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General Discussions => Brewery => Topic started by: sr1200 on July 31, 2012, 05:16:12 PM

Title: Anyone ever used a cloud lifter?
Post by: sr1200 on July 31, 2012, 05:16:12 PM
http://cloudmicrophones.com/cloud12/?page_id=222 (http://cloudmicrophones.com/cloud12/?page_id=222)
Depending on how "clean" this is, it might be good for those having issues with the U87 clone and some happily quiet mics like the shure sm7b (and some ribbons i've used...)

just wanted to see if anyone had any first hand experience with one of these.
Title: Re: Anyone ever used a cloud lifter?
Post by: Hank Dussen on July 31, 2012, 06:06:32 PM
I'm curious too. There's also the Fethead: http://www.tritonaudio.com/index.php?option=com_content&task=category&sectionid=4&id=17&Itemid=33 (http://www.tritonaudio.com/index.php?option=com_content&task=category&sectionid=4&id=17&Itemid=33)
Title: Re: Anyone ever used a cloud lifter?
Post by: pucho812 on July 31, 2012, 06:26:04 PM
it's a phantom powered preamp that goes between the mic pre and a passive mic(passive mic like  adynamic and or regular ribbon). it adds extra gain coming off the mic before the mic pre.  I don't know if it works  or is designed to work with condenser mics, tube mics or any other active(requiring phantom) microphones. I also doubt one needs it for dynamic mics as usually, most people put loud sound sources on dynamics like drums, bass and guitars, etc.

There was a design floating around here a while back that converted your average passive ribbon mic into an active ribbon mic via a phantom powered preamp that was the size of a quarter. It added 13dB of signal off the mic before the mic pre. I have a schemo of anyone is interested and if layed out right could fit inside 99.9% of the ribbon mics out there.
Title: Re: Anyone ever used a cloud lifter?
Post by: usekgb on July 31, 2012, 06:50:54 PM
RODE makes something similar to that that actually fits inside the body of the mic.  I threw one in a 57, and it works really well.

Cheers,
Zach
Title: Re: Anyone ever used a cloud lifter?
Post by: pucho812 on July 31, 2012, 08:03:29 PM
RODE makes something similar to that that actually fits inside the body of the mic.  I threw one in a 57, and it works really well.

Cheers,
Zach

a couple of questions.
 1. what is the model #, part number?
2. what was the need/reason for using that with an SM57?

Title: Re: Anyone ever used a cloud lifter?
Post by: abechap024 on July 31, 2012, 08:35:20 PM
might be good inside a '57 with the transformer removed. Whats the schemo look like? a fet and transistor?
Title: Re: Anyone ever used a cloud lifter?
Post by: pucho812 on July 31, 2012, 09:28:06 PM
the one floating round here was this one. could easily point to point or bread board this one. If anyone wants to layout in either fashion do drop me a copy ;)
Title: Re: Anyone ever used a cloud lifter?
Post by: okgb on July 31, 2012, 10:49:12 PM
Thanks

to below response , check the two transistors , which get power from phantom
Title: Re: Anyone ever used a cloud lifter?
Post by: kevinkace on July 31, 2012, 11:08:19 PM
That schematic is labeled 'Active Ribbon Circuit' but looks like a passive unit to me...?
Title: Re: Anyone ever used a cloud lifter?
Post by: usekgb on August 01, 2012, 01:31:52 AM
RODE makes something similar to that that actually fits inside the body of the mic.  I threw one in a 57, and it works really well.

Cheers,
Zach

a couple of questions.
 1. what is the model #, part number?
2. what was the need/reason for using that with an SM57?

It was the RODE D-Power.  It doesn't look like they make it anymore, sorry for suggesting it.  I put it in a few years ago and have no idea what the schematic is like.  Anyway, I had a 57 that I had removed the transformer from.  I got a D-Power cheap, and decided to throw it in.  It's a good, versatile mic, and sounds great on percussion and vocals.  Here's a pic:

Cheers,
Zach
Title: Re: Anyone ever used a cloud lifter?
Post by: pucho812 on August 01, 2012, 02:38:51 AM
cool.  not to expensive either, only around 59.00 dollars.  Might be worth looking into.
Title: Re: Anyone ever used a cloud lifter?
Post by: mrclunk on August 01, 2012, 09:00:56 AM
The active ribbon pre circuit above works well, i regularly use it on our ribbons, plus its helpful on RE-20's.
I've a pcb layout that will fit in a standard hammond guitar pedal box if anyone wants a copy.. (actually u can fit two per box)

Possibly the cloud lifter is a two stage version of the same circuit, that would give the +25dB.
i think this is the main ribbon booster thread http://www.groupdiy.com/index.php?topic=5743.0
Title: Re: Anyone ever used a cloud lifter?
Post by: usekgb on August 01, 2012, 10:38:01 AM
I haven't needed a booster yet for my SM7, but I usually use it with my Baby Animal pre, which has LOADS of gain.    How transparent is the active ribbon pre?  Does it clip easily?  It might be a fun afternoon project to build one and see how it works, especially if it is small enough to fit in a small Hammond enclosure.

Cheers,
Zach
Title: Re: Anyone ever used a cloud lifter?
Post by: pucho812 on August 01, 2012, 10:47:07 AM
The active ribbon pre circuit above works well, i regularly use it on our ribbons, plus its helpful on RE-20's.
I've a pcb layout that will fit in a standard hammond guitar pedal box if anyone wants a copy.. (actually u can fit two per box)

Possibly the cloud lifter is a two stage version of the same circuit, that would give the +25dB.
i think this is the main ribbon booster thread http://www.groupdiy.com/index.php?topic=5743.0

I'll take one.
Title: Re: Anyone ever used a cloud lifter?
Post by: mrclunk on August 01, 2012, 12:33:59 PM
Think its very transparent but i've not done exhaustive tests..
Use high quality caps for C1, C2. Panasonic FM , FC etc.

Here's my Eagle files for the prr ribbon booster and a pcb pdf.
(rename to .zip)
This was my first pcb layout so its not great...
First thing i would do is swap the in and out xlr conns round.

Title: Re: Anyone ever used a cloud lifter?
Post by: pucho812 on August 01, 2012, 12:56:08 PM
thanks
Title: Re: Anyone ever used a cloud lifter?
Post by: sr1200 on August 01, 2012, 01:40:23 PM
cap ratings?  50v 100v? im guessing at least 50v.
Title: Re: Anyone ever used a cloud lifter?
Post by: pucho812 on August 01, 2012, 02:34:13 PM
since it runs off phantom so yeah 50V would be right
Title: Re: Anyone ever used a cloud lifter?
Post by: Rochey on August 01, 2012, 03:01:02 PM
this would be an ideal project to run on my new pick 'n place machine.

jus' sayin'... it'd be small enough to fit in a mic then.

/R
Title: Re: Anyone ever used a cloud lifter?
Post by: Kingston on August 01, 2012, 06:16:04 PM
this would be an ideal project to run on my new pick 'n place machine.

jus' sayin'... it'd be small enough to fit in a mic then.

/R

well then, what are you waiting for.  :D
Title: Re: Anyone ever used a cloud lifter?
Post by: okgb on August 01, 2012, 06:43:38 PM
I'll buy a couple !
Title: Re: Anyone ever used a cloud lifter?
Post by: pucho812 on August 01, 2012, 07:10:29 PM
I'll buy a couple !

I concur
Title: Re: Anyone ever used a cloud lifter?
Post by: Rochey on August 01, 2012, 08:47:34 PM
Is it a common design, or did a member of this forum design it?

I wouldn't want to step on someone else's toes without permission.

Then the q of resistors and caps... Do we need sumusu precision resistors, or will standard metal film do the trick?
Same for the 100uF caps... Fancy panasonics/muse caps, or run of the mill electrolytics?

Finally, I'm not a mic builder... What's the pcb size got to be below x,y and z.

Cheers

/R
Title: Re: Anyone ever used a cloud lifter?
Post by: okgb on August 01, 2012, 09:12:18 PM
considering it is a balanced circuit , I would match the symetrical parts , resisters as close as possible
not sure where the point of diminishing return is but the common mode rejection is based on that, right ?
Title: Re: Anyone ever used a cloud lifter?
Post by: Rochey on August 02, 2012, 12:14:47 AM
I have 1% metal thick film in stock. Usually good enough... But I've been reading about folks who want specifically constructed resistors for audio.

Dave hill (from crane song) did some interesting research on the topic.

/R
Title: Re: Anyone ever used a cloud lifter?
Post by: mrclunk on August 02, 2012, 04:39:23 AM
Think the circuit was designed by prr. (Check the thread i linked to earlier.) Or you could ask Rossi, he wrote a few articles about this type of circuit for a German electronics mag.

Resistors should be tightly matched. Use 0.1%. I suppose the caps should be too really. Caps should be as high quality as possible, i know nothing of smt so i can't help sorry...
The BJT's also need to have their hfe matched. There might be a dual packaged smd version tho with matched hfe already?
Otherwise i would probably keep the bjt's as a standard package and let the builder match them?

Be cool if the pcb could fit in a Male to female XLR barrel connector.
http://www.neutrik.co.uk/en-uk/accessories/circular-adapters/na3fm
Title: Re: Anyone ever used a cloud lifter?
Post by: Kingston on August 02, 2012, 09:53:17 AM
Some important recap from the thread, more related to PCB design. With perfect transistor matching the caps can be omitted, but probably best use bigger tantalums there. Most people won't bother mathing. Even the suggested 100uF is available in SMD variants these days by the way. Should be transparent enough. The transistors are more of a problem. The one really good option is getting scarce: 2SC3329. There are available replacements but not quite as good. Less so in SMD format. Probably best provide a through hole option for the transistors and those two caps just in case.


Also, do not put anything inside barrel connectors people. In fact don't ever use them for anything. They are a worse idea than they look. It's only a matter of time before someone inserts them in an input slot and it sticks out really nice. Cue busy recording situation and some excited band member snaps the whole input slot right off, with the barrel still attached!
Title: Re: Anyone ever used a cloud lifter?
Post by: Rochey on August 02, 2012, 10:03:02 AM
I was thinking of the mat02/12.

The caps are a cOncern.  50v 100uF tants are nuts.
Title: Re: Anyone ever used a cloud lifter?
Post by: sr1200 on August 02, 2012, 10:10:49 AM
Quote
Also, do not put anything inside barrel connectors people. In fact don't ever use them for anything. They are a worse idea than they look. It's only a matter of time before someone inserts them in an input slot and it sticks out really nice. Cue busy recording situation and some excited band member snaps the whole input slot right off, with the barrel still attached!

Put it in line between 2 mic cables so this wont happen, ala shure sm98 or AKG 418's.  Worst that can happen then is someone steps on it and a scene from Home Alone is re-enacted in the studio.
Title: Re: Anyone ever used a cloud lifter?
Post by: mrclunk on August 02, 2012, 10:21:57 AM
You want it located as close to the mic as pos, plugged straight in ideally.

Transistor wise,
I used 2N4401, there's talk somewhere of paralleling them for lower noise but i didnt.
Title: Re: Anyone ever used a cloud lifter?
Post by: Kingston on August 02, 2012, 10:29:41 AM
Put it in line between 2 mic cables so this wont happen, ala shure sm98 or AKG 418's.  Worst that can happen then is someone steps on it and a scene from Home Alone is re-enacted in the studio.

Yes of course that's how you would use it if you were a professional. But like Y-cables - or anything that can be connected wrong - rest assured someday it will be connected wrong.

The caps are a cOncern.  50v 100uF tants are nuts.

50V? 16V should be enough. They are input caps. The voltage should be very low at that point always. Parallel with some nice ceramics perhaps, or at least provide an option for it.
Title: Re: Anyone ever used a cloud lifter?
Post by: Rochey on August 02, 2012, 11:08:17 AM
I was under the impression the caps were blocking 48V.
Title: Re: Anyone ever used a cloud lifter?
Post by: Kingston on August 02, 2012, 11:12:07 AM
I was under the impression the caps were blocking 48V.

Straight from the designer himself: http://www.groupdiy.com/index.php?topic=5743.msg618140#msg618140

also see zebra50's experiments with no input caps: http://www.groupdiy.com/index.php?topic=5743.msg502892#msg502892
Title: Re: Anyone ever used a cloud lifter?
Post by: sr1200 on August 02, 2012, 11:20:20 AM
So which would you recommend be tant and which electrolytic?
Title: Re: Anyone ever used a cloud lifter?
Post by: Kingston on August 02, 2012, 11:23:00 AM
Use all tantalums. No worries with drying caps. No worries with SMD oven heat. The whole thing could then be implanted into a tiny epoxy clump with only I/O pins sticking out. Set and forget.
Title: Re: Anyone ever used a cloud lifter?
Post by: Kingston on August 02, 2012, 11:32:14 AM
Just putting little brakes on. This kind of productisation of a design should be discussed with the original designer first and foremost, if it's ok to go ahead with it, compensation etc.

There are some mistakes in this area in this forums history.
Title: Re: Anyone ever used a cloud lifter?
Post by: Rochey on August 02, 2012, 11:34:19 AM
agreed. (and I mentioned as much earlier in this thread)

just covering my ass  ;)
Title: Re: Anyone ever used a cloud lifter?
Post by: Rochey on August 02, 2012, 11:44:21 AM
wait - hold the phone. this is just a long tailed pair amplifier isn't it?

Title: Re: Anyone ever used a cloud lifter?
Post by: okgb on August 02, 2012, 12:22:08 PM
Won't be that hard to perfboard it either , just less convenient
Title: Re: Anyone ever used a cloud lifter?
Post by: abbey road d enfer on August 04, 2012, 08:50:44 AM
The caps are a cOncern.  50v 100uF tants are nuts.
These caps see a very small voltage, probably less than a few dozen millivolts. In fact only one is needed, unless one is anal about reverse voltage. With a standard floating mic element, only one of half the value is needed, and the lowest existing working voltage rating (1.8V) is amply sufficient. I believe PRR put two of them and spec'd them at 50V for protection in case of one of the transistors shorting. There are alternatives, if space is at a premium, like doing completely without the input caps and using clamping diodes at the input for protection.
Title: Re: Anyone ever used a cloud lifter?
Post by: PRR on August 05, 2012, 02:06:25 AM
> cap ratings?  ....im guessing at least 50v.

Nobody here can figure-out a 220K-27K voltage divider?
Title: Re: Anyone ever used a cloud lifter?
Post by: zebra50 on August 05, 2012, 03:43:45 AM


also see zebra50's experiments with no input caps: http://www.groupdiy.com/index.php?topic=5743.msg502892#msg502892

Yes, I have three of these kicking around in little boxes, and none of them have input caps! It is probably not good practice, but with well matched components then I could measure no difference in potential across the two inputs. I've used THAT300, 2n4401 with good results.

To be honest, they don't often get used on sessions. If the ribbon mic is working well then a good clean preamp is all that is needed. If not, then the little booster box boosts the noise as well as the signal!

Cheers!

Stewart
Title: Re: Anyone ever used a cloud lifter?
Post by: sodderboy on August 05, 2012, 08:39:43 AM
The Cloudlifter claims no caps, transformers, or resistors in the audio path, so it's only silicon?

And their optimal load impedance is 3K.  That's quite high for most pre's which don't go much above 1K5.

I do not like long mic lines out of personal preference, but have no problems integrating runs over 400 feet when given no choice, either with splitters at the front end or not.  Of importance is not mic level but cable choice and mic pre quality.

If something like this makes a Soundcraft or Mackie sound better, great!
Mike
Title: Re: Anyone ever used a cloud lifter?
Post by: abbey road d enfer on August 06, 2012, 03:28:01 AM
The Cloudlifter claims no caps, transformers, or resistors in the audio path, so it's only silicon?
If you look at PRR's current-feedback schemo, some would trace a direct line from input to input via silicon and say there's no resistors in the signal path and other would say that "everything is in the signal path". Or if you use a THAT 1512, there's only silicon but there are silicon resistors.
Quote
And their optimal load impedance is 3K.  That's quite high for most pre's which don't go much above 1K5. 
That's a limitation due to phantom powering, but with the purely resistive nature of the source impedance it impacts only the max output level. I believe (I don't have the schemo) that the other performance factors are not altered when the load impedance is lower than 3k. Same situation with transformerless phantom-powered mics.
Quote
I do not like long mic lines out of personal preference, but have no problems integrating runs over 400 feet when given no choice, either with splitters at the front end or not. 
Long cable runs are just a fact of life; I don't think anybody would use long cables for any other reason than necessity.
Quote
Of importance is not mic level but cable choice and mic pre quality.
It is debatable; in terms of noise, the actual level is THE most important factor. Betweeen a super-LN pre (Grace, Green River...) and a sub-par one (Brick, TL Audio...) there's only about 5dB difference in EIN, so in the end level is the determining parameter that defines the noise performance. And the greatest cable won't make a bad pre sound good; and the greatest preamp won't compensate for poor cable... Audio degradation is a cumulative problem, all the elements must contribute to the overall performance.
I've never seen (heard) a cable inducing sound quality degradation other than noise; except predictible reduction of BW with long cable runs and high-capacitance cable -hear Starquad. Never had cable inducing distortion (connectors yes).
Quote
If something like this makes a Soundcraft or Mackie sound better, great!
A Cloudlifter won't make a Soundcraft or Mackie, or Neve or whatever sound better. It may make a mic+cable+preamp combination perform better; the reason would be that there is a mismatch in the combo originally. Typically the microphone would see inadequate loading and the mic pre would see inappropriate source impedance, then the addition of an active buffer would sort out the problem.
Title: Re: Anyone ever used a cloud lifter?
Post by: ChuckD on August 08, 2012, 04:06:11 PM
The cloud lifter was just lifted from PRR's FET version created here years ago...
I cracked one open and felt a little stupid for paying 150 bucks for a differential pair.

Here's PRR's :

(http://headfonz.rutgers.edu/2-FET-mikeamp.gif)


The cloud lifter is pretty much this with JFETs instead: LSK170s ...  Just do a google search on the design I am sure you will find one.
(http://upload.wikimedia.org/wikipedia/en/thumb/7/70/Long-tailed-pair.gif/220px-Long-tailed-pair.gif)

I'd post the schematic with values but don't want to get any heat from folks.


Chuck
Title: Re: Anyone ever used a cloud lifter?
Post by: okgb on August 08, 2012, 05:11:26 PM
Let's say if you had a favorite transistor number inspired by that image ,
 what would it be ?
Title: Re: Anyone ever used a cloud lifter?
Post by: ricardo on August 08, 2012, 11:52:58 PM
If you want to know when a Cloudlifter would be good, have a look at Matt's
http://recordinghacks.com/2012/06/18/sm7b-audio-interface-shootout/ (http://recordinghacks.com/2012/06/18/sm7b-audio-interface-shootout/)

If you want to roll your own, read ALL of
http://www.groupdiy.com/index.php?topic=5743.240 (http://www.groupdiy.com/index.php?topic=5743.240)
Loadsa stuff from true gurus and pseudo gurus like me too.  And sources for Unobtainium bits etc.

One suggestion I make is that if you have a low output ribbon with a nominal 200-300R output, you'd be better off making a dedicated preamp using THAT1510 or another of the excellent single chip solutions from TI or AD without P48V.

But making up a complete preamp so it approaches the 1nV/rtHz performance of  THAT1510 is a major undertaking.  In particular, the PCB, wiring and construction has major implications in Low Noise design.

A simpler solution, much more likely to result in success is to take a good existing preamp, remove P48V & other evil bits and optimise it for 300R ribbons.

An obvious candidate is the Seventh Circle box with their T15 modules.

http://www.seventhcircleaudio.com/T15/t15_about.htm

This is a deluxe kit using only the very best components. It costs $99 for a single channel module … and you need a box, power supply etc on top of that.  But if I was rich, had the space and wanted to build a state of the art preamp, I would probably start with one of these.

But you can get a discontinued M-Audio DMP3 for less than US$100 on eBay.  It has a good reputation in some circles but is rather noisy.

If there are sufficient people interested, I'll start a thread on how to convert a DMP3 into a dedicated ribbon preamp with much lower noise along the lines of special order Millenia Media preamps and the AEA TRP

As a pseudo guru, I won't be doing any of the dirty work myself but counting on yus serfs to butcher their DMP3s.