Telefunken VF14 M Vacuum Tube For Neumann U47/U48 Microphone - Used & Tested
A SAD NOTE: I received word tonight (08-16-2022) that Andreas Grosser recently passed suddenly in mid/late July 2022. I'm very grateful for the expert service that he provided to me just prior to his passing with testing and regenerating the VF14M vacuum tube listed here. Speaking on the telephone with Andreas was a pleasure and I could tell that he oozed passion and expertise for his craft. A very talented expert indeed! RIP Andreas.
All of the information below is summarized information that I've gathered/learned over the past few months about VF14's in general supplemented by my conversations with Andreas Grosser in Germany who tested and regenerated this particular Telefunken VF14M tube for me in early June, 2022.
For sale is a rare original Telefunken VF14M vacuum tube utilized in the historically significant Neumann U47 and U48 microphones. This previously used, original Telefunken VF14M tube has just returned back to me from being tested and regenerated by Andreas Grosser in Germany. Andreas is one of a small handful of Telefunken VF14 experts in the world, testing and regenerating VF14 and VF14M's for forty years or so. Andreas' regeneration service is comprised of first testing the tube to benchmark its current values and health using a Funke W19S tube tester, then he runs the tube at or near its maximum rated voltage for some extended hours then retests to check for improvements if any. The Neumann U47/U48 mics run the tube at a much lower "loafing" voltage level during normal use and so "caking" of the tube internal elements can happen over time. Running the tube at or near its true rated voltage spec for multiple hours during regeneration can help break down this caking. Think of it like carbon deposits that can build up in an older vehicle engine if that engine ran all of its life just idling and not being revved up.
Andreas mentioned on the phone with me that the VF14M tube tests good for its age but is somewhat microphonic. He shared that in his 40 years of testing these types of tubes he's never come across one that wasn't microphonic and recommends utilizing an elastic suspension for the microphone body to help alleviate that issue.
This particular tube is the VF14M version which was specifically selected by Neumann for use in their microphones. From what I've read there we're only about 27,000 of these tubes ever manufactured by Telefunken with Neumann hand selecting about 21,000 of them for their microphones.
This VF14M tube comes from my father's personal tube collection and originally was used in a Neumann / Telefunken microphone installed at a Denver, Colorado radio station in the early 1970's. The tube is marked, "Removed 11-23-73" in grease pencil around the outside of the metal tube envelope. Included is the original Telefunken tube box which is a bit tattered due to age (some clear tape is holding it together). Please see pictures for additional information and the test data that was supplied to me by Andreas Grosser.
Not having a Neumann U47 or U48 microphone in my possession, I'm not able to provide subjective information on how the tube sounds while in application, nor am I able to confirm 100% operability in your U47/U48 microphone other than the qualified test data that has been provided to me by Andreas Grosser at MIKROFONTECHNIK. As such, this Telefunken VF14M is being sold without any kind of extended warranty but this tube comes with a 14-day money-back guarantee from the time it's delivered to the new owner. This should give a serious buyer the chance to install and use the tube for themselves before the guarantee expires. If the tube is to be returned for a refund, it must be returned in its original and as-shipped condition with all original packaging material/box and insured for purchase price amount by an approved carrier. For all returns, contact Avanti Audio prior to sending anything back so that we can approve the chosen carrier and supply additional shipping information as needed.
Shipping within the Continental United States ONLY.
The Telefunken VF14M will be packed extremely well for safe transport to its new location. The Avanti Audio $10 Flat Rate Shipping charge applies and I'll use UPS Ground shipping or USPS Priority Mail (insured for purchase price) within the CONUS.
