Preamp for ribbons?

E

ermghoti

New member
I'm one of the group buy guys, so I'm going to need a reasonable excuse for a pre to evaluate the HRM 10's when they arrive.

I am poverty stricken, by recording measures, so just giving Mercenary my CC number is out. I have seen the SP VTB-1 recommended due to its high impedance setting, and good available gain. Any other contenders, in the two channels under/around $500 area? Be gentle, I am building a dedicated recording PC from scratch this spring, so I'm already preparing excuses for my landlord.
 
If you're set on a unit with a variable input Z the one in your price range that comes to mind is the ART MPA Gold. It has two channels with a low and high voltage switched supply for the tube and the input impedance is said to be variable from 150 ohm to 3K ohms. I've never used it on a ribbon mic...mostly as a Bass or E-guitar DI.

See if you can get GC to import one and let you try it out on your mic before you settle. Or, you could simply order one from MF, if you don't like it, send it back.

Sorry I can't help you any more than that.
 
Ribbon

I just got my ribbon mic...

What seems to be the best is:

1) Low input impedance
2) At least 60dB of QUIET gain
 
northsiderap said:
I just got my ribbon mic...

What seems to be the best is:

1) Low input impedance
2) At least 60dB of QUIET gain
Click to expand...

"At Least 60 dB"...really? Which mic pre do you have. At +60 is it still quiet?

Thanks...I gotta know.
 
Which Preamp

punkin said:
"At Least 60 dB"...really? Which mic pre do you have. At +60 is it still quiet?

Thanks...I gotta know.
Click to expand...

I have a bank of Fairchild 692's that are spec'd at +68dB. I also use API 312s, which are JOYOUSLY quiet.

I haven't seen any 629s other than the eight that I have, but I'm sure they're out there somewhere.

Any high-quality pre should have a relatively low noise at high gains. The cost for these ribbon-compatible mic preamps is outrageous, perhaps in part because of the 1:10+ mic input transformer and usually the transformer coupled output... A 1:10 transformer is about +20dB of low-noise gain immediately.

Any low-to-mid cost mic preamp is going to be noisy because they are probably originally well-designed, but costs get cut and quality control goes down for profit's sake during manufacture. My 2 cents anyway.

I've tried my Behringer and Studiomaster preamps with my newly aquired ribbon mic and the noise at even +55 to +60dB is pretty bad.

That's why I'm learning to build them myself.
 
Last edited:
So you decided to stick with the cheap stuff huh? ;) I've read reviews and tech info on those API's. Those look like a real tasty item.
 
Api

Go out and get:

A quality input transformer - anywhere from 1:5 to 1:10 - Probably 1:10 for ribbons something like the JT-115k-E

A Jensen 990 discrete opamp

A decent output transformer... Should be @ $25

A +/- 15V power supply. Helps to have phantom +48V too.

Put it in a metal box with connectors and thingies. You can find a nice schematic for phantom, phase, and -20db switches at www.jensen-transformers.com

Heat to 350 degrees, stirring every half hour. Sprinkle powdered sugar to taste, cool and serve.
 
What no recommended output transformer part number?

You must have a particulare circuit in mind...do tell. :)
 
You must log in or register to reply here.
Back
Top