Can anyone give me info on this transformer.
Looking for info about the marinair T1447
- Thread starter Rob Flinn
- Start date
Help Support GroupDIY Audio Forum:
rafafredd
Well-known member
Isn´t it a 10468-like transformer? I think so...
I really hope so, but can anyone verify this. I believe that they were used by Audix
Tekay
Well-known member
PM Bo Hansen! I think he knows!
peter purpose
Well-known member
Hiya Rob,
It's used as the mic input on a 35102.
Both primaries and secondaries run in series.
I've just put a pair in front of some api 2520s and they sound stellar..!!
peter
It's used as the mic input on a 35102.
Both primaries and secondaries run in series.
I've just put a pair in front of some api 2520s and they sound stellar..!!
peter
Hi Peter
Presumably the pin connections are the same as for a 10468 ? Did you work out the ratio or am I going to have to fire up the millivolt meter ?
Presumably the pin connections are the same as for a 10468 ? Did you work out the ratio or am I going to have to fire up the millivolt meter ?
peter purpose
Well-known member
1:2, but wired backwards..!!
I just got this info from Bo Hansen
To me this equates to a turns ratio of 1:2.83 for the T1447, as opposed to 1:2 for the 10468.
So maybe this could be bodged into a 1290 type mic amp.
To me this equates to a turns ratio of 1:2.83 for the T1447, as opposed to 1:2 for the 10468.
So maybe this could be bodged into a 1290 type mic amp.
MikoKensington
Well-known member
31267 I think.
Anybody have any info on the T1452 and 1454?
I need turns, lams, alloy, leakage, pinout, bobbin, shielding, case,inductance, freq charts, phase shift, saturation, B-H, ... :razz:
I need turns, lams, alloy, leakage, pinout, bobbin, shielding, case,inductance, freq charts, phase shift, saturation, B-H, ... :razz:
rafafredd
Well-known member
Well, the T1452, I´m really sure is the exactly the same as the 31267...
What I`m thinking is trying these with a 1272 style, single BA283 mic pre type circuit. It should give about 3dB more gain overall.
Going by Bo`s data presumably it would be best to make the secondary loading a bit higher than 5K.
Going by Bo`s data presumably it would be best to make the secondary loading a bit higher than 5K.
Family Hoof
Well-known member
[quote author="CJ"]Anybody have any info on the T1452 and 1454?
I need turns, lams, alloy, leakage, pinout, bobbin, shielding, case,inductance, freq charts, phase shift, saturation, B-H, ... :razz:[/quote]
Marinair T1454 = Neve 10468 mic input. 1+1:2+2. usually wired for 1200:4.8k or 300:4.8k.
Marinair T1452 = Neve 31267 line input. 2+2:1+1. usually wired for 10k:2.4k
There were two or three earlier versions of each I believe, i.e. T1444, T1422, T1442. Joe Malone has tests and wiring info for both them here: http://www.jlmaudio.com/Neve%20transformer%20info.htm and Kev has a scan of an original sheet here: http://recording.org/users/kev/transformers_1_a.JPG
Like I said there were a few different versions of each one. Both were originally Marinair products (black case) with the T#### branding and then Neve had them rebranded in the green case with more stringent specs or something like that. That's all the info I can give right now. My research needs reorganizing.
[EDIT]Fixed mistake that Rob Flinn pointed out.
I need turns, lams, alloy, leakage, pinout, bobbin, shielding, case,inductance, freq charts, phase shift, saturation, B-H, ... :razz:[/quote]
Marinair T1454 = Neve 10468 mic input. 1+1:2+2. usually wired for 1200:4.8k or 300:4.8k.
Marinair T1452 = Neve 31267 line input. 2+2:1+1. usually wired for 10k:2.4k
There were two or three earlier versions of each I believe, i.e. T1444, T1422, T1442. Joe Malone has tests and wiring info for both them here: http://www.jlmaudio.com/Neve%20transformer%20info.htm and Kev has a scan of an original sheet here: http://recording.org/users/kev/transformers_1_a.JPG
Like I said there were a few different versions of each one. Both were originally Marinair products (black case) with the T#### branding and then Neve had them rebranded in the green case with more stringent specs or something like that. That's all the info I can give right now. My research needs reorganizing.
[EDIT]Fixed mistake that Rob Flinn pointed out.
Family Hoof
Well-known member
[quote author="Rob Flinn"]What I`m thinking is trying these with a 1272 style, single BA283 mic pre type circuit. It should give about 3dB more gain overall.
Going by Bo`s data presumably it would be best to make the secondary loading a bit higher than 5K.[/quote]
Sounds like a plan to me. Just load the secondary with a different value pot (instead of 5k) or redesigned pad switch (original adds up to ~4.8 or 5k in all positions), whatever gets you closest to 8k or 2k.
[EDIT] My suggestion in context:
option a) put a 40kohm resistor in parallel with a 10klog pot and get an 8k pot. Yes, I believe the curve will change but it may not matter. Neve used a linear port with a 5.6k on the wiper to get a log curve. There are tricks one can use which I don't fully understand at the moment.
option b) see this: http://members.nuvox.net/~zt.robgrow/circuits/neve/nevemicpre.html
Ignore the first circuit because it's erroneous and scroll down to the early JLM version. See that the first 5 clicks are a pad that adds up to 5k in 5dB steps and connected to the trafo secondary? Recalculate so that you get 8k in 5dB steps. Also, go here: http://www.jlmaudio.com/Schematic.htm and click on "hotrod mod" to see Joe's updated switch arrangement. Same type of deal. I can't recall the equation for doing this pad off the top of my head but there are websites that explain and a calculator which does it for you - see here: http://www.quadesl.com/attenuator.html
Going by Bo`s data presumably it would be best to make the secondary loading a bit higher than 5K.[/quote]
Sounds like a plan to me. Just load the secondary with a different value pot (instead of 5k) or redesigned pad switch (original adds up to ~4.8 or 5k in all positions), whatever gets you closest to 8k or 2k.
[EDIT] My suggestion in context:
option a) put a 40kohm resistor in parallel with a 10klog pot and get an 8k pot. Yes, I believe the curve will change but it may not matter. Neve used a linear port with a 5.6k on the wiper to get a log curve. There are tricks one can use which I don't fully understand at the moment.
option b) see this: http://members.nuvox.net/~zt.robgrow/circuits/neve/nevemicpre.html
Ignore the first circuit because it's erroneous and scroll down to the early JLM version. See that the first 5 clicks are a pad that adds up to 5k in 5dB steps and connected to the trafo secondary? Recalculate so that you get 8k in 5dB steps. Also, go here: http://www.jlmaudio.com/Schematic.htm and click on "hotrod mod" to see Joe's updated switch arrangement. Same type of deal. I can't recall the equation for doing this pad off the top of my head but there are websites that explain and a calculator which does it for you - see here: http://www.quadesl.com/attenuator.html
This is incorrect according to Kevs info. The 31267 has by the looks of it 2 5k primarys & 2 1k2 secondarys. i.e 2+2:1+1 which makes it 2:1 by my estimation
Family Hoof
Well-known member
[quote author="Rob Flinn"]
This is incorrect according to Kevs info. The 31267 has by the looks of it 2 5k primarys & 2 1k2 secondarys. i.e 2+2:1+1 which makes it 2:1 by my estimation[/quote]
Right! I knew that couldn't be right. I should've checked my notes. Of course it must be 2:1 because that's how people are able to use it in reverse for 1:2. I obviously wasn't thinking there. Thanks!
This is incorrect according to Kevs info. The 31267 has by the looks of it 2 5k primarys & 2 1k2 secondarys. i.e 2+2:1+1 which makes it 2:1 by my estimation[/quote]
Right! I knew that couldn't be right. I should've checked my notes. Of course it must be 2:1 because that's how people are able to use it in reverse for 1:2. I obviously wasn't thinking there. Thanks!
Tekay
Well-known member
In Audix the T1447 is used with both sides in serie, remember that pin 7 & 10 is prim! The transformer then feeds a 5534 based input stage with a 9k1 loading resistor for the transformer secondary winding, no cap here!
As the "pinning" is backwards , maybe it's line-in transformer backwards?
The line in T1448 in the Audix modul is connected normaly!
As the "pinning" is backwards , maybe it's line-in transformer backwards?
The line in T1448 in the Audix modul is connected normaly!
Golgoth
Well-known member
@Rob Flinn I know it's been a while, but could you share some details of your wiring of the T1447 for mic levels?
I think from memory you just wire it up like you would a 31267 for mic use. It just gives you a bit more gain because the ratio is slightly different.
Golgoth
Well-known member
Thanks a lot, I will try it out. Getting more gain is actually a nice perk! Did you compare the sound to a 10468?
