EZ Tube Mixer

[anjing]

Hi Ian!
  I just wanted to tell you that i have two cinemag CMLI-15B in the mail for the EZMixerTwinLineChannel. I Know you have quiet a few projects going on at the same time so your plate is probably full! When the time comes if i can help either by having a pcb done or sending you the transformers for testing just let me know!
 
  Regards from Montréal,

Pierre

 

[wave]

Pierre,
Are you using those for the output of your mixer? I was talking to Dave at Cinemag the other night and I believe that model was talked about.

This project is super cool. I'm actually soldering up my first prototype channel right now!

Dave

 

[anjing]

Hi Dave,
    i'm using some carnhill VTB2281 for the output. The cinemag CMLI-15B are for a twin line input card that Ian has in store for us. I plan to use it to add line inputs in the 2x 14hp empty space i have....
    Keep us informed about your progress!

Pierre

 

[ruffrecords]

Hi Ian!
  I just wanted to tell you that i have two cinemag CMLI-15B in the mail for the EZMixerTwinLineChannel. I Know you have quiet a few projects going on at the same time so your plate is probably full! When the time comes if i can help either by having a pcb done or sending you the transformers for testing just let me know!
 
  Regards from Montréal,

Pierre

It's interesting you should mention the twin line channel board. I was on the phone last night with a guy from Iceland talking about  10 channel line mixer with EQ - but he wants 10 stereo channels for which the twin line card would be ideal. This also means I need to look at stereo versions of the Helios and Pultec EQs.

Cheers

Ian

 

[anjing]

Hi Ian!
  I just wanted to tell you that i have two cinemag CMLI-15B in the mail for the EZMixerTwinLineChannel. I Know you have quiet a few projects going on at the same time so your plate is probably full! When the time comes if i can help either by having a pcb done or sending you the transformers for testing just let me know!
 
  Regards from Montréal,

Pierre

It's interesting you should mention the twin line channel board. I was on the phone last night with a guy from Iceland talking about  10 channel line mixer with EQ - but he wants 10 stereo channels for which the twin line card would be ideal. This also means I need to look at stereo versions of the Helios and Pultec EQs.

Cheers

Ian

Hi Ian,
  10 channels  would probably fit in the 84hp, 5 stereo modules and 1 master channel...Isn't the universal eq stereo ready with the switches off board? A grayhill board for 2 deck, 2 pole/deck switches would be all you need.

Cheers,

Pierre

 

[ruffrecords]

Hi Ian!
  I just wanted to tell you that i have two cinemag CMLI-15B in the mail for the EZMixerTwinLineChannel. I Know you have quiet a few projects going on at the same time so your plate is probably full! When the time comes if i can help either by having a pcb done or sending you the transformers for testing just let me know!
 
  Regards from Montréal,

Pierre

It's interesting you should mention the twin line channel board. I was on the phone last night with a guy from Iceland talking about  10 channel line mixer with EQ - but he wants 10 stereo channels for which the twin line card would be ideal. This also means I need to look at stereo versions of the Helios and Pultec EQs.

Cheers

Ian

Hi Ian,
  10 channels  would probably fit in the 84hp, 5 stereo modules and 1 master channel...Isn't the universal eq stereo ready with the switches off board? A grayhill board for 2 deck, 2 pole/deck switches would be all you need.

Cheers,

Pierre

He wants 10 stereo channels - equivalent to 20 mono channels! This would need 10 twin line input cards. He also wants slider faders and possibly a meter bridge.

Cheers

Ian

 

[zayance]

You guys make me want to build one, nice project Ian.

 

[ruffrecords]

I have just about finished the PCB layout for the twin line amp. This has space for two line input transformers and contains the usual pair of amplifiers as on the mic pre except both have just a preset pot for setting gain. The amp inputs and the transformer secondaries are brought out to pads so you can insert passive EQ if required.

I mentioned some time ago that by changing a couple of component values you could make a decent all tube stereo headphones amplifier from the Eurochannel board. Basically, all you do is change the 6922 cathode resistor values and use a different output transformer. This will drive most headphones to uncomfortable levels but if you do need a greater drive capability then you need to change the 6922s to ECC99s. Unfortunately, the ECC99 has a different heater arrangement to the 6922 so I have modified the PCB layout to include some extra links so you can fit a pair of either type of tube by making and breaking the appropriate links.

I am going to do a few more checks and then have a batch made to offer on my white market page at the same price as the Eurochannel V3 PCB- unless there is a sudden demand that makes a group buy worthwhile in which case you can get them at cost.

Cheers

Ian

 

[Holger]

Very nice Ian, I'll take two.

 

[braeden]

H69 Faceplate Alternative, I was bored  :-\

If there is any interest I could convert it for use with FrontDesign (HPGL).
This design may even be cheaper than Ian's, but don't take my word for it... I'll have to actually try it out and see.

All the best,
Braeden

 

[ruffrecords]

@Braden

That is a gorgeous looking front panel. Really nice font, very clean and perfectly legible. The graphics for the EQ are excellent too. It would be great if you could do it in front panel designer format. Next time you are feeling bored could you do the pultec channel?

Cheers

Ian

 

[braeden]

@Braden

That is a gorgeous looking front panel. Really nice font, very clean and perfectly legible. The graphics for the EQ are excellent too. It would be great if you could do it in front panel designer format. Next time you are feeling bored could you do the pultec channel?

Cheers

Ian

Sure, not a problem, I could draw up a whole set. It will be up to the person using these front panels to ensure that the measurements/drill holes are correct however and that the dials/knobs you choose ideally do not obstruct the view of the text on the front panel. I believe I have left enough space for a suitable knob diameter (10-12mm) but I don't know how much leeway there is to move drill holes around (e.g. components may be PCB mounted, tight fit etc.)

Ian, Is the gain pot in that specific position (far left) because the tube doesn't have a whole lot of clearance in the chassis (and as a result the PCB is pushed slightly further left)? It's not a big deal, I just usually prefer to have everything aligned perfectly center on the front panel if it's possible. You can just notice that most of the graphics are positioned slightly more left than directly center with a slither of white space on the right.

I hope to finally get enough money to put an 8-channel together at some point (didn't realise how much 2 MK47's would cost me) :-X

I'll see how I go with the Front Panels, feedback is welcome.

Thanks,
Braeden

 

[ruffrecords]

The gain pot is actually a Grayhill switch soldered direct to the PCB. The PCB is attached to the front panel using a standard bracket which is bolted to the front panel using standard holes in standard positions. This ensures the panels fit correctly into the sub-rack and the PCB connector mates properly with the backplane PCB. The position of the switch is therefore pre-determined and as you rightly point out a little too far to the left. The EQ is mounted on a separate PCB that is held to the front panel by the three switches. As this PCB has no rear connector we can place it more or less where we like so I moved it to the right so the switches are easier to label.

Bottom line is there is not much we can do about the gain switch position other than use one mounted off the PCB and hand wire it to the PCB which is a PITA. At present my best solution is to use a Grayhill switch version with a one eighth inch shaft and a 12mm diameter knob.

Cheers

Ian

 

[anjing]

I'll take 4 of the twin line amp Ian.


Pierre

 

[ruffrecords]

I'll take 4 of the twin line amp Ian.


Pierre

Thanks Pierre. Looks like there will be enough interest so I'll start a group buy thread in the black market.

Cheers

Ian

 

[wave]

H69 Faceplate Alternative, I was bored  :-\

If there is any interest I could convert it for use with FrontDesign (HPGL).
This design may even be cheaper than Ian's, but don't take my word for it... I'll have to actually try it out and see.

All the best,
Braeden

Braeden,
Your panel is very cool. What do you use to draw? Also, how do you go about converting to HPGL or do you just do everything in Corel?

Thanks,
Dave

 

[braeden]

Thanks wave.

I typically design my drill layout in FrontDesign, I then export the file from FrontDesign to an .SVG format. Illustrator is capable of handling this file format so it's great for adding in all the text that you want to be displayed on the front panel. I have to zoom into 150% to view the file in it's proper dimensions. I then save it as a separate .AI file, remove all the drill hole circles, reference 'crosses' and import the .ai file into Corel Draw (I have to run this through Parallels Desktop because I'm on Mac which makes the process slightly annoying). I then follow the HPGL conversion procedure as per the Instruction Guide from Front Panel Express.

Also, Ian, as requested, here is a 'rough copy' of the Pultec. I would say most/all of the drill holes and switches have been moved slightly to accommodate the new layout. I don't believe this is a problem as I am sure that all those pots/toggles are mounted off PCB and wired directly? Anyhow, no big thing to revert it to the original layout, this one was a little harder to design than the Helios in that - there is slightly more text and it's a bit harder to keep things legible but 'elegantly symmetrical'.

The knobs/dials used are 12mm, 18mm. I wouldn't recommend going over 14mm for the boost/cut sections as you risk obscuring parts of the panel. If you have the right money I think these could be nice (silver/black).
When I was designing the panel I kinda imagined it to come out with a Neve bluish/red theme, but we all know those knobs cost an absolute fortune and I don't think they come in smaller sizes.

• http://www.banzaimusic.com/Harmony-Knob-Black.html
• http://www.banzaimusic.com/Mini-Fluted-ABS-knob-black.html
• http://www.banzaimusic.com/Aluminum-knob-black-notched-tip-19mm.html

Don't mind me just taking up all the space in the thread :-X

Without knobs/dials so you can see if everything fits.

I may start drawing up the HPGL files soon when I get the time, my mic bodies just arrived ;-)

Take care,
Braeden

Edit: My dividers got messed up for some reason, they should be centred and not biased in length to the right.

 

[ruffrecords]

On the Pultec I am not sure about the AUX2 pot and those vertically in line with it. The pots I use are 17 mm in diameter so the centre of its mounting hole needs to be at least 9mm from the right hand edge and preferably 10mm.

Cheers

Ian

 

[braeden]

On the Pultec I am not sure about the AUX2 pot and those vertically in line with it. The pots I use are 17 mm in diameter so the centre of its mounting hole needs to be at least 9mm from the right hand edge and preferably 10mm.

Cheers

Ian

Thanks for bringing that to my attention. I now understand why my graphic looks strange, Illustrator didn't export the graphic properly. As a result, it has cut off a few mil from the right side of the graphic. The horizontal orientation of the pot drill holes hasn't changed from the original, just where it sits vertically. There is a radius of 10.425mm from the dead centre of the drill hole.

Sorry for the confusion
Braeden

 

[wave]

Braeden,
Thanks for the explanation. I too use Mac so I was asking your method as I was wanting to find out if there was a way to do the drawing without having to do the Paralles/Corel transfer. Alas, we are in the same boat.

Your panel look great tho! BTW, what version of Corel are you running?

Also, Ian do you have a logo?

Dave