Jensen's JT-11P-1 is without doubt the finest audio input transformer of its type in the world. Its wide, ruler-flat bandwidth (-3 dB at 0.25 Hz and 100 kHz), vanishingly low distortion (less than 0.001% at 1 kHz with a maximum of 0.025% at 20 Hz), and negligible linear phase deviation (a maximum of +0.6 degrees at 20 Hz) make it the most transparent device of its type available.
As far as that statement off the pro audio site, i am a little sceptical, and when it is referred to as "the finest audio input transformer of its type in the world" ,it sounds more like what a marketing rep would say.
Don't get me wrong, I'm sure they are excellent transformers, and I am very impressed by the lack of deviation of linear phase shown in the data sheet. THD is not the best around, but I don't know how much of any of this stuff is actually audible *sigh*
Edit: Damn! I think I may get a pair of these just for curiosities sake down the track a bit, but only if I have cash to throw around 😉 I think I'm getting a little obsessed with all these transformers 😀
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an older post from franz:
i think the normal cables have 50ohm.
post from samoloko:
post from kesa32:
its a galaxy maggiorato case:
modushop.biz
greetings,
Chris
If i use rca connectors, does it make sense to use a 75ohm coax-cable or are normal HF-cables ok then?Conclusion in the context of the Gigaworks DAC, what this thread is about: RCA is O.K. for SPDIF input.
i think the normal cables have 50ohm.
post from samoloko:
I bought it at reichelt.de: http://www.reichelt.de/?ACTION=3;ARTICLE=27112;PROVID=2402xTreme
where did you bought your Talema pcb transformer (what VA) and box
post from kesa32:
xTr3Me , what case is that you have used ? looks nice
cheers ken
its a galaxy maggiorato case:
modushop.biz
greetings,
Chris
Yeah, 75ohm is the standard. That's what the TV cable companies use. From my limited experience, different cables will sound noticably different unless the transfer process from one unit to the other is perfectly matched with no reflections. Don't sweat it unless you are running it more than 2 m. A 50mhz scope is necessary to really see what's going on, but your ears can tell too.
well we already had that discussion about bnc/75ohm and so on but i wonder if it makes sense to use a 75ohm cable if ur using normal rca connectors anyway.
DO you mean using normal rca connectors anyway, regarding the anolog connection from the DAC to the amp?
If yes, then yes it still matters, as it has no relationship to the cable used for the digital signal from the transport to the DAC.
Or, if you are talking about the accusal connector plugs being the RCA type on the coaxal cable used with the digital signal, then it still matters and those plugs need to be 75ohm also, as far as I understand it. (75ohm cables = 75ohm wire + 75ohm plugs) I think.
If yes, then yes it still matters, as it has no relationship to the cable used for the digital signal from the transport to the DAC.
Or, if you are talking about the accusal connector plugs being the RCA type on the coaxal cable used with the digital signal, then it still matters and those plugs need to be 75ohm also, as far as I understand it. (75ohm cables = 75ohm wire + 75ohm plugs) I think.
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DO you mean using normal rca connectors anyway, regarding the anolog connection from the DAC to the amp?
No.
I want to connect the dac with spdif to my m-audio 2496 spdif out. the spdif out
from the m-audio only has normal rca-connectors. after the last discussion about
digital cables and the problem with the 75ohm franz said, that its ok for me to use
normal rca connectors, since the m-audio doesnt have bnc-connectors and the
dac also doesnt have a bnc-connector.
so now i want to connect the dac with spdif, using normal rca connectors. the last
question that isnt clear for me is, if it matters if I use 50ohm or 75ohm cables, when I
use the normal RCA connectors anyway.
i hope u got me now, my english ist quite bad because i dont practice enough since
about 2-3 years 🙁
Your English is better than that of some Australians I know 😉
I think I got you, and I think if using a RCA type spdif connection (that's coax digital), then 75ohm might be a good idea still.
Just for an example have a look at this site see how they sell wire that is spec'ed at 75ohms and RCA plugs that are also spec'ed at 75ohms.
I hope I understood.
Just so you know, I am only using a standard RCA cable at the moment, but i will try 75ohms type in the near future 🙂 SO yes, you can use a standard RCA cable, but a 75ohm one may get a better result.
I think I got you, and I think if using a RCA type spdif connection (that's coax digital), then 75ohm might be a good idea still.
Just for an example have a look at this site see how they sell wire that is spec'ed at 75ohms and RCA plugs that are also spec'ed at 75ohms.
I hope I understood.
Just so you know, I am only using a standard RCA cable at the moment, but i will try 75ohms type in the near future 🙂 SO yes, you can use a standard RCA cable, but a 75ohm one may get a better result.
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I tried some inexpensive cables like Belden 1695A, Silver Sonic D-75 or Mogami 2964 (all 75 Ohm) and had a pleasant surprise with a Eichmann eXpress 75 ohm Digital cable with copper Bullet plugs. Not really expensive and really nice sounding.
well now I planing the following thing:
Solder a 75ohm cable directly to the gigaworks PCB
-> solder the other end to a neutrik rca connector in the backplate of my enclosure
-> use a normal rca-connector with 75ohm cable to connect the dac with my m-audio soundcard.
i didnt find a crimp rca connector.. but i guess it doesnt matter anyway.
Solder a 75ohm cable directly to the gigaworks PCB
-> solder the other end to a neutrik rca connector in the backplate of my enclosure
-> use a normal rca-connector with 75ohm cable to connect the dac with my m-audio soundcard.
i didnt find a crimp rca connector.. but i guess it doesnt matter anyway.
I am using my DAC with shuntregs now.
A slightly modified verision of this http://www.diyaudio.com/forums/powe...-voltage-shunt-regulator-151.html#post1983367
You get 3x5v from it,the last 5v+ isnt neded if you arent going to use the USB input.
The first impression is a thighter sound,I´ll post more impressions later when I have listened more.

A slightly modified verision of this http://www.diyaudio.com/forums/powe...-voltage-shunt-regulator-151.html#post1983367
You get 3x5v from it,the last 5v+ isnt neded if you arent going to use the USB input.

The first impression is a thighter sound,I´ll post more impressions later when I have listened more.
Looks good, Ryssen 🙂
Where did you source the board for the Shunt Reg?
I was wondering the same thing myself data. 😉
I am using my DAC with shuntregs now.
![]()
A slightly modified verision of this http://www.diyaudio.com/forums/powe...-voltage-shunt-regulator-151.html#post1983367
You get 3x5v from it,the last 5v+ isnt neded if you arent going to use the USB input.
![]()
The first impression is a thighter sound,I´ll post more impressions later when I have listened more.
Did you bypass the supplier on the board? Seems not, and why, if you use trafos, still use the +15 for the analog parts?
Were did you get the PCB for the salas low voltage regulators?
I bought the pcb from Mr quanghao http://www.diyaudio.com/forums/group-buys/155960-dac-end-andrea-ciuffoli-group-buys.html he sells them for 15$ each.These boards are for -+5v and one +5v,as there are no negative 5v on "our"DAC don´t use that part.The voltages after the regs on the DAC boards are 15v+15v +5v +5v +5v.The last one of the +5v is for the usb reciever,so it´s up to you if you will use that one,or use the regulator on the board or a shunt one,in that case you have to buy another shunt pcb and use one +5v part on that.I cut the traces after the original regulators on the DAC board,you will have to use the 9v trafo to the DAC board as there are some 3v regultors on the board that need power.And I even used the same 9v trafo to feed the shunt board.
There is no reason why I have the 15v trafo connected,it might as well be disconected...
There is no reason why I have the 15v trafo connected,it might as well be disconected...
BTW:
I can offer two pairs of the Digitec Trannies, I mentioned before in this thread.
50 US$ a pair plus 20$ Shipping (flatrate). Paypal preferred.
Just drop me a mail to franzfgysi at bluewin.ch
First come, first served.
Franz
I can offer two pairs of the Digitec Trannies, I mentioned before in this thread.
50 US$ a pair plus 20$ Shipping (flatrate). Paypal preferred.
Just drop me a mail to franzfgysi at bluewin.ch
First come, first served.
An externally hosted image should be here but it was not working when we last tested it.
Franz
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I bought the pcb from Mr quanghao http://www.diyaudio.com/forums/group-buys/155960-dac-end-andrea-ciuffoli-group-buys.html he sells them for 15$ each.These boards are for -+5v and one +5v,as there are no negative 5v on "our"DAC don´t use that part.The voltages after the regs on the DAC boards are 15v+15v +5v +5v +5v.The last one of the +5v is for the usb reciever,so it´s up to you if you will use that one,or use the regulator on the board or a shunt one,in that case you have to buy another shunt pcb and use one +5v part on that.I cut the traces after the original regulators on the DAC board,you will have to use the 9v trafo to the DAC board as there are some 3v regultors on the board that need power.And I even used the same 9v trafo to feed the shunt board.
There is no reason why I have the 15v trafo connected,it might as well be disconected...
Thanks! 🙂
message for Legarem
you explain how to connect the pins of the transformer UTC Ha-108.
thanks 😀
Join pins 3 and 4 together and use pins 1 and 6 for primary
Join pins 9 and 10 together and use pins 7 and 12 for secondary
Join pins 3 and 4 together and use pins 1 and 6 for primary
Join pins 9 and 10 together and use pins 7 and 12 for secondary
many thanks Legarem 😀
I try tc HA-108 and then tell.
I also find UTC HA-101, you suggest how I can connect ..
you trying transformer on current mode ?
thanks and greetings
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