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Gear / Technical Help => Remote Power => Topic started by: Jhurlbs81 on August 28, 2009, 08:18:02 AM

Title: powering tube mics in the field?
Post by: Jhurlbs81 on August 28, 2009, 08:18:02 AM
Hey Guys-

I'm trying to help a friend  come up with a rechargeable option for powering his tube mics in the field.  I am curious how the battery pack for the Schoeps/Elvo tube set-up works.  Currently, we are powering Telefunken USA's redesign of the Ela m260s tubes with 4 30v cells.  The batteries are extremely expensive and taping a single show runs at least $40.  I really don't know what my options are for rechargeable cells that might be practical for this application.  Any ideas gents?

Thanks!
Jesse
Title: Re: powering tube mics in the field?
Post by: sunjan on August 28, 2009, 09:17:31 AM
Three wally world batteries serially connected? 3*9V=27V
Title: Re: powering tube mics in the field?
Post by: page on August 28, 2009, 09:48:17 AM
If you need roughly 110v/120v to power this stuff, then I'd look into a DC up converter of some sort. Do they really eat 110v of DC power or does it take that and drop it down in the mic power module? Is it 60v per mic or 120v per mic?
Title: Re: powering tube mics in the field?
Post by: Teen Wolf Blitzer on August 28, 2009, 11:32:50 AM
I want this too!!!  So I will follow this thread with interest.   ;D
Title: Re: powering tube mics in the field?
Post by: NOLAfishwater on August 28, 2009, 11:40:05 AM
I am guess in you will need some kind of DC to AC adapter inline between your battery. Then figure out what voltage you want to run them on. I use a Batteryspace 10-14-100 to power my two Schoeps M222/NT222 DC, which take DC power so I do not need any dc to ac adapter.

I wonder if something like this would work in reverse?
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2660
Title: Re: powering tube mics in the field?
Post by: H₂O on August 28, 2009, 11:47:17 AM
I have a Grace Custom Power Supply/Pre amp that was built in 1995 and uses a Apogee DC-DC converter (these are no longer produced) to generate 120V needed for the Capsule voltage - the 4V heating voltage is provided off the 5V bus power through a Zener Diode.   The unit runs off +6V and pulls a max of about 600mA with the PreAmp and Power Supply running for 2 Channels.  This powers my AC701 Schoeps Vintage m221b mics.

I also have a pair of Elvo NT222DCs - These run of 10-16V and pull about 300mA each when running (peak at about 1A a piece when the tube is warming up - according to the manual).

You could look to have a DC-DC converter built that output's 120V and then the heating voltage as well, or you could grab some off the shelf isolated dual output convertors and have them chained together (4 x 15V/-15V DC-DC convertors to get to 120v)

Here is a link to a company that makes high quality DC-DC convertors - and in particualar the line I would look at for your needs:
http://www.recom-international.com/powerline.html

I would definitely look at the DC-DC converter route versus using banks of batteries.
 
Title: Re: powering tube mics in the field?
Post by: NOLAfishwater on August 28, 2009, 11:47:27 AM
You need an INVERTER



http://www.i4at.org/lib2/inverter.htm


(http://www.i4at.org/lib2/inverter.gif)

An Inverter is a device that converts 12 volts d.c to 120 volts a.c. , which is what we use in our homes.  This project will handle about 300 watts, which is perfect for lights, small T.V.'s and radio equipment.

This Inverter takes 12 volt d.c  and steps it up to 120 volt a.c.  The wattage depends on which transistors you use for Q1 and Q2, as well as the "Amp Rating" of the transformer you use for T1. This inverter can be constructed to supply anywhere from 1 to 1000 (1 KW) watts. If Q1, Q2 are 2N3055 NPN Transistors and T1 is a 15 A transformer, then the inverter will supply about 300 watts. Larger transformers and more powerful transistors can be substituted for T1, Q1 and Q2 for more power. Note: Don't try to run inductive loads (motors...) off this inverter.

Parts

.  
C1, C2     68 uf, 25 V Tantalum Capacitor
R1, R2     10 Ohm, 5 Watt Resistor
R3, R4     180 Ohm, 1 Watt Resistor
D1, D2     HEP 154 Silicon Diode
Q1, Q2     2N3055 NPN Transistor (see "Notes")
T1    24V, Center Tapped Transformer  
Misc.    Wire, Case, Receptacle (for output)
    Fuses, Heatsinks, etc.

 

Title: Re: powering tube mics in the field?
Post by: page on August 28, 2009, 11:49:11 AM
I am guess in you will need some kind of DC to AC adapter inline between your battery. Then figure out what voltage you want to run them on. I use a Batteryspace 10-14-100 to power my two Schoeps M222/NT222 DC, which take DC power so I do not need any dc to ac adapter.

I wonder if something like this would work in reverse?
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2660

You can get them for cars. We used to travel on business and plug them into the the cigarette lighters so we could use our laptops while traveling. We had an older one that was loud (e.g. older computer fan from the 90s type loud), so I don't know if there are quieter ones. Had maybe 3 or 4 AC outlets on the box. Thats the first thing I could think of.
Title: Re: powering tube mics in the field?
Post by: NOLAfishwater on August 28, 2009, 11:49:32 AM
Here are more schematics for 12DC to 120VAC  INVERTERS

http://www.discovercircuits.com/C/co-dctoac.htm
Title: Re: powering tube mics in the field?
Post by: H₂O on August 28, 2009, 11:52:33 AM
Tubes run on DC not AC!   You do not need to covert back into AC to make this work.  An inverter is overkill - unless you want to go out and buy one in the store.
Title: Re: powering tube mics in the field?
Post by: page on August 28, 2009, 11:54:20 AM
Tubes run on DC not AC!   You do not need to covert back into AC to make this work.  An inverter is overkill - unless you want to go out and buy one in the store.

Bingo. If Jesse can find someone to build him a DC-DC converter, thats optimum, but if he can't find someone to build one, then your down to the DC-AC-DC conversion, or continuing your exercise program...
Title: Re: powering tube mics in the field?
Post by: H₂O on August 28, 2009, 12:22:51 PM
Here is an original schematic for the m260 - looks like in this version a different tube is used (AC701).

The newer version uses a Telefunken EF-732  (there may have been many versions with different Tubes of the original - i.e. the m 251's)

Jesse - Can you provide the input voltages and required current?  Looks like Pin's 2 and 4 from the Schematic - Pin 2 = Heating and Pin 4 = Capsule - pretty simple deaign.

More info on the EF732:
http://recforums.prosoundweb.com/index.php/t/19774/0/
http://www.radiomuseum.org/tubes/tube_ef732.html

Looks like filament/heating is 6.5V at 150mA (i.e. Pin2)


Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on August 28, 2009, 12:35:22 PM
Wow! Thanks for all the replies and interest.  I'll share this info with the designers of the original box I've nbeen using and see what other info I can gather.

Thank you guys so much!


Imaginary +Ts all around :)

Title: Re: powering tube mics in the field?
Post by: Walstib62 on August 28, 2009, 02:00:31 PM
Most vacuum tubes use about 6.3 v ac to heat the filament. The cathode in the tube pictured in your schematic employs an indirectly heated cathode, very common to tube circuits. you still need ac to heat the filament, more than likely.
If the power supply unit itself has a 110 ac plug on it, then the easiest way to power it is to get a 12v battery and connect a store bought ac invertor to it, then simply plug in your power supply.
There is some power loss within the invertor ckt. whenever it is turned on, even if whatever is plugged into it is off because it will be generating ac all the time.
Title: Re: powering tube mics in the field?
Post by: Walstib62 on August 28, 2009, 02:21:09 PM
actually, the filament could be ac or dc. If you had a shematic of the power supply unit, it would be very helpful.
Title: Re: powering tube mics in the field?
Post by: H₂O on August 28, 2009, 02:53:01 PM
Some tube's can use both, but I do know for a fact the AC701k in the power supply schematic's I have seen use DC power - (i.e. Neumann KM5x, Schoeps m221, etc)

Looking to the mic body schematic I provided before (which is VERY similar to m221b) It appears that Pins 3 and 6 are a common ground.

The from some of the links I provided before the EF732 does appear to support both AC and DC current types.
http://www.radiomuseum.org/tubes/tube_ef732.html


Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on August 28, 2009, 04:42:06 PM
I spoke with Alan over at the Telefunken USA.  He is going to provide all the required specs to help make this happen.  Probably won't have them till next week sometime. 

Quote
Looking to the mic body schematic I provided before (which is VERY similar to m221b) It appears that Pins 3 and 6 are a common ground.
Since this is a redesign of the original, not a replica, won't the schematics vary?

Title: Re: powering tube mics in the field?
Post by: page on August 28, 2009, 04:52:14 PM
Since this is a redesign of the original, not a replica, won't the schematics vary?



Maybe so, maybe not.  ;D
Title: Re: powering tube mics in the field?
Post by: twatts (pants are so over-rated...) on August 28, 2009, 05:43:42 PM
Someone around here uses something like this:

http://www.tonnocover.com/Batteries_Chargers/RoadPro_12_Volt_Battery_Jump_Starter_Air_Compressor_T451061.html#

Its a roadside car battery charger and emergency kit...  But it uses a 12v battery and has a built in inverter for 120vAC... 

Just found one with AC Inverter:

http://www.tonnocover.com/Batteries_Chargers/RoadPro_12_Volt_Portable_5_in_1_Power_System_T451464.html


Terry


Title: Re: powering tube mics in the field?
Post by: Walstib62 on August 28, 2009, 07:13:44 PM
The answer to the original question lies in the layout of the power supply module. Without that, I cannot advise on the best powering option for this unit. If you can get that schematic, I would be interested in seeing it. My guess is that there is a filament regulator circiut there. What it needs for an input I can only guess without a schematic. One thing for sure is that it would certainly need a constant current output. If the filament current is excessively low, then the cathode will be starved, thus decreasing the tube current. If the current is too high, then there is risk of damaging the filament or at least decreasing filament life.
And yes, the plate voltage is  higher than the capsule voltage since there is a 500K res. in series with the cap and 200K in series with the plate.

As to the ac vs. dc issue, isn't the filament electrically isolated from the cathode-therefor not in the signal path?
I deal with tubes every day, but they are much bigger, have 150 KV across them and emit X-ray.

Thanks!
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on August 29, 2009, 12:36:51 PM
Is sound quality affected when powering the caps though a dc-dc convertor (assuming the quality is good)?  Would there be any sonic benefit to running these off a bank of batteries instead of converting the voltage?

Thanks
Jesse 
Title: Re: powering tube mics in the field?
Post by: H₂O on August 29, 2009, 12:56:06 PM
Is sound quality affected when powering the caps though a dc-dc convertor (assuming the quality is good)?  Would there be any sonic benefit to running these off a bank of batteries instead of converting the voltage?

Sound quality should not be affected as long as correct filtering and shielding is applied to the design.  DC-DC converters typically use a switching component which can add noise but this can be managed.

Most modern recorders, pre-amps, etc have dc-dc converters in them already (to take your battery power and convert it into the various required voltages to operate the various components).

Example is that the Oade m148 uses a battery bank of 4 12v SLA's to get the 48v for phantom power and the E.A.A. PSP-2 uses a custom DC-DC converter to convert 5-9V to the required 48V.  Both sound amazing and similar - but the PSP-2 is 1/4 the size and probably a quarter or an eighth the weight.






Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on August 29, 2009, 02:19:17 PM
Quote
The biggest load is the filament, so it's best to run that directly from the appropriate batteries (probably 4x C or D) to avoid conversion losses.  The higher plate voltage could be generated with a DC converter or simply a stack of batteries.  Since the current required for the high voltage supply is small that should be economical.

Yeah, the current battery box I've been using uses 4 C batteries and 4 30v cells. 
Title: Re: powering tube mics in the field?
Post by: Walstib62 on August 30, 2009, 01:26:40 PM
Thanks for the clarification. Certainly I can see where an induced ac component of even several milivolts could cause problems. I haven't dealt with basic vacuum tube theory in years, so I am pretty rusty.
 
Title: Re: powering tube mics in the field?
Post by: dactylus on August 31, 2009, 10:51:13 AM


Very interesting reading.

I have a pair of Neumann Gefell M582 tube mics that were refurbished by Peter Drefahl that I'd love to be able to run in the field. 

I currently have an ac power supply built by Peter Drefahl to power these mics.  When I inquired about the possibility of using dc power in the field I didn't receive a very encouraging response as to the possibility of finding a practical solution. 

The m582 mics use "Telefunken" EC92 tubes and will accept a wide variety of the Neumann and Gefell sd caps that I have, as well as the multipattern, large diameter, Gefell UM70.  It would be GREAT to come up with a practical, workable solution to run these remotely...

 ;D




Title: Re: powering tube mics in the field?
Post by: Walstib62 on August 31, 2009, 11:32:14 AM
Can you get the schematics?
Title: Re: powering tube mics in the field?
Post by: Teen Wolf Blitzer on August 31, 2009, 12:18:10 PM
I'll hit up Busman for schematics to his toobes.   ;D
Title: Re: powering tube mics in the field?
Post by: H₂O on August 31, 2009, 03:08:44 PM
What you really need is schematics of the power supplies showing output voltages and maximum currents by pin.
Title: Re: powering tube mics in the field?
Post by: Teen Wolf Blitzer on August 31, 2009, 08:11:54 PM
That's what I meant.  The supplies not the mics.  I sent Chris an email but have yet to hear back.  I would guess he can provide or get that answer ???
Title: Re: powering tube mics in the field?
Post by: dactylus on August 31, 2009, 08:39:48 PM


Very interesting reading.

I have a pair of Neumann Gefell M582 tube mics that were refurbished by Peter Drefahl that I'd love to be able to run in the field. 

I currently have an ac power supply built by Peter Drefahl to power these mics.  When I inquired about the possibility of using dc power in the field I didn't receive a very encouraging response as to the possibility of finding a practical solution. 

The m582 mics use "Telefunken" EC92 tubes and will accept a wide variety of the Neumann and Gefell sd caps that I have, as well as the multipattern, large diameter, Gefell UM70.  It would be GREAT to come up with a practical, workable solution to run these remotely...

 ;D

^^

It looks like my Telefunken ec92 tubes will support ac or dc too.

http://www.radiomuseum.org/tubes/tube_ec92.html


Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on September 01, 2009, 08:28:51 AM
Just out of curiosity, if one were to go with a bank of batteries to make this happen, what would you guys suggest?

Title: Re: powering tube mics in the field?
Post by: H₂O on September 01, 2009, 11:06:39 AM
I know of 4 portable tube power supplies that where made for tapers in the last 15 years or so:
 2 by Mike Grace
 2 by ??? maybe Bill Bradley

Both sets where for AC701 tube mics and ran 120v and 4v DC.

2 by Mike Grace used DC-DC converters (one for a sm69 and one for a pair of KM56's (I now have this one))
2 by ??? used Banks of Alkaline Batteries (one for a pair of KM254's and don't know the other)

For batteries, There are probably a few ways you could do this as the 120V current will be very low - you could use 10 small 12V SLA's and then recharge as needed (i.e. similar to the ones in the m148).
May be something like 10 of these:
http://www.advancedbattery.com/itemdesc~product~abs+12v0.8t5lt+-+12v+0.8ah+sla+battery~ic~12v0.8t5lt~eq~~tp~.htm

Suppling the 6.5V you need for filement voltage would be fairly easy and you could use a linear voltage regulator off another SLA to get the right voltage (if you are concerned about noise).
Title: Re: powering tube mics in the field?
Post by: H₂O on September 01, 2009, 12:32:42 PM
Another option would be to have Battery Space build a custom ~120V pack.

http://www.batteryspace.com/index.asp?PageAction=VIEWCATS&Category=894

I would see if you can find out the high voltage range (i.e. The Grace I have output more like 110V under load instead of 120V and I verified with Schoeps that this would be ok before I tried to run a show on it).

The more critical voltage is the filament voltage (i.e. AC701 tube needs to be within 0.2 V of 4 V or you will start to damage the tube and shorten the lifespan) - don't know about the EF732 it seems to be a newer design than the 701 so it may have greater tolorances.

Title: Re: powering tube mics in the field?
Post by: Walstib62 on September 03, 2009, 06:11:15 PM
So Jesse,

What did you figure out? Anything?
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on September 04, 2009, 11:07:57 AM
I'm waiting to hear back from Telefunken on the voltage tolerances..
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on December 28, 2009, 02:32:01 PM
I figured I'd update this for those who were interested.

I finally got the PSU schematics.

Input voltages/tolerances
6V, 140mA (250mA peak)
140V, 4.8mA (5.2mA peak)

A TSer has offered to build me a custom box using DC-DC convertors to generate the 120V off a 9+V battery.  The circuit will also provide the 6v heating voltage.




Title: Re: powering tube mics in the field?
Post by: H₂O on April 27, 2010, 01:07:09 AM
Maybe this black box can help  >:D
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on April 27, 2010, 09:36:48 AM
There she is!!  ;D
Title: Re: powering tube mics in the field?
Post by: Teen Wolf Blitzer on April 27, 2010, 12:04:17 PM
Wait...Is that a portable tube power supply?#@$  I must have one.  Did you make that?
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on April 27, 2010, 05:33:51 PM
H2oDC+  8)
Title: Re: powering tube mics in the field?
Post by: H₂O on April 28, 2010, 03:02:15 PM
It's in the mail!


Looking forward to hearing some recordings made your new setup - sounded great in my basement recording the TV!
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on May 02, 2010, 11:08:14 AM
I ran the DC box last night for the first time.  Everything went very smoothly. I ran the Telefunkens stagelip XY for a multitrack recording.  I used a Tekkeon 3450 to power the DC box and my Microtrack 2 off the USB.  After the show (2hr 30min) I still had 5 of the 8 LEDs on the Tekkeon, so battery life will not be a concern.  So far, so good!  :)
Title: Re: powering tube mics in the field?
Post by: tbone65 on May 02, 2010, 02:36:30 PM
telefunken usa will have  a magic box out in  a few moths.specifically being made to power up tube mics. call tony and talk to him .im sure he can be of assistance.
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on May 04, 2010, 10:39:03 AM
LOL! This is the magic box.  TS member H20 is the one developing the box for Telefunken USA.
Title: Re: powering tube mics in the field?
Post by: 108Ω on May 07, 2010, 11:35:34 AM
My old Atwater-Kent used two batteries, A and B
"A" voltage was for filament and it came from the A-battery; "B" voltage fed the plates and (oddly) came from the B-battery.  (B+)
Sometimes a "C" cell was used to power grids, but usually a rheostat could provide it, tapped off of the B+ line.

Then the power company came along an put up all those dag-burned poles and it all changed.
Lot of good men lost putting up those wires, back in the day, yessiree.
No one even remembers the sacrifices made to bring utilities to these here parts atall.

(http://img.photobucket.com/albums/v114/bobw1/WaterJar.jpg)



Be careful with 120 vdc field wiring, it can burn and/or kill.
In fact, high DC voltages are even more dangerous than wall outlets.
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on May 07, 2010, 01:09:59 PM
Quote
Be careful with 120 vdc field wiring, it can burn and/or kill.
In fact, high DC voltages are even more dangerous than wall outlets.

So running this setup in the rain last summer was a bad idea?  :-\  ;)
Title: Re: powering tube mics in the field?
Post by: H₂O on July 15, 2010, 05:51:35 PM
And then their was two...
Title: Re: powering tube mics in the field?
Post by: OOK on July 16, 2010, 12:32:37 AM
And then their was two...

What is the run time.......and what type of battery.... is it internal or external.... seriously cool...  I already have way to much gear but this is intriguing........ man the wife would be pissed...

Let me pose the next logical question....is there one in development with switchable pattern control for multi pattern tube mics?

OOK
Title: Re: powering tube mics in the field?
Post by: H₂O on July 16, 2010, 08:52:53 AM
pulls about 400mA or so


runs on external 9-16V DC -> you can use SLA, Tekkeon's, DVD batt's, etc


I should be able to add a pattern control(s).






 
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on July 16, 2010, 09:38:03 AM
mine powers the Telefunken usa tubes for about 4-4.5 hrs off one Tekkeon 3450. 
Title: Re: powering tube mics in the field?
Post by: Walstib62 on July 16, 2010, 10:51:20 AM
My old Atwater-Kent used two batteries, A and B
"A" voltage was for filament and it came from the A-battery; "B" voltage fed the plates and (oddly) came from the B-battery.  (B+)
Sometimes a "C" cell was used to power grids, but usually a rheostat could provide it, tapped off of the B+ line.

Then the power company came along an put up all those dag-burned poles and it all changed.
Lot of good men lost putting up those wires, back in the day, yessiree.
No one even remembers the sacrifices made to bring utilities to these here parts atall.

(http://img.photobucket.com/albums/v114/bobw1/WaterJar.jpg)



Be careful with 120 vdc field wiring, it can burn and/or kill.
In fact, high DC voltages are even more dangerous than wall outlets.
Not exactly true. 60Hz ac is the most lethal to the heart tissues because it dirupts the electrical activity of the heart at much lower current levels than DC. DC is more likely to induce the "cannot let go" response because it affects the nervous system and tends to lock up motor activity. Either can cause severe burns at the site of contact.
Title: Re: powering tube mics in the field?
Post by: OOK on July 16, 2010, 11:33:32 AM
pulls about 400mA or so


runs on external 9-16V DC -> you can use SLA, Tekkeon's, DVD batt's, etc


I should be able to add a pattern control(s).

Wow.........that is seriously cool... T+ final question, how much does one of these magic boxes cost....?
Title: Re: powering tube mics in the field?
Post by: Walstib62 on July 16, 2010, 12:10:45 PM
So, you can have a variable intput, but I'm assuming you designed it for a constant DC output specific to the Telefunken mics it was designed to power(?) If you could then tweek the output to supply other mics on a custom basis, you might have something there.
I love the sound of tube mics. The U47 is still the greatest ever, right?
I wonder, though, in a blind test, if one were to run a good LD FET mic thru a tube pre, how much difference in that good 'ol tube sound would there be? 
Title: Re: powering tube mics in the field?
Post by: pyiteac on July 22, 2010, 02:33:48 AM
H2O

You are such a nerd.  Good work bro.
Title: Re: powering tube mics in the field?
Post by: H₂O on February 23, 2011, 09:34:42 PM
Number 3 - For a pair of Gefell M582's





Title: Re: powering tube mics in the field?
Post by: NOLAfishwater on February 24, 2011, 12:17:13 AM
 :clapping: :cheers:  great job on figuring this all out.
Title: Re: powering tube mics in the field?
Post by: page on February 24, 2011, 12:51:03 AM
:clapping: :cheers:  great job on figuring this all out.
Title: Re: powering tube mics in the field?
Post by: Teen Wolf Blitzer on February 24, 2011, 10:27:44 AM
Yer killing me.  I need a power supply for my toobes.   :'(
Title: Re: powering tube mics in the field?
Post by: F.O.Bean on February 24, 2011, 05:55:09 PM
AWESOME Work guys!
Title: Re: powering tube mics in the field?
Post by: dactylus on March 01, 2011, 05:55:11 PM
Number 3 - For a pair of Gefell M582's

^
Looks great Richard.  Thank you for enabling me to run the Gefell tubes in the field!

 ;D
Title: Re: powering tube mics in the field?
Post by: Gutbucket on March 01, 2011, 07:04:08 PM
Number 3 - For a pair of Gefell M582's

Beautiful.
Nice work.

Saw that post and figured that one was for you David.
Congratulations.
Title: Re: powering tube mics in the field?
Post by: Tim on March 04, 2011, 03:10:29 PM
This thread is awesome. Well done H20
Title: Re: powering tube mics in the field?
Post by: Jhurlbs81 on March 04, 2011, 06:40:28 PM
I taped My Morning Jacket this past summer running the Telefunken USA Ela m260s powered by Richard's box.  If you look close in the archive picture you can see the mics DFC/FOB .
This was my first MMJ show and they blew me away! Can't wait to see them again soon.

http://www.archive.org/details/mmj2010-08-29.m260.flac16

Thanks Again Richard. This thing is awesome.
Title: Re: powering tube mics in the field?
Post by: F.O.Bean on March 05, 2011, 02:20:24 AM
I taped My Morning Jacket this past summer running the Telefunken USA Ela m260s powered by Richard's box.  If you look close in the archive picture you can see the mics DFC/FOB .
This was my first MMJ show and they blew me away! Can't wait to see them again soon.

http://www.archive.org/details/mmj2010-08-29.m260.flac16

Thanks Again Richard. This thing is awesome.

Do you still own the Schoeps?

I cant wait to hear tonedeafs Schoeps t00bes.....
Title: Re: powering tube mics in the field?
Post by: OOK on March 05, 2011, 09:01:32 PM
I taped My Morning Jacket this past summer running the Telefunken USA Ela m260s powered by Richard's box.  If you look close in the archive picture you can see the mics DFC/FOB .
This was my first MMJ show and they blew me away! Can't wait to see them again soon.

http://www.archive.org/details/mmj2010-08-29.m260.flac16

Thanks Again Richard. This thing is awesome.

This show sounds awesome......to me there is such a perfect balance in the tones......its almost creamy.....
Title: Re: powering tube mics in the field?
Post by: newplanet7 on March 05, 2011, 10:18:31 PM
I taped My Morning Jacket this past summer running the Telefunken USA Ela m260s powered by Richard's box.  If you look close in the archive picture you can see the mics DFC/FOB .
This was my first MMJ show and they blew me away! Can't wait to see them again soon.

http://www.archive.org/details/mmj2010-08-29.m260.flac16

Thanks Again Richard. This thing is awesome.
Holy hell that sounds fantastic. The music doesn't appeal to me but that tape is nasty. Props, great job.
Title: Re: powering tube mics in the field?
Post by: H₂O on March 06, 2011, 11:20:48 AM
I cant wait to hear tonedeafs Schoeps t00bes.....

If you want to hear m221b's in action you can listen to:

http://bt.etree.org/?searchz=M221B&cat=0&incldead=1
Title: Re: powering tube mics in the field?
Post by: dactylus on March 06, 2011, 11:34:13 AM
I cant wait to hear tonedeafs Schoeps t00bes.....

If you want to hear m221b's in action you can listen to:

http://bt.etree.org/?searchz=M221B&cat=0&incldead=1

^
There are no seeders for each of these 3 torrents torrents.  I just hopped on, hopefully a few more will follow.  Seed anyone?

The Neumann/Gefell tubes accept nickel diaphragm, sd card caps (m70 & m94) & mylar omnis (m69 & m93) & Gefell UM-70 multipattern LD caps.  I can't wait to put these into action!!  Thanks again Richard.  You had the m93 omni caps for testing.
Title: Re: powering tube mics in the field?
Post by: dactylus on March 06, 2011, 02:13:54 PM



If you want to hear m221b's in action you can listen to:
http://bt.etree.org/?searchz=M221B&cat=0&incldead=1



^
There are no seeders for each of these 3 torrents torrents.  I just hopped on, hopefully a few more will follow.  Seed anyone?

Title: Re: powering tube mics in the field?
Post by: H₂O on May 15, 2011, 10:11:53 PM
Number 4 almost done (for ac701 tube mics)


Title: Re: powering tube mics in the field?
Post by: F.O.Bean on May 16, 2011, 10:25:20 PM
Number 4 almost done (for ac701 tube mics)




Is that for Steve's Schoeps t00bes ???
Title: Re: powering tube mics in the field?
Post by: H₂O on May 16, 2011, 10:34:38 PM
Yes
Title: Re: powering tube mics in the field?
Post by: F.O.Bean on May 16, 2011, 10:45:49 PM
Yes

Awesome, we'll get to run them for Summer Camp :) We'll have ALOT of taping stuff for that festie ;D We should both be able to run 2 setups :)
Title: Re: powering tube mics in the field?
Post by: dactylus on July 04, 2011, 12:17:57 PM


Matisyahu - 06/30/2011 - MN Zoo, Apple Valley, MN **Neumann Gefell tubes**       

http://bt.etree.org/details.php?id=546318



Number 3 - For a pair of Gefell M582's
Title: Re: powering tube mics in the field?
Post by: dactylus on July 04, 2011, 02:25:12 PM

North Mississippi Allstars Duo- 06/30/2011 - MN Zoo, Apple Valley, MN - **Neumann Gefell tubes** 

http://bt.etree.org/details.php?id=546322

 ;D
Title: Re: powering tube mics in the field?
Post by: H₂O on August 01, 2011, 02:50:01 PM
Glad to see this out in the field  :)