Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Tube DIY Asylum ]

---

[ Alert Moderator ]

---

Hooked up the Ixys IC CCS tonight - preliminary results

Posted by Maxamillion (A) on July 11, 2009 at 20:04:06

After the very positive results from the SiC Schottky diode bias mod on my Supratek Chenin tube preamp (thread below), I decided to give the CCS described by Pete Millett on his DIY page a shot. It consists simply of an IXYS IXCP10M45S IC and a resistor, which is used to select the output current. I used a 500ohm wirewound pot instead of a fixed resistor, so I could vary the current level to find the optimum value.

The IXYS chip seems to be an IC version of the typical discrete CCS designs avaiable now. The datasheet is attached.

I replaced the 35K pots I was using as plate resistors (set to 15K) with the IXYS/500ohm pot combination and fired the preamp up. I set the pot to 280ohms, which should give a current of ~11mA, which was the current produced at idle using the 15K plate resistor.

My first impression was that it was very clean sounding, and didn't seem to lose any air or high end at all versus the resistor. The highs were just as nice as before, and may have had a little bit less sizzle, which is not a bad thing at all. The bass seemed to be a bit less than what I had with just the resistor - not sure if I was hearing less real bass or less distortion. I will need further listening to tell for sure. I also detected an increase in gain, which is to be expected with a horizontal load line.

Unfortunately, major thunderstorms just rolled in, so the evaluation had to be put on hold for a little while as I unplugged my gear.

More to follow.

• http://ixdev.ixys.com/DataSheet/98704.pdf   (Open in New Window)

Edits: 07/11/09

This post is made possible by the generous support of people like you and our sponsors:

Kimber Kable

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---