mrclunk

Re: All Tube Sidecar
« Reply #20 on: January 24, 2018, 06:49:08 AM »
A stem RE:Mixer/summing box would be very cool.

Like G-sun said a couple of full channels for overdubs / vocals.
Maybe the eq's could be switched between the two full mic channels and the main LR outs for mix down?
Buffered inserts on the main LR.

For the summing part, 8 stereo channels would work, then you could do panning/solo ITB?

But on the summing channels i'd want auxiliaries for fx...
I generally re-apply verb/echo when remixing and that's normally real tapes/plates.  Mono fx sends would be ok.
Inserts switches on the summing inputs would be nice but this could be done on a patchbay.
Headphone out for the talent.
Sorry that's completely different to what you originally asked...
« Last Edit: January 24, 2018, 06:59:38 AM by mrclunk »


ruffrecords

Re: All Tube Sidecar
« Reply #21 on: January 24, 2018, 08:47:00 AM »
Sorry that's completely different to what you originally asked...

Doesn't matter, in fact it is good. I initially assumed nobody would want a small tube mixer for tracking because there was no way to include things like 8 AUXes per channel and all the other stuff you get in a mainstream mixer. So I thought the obvious application for it was as a sidecar. But is looks like there are other possible applications such a tracker/summer.

Tube summers with balanced inputs are easy to do. What is hard to do is FX sends. The 'obvious way to do them is to unbalanced each input, then its just like any line input and you can add AUX sends, pan, sole etc etc. But, in a tube mixer you need a transformer to unbalance each input so with 8 stereo stems that's 16 transformers which is potentially rather expensive. You  might be able to do one, perhaps two fully balanced AUXes without the need to unbalance the inputs but it will probably mean the DACs will need to be able to dive a load much lower than the regular 10K. I will look into it. In the past I have also looked at low cost 10K:10K line input transformers for just this sort of application so I will revisit that again as well.

Cheers

ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

mrclunk

Re: All Tube Sidecar
« Reply #22 on: January 24, 2018, 09:03:28 AM »
I apologise unreservedly but dare I say...
Aux send /returns with solid state!!
Alot of extra power and heat, with valves on auxes, for minimal sonic gain.

« Last Edit: January 24, 2018, 09:26:19 AM by mrclunk »

ruffrecords

Re: All Tube Sidecar
« Reply #23 on: January 24, 2018, 09:59:36 AM »
I apologise unreservedly but dare I say...
Aux send /returns with solid state!!
Alot of extra power and heat, with valves on auxes, for minimal sonic gain.

You may dare but you won't get it from me!!

Not really much extra heat; it is only one and a half extra tubes per AUX bus so with a couple that's three more tubes and maybe 10W of power/heat. The bigger problem is the cost/weight of all the input transformers.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: All Tube Sidecar
« Reply #24 on: January 24, 2018, 01:01:38 PM »
I think of a sidecar as being a bank of channel strips with direct outs. If it has a master section and auxes and can do monitor mixing or summing, I would call it a small console.

I would think a tube sidecar would be a more commercial idea.  There isn't a lot like that, and it provides consistency across tracks and a relatively compact rig (compared to outboard tube channels) like a console without duplicating functionality that most people in the market for it would already have in their daw.

If I were in the market I'd want a fairly simple eq, mic/line switch, input pad,  and linear output attenuator (rotary or fader)  to a direct transformer balanced out per channel, and individually switchable phantom power. Maybe a second output for each channel too.  If I was going to mix back through it - which I would only do sometimes if it was only 8 channels - I'd just send the individual outs to a separate summer.

It could have an empty 500 series slot instead of the channel EQ with an optional EQ module that could fill those slots.  That would attract some different users who could simplify transitioning to this type of gear.

bluebird

Re: All Tube Sidecar
« Reply #25 on: January 24, 2018, 04:43:34 PM »
Might be advantageous to have a separate transformerless line input stage.

ruffrecords

Re: All Tube Sidecar
« Reply #26 on: January 24, 2018, 05:19:47 PM »
Might be advantageous to have a separate transformerless line input stage.

Maybe, but for 16 inputs it needs 16 extra tubes. Not quite as expensive or as heavy as 16 transformers but another 60W of heater power required. But definitely worth considering.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

ruffrecords

Re: All Tube Sidecar
« Reply #27 on: January 25, 2018, 06:19:12 AM »
I just found a very economical line inut transformer from OEP. It is 10K:10K and is housed in a mu-metal screened  can. Max input level is +22dBu. Part number is Z21807C and it costs Just £12.50 + VAT from Canford:

http://www.oep.co.uk/page-content/datasheets/1444119292Z21807C%20issue%205.pdf

RS lists it as discontinued but Canford still have it.

Cheers

ian
« Last Edit: January 25, 2018, 12:47:01 PM by ruffrecords »
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

mrclunk

Re: All Tube Sidecar
« Reply #28 on: January 25, 2018, 06:28:05 AM »
If they're anything like the OEP A262x series they won't handle low frequency signals well at all.
There's Edcor in the US that make reasonably priced open frame 10k:10Ks?
« Last Edit: January 25, 2018, 06:39:21 AM by mrclunk »

ruffrecords

Re: All Tube Sidecar
« Reply #29 on: January 25, 2018, 10:39:20 AM »
If they're anything like the OEP A262x series they won't handle low frequency signals well at all.
There's Edcor in the US that make reasonably priced open frame 10k:10Ks?

I already looked at the A262 series but discounted them for that very reason. The Z21807C seems much better specified at LF but it is about the same size so who knows.

The Edcors are indeed reasonably priced but their chipping costs to Europe effectively double the price. I have used the XSM series for outputs and found them to be very good but they would be very bulky and heavy for inputs. The WAM series might be OK for inputs as it will handle 10V rms (+22dBu) but they have no shielding and are still quite heavy. Each one weighs 0.4 lbs so 16 would be 6.4lbs.

This is not an easy question. Somewhere there must be a reasonably priced input transformer with a reasonable spec.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


mrclunk

Re: All Tube Sidecar
« Reply #30 on: January 25, 2018, 10:59:58 AM »
As always, many steps ahead of me. :)
You've posted before about the OEP Z3003E.
Possible option and still made? £14 each.
http://docs-europe.electrocomponents.com/webdocs/0d6b/0900766b80d6b42f.pdf

ruffrecords

Re: All Tube Sidecar
« Reply #31 on: January 25, 2018, 11:37:39 AM »
As always, many steps ahead of me. :)
You've posted before about the OEP Z3003E.
Possible option and still made? £14 each.
http://docs-europe.electrocomponents.com/webdocs/0d6b/0900766b80d6b42f.pdf

I don't know about many steps ahead but I have looked at a few alternatives in the last couple of days. None of them seems perfect but each has its attractions:

A187A13C, 25H inductance (good) mu-metal core (good), £20.84 from RS (not bad), mu-metal shielding (good), no spec for maximum level (sigh), 20Hz distortion @0dBu is 0.09% but no info about higher levels.

K30A06C seems to be similar but more expensive (£33.33 @ RS) and distortion at 20Hz 0dBu is just 0.01%. Primary inductance of  119H is very good (Sowter territory).Definitely a larger core and the weight at 0.11Kg is as heavy as some of the smaller Edcors. Again no maximum level spec but it does have a mu-metal screen.

Z3002E and Z3003E appear to be the same transformer but the 03 has a spilt primary an is unaccountably cheaper (£14.44 plays £22.50) and I did test the 03 years ago. Both have a primary inductance of 61.2H (good), are inexpensive (good) and are quoted as having THD: 1% max at +20dB which sounds good but is more or less meaningless. No mu-metal screen (bad) but one is available as a separate part for £10.35. Not as big as the K30 but with a mu-metal screen it is about the same price.

Lastly the Z21807C, no spec for inductance (bad), but 40Hz 3% THD at +22dBu is the only one to specify a high level low frequency distortion (good). has a mu-metal case (good) and weighs only 45g.

I have already contacted OEP about pricing so I think I will ask for spec details on the others to fill in the obvious gaps, mainly core material, primary inductance, maximum operating level and 20Hz distortion at this level.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

ruffrecords

Re: All Tube Sidecar
« Reply #32 on: January 25, 2018, 12:50:00 PM »
For the summing part, 8 stereo channels would work, then you could do panning/solo ITB?

But on the summing channels i'd want auxiliaries for fx...
I generally re-apply verb/echo when remixing and that's normally real tapes/plates.  Mono fx sends would be ok.
Inserts switches on the summing inputs would be nice but this could be done on a patchbay.


Just going back to this point, if we  can get a decent input transformer, are your inputs all stereo? If so how does a mono FX send work from a stereo input - just a dual pot, one part per channel, fed to the same bus?

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: All Tube Sidecar
« Reply #33 on: January 25, 2018, 04:52:01 PM »
Just going back to this point, if we  can get a decent input transformer, are your inputs all stereo? If so how does a mono FX send work from a stereo input - just a dual pot, one part per channel, fed to the same bus?

Cheers

Ian

Hello

Mono Aux send from stereo input can be L/R sum.
My current desk have this for stereo channel, not an issue as far as Aux return is stereo, (I feed all FX/Rev a mono signal)
This keep compatibilities between mono and stereo channel regarding Aux routing, and Aux bus count.
In your case with "only" two Aux send and bus, having mono channels that have two mono Aux and stereo with one stereo Aux on the same two bus will not be practical.

But now I have a doubt, you mean dual pot for L and R Aux 1 send (same for Aux 2) ?

Best
Zam

ruffrecords

Re: All Tube Sidecar
« Reply #34 on: January 25, 2018, 07:29:06 PM »

But now I have a doubt, you mean dual pot for L and R Aux 1 send (same for Aux 2) ?

Best
Zam

Half the dual pot is in the left signal path and the other half is in the R (just like it would be for a stereo level control. The wipers can each feed their own bus feed resistor which are then connected to the single (mono) AUX bus. And you would do the same for AUX2 .

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


ruffrecords

Re: All Tube Sidecar
« Reply #36 on: January 26, 2018, 04:14:45 AM »
HI Ian

Try searching RS for Z21807 (no 'C'),

Hope this helps
Peter

That is interesting. The spec is identical to the Z3003E and the Z21807C is the mu-metal encapsulated version. So it looks like the Z21807C is just a Z3003E in a mu-metal box..

Thanks for that.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

G-Sun

Re: All Tube Sidecar
« Reply #37 on: January 26, 2018, 09:01:50 AM »
That is a very interesting product idea. A bit like a cut down version of API The Box. What control, if any, would you want over the stems?
Tracking and bus-work can be a little different.
Tracking: HPF, LoShelf, HiShelf, Comp fast/medium/slow attack, fast/medium release
 Then color midbands and/or versatile midbands
MasterBus: LoShelf, HiShelf, Transparrant option (like SS line In/Out), Comp fast/med at., auto/slow/very slow release. Solid metering and stereo-tracking.

It's very much about the color and versility, yet, to not too much for masterbus

Like, I got this Blue Robbie, very clean tube preamp, SS in/out,
thought it would be nice on master mid-channel,
but had to take if of.
Then again, for tracking it's pretty transparent.
So, could be hard to nail the all-in-one box :)

Some inspiration could be Warm Audio Tonebeast
and Lauder than Liftoff Silver Bullet.

From a technical point of view,
i guess passive summing in on DB25 is fairly easy to add.
« Last Edit: January 26, 2018, 09:07:42 AM by G-Sun »
HJFP2, ssl9k, Harrison Ford Filters
My music

ruffrecords

Re: All Tube Sidecar
« Reply #38 on: January 26, 2018, 12:09:26 PM »
Tracking and bus-work can be a little different.
Tracking: HPF, LoShelf, HiShelf, Comp fast/medium/slow attack, fast/medium release
 Then color midbands and/or versatile midbands
OK so you are talking about a compressor per channel for tracking as well as EQ. Is that right?
Quote
MasterBus: LoShelf, HiShelf, Transparrant option (like SS line In/Out), Comp fast/med at., auto/slow/very slow release. Solid metering and stereo-tracking.
So you would want simpler EQ on the master bus and different compressor options including (obviously) stereo tracking
Quote
It's very much about the color and versility, yet, to not too much for masterbus

So, could be hard to nail the all-in-one box :)
So inserts on channels and master bus would be good because you could then plug in anything?
Quote
From a technical point of view,
i guess passive summing in on DB25 is fairly easy to add.
Yes it easy as long as all you want is to sum them to the master bus.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

G-Sun

Re: All Tube Sidecar
« Reply #39 on: January 26, 2018, 03:33:36 PM »
OK so you are talking about a compressor per channel for tracking as well as EQ. Is that right?So you would want simpler EQ on the master bus and different compressor options including (obviously) stereo trackingSo inserts on channels and master bus would be good because you could then plug in anything?Yes it easy as long as all you want is to sum them to the master bus.
These are just a few ideas based on my personal usage and workflow.
I wouldn't know every detail before putting the unit into actual usage.

Comp: Depends, just pre/eq is a nice thing as well.
Insert: Yes, but that's not mandatory. I could put a compressor after this unit as well.

I've tried a few tube-preamps now, the Robbie, DBX 676, Sound Sculptor 566. Very different units/flavors,
and they all falls short on masterbus due to not clean enough.
But with a design-goal of clean and transparent, combined with eg. Lundahls in/out it could be something.
And added distortion/saturation-stage with a type of wet/dry would be ideal,
yet, preserving a punchy low-end often seems hard.

I know many folks use 2ch Pultec on masterbus, but I've never tried it,
and often leave masterbus eq to the mastering-guy. But if it sounds good :)

HJFP2, ssl9k, Harrison Ford Filters
My music