I haven't presented a cool link in a while. After I received a delivery of swedish iron a few weeks ago, I got some US made transformers this week. From Dave Slagle's intactaudio. So it is about time that I write about his website.
I know Dave from the early days of Sound Practices. We both participated in a discussion forum related to the magazine, the JoeNet. It was not like todays forums but a mailing list. The JoeNet still existsts in it's original form today. Those were really exciting times for tube audio enthusiasts. In Sound Practices and the JoeNet ideas and thoughts about things like directly heated triodes and single ended circuits were shared. Back in the early 90ies this was pretty uncommon in the western world.
Out of that mailing list the idea for a meeting for tube enthusiasts came up which resulted in the NYnoise which was hosted by JC Morrison in New York City. At one of the early NYnoise festivals I met Dave personally the first time. This was 1999.
Back then he was already into magnetics and wound his own stuff. He put a lot of effort and energy into developing transformer volume controls. These efforts resulted in excellent sounding TVCs. More and more people got aware of Dave's work and asked him to wind stuff for him. So some years later he founded the company intact audio.
Since I'm an avid user of all things wound on iron or other metals, especially volume controls, Dave was the natural choice for supplying my needs when I started to go commercial with tube audio. I get all my volume controls from Dave. Most of them are custom made to my specs, but occasionally I use his standard TVCs too. Dave also winds inductances for me for LCR RIAAs and other stuff.
Here is a recent delivery from Dave:
Volume controls on the left side, EQ coils in the diagonal line. These are intended for the variable EQ mono phonostage I wrote about in an earlier post. More about that phonostage soon! On the right are 8 1dB/step volume controls which will be used in a passive line level crossover for fine adjustment of each channel.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgcvs-cNMvxd8JTE-Aozj09BQJACjDc3brViJ3zevPtIfPIKRHmZzvFYKV-LPMMpRsnbHG2cyxCcKKzBCddPA3_nk32PNMcWaeMyH5PdlVTk9qyBG0PxnXGMot-oTjzYECKnXVW-zB3I5cw/s320/AVC28-1.jpg)
The 14 step AVCs are wound on the same core size as the 28 step version. Pins are only located on one side. Soundwise this solution is very similar to the one with the 'big' AVC.
The core material used in the AVCs and coils is nickel. Dave's preferred material. The coils make use of the available pins on the bobbin. These are used to bring out some taps for fine adjustment of the inductance. Very simple and effective. Besides this the inductance can be controlled by simply changing the airgap or by rearranging the way the laminations are stacked. Dave can supply paper pieces of different thicknesses for precise adjustment of the airgap.
It is great to have Dave as a reliable source for my special needs for anything which needs wire to be wound on exotic materials in a special way. I also consider him as a good friend. The photo on the right shows the man himself. Keep up the great work Dave!
Best regards
Thomas
Best regards
Thomas
Hi Thomas,
ReplyDeleteschöner Bericht über Dave und seine Arbeit! Da ich ja auch die "kleine" TVC von ihm/dir habe, musste ich natürlich gleich mal im verlinkten Forum stöbern. Dort bin ich auf die interessante Diskussion zum Thema Luftspalt gestoßen. Gehe ich recht in der Annahme, dass die Autoformer "von Werk aus" ohne Luftspalt ausgeliefert werden?
Viele Grüße,
Peter
Hallo Peter,
ReplyDeleteich beziehe die TVCs immer mit kleinem Luftspalt. So haben sie zwar eine geringe Induktivität und müssen niederohmig angesteuert werden. Klingen so aber auch am besten. Für die Oktalvorstufe musst Du nichts ändern. Für andere Anwendungen kannst Du z.B. die Bleche wechselseitig schichten.
Viele Grüße
Thomas