Hammond Transformers

[matriachamplification]

Hello friends of GDIY!

As we are clearing out the farm the kids came across a small cache of Hammond Transformers. Being Canadian it caused me to think...

"Is there a Hammond Transformer equivelent to the Jensen JT115KEPC or the Jensen JT-11P-1HPC for our Custom Tube Console build?"

https://www.hammfg.com/electronics/transformers/audio/1140
After some research utalizing my underdeveloped skills in magnetic technology I deduced that there is no off the shelf Hammond products that match the JT115EPC. We think.
The JT-11P-1HPC may have an off the shelf product but I cannot figure out which one it woud be.

Hammond does have a custom transformer option that we may ask about.

We know Cinemag and Sowter are options as well, but it would be cool to add some Canadian timbre to this build.

Any help with selecting the right Hammond transformer is appreciated.


Wall

 

[emrr]

1140-MN-A is about the same.

850NA or 808A or 812A or 842A or 844A are the classic Hammond.

 

[matriachamplification]

1140-MN-A is about the same.

850NA or 808A or 812A or 842A or 844A are the classic Hammond.

Before we celebrate with some Strongbow.

When we say "about the same". What do we mean?

Should I order a couple to test out?

... or are there modifications outside of my skills to take on.


Wall

 

[emrr]

This is ear/opinion territory. No one can tell you what you will like. There are some gain differences as well.

 

[matriachamplification]

This is ear/opinion territory. No one can tell you what you will like. There are some gain differences as well.

Understood. Thanks so much!

 

[Murdock]

I don't know if it is of any help, but I have two old Hammond 812 transformers (150:48k) and they measure really good in terms of frequency response. Better than a few other high quality transformers I have. But I didn't listen to them yet.

 

[matriachamplification]

I don't know if it is of any help, but I have two old Hammond 812 transformers (150:48k) and they measure really good in terms of frequency response.

Old 812 Hammond Transformers sound very intriguing. Interest peaked.

Before I get ahead of myself... I am green'ish to transformers.

The Hammond 812 is Signal Level Transformer.

Is there another term used for a Signal Level Transformer?

Where in regards to a Twin Line Amp card would one use this?

I have been trying to find a connection but am coming up blank.

Any help is appreciated.

Wall

 

[abbey road d enfer]

The Hammond 812 is Signal Level Transformer.

Is there another term used for a Signal Level Transformer?

My understanding is that it's a type of transformer that transforms the signal level, in other words it's either a step-up or step-down transformer. Emphasis is on level matching more than impedance matching, although one cannot happen without the other.

 

[matriachamplification]

My understanding is that it's a type of transformer that transforms the signal level, in other words it's either a step-up or step-down transformer. Emphasis is on level matching more than impedance matching, although one cannot happen without the other.

Thanks abbey! Now I have a clearer idea of whats needed.

 

[ruffrecords]

Ther EZTubeMixer design uses a 1:10 ratio mic input transformer often specified by manufacturers as 150:15K such as the Jensen JT115KEPC. The Hammond 1140-MN-A is similarly specified so it is definitely worth a try. The only thing you need to think about is how to mount it.

At the output, the EZTubeMixer uses a 2:1 ratio transformer often specified as 2400:600. The standard type I use is the Carnhill VTB2291. Hammond do have a 2:1 output transformer the 1140-LU-F but it is specified as 600:150 so it is not really suitable. It also has an 80% Nickel core and recommends that it is driven by a low source impedance which the EZTubeMixer does not provide.

Cheers

Ian

 

[abbey road d enfer]

Hammond do have a 2:1 output transformer the 1140-LU-F but it is specified as 600:150 so it is not really suitable. It also has an 80% Nickel core and recommends that it is driven by a low source impedance which the EZTubeMixer does not provide.

I haven't found this caveat on their website. I would think it's because of the low nominal impedance, since Ni cores usually behave better than iron in presence of high-Z sources.

 

[matriachamplification]

Ther EZTubeMixer design uses a 1:10 ratio mic input transformer often specified by manufacturers as 150:15K such as the Jensen JT115KEPC. The Hammond 1140-MN-A is similarly specified so it is definitely worth a try. The only thing you need to think about is how to mount it.

This site has deeper look at the 1140-MN-A which reveals an 1140-MN-B that may be an option.

https://www.tubesandmore.com/products/transformer-hammond-microphone-input-transformers