For Sale Audio Transformers

[Potato Cakes]

They are tippically 500-600, but I made 3 versions, 600-600 and 215 -600 , same is Lo1166. I did that because I replace my lo1166 in 1073 with 215-600 1802. Crazy big sounding. Absolutely love that sound! Not perfectly liner, but Hudge.

Since you are using these in your 1073s, I take it the 1802s are gapped or are you routing VDC to your output transistor via a dropping resistor and then using a blocking cap before this transformer?

Thanks!

Paul

 

[KraftWerk]

215-600 version is gapped. But interesting, ungapped works too.I tried booth.

 

[Potato Cakes]

I recently found out that a pair of 1166 style transformers I had been using in a prototype were not gapped and I may have damaged them as they were wired as you should for a gapped version. I had been fighting noise issues in this unit for about a year with this particular build and once I found out that they were ungapped, I rebuilt the unit with gapped 1166 style transformers and now there is no noise. My circuit worked but I kept chasing other possibiltles as the source of the noise and ruined a number of components in the process.

If using a non-gapped transformer for traditional BA283 style wiring, I recommend using a small dropping resistor (approximately 12 ohms 2W+) to get VDC to the output transistor and then using a large coupling capacitor to go from the transistor to the output transformer as is done with 2520 style op amps.

Thanks!

Paul

 

[KraftWerk]

At the moment, we are building a transformer-based ColorBox, also incorporating the BAE 283, where we will have four pairs of interchangeable output transformers (copies of LO1173, LO1166, LO1366, and T1802, all Marinair) and three pairs of interchangeable input audio transformers, allowing for all possible combinations.

In my experiments, I used an AML EZ73, into which I installed an insert point for output audio transformers and tested them in real-world conditions. I have never noticed even the slightest noise issue when swapping these transformers on the fly, even after testing hundreds of prototypes. I don’t even turn off the device—I swap them instantly.

This allows me to easily measure how these transformers perform in a real NEVE clone environment. In such a setup, with DC voltage on the primary, the T1802 produces a massive sound with a +1 dB bump at 20 Hz while extending all the way to 70 kHz (±3 dB). The sound is unique.

I design my transformers by listening first, and only then do I measure their characteristics. I don’t think of them as just balancing components, but rather as sources of sonic coloration.

 

[KraftWerk]

 

[KraftWerk]

Aml ez 73

 

[KraftWerk]

The 1802 photos look like a much bigger transformer (at least thicker) than the others, but on the dimension drawings they are all the same. Is this an optical illusion regarding the photos or is there an error on the datasheet for the 1802?

Thanks!

Paul

Here you can see visual difference between full size LO1166 ( NOT 500 series size which is narrower) and 1802.

 

[Potato Cakes]

What is the actual width of the winding of the 1802. That appears to be wider than the 42.42mm that is shown on the drawing which is the same as the 1166. I am trying to determine how many channels I can fit in a rack enclosure.

Thanks!

Paul

 

[KraftWerk]

What is the actual width of the winding of the 1802. That appears to be wider than the 42.42mm that is shown on the drawing which is the same as the 1166. I am trying to determine how many channels I can fit in a rack enclosure.

Thanks!

Paul

60 mm

 

[Potato Cakes]

Well, looks like I won't be fitting 8 of those in the same box!

 

[KraftWerk]

I told you they are big and bad

 

[KrIVIUM2323]

And now i want some...grrr!

 

[KraftWerk]

And now i want some...grrr!

You can always make case bigger

 

[KrIVIUM2323]

I won't need 8 of them, it should do. But i see you had a good solution anyway.

You drive them with 283AM that's it?

 

[KraftWerk]

In this moment I drive them with 1073, BAE283 ( BASICALLY third stage 1073) will be Finnish in few days...I will make you some comparison maybe tomorrow,samples,with all transformers

 

[SubSpec]

To report back, installed the 1166VT in my Heritage TT-73 with stellar results (replacing a VTB1148). No objective measurements or anything to offer, simply my objective impression that it sounds awesome, specifically more awesome than it did before. I don't love to detail the why since it is just subjective impressions, but I'll share anyway, take it for what it's worth.

When I first powered on and plugged in a mic, United Twin87 to be exact, the mic sounded "bigger" than it ever has on any of my preamps, including the TT-73 before the swap. Sonically related but somewhat distinct, it felt "stronger" throughout, carried by more solid feeling lows.

This next one I assume is simply me imagining things, as given the similarity in specs I don't think there is any technical reason that would be. All the same I feel like it doesn't break up at the same point it did before (i.e. more headroom) when being driven. When it does I also don't feel like the bottom drops out as drastically as it did before, leaving the euphonic distortion without totally sucking out the low end response.

One specific for the TT-73 I'll mention in case it might suggest slotted mounts as the VTB1148, the mount points in the TT-73 are around 73mm apart so it wouldn't mount in the original spot (without modification). In the end I think it is better positioned where I ended up placing it anyway, but slotting (as the Carnhill) might be an option to allow for more flexible mount options.

 

[KraftWerk]

To report back, installed the 1166VT in my Heritage TT-73 with stellar results (replacing a VTB1148). No objective measurements or anything to offer, simply my objective impression that it sounds awesome, specifically more awesome than it did before. I don't love to detail the why since it is just subjective impressions, but I'll share anyway, take it for what it's worth.

When I first powered on and plugged in a mic, United Twin87 to be exact, the mic sounded "bigger" than it ever has on any of my preamps, including the TT-73 before the swap. Sonically related but somewhat distinct, it felt "stronger" throughout, carried by more solid feeling lows.

This next one I assume is simply me imagining things, as given the similarity in specs I don't think there is any technical reason that would be. All the same I feel like it doesn't break up at the same point it did before (i.e. more headroom) when being driven. When it does I also don't feel like the bottom drops out as drastically as it did before, leaving the euphonic distortion without totally sucking out the low end response.

One specific for the TT-73 I'll mention in case it might suggest slotted mounts as the VTB1148, the mount points in the TT-73 are around 73mm apart so it wouldn't mount in the original spot (without modification). In the end I think it is better positioned where I ended up placing it anyway, but slotting (as the Carnhill) might be an option to allow for more flexible mount options.

View attachment 145917

You're talking about exactly what I heard when I replaced the original transformer in the AML EZ1073 with a vintage Marinair LO1166... Thanks for the detailed report.

 

[paulcheeba]

They look Amazing! great work. Can you do Tube Telefunken era? V41, V72, V76 etc.

 

[KraftWerk]

I'm doing now inputs and would like to do som microphone transformers, but if I collect enough info about telefunkens, that will be amazing to do...