CJ
Well-known member
I set the camera to 600-800 pixels.
Then Ethan does the rest.
Nice avatar! Needs a little lightening.
Then Ethan does the rest.
Nice avatar! Needs a little lightening.
Mo Metal
- Thread starter CJ
- Start date
Help Support GroupDIY Audio Forum:
[quote author="CJ"] Weirdness, after I saturated the heck out of the new Sowter, the henries jumped from 2.4 to 3 on the secondary.
Maybe this breakin stuff ain't fiction after all.
I know a guy who tunes his SE power outputs like this.
Hit's them with 60 cps at 1 amp on the secondary until the henries match.
:?:[/quote]
This is indeed interesting. Any guesses at an explanation of this effect?
I could surely use some of this effect when fine-tuning large equalizer inductances..!
Jakob E.
Maybe this breakin stuff ain't fiction after all.
I know a guy who tunes his SE power outputs like this.
Hit's them with 60 cps at 1 amp on the secondary until the henries match.
:?:[/quote]
This is indeed interesting. Any guesses at an explanation of this effect?
I could surely use some of this effect when fine-tuning large equalizer inductances..!
Jakob E.
tommypiper
Well-known member
CJ, you're mad. :grin: I just stumbled on this thread. Fun. I woulda come over during the holidays had I seen it. How 'bout this weekend to do those listening tests?
-tommypiper
-tommypiper
CJ
Well-known member
OK, I managed to squeeze some enameled wire thru the core window on the transformers that I can not take apart, ala PRR method of getting turns without all the drama of using a blow torch.
The results were pretty stable, as xfmr's have pretty low turns to begin with so the linkage was pretty good.
Here are the numbers:
Marinair 1166A:
Pri.-pins 1-2 = 311 t pins 3-4 = 311 t , total pri = 622 t
Sec.-pins 5-6 = 523 t pins 7-8 = 523 total = 1046
Ratio = 1:1.68 which comes down a bit when loaded for some strange reason
Carnhill Re-issue:
Pri.- pins 1-2 = 304 t pins 3-4 = 304 t pri total = 608 t
Sec.- pins 5-6 = 516 t pins 7-8 = 516 t sec. total = 1032
Ratio = 1:1.7
Sowter:
Pri.- 579 t total (Sowter does not break out the pri windings seperately)
Hey, that's weird come to think of it. Are you not supposed to connect the primaries and secondaries in paralell in the Neve outputs?
Can not do that with the Sowter. Hmmm, I must be wrong on that.
Sec.- 436 turns each, 872 total
Ratio = 1:1.50
Sowter turns are lower, but inductances higher due to larger core.
The results were pretty stable, as xfmr's have pretty low turns to begin with so the linkage was pretty good.
Here are the numbers:
Marinair 1166A:
Pri.-pins 1-2 = 311 t pins 3-4 = 311 t , total pri = 622 t
Sec.-pins 5-6 = 523 t pins 7-8 = 523 total = 1046
Ratio = 1:1.68 which comes down a bit when loaded for some strange reason
Carnhill Re-issue:
Pri.- pins 1-2 = 304 t pins 3-4 = 304 t pri total = 608 t
Sec.- pins 5-6 = 516 t pins 7-8 = 516 t sec. total = 1032
Ratio = 1:1.7
Sowter:
Pri.- 579 t total (Sowter does not break out the pri windings seperately)
Hey, that's weird come to think of it. Are you not supposed to connect the primaries and secondaries in paralell in the Neve outputs?
Can not do that with the Sowter. Hmmm, I must be wrong on that.
Sec.- 436 turns each, 872 total
Ratio = 1:1.50
Sowter turns are lower, but inductances higher due to larger core.
> Ratio = 1:1.68 which comes down a bit when loaded for some strange reason
The ratio stays the same. The voltage you see at the terminal is that ratio times the resistance divider formed by winding resistance and load resistance. It would not be unusual for winding resistance to be 5% of design load, so the observed voltage will be 5% low. Instead, to get ratio you should drive with a very low impedance (an old Crown D-75), in the middle of the audio band (400 is conventional), and have "no load" at the output.
For iron like these, your voltmeter is an OK load, 600Ω confuses your winding resistance into your ratio measurement. For very high impedance windings (grid transformers) even the capacitance of an o'scope can be too much (though it mat be similar to an actual grid) and many classic VTVMs have way more input capacitance than a grid transformer can drive well. (Working at 400Hz is better than 1KHz for this situation.)
> Are you not supposed to connect the primaries and secondaries in paralell in the Neve outputs?
That may not make sense. Classic tranny outputs have a fully floating output (secondary) winding.
You may be confused with the fact that some of these have split primaries (to reduce leakage inductance) which must be connected together externally. Sowter may not have split the primary, or may have multi-split it so much that Brian choose to do the fiddly connections internally instead of letting you screw it up (get windings out of phase, etc, and whine about crappy results).
The ratio stays the same. The voltage you see at the terminal is that ratio times the resistance divider formed by winding resistance and load resistance. It would not be unusual for winding resistance to be 5% of design load, so the observed voltage will be 5% low. Instead, to get ratio you should drive with a very low impedance (an old Crown D-75), in the middle of the audio band (400 is conventional), and have "no load" at the output.
For iron like these, your voltmeter is an OK load, 600Ω confuses your winding resistance into your ratio measurement. For very high impedance windings (grid transformers) even the capacitance of an o'scope can be too much (though it mat be similar to an actual grid) and many classic VTVMs have way more input capacitance than a grid transformer can drive well. (Working at 400Hz is better than 1KHz for this situation.)
> Are you not supposed to connect the primaries and secondaries in paralell in the Neve outputs?
That may not make sense. Classic tranny outputs have a fully floating output (secondary) winding.
You may be confused with the fact that some of these have split primaries (to reduce leakage inductance) which must be connected together externally. Sowter may not have split the primary, or may have multi-split it so much that Brian choose to do the fiddly connections internally instead of letting you screw it up (get windings out of phase, etc, and whine about crappy results).
DrFrankencopter
Well-known member
[quote author="gyraf"][quote author="CJ"] Weirdness, after I saturated the heck out of the new Sowter, the henries jumped from 2.4 to 3 on the secondary.
Maybe this breakin stuff ain't fiction after all.
I know a guy who tunes his SE power outputs like this.
Hit's them with 60 cps at 1 amp on the secondary until the henries match.
:?:[/quote]
This is indeed interesting. Any guesses at an explanation of this effect?
I could surely use some of this effect when fine-tuning large equalizer inductances..!
Jakob E.[/quote]
Any change this could be magnetization of the transformer core? If so, it probably wouldn't work too well with air-core inductors. Can you get the same effect by dropping the transformer on a hard surface?
Cheers,
Kris
Maybe this breakin stuff ain't fiction after all.
I know a guy who tunes his SE power outputs like this.
Hit's them with 60 cps at 1 amp on the secondary until the henries match.
:?:[/quote]
This is indeed interesting. Any guesses at an explanation of this effect?
I could surely use some of this effect when fine-tuning large equalizer inductances..!
Jakob E.[/quote]
Any change this could be magnetization of the transformer core? If so, it probably wouldn't work too well with air-core inductors. Can you get the same effect by dropping the transformer on a hard surface?
Cheers,
Kris
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SSLtech
Well-known member
[quote author="PRR"]>Are you not supposed to connect the primaries and secondaries in paralell in the Neve outputs?
That may not make sense. Classic tranny outputs have a fully floating output (secondary) winding.[/quote]
I'm not sure, But I think that CJ might have meant "connect the two primary windings in parallel, and connect the two secondary windings in parallel"...
I might be mistaken, however CJ's wording is ambiguous.
Keith
That may not make sense. Classic tranny outputs have a fully floating output (secondary) winding.[/quote]
I'm not sure, But I think that CJ might have meant "connect the two primary windings in parallel, and connect the two secondary windings in parallel"...
I might be mistaken, however CJ's wording is ambiguous.
Keith
CJ
Well-known member
We were discussing some Neve stuff a while back and one of the docs that shows the OPT does not have all the pri's and sec's drawn in. It was inferred that that the transformer windings are to be paralelled.
Doc, I used ac only on the Sowter OPT, so I do not think it was magnetism.
Dropping it, I do not know, but I do know that Steveie Ray Vaughn used to take a hammer to his Fender output transformer cores.
More weirdness, the Sowter, after a week on the shelf, is back to it's original inductance spec of 2.4 henries on the secondary!
I will have to saturate it again to see if it does the same thing.
Doc, I used ac only on the Sowter OPT, so I do not think it was magnetism.
Dropping it, I do not know, but I do know that Steveie Ray Vaughn used to take a hammer to his Fender output transformer cores.
More weirdness, the Sowter, after a week on the shelf, is back to it's original inductance spec of 2.4 henries on the secondary!
I will have to saturate it again to see if it does the same thing.
That sounds like some form of magnetization.
I started doing some testing on mic output and input trannies with respect to shorted phantom lines, and ran into some interesting characteristics with the output tranny from a U87.
My tests were confined to distortion changes vs mag current, but it also showed changes that disappeared after a while.
I need to get back to it, but finding time is tough. It's a fair setup to eliminate noise and other influences in the test rig.
I started doing some testing on mic output and input trannies with respect to shorted phantom lines, and ran into some interesting characteristics with the output tranny from a U87.
My tests were confined to distortion changes vs mag current, but it also showed changes that disappeared after a while.
I need to get back to it, but finding time is tough. It's a fair setup to eliminate noise and other influences in the test rig.
CJ
Well-known member
OK, hit the Sowter with 45 cps for 1/2 an hour.
Secondary Henries jumped from 2.4 to 3.6!
So I wasn't on crack after all. I will let it sit and measure it tomorrow.
Magnetism would cause a decrease in inductance, no?
So I think it's the core molecules getting loose thus increasing the perm.
This is a gapped x-former and I am not using dc, so I do not know if the above would hold true in an in circuit situation.
OK, 5 minutes later and it's down to 3.2 henries.
Heat should not be a factor, it's not getting even warm.
OK, I repeated the test only this time used the Gen Rag bridge to quell any thoughts that the Sencore bridge might be spiking the x-former with dc.
Sure enough I can dial in a null on the meter and watch it drift, turn the inductance knob back to get a null, and it drifts again. So the inductance is changing over time after being removed from the low frequency.
Secondary Henries jumped from 2.4 to 3.6!
So I wasn't on crack after all. I will let it sit and measure it tomorrow.
Magnetism would cause a decrease in inductance, no?
So I think it's the core molecules getting loose thus increasing the perm.
This is a gapped x-former and I am not using dc, so I do not know if the above would hold true in an in circuit situation.
OK, 5 minutes later and it's down to 3.2 henries.
Heat should not be a factor, it's not getting even warm.
OK, I repeated the test only this time used the Gen Rag bridge to quell any thoughts that the Sencore bridge might be spiking the x-former with dc.
Sure enough I can dial in a null on the meter and watch it drift, turn the inductance knob back to get a null, and it drifts again. So the inductance is changing over time after being removed from the low frequency.
Damned..!
Yet another complex time-domain parameter for the plug-in guys to algoritmically describe. Poor bastards.. :grin:
I really find this a bit disturbing - I haven't come across any information mentoning this effect... :?
Jakob E.
Yet another complex time-domain parameter for the plug-in guys to algoritmically describe. Poor bastards.. :grin:
I really find this a bit disturbing - I haven't come across any information mentoning this effect... :?
Jakob E.
CJ
Well-known member
I will put the Sowter in our enviromental chamber to make sure it isn't tempeture.
Also, I will dothe same inductance test on the old Marinair that has been broken in for years.
cj
Also, I will dothe same inductance test on the old Marinair that has been broken in for years.
cj
CJ
Well-known member
OK, I did the inductance test on the Marinair LO1166A.
It read 1.8 henries before saturation and 2.1 henries after. Same effect as the Sowter, but not as dramatic a henry change. Maybe because it is more broken in and therefore more stable.
Then I put the Sowter in the enviromental chamber.
At 70 degrees F the Sowter read 2.5 henries.
At 109 degrees F the inductance went up to 2.8 henries.
So a little change, but not as dramatic as before and after saturation.
I will ask Brian to see if he knows what's uhh, the deal. (Obscure Pink Floyd song)
.
It read 1.8 henries before saturation and 2.1 henries after. Same effect as the Sowter, but not as dramatic a henry change. Maybe because it is more broken in and therefore more stable.
Then I put the Sowter in the enviromental chamber.
At 70 degrees F the Sowter read 2.5 henries.
At 109 degrees F the inductance went up to 2.8 henries.
So a little change, but not as dramatic as before and after saturation.
I will ask Brian to see if he knows what's uhh, the deal. (Obscure Pink Floyd song)
.
Consul
Well-known member
Well, hurry up, 'cause there's a cold wind blowing in my soul, and I think I'm growing old...
(Right back at ya!) :thumb:
(Right back at ya!) :thumb:
clintrubber
Well-known member
from CJ:
I only just found out some about the use of 2567 + 1310 instead of gapped 1166
1310 as measured by JC does only 650mH, that's far away from those ~2H. Adding a 2567 or other non-gapped TX on that '283-pin further reduces the total load the output-amp sees. Guess that total induct. load is all not too critical then...
So does the 2567 + 1310 combination actually sound comparable with a lonely 1166 ?
One would think so, since for instance this micpre seems to use them as available:
Thanks,
Peter
I only just found out some about the use of 2567 + 1310 instead of gapped 1166
1310 as measured by JC does only 650mH, that's far away from those ~2H. Adding a 2567 or other non-gapped TX on that '283-pin further reduces the total load the output-amp sees. Guess that total induct. load is all not too critical then...
So does the 2567 + 1310 combination actually sound comparable with a lonely 1166 ?
One would think so, since for instance this micpre seems to use them as available:
http://www.danalexanderaudio.com/DanPre/proaudioreview.htm
Thanks,
Peter
Kid Squid
Well-known member
Hiya Chris,
have you got another link to the images - the current links are down.
would love to see the dissection pics....
Steve :thumb:
have you got another link to the images - the current links are down.
would love to see the dissection pics....
Steve :thumb:
phishman13
Well-known member
All of the links and images from this thread are broken. CJ, or anyone else for that matter, do you have the images, or a new location that I could find them? I could really use the info from this for a project I'm working on for school.
okgb
Well-known member
I want to know how you are ? [ or how is it , that you are ? ] after that
how about transformer recommendation for gtr tube preamps
two requirements
1 ] to invert the polarity of one of the channels , this could come after a 100k plate stage
or the cathode follower , any " good "grunge or limited freq response IS acceptable [ it is a gtr pre after all ]
2 ] to balance the output , for ground iso and possible grunge mojo [ or the impossible getting something to feel
like a loud amp when it is not .
A re-amping friend likes to edit the clean signal [ finds it easier & more precise ] the direct recording can be acceptable
certainly quicker but not usually as good as mics , but I've found tubes & transformers in the path DO help .
how about transformer recommendation for gtr tube preamps
two requirements
1 ] to invert the polarity of one of the channels , this could come after a 100k plate stage
or the cathode follower , any " good "grunge or limited freq response IS acceptable [ it is a gtr pre after all ]
2 ] to balance the output , for ground iso and possible grunge mojo [ or the impossible getting something to feel
like a loud amp when it is not .
A re-amping friend likes to edit the clean signal [ finds it easier & more precise ] the direct recording can be acceptable
certainly quicker but not usually as good as mics , but I've found tubes & transformers in the path DO help .
