Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: exnihilfit on April 15, 2025, 08:34:23 pm
-
I got a couple of these transformers for $1 each, but I have no clue what they are good for, are they any use in a tube amp?
here is what the spec sheet says:
1140-LN-E
LINE INPUT TRANSFORMER
1:1 TURNS RATIO WITH SPLIT WINDINGS
This transformer is designed for high input levels up to
+19dbu, along with a wide bandwidth and low distortion.
This transformer can be used in multiple configurations 1:2,
1:1, or 2:1
It also has excellent shielding from the mu metal can.
PRI:ORG - BRN: 150 O
PRI:WHT - BLK: 150 O
SEC:GRN - GRN/YEL: 150 O
SEC:RED - RED/YEL: 150 O
MADE IN CANADA
GRY: SHIELD
VIO : CAN GROUND
DATE
-
What mean 150 O ?
-
What mean 150 O ?
"150 O" = "150Ω"
Hammond 1140-LN-E (https://www.hammfg.com/part/1140-LN-E)
... are they any use in a tube amp?
If you already know how to use them, then they are useful.
They could be used for preventing ground-loops in something like an Effects Send. However, we would wish for somewhat different specs for a transformer at the input jacks of an amp.
You could also probably use one in a box designed to break ground loops & provide isolation in a multi-amp setup (or where multiple items in your rig have grounded power cords, and would otherwise create ground loops).
-
What mean 150 O ?
"150 O" = "150Ω"
Thank's
-
yeah, I copy/pasted the specs and the Ohm symbol turned into a square sorry so I substituted it with an O with is what we used back in the day in my college EE classes :-)
-
If you already know how to use them, then they are useful.
They could be used for preventing ground-loops in something like an Effects Send. However, we would wish for somewhat different specs for a transformer at the input jacks of an amp.
You could also probably use one in a box designed to break ground loops & provide isolation in a multi-amp setup (or where multiple items in your rig have grounded power cords, and would otherwise create ground loops).
Thanks, do you have any online pointers on how do I learn more about them?
A long time ago I built an isolated AB/Y box using a schematic from BYOC which still works great with a transformer that ironically cost 3 times as much as these ($3 :-) ), so building a new version of that and comparing is interesting, thats a good idea since I do use it frequently to run tube amps in stereo, maybe I can do a 1->3 isolation box with these, so I can run three amps just for kicks...
Given that I only have two of these at this price and that they are absolutely prohibitedly expensive normally, I'm just looking for a project to give them some use...