Unbalanced Thermionic Culture Vulture....

[bradholland]

Good afternoon peeps!

So, we bought one of these but its i/o is unbalanced.

Are there any DIY plans around or something that we can knock something up to give us nice balanced I/O ?

We have a load of NEVE carnhill torodial transformers, could we utilise these somehow???

cheers
Brad

 

[pucho812]

have you asked thermionic culture?

 

[mjrippe]

They are pretty friendly folk.

 

[Dreams]

You probably don't need to worry about balancing unless you need a few hundred feet of cable between the unit and the patch point.

These things will OBLITERATE any improvement you might get by going balanced. The noise floor alone...

When we first got ours, I had the same thoughts about switching from unbalanced. After using it once or twice, I forgot about making the change.

What are you hoping to improve by balancing the I/O?

 

[bradholland]

Well we are going to be using it for applying subtle tube warmth (with as little noise as possible) on tracks rather than a full on distortion box.  The main difference between the CV and the CV mastering edition is the balanced ins and outs and the stepped pots, which commands an extra $1k.  I figured we could basically convert this into the mastering edition (without stepped pots) by transformer balancing the IO, as we have these very nice Carnhill TFs out of a Neve console.  There has to be some benefit of the balancing or Thermionic would not have bothered making 2 versions, thats my POV anyway....

 

[Dreams]

I think we'll just have to agree to disagree on this one. 

IIRC, there is plenty of room toward the back of the unit to install some iron. Probably use 1:1 or maybe even a step down xfmr, depending on what you need. These can get pretty loud...

While you're in there, take some measurements of the regulated filament circuit. The one on ours blew up some time ago, and I still don't know why. Internet searches reveal that it's a problem these units have. The internet also says that Thermionic Culture recommends up-rating the bridge rectifier to fix the problem, but the part that comes stock has more than enough current capability to handle the heaters, so I don't know. Something to look out for.

Should it come up, the exact replacements are:
Taiwan Semiconductor - TS7806
Rectron - BR32  <--though it should probably be up-rated

Good luck with this balancing job. Pop in and show your work?