10:2 Line Level Tube Mixer

[Holger]

[font=arial, sans-serif]Here is my latest build, a 10:2 line level tube mixer in a 2 HU case.[/font]

[font=arial, sans-serif]Each channel has a 10k:10k shielded input transformer. The debalanced signal goes to a channel PCB which has a volume pot, a mute switch and a pan pot. The stereo bus is done with a ribbon wire attached to all the channel PCBs.[/font]
[font=arial, sans-serif]The stereo signal passes a virtual earth amplifier, followed by a fader and a final voltage amplifier stage. The tube stages base on the design by Ian Tompson-Bell.[/font]
[font=arial, sans-serif]The nice little Simpson meters were buffered by Joe Malones VU meter buffer which I recommend again here.[/font]
[font=arial, sans-serif]The mixer has an external PSU.[/font]
[font=arial, sans-serif]And yes, the master knob is not final.[/font]

 

[emrr]

Looks great

 

[ruffrecords]

And we should give due credit to CJ for designing the output transformers.

Cheers

Ian

 

[Holger]

I wasn't aware of that. Thanks CJ
The mixer works very good. I will do some measuremnts once it is finished.

 

[[silent:arts]]

Nice Krässemaschinenbaby  8)

 

[Rocinante]

As always your work is impeccable and lovely looking.

 

[mjrippe]

Beautiful work.  I have seen commercial pieces that look much worse!

 

[Gold]

Looks beautiful.  Did The project use Ian’s designs and PCB’s or did you lay out the PCB’s yourself?

 

[Holger]

Thanks for liking, gentlemen
Paul, it's my PCB layout of Ian's TLA. I've used the same PCB for my modular tube pre amp. It's an 180mm euro card that can be used in multiple ways. Just add a mic front end and it's a mic preamp. 

 

[Gold]

Paul, it's my PCB layout of Ian's TLA. I've used the same PCB for my modular tube pre amp. It's an 180mm euro card that can be used in multiple ways. Just add a mic front end and it's a mic preamp. 

Ian's designs look so attractive. I'm not a tube guy but it looks like it sounds great. I never under estimate that. I'd love to build a line amp one day to check out.

 

[ruffrecords]

I wasn't aware of that. Thanks CJ
The mixer works very good. I will do some measuremnts once it is finished.

Yes, I had a thread here about designing a low profile output transformer. CJ came up with a design, knocked one up and tested it. He posted the design details and I got Electro Mag here in the UK to make some. The rest you already know.

I will be interested to hear about your test results. I notice in the picture of a module you posted that you are using an OEP 187A15C mic input transformer. I am using one in the current Mark III design but recent tests have show it has poor  HF response when used with a 150 ohm source.

Cheers

Ian

 

[Holger]

Ian, I never had the time to test the OEP stuffed modules as mic preamps, I just did functional test with line level signals. I will look at the issue once I'll have some time.

 

[ruffrecords]

Ian, I never had the time to test the OEP stuffed modules as mic preamps, I just did functional test with line level signals. I will look at the issue once I'll have some time.

Thanks Holger. No rush.

Hope you and your family are OK.

Cheers

Ian

 

[Sorr]

Yes, I had a thread here about designing a low profile output transformer. CJ came up with a design, knocked one up and tested it. He posted the design details and I got Electro Mag here in the UK to make some. The rest you already know.

I will be interested to hear about your test results. I notice in the picture of a module you posted that you are using an OEP 187A15C mic input transformer. I am using one in the current Mark III design but recent tests have show it has poor  HF response when used with a 150 ohm source.

Cheers

Ian

Sorry Ian, I don't know the story. Could you let me know? Thanks

 

[ruffrecords]

Sorry Ian, I don't know the story. Could you let me know? Thanks

Here is a link to the original thread thagt lead to this transformer design. It is a long thread but full of good stuff:

https://groupdiy.com/index.php?topic=70199.msg895583#msg895583

Cheers

Ian

 

[boji]

Great stuff.  Thanks again Ian for all your design sharing and Holger, your rack mixer is Soooooo clean!  Really nice job. Thanks for sharing picts.

 

[Rocinante]

Holger or Ian, I love the design of the vertical tube pcb's! Is that part of the Ian tube preamp?

 

[ruffrecords]

Holger or Ian, I love the design of the vertical tube pcb's! Is that part of the Ian tube preamp?

Yes and no.

The original EZTubeMixer version of this design had the tubes mounted directly at right angles to the PCB. That is why the modules had to be 2.8 inches wide.

Later, both Holger and I independently developed vertical tube PCBs so we could make narrower modules. Holger has extended the depth of his modules as well so as to be able to accommodate output transformers in a 3U module.

Cheers

Ian

 

[Kid Squid]

Great work Chaps 

 

[echoplex]

Wow Holger and Ian.. I'm truly impressed. Amazing work and craftmanship.
This mixer looks like color for days