4
QTP-DB25Y                 Yamaha Male
QTP-WBS                    WBS-High Density Breakout  – TBA NAB-2015


QTP-BOB-XLR-F           Female

QTP-BOB-XLR-M         Male
QTP-BOB-XLR-FM       Female / Male

QTP-BOB-XLR-MF       Male / Female
QTP-BOB-BNC             AES / SPDIF
QTP-BOB-BNC10         AES / SPDIF w/ 10dB pad


QTP-XX-*-XLR-F           Female
QTP-XX-*-XLR-M         Male4-1QTP-5-2-M 

QTP-XX-*-XLR-FM       Female / Male
QTP-XX-*-XLR-MF       Male / Female

2-2QTP-XX-*-PHNX           PHOENIX

3-1QTP-XX-*-TRS              Tip Ring Sleeve

QTP-XX-* -U                 User-terminated
XX = Cable Length (ft)   3, 5, 15, 30
*  = Tail Length (ft) 1, 2, 3, 4

QTP – Kits

QTP-CAT6-KEY              Keystone Termination
QTP-HSK-1                    1’ Heat Shrink Kit
QTP-HSK-2                    2’ Heat Shrink Kit


QPNL-3-DB25               2RU ¼ Panel
QPNL-4-DB25               2RU ¼ Panel

Tristan Miller vs 1000 feet of Quad Twisted Pair

We were lucky enough to have Tristan Miller of Catherine North Audio over for the day to give Quad Twisted Pair an examination.  Tristan is an Electronics Technician with a comprehensive background in Electrical systems being a licensed Electrician.  Having implemented over a thousand channels of QuadTwisted Pair in his recording studio(s), he has been a great influence of the ideas surrounding implementation and execution.   His understanding of Electrical and audio systems is like no other.   He came armed with a brand new 1000 foot box of CAT5e Quad Twisted Pair cable to play with.  Along with repeating our original tests, some new tests were conducted to compliment our original findings.

We let Tristan drive the Audio Precision 2700 so all  tests results were independently confirmed:
2015-03-05 15.37.41 Continue reading Tristan Miller vs 1000 feet of Quad Twisted Pair