Gas Cooker

[cfreeborn]

Has anyone here ever looked under the hood of a Gas Cooker pre- DI?
British made, getting very hard to find - Choice of Richard Thompson, among others.
I'm getting increasingly interested in building a valve pre-amp that can feed via DI to house board, or to a SS power amp and speakers.

Thanks.

-C


Specs for the Gas Cooker:

The Gas Cooker mic pre
Specifications
 
Front panel controls       Output gain controls with unity gain markings
Earth lift switches
-20dB pad switches
 
Front panel in/outs
     Unbalanced jack outputs (pre gain control)
Balanced XLR outputs

Rear panel controls
     Illuminated power on/off switch
IEC mains input
Voltage selector 120v/240v
Unbalanced line outputs (post gain control)

Max gain
     30x to unbalanced output
3x to balanced output

Frequency response
    28Hz to 25kHz (-3dB)
Input impedance
    1 M ohm
Output impedance
     500 ohms balanced
1.5 k ohms unbalanced

Noise at max gain
    Better than -65 dB
Dimensions
     305 mm (w)
190 mm (d)
72mm (h)

    
Transformer balanced, hand-built, CE approved

[proaudioguy]

You can build just about any preamp then contact Bill Whitlock at Jensen transformers and tell him the output impedance and that you want to go from the transformer into a mic pre and he'll have one of the finest (not cheap) DI transformers money can buy.  Make sure your pin 1 on your xlr connects to an spst switch before connecting to audio ground (not power ground).  That will be your ground lift switch. No one uses their own DI into my desk unless it has a ground lift. Amazing how many bass amps do not have them I end up having to take your DI into another very expensive DI which is stupid and many vendors I work for don't have those particular 2-3 models that have xlr inputs so after you and I have it out I end up taking your guitar direct and you are unhappy but I don't get a hum! 
Soundguy rant on....So many guitar and bass players tell me, "it never does that" when it makes lots of noise and I have to go through all the motions of proving my rig is dead quiet then it always turns out to be a loose wire in the guitar, bad 1/4" cable, or a dead preamp battery in an acoustic "but I just changed that battery before I left the house!" rant off.
Btw I don't care how loud your amp is on state just remember the pa covers much more evenly and if the amp is too loud the pa won't have much guitar in it unless its a huge festival. Also if your singer can't hear themselves because my wedges won't make them bleed it's probably because the guitar is too loud and/ or they are standing next to the cymbals.  That being said as a player I want my amp loud enough to hear over the band where I am on stage. Tilt back legs or an amp stand facing your head is very helpful.  Those beam blockers look interesting too.  As a foh engineer I prefer in ear monitors and no speakers on state but as a player I want the amp.

[cfreeborn]

Many thanks.
You're not kidding the Jensen transformers are pricey. I'm sure you get what you pay for, and I've never regretted buying quality.
-C

[proaudioguy]

Definitely get with Bill though. He's a genius about transformers.  They have so many options and many are not obvious.  He'll know exactly what you need.

[embotone]

I recently built a stereo tube pre based on the Hamptone hvpt.  They are sold in kit form now but originally it was from an article in TapeOp magazine for a DIY project.  http://www.hamptone.com/oldsite/tape_op_art.htm

Here is the current kit:
http://hamptone.com/hvtp2_info.html

Here is the info for the diy project:
http://www.hamptone.com/oldsite/mic-pre_kit.htm

I used cinemag transformers and off the shelf power supplies from Mouser.  I have a ground lift on the back.

[cfreeborn]

Many thanks for the info. Beautiful gear. I'll read through the specs to see if it matches my requirements.
-C

[HotBluePlates]

... and off the shelf power supplies from Mouser.  ...

You might be surprised to find folks making very expensive mic pres using those same power supplies.

Or maybe you wouldn't be surprised...