The No.1 Website for Pro Audio
 All  This Thread  Reviews  Gear Database  Gear for sale     Latest  Trending
1073 transformer history?
Old 9th July 2019
  #31
Here for the gear
 

HI guys,
i currently got two LI.31267 XL.T1452 vintage green transformers, to replace and test on a new BAE 1272 racked clone, i replace the new green carnhill for the vintage green cans and noticed that the output was much lower, i swaped the capacitor and resitor going from pin ten to 7 and everything was wired like the original BAE was.

My question is, do i need to wire them different to get more output, i'm new to transformer swap and i had a single Original 1272 racked and sounded big and had a grit, so i was hoping to recreate that sound with the BAE.

an other question i have is that both the vintage t1452 had different pins and resistor layout, one had 3 and 4, 7 and 8, and 9 and 10 connected to each other, and the other transformer had just a resistor going from 7 to 10, and 3 and 4 connected, so i wonder what those connection are for what use... any information will help to not only have a more clear wiring clearance but to know what are the purposes or this wiring differences.. thanks.
Old 9th July 2019
  #32
API
Lives for gear
 
API's Avatar
 

Your problem is that the 1272 never used a T1441/t1452/31267 transformer.
It had the T1444/T1454/10468 which is usually a mic input transformer.

You could wire the 31267 backwards using only one half of the transformer to get a similar result.
JLM audio have good info on their site hiw to do that.
Old 20th July 2019
  #33
Here for the gear
 

Thank you I will look at their site
Old 20th July 2019
  #34
Here for the gear
 

Would you have the link to that info? I just looked and can’t find it! Thanks
Old 20th July 2019
  #35
Lives for gear
 
Geoff_T's Avatar
 

I can't find it either....

Basically you wire the 31267 backwards.

You connect the original secondary in series to get the new primary and take the secondary off one of the primary windings....

I believe that's how it went....I've never tested it to see the performance
Old 3 weeks ago
  #36
Here for the gear
 

What wiring is this?
Attached Thumbnails
1073 transformer history?-c551e988-4d95-4b61-8d13-377f7a4bd7f4.jpg  
Old 3 weeks ago
  #37
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
What wiring is this?
Series primary, parallel secondary.

If that's a 31267 that would be 10Kohm input and 600 ohm output.
Old 3 weeks ago
  #38
Here for the gear
 

Sorry for my ignorance, is that wired in reverse?
Old 3 weeks ago
  #39
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
Sorry for my ignorance, is that wired in reverse?
No, it's correctly wired. Low numbers are primary, high numbers are secondary.

It's wired as a step down and probably came out of an old switching unit.

The loading resistor is on the secondary.

Last edited by Geoff_T; 3 weeks ago at 11:12 PM..
Old 3 weeks ago
  #40
Here for the gear
 

I wish I found a picture of how to wire it in reverse, so I can graspe my head around it
Old 3 weeks ago
  #41
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
I wish I found a picture of how to wire it in reverse, so I can graspe my head around it
http://www.jlmaudio.com/Neve%20transformer%20info.htm
Old 3 weeks ago
  #42
Here for the gear
 

Quote:
Originally Posted by Geoff_T View Post
I can't find it either....

Basically you wire the 31267 backwards.

You connect the original secondary in series to get the new primary and take the secondary off one of the primary windings....

I believe that's how it went....I've never tested it to see the performance
would this work for a 10368 transformer as well?
Old 3 weeks ago
  #43
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by hodgepodge View Post
would this work for a 10368 transformer as well?
The 10368 has a 5K primary rather than the 10K primary on the 31267.

It might work with the primaries in series and using both windings rather than the one shown on JLM's page but, seeing as I have never tried either version, I can't personally say it will work as well as the 31267.

Old 3 weeks ago
  #44
Here for the gear
 

Quote:
Originally Posted by Geoff_T View Post
The 10368 has a 5K primary rather than the 10K primary on the 31267.

It might work with the primaries in series and using both windings rather than the one shown on JLM's page but, seeing as I have never tried either version, I can't personally say it will work as well as the 31267.

Thanks for your thoughts, Geoff!
Old 3 weeks ago
  #45
Here for the gear
 

Quote:
Ok so I tried using them in a diy fivefish audio and they sound great, I’m getting the grit that was missing from the new carnhill tranny, my question if you can help me, when I swapped the transformers it’s a IOU’s I lost a few dB of output gain, can I add a resistor or capacitor on the I put or output of the transformer to make up for the gain loss? Sorry I’m new to this so any help as a beginner would be helpful! I was thingking I could attach a capacitor or a resistor to the pins of the transformer before it hits the pream? Idk just thinking out loud.
Attached Thumbnails
1073 transformer history?-ef6d159f-6d9a-4a5d-8e75-3d8441490286.jpg   1073 transformer history?-ce7e25ff-bf03-4e9b-afa4-73174dfe6446.jpg  
Old 3 weeks ago
  #46
Here for the gear
 

Sorry for the typos, I’ve attached a photo with markings of where I could possibly insert the resistors or capacitors to give it a boost of volume, if you can guide me if this is possible where would I insert them what pins that is.... thanks
Attached Thumbnails
1073 transformer history?-f34bdd7f-63f8-4474-b498-c63814d4f2af.jpg  
Old 3 weeks ago
  #47
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
Sorry for the typos, I’ve attached a photo with markings of where I could possibly insert the resistors or capacitors to give it a boost of volume, if you can guide me if this is possible where would I insert them what pins that is.... thanks
Hi

You have to appreciate that, while I know a little about Neve products, I know nothing about FiveFish....

Adding something to the transformer is not the best way to get corrective gain.

Hopefully that module has a trimpot to set overall gain and you would set that for the gain you want.
Old 3 weeks ago
  #48
Here for the gear
 

Oh ok I just thought maybe adding something similar to a pad but some kind of gain instead .... well I appropriate all the information provided I’m just going to hunt for actual mic input transformers instead of the line level ones. So I could replace my trannys on my 1272.
Old 3 weeks ago
  #49
500 series nutjob
 
pan60's Avatar
 

contac FiveFish and let him know what you have done ask ( usiming theres no trim pot ) what resister you need to chane to more gain?
do dont know anything about this but thats probably what i would do.
Old 2 weeks ago
  #50
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
Oh ok I just thought maybe adding something similar to a pad but some kind of gain instead .... well I appropriate all the information provided I’m just going to hunt for actual mic input transformers instead of the line level ones. So I could replace my trannys on my 1272.
Hi

If you told us which module it was we might be able to figure a fix...

Old 2 weeks ago
  #51
Here for the gear
 

Hi! I did mention the module, first it was the 1272 and second was the five fish audio
Old 2 weeks ago
  #52
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
Hi! I did mention the module, first it was the 1272 and second was the five fish audio
Hi

I know but five fish make a bunch of different modules.

https://www.fivefishstudios.com/

Old 2 weeks ago
  #53
Here for the gear
 

Oh sorry it’s the x-72 mk5ii
Old 2 weeks ago
  #54
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
Oh sorry it’s the x-72 mk5ii
I had a quick look... it uses a single gain block with no provision for gain adjustment other than the knob on the front panel.

Old 2 weeks ago
  #55
Here for the gear
 

I messaged five fish audio and they got back to me fast I’ve attached the response below.
Attached Thumbnails
1073 transformer history?-1808e5f8-d56f-4e21-abd4-0131e472d1b5.jpg  
Old 2 weeks ago
  #56
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
I messaged five fish audio and they got back to me fast I’ve attached the response below.
Go for it!
Old 2 weeks ago
  #57
Here for the gear
 

Quote:
Originally Posted by Geoff_T View Post
Go for it!

Ok so I got it working. Under the discrete op amp is resistor in R27 section, it had a 22k resistor simply I replaced it for a 47k and got almost 15db I’d gain, I’m going to add a 60k tomorrow and see if that brings it up a bit more. Now it’s close to loud like my BAE 1073 500 series module.
If anyone cares I added a picture of the resistor location to swap.
Attached Thumbnails
1073 transformer history?-074188d8-b5f3-4f94-ad5c-36ca3ef08785.jpg  
Old 2 weeks ago
  #58
Lives for gear
 
Geoff_T's Avatar
 

Quote:
Originally Posted by cesar delly View Post
Ok so I got it working. Under the discrete op amp is resistor in R27 section, it had a 22k resistor simply I replaced it for a 47k and got almost 15db I’d gain, I’m going to add a 60k tomorrow and see if that brings it up a bit more. Now it’s close to loud like my BAE 1073 500 series module.
If anyone cares I added a picture of the resistor location to swap.
Hi

As that module uses an adapter board for the transformer... did you do the conversion mod or just fit that PCB?

I'd be concerned if you were just cranking on gain but throwing level away at the input.

You may run into headroom problems....
Old 2 weeks ago
  #59
Gear Head
 

I'm confused about your mod. The note from fish said R27 should be 10k and they were suggesting you reduce that value to 5k by either replacing it or soldering on a 2nd 10k resistor to the same terminals (two 10k resistors in parallel = 5k). But you're saying the original R27 was 22k and you've swapped that out with a 47k resistor. That should have reduced your gain instead of increasing it, no?
Old 2 weeks ago
  #60
Here for the gear
 

Quote:
Originally Posted by Geoff_T View Post
Hi

As that module uses an adapter board for the transformer... did you do the conversion mod or just fit that PCB?

I'd be concerned if you were just cranking on gain but throwing level away at the input.

You may run into headroom problems....

That pub comes with the module, I simply just took out the original carnhill and added the vintage line transformer. Everything sounded great just a bit low on volume. Hope this helps.
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump