Neve Lo1066 clone vs. Carnhill VTB 2569

[CJ]

https://groupdiy.com/threads/primary-inductance-test.73039/

 

[Dylan W]

Following Cj's instructions and his scheme, I managed to make a faithful copy of LO 1166 down to the smallest detail. Wire thickness, arrangement of coils, insulation, gap... In the picture it is this beauty on a wooden stand. There was enough space to fit all the wire...but not even one layer would fit. The hammer worked over the wood. In my AML EZ 73 it sounds rich and creamy, but darker than the Carnhil WTB 2569. I am very satisfied. At first I was worried and tried to find a way to make the transformer a little more open, but I realized that it was wrong. The original specifications are important here. I also made another transformer that is almost identical in sound to the Carnhill wtb.
My wife took care of the styling of the cable , so I can say that this creation is a limited edition... I still haven't put it in the vacuum oven, I'll do that in a few days.
I will give myself some effort and try to measure the inductance and capacity..does anyone know a simple and efficient way to do it?

You did a nice job fixing the high end, I’m interested to know what changes you made to get it perfect!

Also curious to know how you achieved the difference between the “darker” and “WTB-clone” revisions.

 

[KraftWerk]

https://groupdiy.com/threads/primary-inductance-test.73039/

Thanks CJ..According to your directions, I measured Inductance.. Result is : 0.5213 for P1 + P2...On original sheme I see P1 305 MH and P2 305 MH...is that together 0.610? I try to measure independent P1 and have some strange results.

 

[KraftWerk]

You did a nice job fixing the high end, I’m interested to know what changes you made to get it perfect!

Also curious to know how you achieved the difference between the “darker” and “WTB-clone” revisions.

Hi Dylan! I'm not do much, I just stick to original CJ plan and change my first winding arrangement , I found that is very important to look at layers with small amount of turns, ( 40,20,26 ) and even wind them accros the layer...I made Opt with exactly numbers of leyers and turns inside layer and all is exactly the same schematics...before I experiment with changing numbers of turns with nice success,but that is not Lo1166...I like the sound of Carhill transformer,CJ sad that this one wtb 2569 is modern one and have little extended range, I like that so I made one Opt with similar Freq range..today I will start to experiment with LO2567. Similar but different wire and number of turns...I enjoy in this proces..do you have some precise schematics? I will like to make them all.

 

[CJ]

two coil sections in series will quadruple your inductance,

connected in parallel you will get the same inductance as 1 section,

do you have the equipment to measure inductance at 20 Hz?

and increase voltage to 5 or 10 volts if possible,

 

[KraftWerk]

two coil sections in series will quadruple your inductance,

connected in parallel you will get the same inductance as 1 section,

do you have the equipment to measure inductance at 20 Hz?

and increase voltage to 5 or 10 volts if possible,

 

[KraftWerk]

I did some measurements..all is on attachment picture. I burn out my LCR meter, it just stoped working...I must wait for another now...anyone know for cheap solution so I can measure directly OPT capacitance ?

 

[Disco Volante]

I just bought lams and bobbins from italtras in italy. Excellent service, very helpful staff (but they're not very good at english). I have some knowledge of a few European languages, so we got it sorted.
Got the tip from Whoops...

Great work on those OPTs, love it.

 

[CJ]

mV is milli Henrys, right?

looks good, you can see the effect of the butt stacked core by keeping L flat over the 20 to 100 Hz range,

 

[KraftWerk]

mV is milli Henrys, right?

looks good, you can see the effect of the butt stacked core by keeping L flat over the 20 to 100 Hz range,

20 hz 1V - 1,56 H
40 Hz 1V - 0,78 H
100 hz 1V - 0.312 H
1 kHz 1V - 0.001 H

20 hz 7V - 1,554 H
40 Hz 7V - 0.777 H
100 Hz 7V - 0.311 H
1 kHz 7V - 0.0009 H

 

[KraftWerk]

I just bought lams and bobbins from italtras in italy. Excellent service, very helpful staff (but they're not very good at english). I have some knowledge of a few European languages, so we got it sorted.
Got the tip from Whoops...

Great work on those OPTs, love it.

I would also be interested in buying some things, do you have some sort of catalog of them? I'm in Germany so I believe shipping is not a problem...

 

[Disco Volante]

check out italtras.us
they had no trouble shipping to Denmark, expedient and very reasonable.
V!

 

[KraftWerk]

I f anyone interested...On next picture you can clearly see same transformer with butt stack lamination and ccrosswise allingment..difference is clear at low frequencies.

 

[KraftWerk]

check out italtras.us
they had no trouble shipping to Denmark, expedient and very reasonable.
V!

Thanks! I already checked, but unfortunately, they dont have EI57...Closest is EI54 and EI60..

 

[andia]

I also tried to wind a lo1066 now, here are my results:
I only had EI60, so the core is bit larger, could not find EI57 bobbins here. Core material is M6, primary wirediameter is 0.35mm, secondary wirediameter is 0.25mm. I wound the coils according to the info in CJs winding sheet but I tried to spread the layers evenly, so that every layer uses the whole width of the bobbin.
Then I did one measurement with alternate stacking and one measurement with buttstacked version (0.05mm gap).

A question I have is what is the advantage of the gap? and what is the sense behind the reverse wound primary coil?

alternate stacking (here I forgot to remember inductance values...):

freq response (loading: 200k, 10k, 600ohms)


THD at fixed frequencies (20Hz, 30Hz, 50Hz):


THD at fixed levels (-10dBu, 4dBu, 15dBu):



buttstacked with gap (0.05mm):

Pri:
inductance: 830mH @100Hz
leakage inductance: 1.24mH
Primary DCR: 12,2ohms
Sec:
secondary inductance: 2.24H @100Hz
secondary DCR 42.18ohms

freq response (loading: 200k, 10k, 600ohms)


freq response (loading: 200k, 10k, 600ohms)


THD at fixed levels (-10dBu, 4dBu, 15dBu):

 

[KraftWerk]

A question I have is what is the advantage of the gap? and what is the sense behind the reverse wound primary coil?

Hi Andria,thanks for joining this thread..your experience for sure can help...this question is for CJ, he is expert with much experience,I can tell only what I read from book. I read that gap is necessary evil for transformers which use DC bias, because gap, core later go to saturation..gap does affect little low end,but not too much ....what mostly interesting me is: are you happy with sound of your Opt? Did you compare your Opt with real Lo1166? I'm thinking about buying one original just to compare..

 

[KraftWerk]

Today I tested my 2 LO 1166 OPT.
First I want to se how close I can make two of them. That is first graph.
After that,subjective test. I want to see effect of saturation.
This is results.
Apogee DAC , AML EZ 73 host. 192 khz 24 bit....link:

https://drive.google.com/drive/folders/1WxdhCl9ah_8mA_Q0jX6Gvo_GVABK5rnJ

 

[CJ]

You have a scope with X Y inputs?

You can build an integrator and have a ton of fun generating BH curves, gonna need some horsepower behind the signal generator, maybe use a stereo receiver that will do 20 hz at 100 watts without blowing up,

 

[KraftWerk]

You have a scope with X Y inputs?

You can build an integrator and have a ton of fun generating BH curves, gonna need some horsepower behind the signal generator, maybe use a stereo receiver that will do 20 hz at 100 watts without blowing up,

I have cheap OSCILOSCOPE Hantek DSO2c10 with software for DSO2c15, so signal generator works. Can generate 7V Peak to Peak.
You telling me to connect signal generator to input of amplifirer, and then to osciloscope? And then?

 

[KraftWerk]

Here is LO 1166 with and without varnish...and one funny thing...LO1166 without laminations, only bobbin