TF10014 neve iron
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daArry
Have you seen Geoff Tanners rec.audio.pro posting on this... (I saw it a few months ago 'cos somebody was flogging those Beclares - I didn;t buy)
Anyway, from memory (and please allow for slight deviation in facts
remembered from 20+ years ago!) there were three transformers in this
series, TF10014, TF10015 and TF10016.
Taking your TF10014 as an example, these were loosely based around the
characteristics of the 31267 so are 1200 ohm primary (actually pins 7 and 8
= normal secondary) and this was achieved by loading the secondary (actually
pins 1 to 4 = normal primary) around 20Kohm.
The TF10015 was the line input version but had a defect (that I can't recall
now... only the fix) where the normal secondary impedance was doubled, to
reflect double the impedance to the primary, and two 10K resistors were
fitted in series across the primary to drag the impedance back down to
10Kohm. (rather like what was done above to pad out the secondary)
Now you know why I personally prefer dealing with 10468 and 31267's.... no
bodges required!
What totally blew my mind with the TF10014 was that Belclere started
delivering them with a serious microphony problem. When fitted to the 34128
channel amplifier, for instance, you could produce a noise like thunder if
you tapped the front panel or turned the sensitivity switch.
What would you do in the circumstances? Throw them back at the manufacturer
and get them replaced with a non-microphonic version?
Nah! Not Neve! They made an expensive steel cradle to support the
transformer mounted up side down, wrapped in a cocoon of plastic foam. They
then had to wire long cables from the pcb pads below the inverted
transformer so that they would reach the upward pointing pins on the
inverted transformer. So, in effect, they fixed the symptom and not the
fault... which was precisely contrary to any prior thinking at the place.
There were other bodges performed to the consoles but I'm saving them for
the book I'm writing!
Anyway, look out for the bad transformers because they are easy to spot in
that cradle and yes, like most transformers, you can use them either way
around.
Have you seen Geoff Tanners rec.audio.pro posting on this... (I saw it a few months ago 'cos somebody was flogging those Beclares - I didn;t buy)
Anyway, from memory (and please allow for slight deviation in facts
remembered from 20+ years ago!) there were three transformers in this
series, TF10014, TF10015 and TF10016.
Taking your TF10014 as an example, these were loosely based around the
characteristics of the 31267 so are 1200 ohm primary (actually pins 7 and 8
= normal secondary) and this was achieved by loading the secondary (actually
pins 1 to 4 = normal primary) around 20Kohm.
The TF10015 was the line input version but had a defect (that I can't recall
now... only the fix) where the normal secondary impedance was doubled, to
reflect double the impedance to the primary, and two 10K resistors were
fitted in series across the primary to drag the impedance back down to
10Kohm. (rather like what was done above to pad out the secondary)
Now you know why I personally prefer dealing with 10468 and 31267's.... no
bodges required!
What totally blew my mind with the TF10014 was that Belclere started
delivering them with a serious microphony problem. When fitted to the 34128
channel amplifier, for instance, you could produce a noise like thunder if
you tapped the front panel or turned the sensitivity switch.
What would you do in the circumstances? Throw them back at the manufacturer
and get them replaced with a non-microphonic version?
Nah! Not Neve! They made an expensive steel cradle to support the
transformer mounted up side down, wrapped in a cocoon of plastic foam. They
then had to wire long cables from the pcb pads below the inverted
transformer so that they would reach the upward pointing pins on the
inverted transformer. So, in effect, they fixed the symptom and not the
fault... which was precisely contrary to any prior thinking at the place.
There were other bodges performed to the consoles but I'm saving them for
the book I'm writing!
Anyway, look out for the bad transformers because they are easy to spot in
that cradle and yes, like most transformers, you can use them either way
around.
CJ
Well-known member
Lord Mercy.
That's like Heathkit putting a "tweeter saver" sircuit on their amp with the Peerless transformer that would break into HF oscillation.
That's like Heathkit putting a "tweeter saver" sircuit on their amp with the Peerless transformer that would break into HF oscillation.
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