All Tube 6 into 2 mixer finished!

[ruffrecords]

I just finished my first all tube mixer. 6 channels,  with phantom power, phase, pads and HPF plus genuine RCA knobs. Left and right outputs, twin VUs  plus integrated stereo all tube headphone amplifiers. Up to 80dB gain, separate PSU. Attached is a rather grainy pic of the front. Still need to spray paint the sub-rack ears and do a few final tests but otherwise it is done.

Cheers

Ian

 

[pucho812]

nice very nice. looks sexy. does it have direct out as well?

 

[ruffrecords]

nice very nice. looks sexy. does it have direct out as well?

No direct outs but they would be possible with little modification. It is designed for a guy in the USA who wants it for recording classical music straight to stereo. There are no pan pots; just two routing switches labelled left and right. Select one on its own and the input is panned hard that way; select both and it is panned centre.

Cheers

Ian

 

[tmuikku]

Hey! That's cool alright!

 

[pucho812]

can we have a look under her knickers?

 

[gemini86]

Wow! Looks great! I love the old telecom look. The pan assignment is a neat way of doing it. Just took care of pan and mute with just two toggles.

 

[Joechris]

Thats just great! Big inspiration for my poor man 8 channel line mixer . Would love to see your summing/make up amp arrangement. Do you use the same mu amp as in the eq?

 

[ruffrecords]

As requested a few pics of the innards:

First the four PCBS. Each hold two channels and the fourth acts as the mix amp and and VU drivers:

PCB with the front panel attached:

Channel and master modules nearing completion:

The separate power supply:

And finally, the rear of the sub rack showing the power and signal buses and the headphones amp on the left:

Cheers

Ian

 

[zayance]

Very Nice Monsieur...

 

[ruffrecords]

Thats just great! Big inspiration for my poor man 8 channel line mixer . Would love to see your summing/make up amp arrangement. Do you use the same mu amp as in the eq?

Yes, it is exactly the same mu follower as in the poor man's tube gain make up. If you look at the last picture of the rear of the rack you will see two of those PCBs modified to SRPPs and fitted with ECC99s to make the headphones amp. The transformers above of the big expensive Sowter headphones ones.

The summing is straightforward passive unbalanced. The Left and Right switches ground the summing resistors in the deselected position and connect them to the mu output when selected (mu follower output R is about 800 ohms). I used 47K bus resistors and the bus is loaded by the 100K log master pot which gives a bus loss with 6 channels of close to 16dB. With 26dB in the mu follower gain make up that leaves 10dB in hand on the master fader.

Cheers

Ian

 

[pucho812]

gotta quote darth vader on this one


Impressive most impressive. keep up the great work.

 

[helterbelter]

Nice. And certainly impressive.

 

[zayance]

Hello Ian,

Where do you get those plastic stands for the standing resistors?

 

[ruffrecords]

Hello Ian,

Where do you get those plastic stands for the standing resistors?

I get them here:

http://www.rapidonline.com/Electronic-Components/Semiconductor-Hardware/LED-And-Crystal-Mounts/Diode-mounts/29793/kw/diode

Cheer4s

Ian

 

[Ptownkid]

Very impressive...nice work Ian!

 

[radiance]

Very, very nice!