[g0ldl10n]

Shout out to @triod750 for pointing out a seller that had some beautiful NOS Fivre 6AX5GT tubes for a great price with the lovely tax stamps (I think) and all. Working just beautifully in the Mini right now.

The seller also had a NOS TFK EZ12 rectifier for a great price - picked that up as well - I am sure that could look and perform even better. Time will tell.

In regards to the variable heater mod, the testing is basically complete with a resounding success. Now, all that is left is placing it all inside the chassis with the converter mounted to the side and as flush as possible. Also, on a side note, my Mini has never been quieter with the input heater now running off of DC rather than AC.

 

[albertmuc]

A unique selling point of the UltimatE is its adaptability to the respective headphones.
More bass for the HD800s: EL39. Reduce the treble of the HEKSE: 6BW7, it's that simple

 

[Nick Ryan]

Yep we all agree on that matey.

 

[triod750]

But you can also combine tubes in a way that lets you enjoy just one pair of headphones and take it in good but different directions. Isn't that even more impressive?

 

[jonathan c]

But you can also combine tubes in a way that lets you enjoy just one pair of headphones and take it in good but different directions. Isn't that even more impressive?

... but Captain & Tennille will still ...

 

[g0ldl10n]

Extremely gorgeous trio in the back of the Mini.. the slotted plates on the power tubes, and that rectifier look stunning - thought id share with the rest of my fellow addicts

 

[David A Silva]

Extremely gorgeous trio in the back of the Mini.. the slotted plates on the power tubes, and that rectifier look stunning - thought id share with the rest of my fellow addicts

Gorgeous indeed!

 

[g0ldl10n]

Gorgeous indeed!

Oh, and it doesn't hurt the 6CK4 is quite an amazing sounding tube - a well known builder who sadly is not with us anymore called the 6CK4 half of a 6AS7, but better sounding. Now, it's not exactly the equivalent to 1/2 of a 6AS7, its close, but the "better sounding" part is very true.

Tbh, the 6CK4 has cured my curiosity at exploring any other output in the Mini, period.

 

[OctavianH]

Extremely gorgeous trio in the back of the Mini.. the slotted plates on the power tubes, and that rectifier look stunning - thought id share with the rest of my fellow addicts

As far as I see, size matters also in the Mini.

 

[g0ldl10n]

And as promised the completed input variable heater modification fully internal - very tight squeeze getting that converter flush and mounted securely - I am sure, the 'Super' Ultimate with the larger chassis, this would haven't been much of an issue - a couple pictures of how the step up/down converter is mounted to the amp - can go from 1.5V - 36V for the input only.

Internally, there is a small rectifier responsible for rectifying the 6.3VAC to DC, which connects to the input of the converter, and its outputs are routed to the heater wires of the input tube. Simple really - the hardest part by far was getting the hole cut out in the metal chassis with only a hand drill and a dremel

 

[LoryWiv]

And as promised the completed input variable heater modification fully internal - very tight squeeze getting that converter flush and mounted securely - I am sure, the 'Super' Ultimate with the larger chassis, this would haven't been much of an issue - a couple pictures of how the step up/down converter is mounted to the amp - can go from 1.5V - 36V for the input only.

Internally, there is a small rectifier responsible for rectifying the 6.3VAC to DC, which connects to the input of the converter, and its outputs are routed to the heater wires of the input tube. Simple really - the hardest part by far was getting the hole cut out in the metal chassis with only a hand drill and a dremel

Impressive work, clearly not for the faint of heart like myself when it comes to DIY.

 

[David A Silva]

And as promised the completed input variable heater modification fully internal - very tight squeeze getting that converter flush and mounted securely - I am sure, the 'Super' Ultimate with the larger chassis, this would haven't been much of an issue - a couple pictures of how the step up/down converter is mounted to the amp - can go from 1.5V - 36V for the input only.

Internally, there is a small rectifier responsible for rectifying the 6.3VAC to DC, which connects to the input of the converter, and its outputs are routed to the heater wires of the input tube. Simple really - the hardest part by far was getting the hole cut out in the metal chassis with only a hand drill and a dremel

Really Slick job!!! Like fitting a V6 to a VW Bug!

 

[g0ldl10n]

Impressive work, clearly not for the faint of heart like myself when it comes to DIY.

Well, if someone has adequate tools to cut that rectangle slot for the converter, isn't too bad - another option would be to use a different style converter, which wouldn't require the large slot cutout - and another option would be to use a different style converter which is housed within the chassis as well, then remove the manual pot and replace it with a pot (like a volume knob) and mount it to the outside, while also connecting a voltage meter mounting that near the voltage pot.

The 2nd option there is the easiest, but not as user friendly when adjusting voltages, and also wouldn't be as aesthetically pleasing imo.

 

[mordy]

And as promised the completed input variable heater modification fully internal - very tight squeeze getting that converter flush and mounted securely - I am sure, the 'Super' Ultimate with the larger chassis, this would haven't been much of an issue - a couple pictures of how the step up/down converter is mounted to the amp - can go from 1.5V - 36V for the input only.

Internally, there is a small rectifier responsible for rectifying the 6.3VAC to DC, which connects to the input of the converter, and its outputs are routed to the heater wires of the input tube. Simple really - the hardest part by far was getting the hole cut out in the metal chassis with only a hand drill and a dremel

And as promised the completed input variable heater modification fully internal - very tight squeeze getting that converter flush and mounted securely - I am sure, the 'Super' Ultimate with the larger chassis, this would haven't been much of an issue - a couple pictures of how the step up/down converter is mounted to the amp - can go from 1.5V - 36V for the input only.

Internally, there is a small rectifier responsible for rectifying the 6.3VAC to DC, which connects to the input of the converter, and its outputs are routed to the heater wires of the input tube. Simple really - the hardest part by far was getting the hole cut out in the metal chassis with only a hand drill and a dremel

Beautiful work!

 

[g0ldl10n]

Beautiful work!

Thanks man - glad I was able to make it work so well without messing anything up.

There was a slight scare after my first round of testing after I got the hole cut, converter mounted and seemingly all completed - no sound from the left channel, and only buzzing noise when the RCA cable was connected to the inputs!!

I found that somehow, probably thru my own fault when soldering up the new coupling caps a few weeks ago, the soldering joint connecting the lead to the output tube failed - resoldered that and mini disaster averted