The background of this tube load and comparison against other principles can be read in this article. To prove the principle, we designed small PCB's containing all parts. These PCB's can be used to replace a resistor, mu-stage or choke load. It only takes three wires and no external power supply. This is a good way to try out CCS in your amplifier. When it is not better, we will refund your money!

This circuit can also be used very well in the tail of long tailed pair phase splitters (current sink). Normally there is a resistor there, but the signal error is equivalent to the cathode impedance devided by this resistor. Mostly this is compensated by a variable resistor in the anode of one of the tubes. When the impedance in the tail is very high (ie CCS) this error reduces to zero and you will get a very good phase splitter, making the sound better, without a variable resistor which need to be tuned all the time. The new Version 1-2 is suitable for current sink applications.

Features:

• Simple and versatile, easy to build and apply mono CCS boards for a wide range of voltages and currents.
• Easy to configure to voltages up to 300V (over the transistor, so higher supply voltages are possible), and upto 500mA current. Maximum power dissipation (Pmax = V*I) 2 Watts, more with larger heat sink. Please ask me about you configuration if you are not sure.
• No power supply or extra parts needed.
• Very small boards, easy to mount in any amplfier.
• Usable as anode load and current sink

Kit	Price kit	Price fully build
Stereo CCS, including two mono PCBs and all parts	28.50	49.00

Building and using CCS:

Before you start, read this article about soldering and the disclaimers. If you have questions about the manual, about the kit, about your configuration, or anything else, please do not hesitate to ask us. We will do all we can to help you getting the best out or our DIY kits.

Every tube has a different setting, therefore these CCS board always will be adjusted to your typical application. Please contact me about this application and we will work out the best configuration for you. Parts in the kit will be adjusted to your configuration. We found out that adding a resistor in series with the CCS makes the sound even better. Please ask us before ordering, we can tell you what resistor you need (depends on the circuit).

WARNING: This circuit is designed to work with high voltages. Do not touch the heat sink, or any other parts of this circuit when voltage is applied!

Description Version 1-2:

1. Mount the parts like you see in the picture. The colour codes of the resistors are noted in the partslist. The plus mark on the tape of the LED should be mounted at the A-side on the PCB for anode load and at the B-side for current sink.
2. The current of the CCS will be determined by R1, according to R1 = 1.1/I. So for 12 mA you will need a value of R1 = 1.1 / 12mA = 92R
3. Now the MJE350 (anode load) or MJE340 (current sink) have to be mounted. The transistors first have to be mounted on the heat sink. The parts should be use in the order: bold, flat ring, MJE3X0 (metal side to the heat sink), heat sink, spring ring, nut (comparable to this Picture). Take care that the transistor is straight in the middle of the heatsink and screwed stuck strongly (comparable to this Picture).
4. Mount the transistors on the PCB. First put the pins of the transistors through the holes in the PCB. Now screw the first parker screw in so far that it just holds the heat sink. Now screw in the other one, so that the heat sink is stuck solid to the PCB. Finish the first parker screw. Solder the transistor pins at the bottom.
5. For Anode load: Apply the high voltage to the Y-pin, the amplifier power supply ground to the X-pin and the anode of the tube to the Tube pin.
6. For Current sink: Apply the high voltage to the X-pin, the amplifier power supply ground to the Y-pin and the cathodes of the tubes to the Tube pin.
7. Now power up the amplifier. The voltages and currents should be like we have discussed. If not, please power down the amp and let me know.