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R/E/P => R/E/P Archives => Klaus Heyne's Mic Lab => Topic started by: Silvertone on January 08, 2011, 08:07:12 AM

Title: AC701 tube
Post by: Silvertone on January 08, 2011, 08:07:12 AM
Is it worth making again?   Would there be enough applications to warrant bringing this tube back in production?  Thoughts?
Title: Re: AC701 tube
Post by: Barry Hufker on January 08, 2011, 02:42:36 PM
Sounds like you have a thought about that -- or maybe even a plan...

Barry
Title: Re: AC701 tube
Post by: Silvertone on January 09, 2011, 08:23:10 AM
Yes, I'd like to know if in 2011 it's a viable business to make this particular tube. I believe the AC701's application goes beyond the recording industry.

Thoughts?
Title: Re: AC701 tube
Post by: Klaus Heyne on January 09, 2011, 02:29:02 PM
First consideration for any new product: supply and demand.

How many original AC701 are still out there? (My guess is in excess of 10,000)
How many buyers of a copy (fake) AC701 manufactured by an aftermarket company would there be, considering the ample supply of originals?

Second consideration: production cost, profitability.

There is great difficulty in delivering 100% operational AC701-type tubes with a warranty to customers (read historic accounts of the development of this tube on this forum): Telefunken had to take back a financially unacceptable percentage of AC701 because of failure. No start-up would take that high of a risk that giant Telefunken, as part-owner of Neumann, could write off.

Title: Re: AC701 tube
Post by: zebra50 on January 09, 2011, 05:24:58 PM
We recently saw a long discussion about the pros and cons of remanufacturing extinct tubes (VF14) in this thread:

http://recforums.prosoundweb.com/index.php/t/32975/3507/

Many of the same economic & technical considerations would apply to the AC701k.

Stewart
Title: Re: AC701 tube
Post by: ttown on January 10, 2011, 02:43:06 AM
It's funny about the AC701.  I have about 8 mics, Neumann and Schoeps, that use the AC701 and AC701k.  I've never had an issue with a tube going out.

Why?  If you read posts from Klaus and Oliver, they will tell you that the key is calibrating +H voltage to deliver somewhere between 3.85-3.95V (but never over 4.00 V!).

I calibrate my PSUs every 2-3 months, and don't have the slightest sign of a tube going out.  So, not sure that replacement AC701s would be needed, at least for those who practice 'religious' PSU calibration.

-Terrence
Title: Re: AC701 tube
Post by: joeyhavoc on January 10, 2011, 10:04:33 AM
Klaus Heyne wrote on Sun, 09 January 2011 13:29

How many original AC701 are still out there? (My guess is in excess of 10,000)

Hi Klaus,

Can you explain how you've come to that quantity estimate?

This is not a trick question in any way.  I'm just surprised that the number would be that high given the current price that these tubes sell for on ebay and other sites.

Joe Hauck
AMI, Inc.

Title: Re: AC701 tube
Post by: Klaus Heyne on January 10, 2011, 09:29:06 PM
I know of a few European collectors who each sit on excess of 1000 AC701. Additionally, I was offered a package recently for 5,000 pieces out of Denmark. Adding all this up and extrapolating from there- that's how I came up with the number.
Title: Re: AC701 tube
Post by: joeyhavoc on January 11, 2011, 09:29:36 AM
Thank you Klaus!  Economically that makes sense to me now.

With 10K+ tubes in existence, I would expect the after market prices to be lower than they are.  But knowing that a few suppliers sit on the majority of the remaining inventory, the current pricing makes sense.

Joe Hauck
AMI, Inc.
Title: Re: AC701 tube
Post by: ssltech on January 11, 2011, 09:34:18 AM
joeyhavoc wrote

With 10K+ tubes in existence, I would expect the after market prices to be lower than they are.


Significant hoarding of finite resources ALWAYS distorts values upwards.

-And if you happen to be the owner of a significant part of the resource in question, it's human nature to seek to manipulate your good fortune/judgment to even greater advantage.

The fun happens "when the music stops".

Keith
Title: Re: AC701 tube
Post by: joeyhavoc on January 11, 2011, 02:11:30 PM
ssltech wrote on Tue, 11 January 2011 08:34

Significant hoarding of finite resources ALWAYS distorts values upwards.

Absolutely!  Given Klaus's original estimate of existing quantity and the current after market pricing, I thought that this would be the case.  I'm happy that Klaus was able to confirm it.

Joe Hauck
AMI, Inc.