REDDI DI

[CJ]

Yes,

 

[jdasbeck]

Hello,
I am new here in the forum and find the topic super exciting!
For newbies it is difficult to find the final status now that the project is finished (due to some changes.).
Is someone too kind and post again all the needed documents (schematics etc.) to build the device?
Preferably the original version without the output control (if there was one - unfortunately I can't find it).

And one more question... is there an alternative to the Carnhill VTB 2290? It is not easy to get in Germany at the moment. I don't have the confidence to make it myself at the moment.

Kind regards!

 

[MicDaddy]

Hello,
I am new here in the forum and find the topic super exciting!
For newbies it is difficult to find the final status now that the project is finished (due to some changes.).
Is someone too kind and post again all the needed documents (schematics etc.) to build the device?
Preferably the original version without the output control (if there was one - unfortunately I can't find it).

And one more question... is there an alternative to the Carnhill VTB 2290? It is not easy to get in Germany at the moment. I don't have the confidence to make it myself at the moment.

Kind regards!

wouldn't that be nice
"welcome to the party, pal" -groupdiy'ers scrambling across pages and threads and notes hoping someone already has a BOM put together that has no parts shortages.
I hope someone does but you might get there faster putting it together yourself.

 

[din_mentor]

Hello,
I am new here in the forum and find the topic super exciting!
For newbies it is difficult to find the final status now that the project is finished (due to some changes.).
Is someone too kind and post again all the needed documents (schematics etc.) to build the device?
Preferably the original version without the output control (if there was one - unfortunately I can't find it).

And one more question... is there an alternative to the Carnhill VTB 2290? It is not easy to get in Germany at the moment. I don't have the confidence to make it myself at the moment.

Kind regards!

Isnt excactly that on the previous page?

 

[buchholzstudio]

Hello!
I would also like to build the Tube DI Box. Unfortunately, I'm already having problems sourcing the parts. Since Brexit it seems to be difficult to get the Carnhill Transformer. The VTB2290 seems to be sold exclusively at AML. Are there any alternatives?
I‘m from Germany
Best regards

 

[Jim50hertz]

If CJ is still rolling transformer that's what I have in mine. Sound great to me.

 

[buchholzstudio]

@CJ Would you also ship a Transformer to Germany?

 

[buchholzstudio]

I now have almost all the components together to start my project. I'm trying to realise everything according to CJ's scheme. I still have two small questions:
Which toroidal transformer are you using? I can't find anything about it. And I haven't found any wattage data for some of the resistors. Can anyone give me a tip?
Best regards

 

[CJ]

I will get you a part number for the pwr xfmr but you might find something closer to you for cheaper.

Not many resistors, 1 watt should cover everything ,

 

[buchholzstudio]

Okay thanks for the info! I've actually found a way to import a Carnhill VTB2290 from the UK. All I need now is a toroidal power transformer

And if I understood your answer correctly, I'll get all the resistors on your schematic with 1W (except for the ones specified with 3W)

 

[CJ]

2290 = low inductance

 

[CJ]

Power Transformer for bass di

https://www.antekinc.com/as-05t240-50va-240v-transformer/

 

[buchholzstudio]

2290 = low inductance

But it has been used successfully by some people here, hasn't it?

Power Transformer for bass di

Super thanks! Then I'll see if I can find something comparable

 

[beatnik]

Power transformer

https://www.tube-town.net/ttstore/en/toroidal-30va-8808.html
Output transformer

You could ask Lundahl to make you a LL1680 with more primary current than the stock 5mA

Carnhill is a small low cost transformer, of course it can be used but frequency response and distortion won't be as good.

 

[buchholzstudio]

I now have all the necessary parts at home! Do you think the power transformer is too close to the output transformer? I once read that this can lead to interference noise

 

[rock soderstrom]

I now have all the necessary parts at home! Do you think the power transformer is too close to the output transformer? I once read that this can lead to interference noise

Yes, that's pretty close and the OPT is not shielded.

You can test it and try positioning the two transformers to find the position that causes the least problems. The alignment of the two transformers to each other (and their magnetic field lines) plays an important role.

The point where the cables come out of the toroidal transformer (does it have to be that big?) is problematic, try to have it far away from the OPT as well.

Maybe a mu metal ring around the power transformer and/or an aluminium wall with mu metal foil (or similar) on both sides as shielding will help.

 

[beatnik]

The solution someone posted a while ago is worth looking into, using a simple ready made SMPS "nixie tube" type and keeping the transformer externally on a wall wart. Should reduce hum problems and also make the enclosure a lot smaller.

 

[rock soderstrom]

External power supplies are certainly the quietest. If you still want to have all in one box, the distance between the two transformers (and, as described, the orientation) is the most important thing.

Rethink your layout and maximise the distance between the two transformers. You do not need a PCB for this circuit, you can save a lot of space with P2P or turret based wiring.

 

[rock soderstrom]

or

 

[buchholzstudio]

Thanks for the good tips! I will reconsider the positioning!

lot of space with P2P or turret based wiring.

Do you have an example for me? I can't find anything on the web