Hi there, just wondering if anyone has used either the MachMar VCCS and/or TentLabs Tube Filament Supply ? I am planning on using this for a 300B SE? It is touted that these are great for DHT/Directly Heater Triodes. Any experiences/observations/etc? All comments welcomed!
(Before you ask, I am feeling a little lazy building my own one point-point. Why not get a PCB for something like this, nice, simple and discrete. However, if I were to build one point-to-point, what are the various schematics around?)
(Before you ask, I am feeling a little lazy building my own one point-point. Why not get a PCB for something like this, nice, simple and discrete. However, if I were to build one point-to-point, what are the various schematics around?)
I've use the Tentlabs supplies and have been very pleased with the results. Both units are high impedance devices, and probably have high enough bandwidth, so should work similarly. One major difference is that the Tentlabs unit is very low dropout. If you have a 5V winding, you can regulate at 5VDC. It looks like the machmat unit requires at least 3 volts higher for the AC input.
Sheldon
Sheldon
Sheldon, thanks for sharing your experiences/knowledge. The Tentlabs also seem to offer a better value option, and given you note about the low votlage dropout could be the better option in my opinion.
Let me ask and get this right, you will one board per heater. You cannot parallel or serial multiple tubes with one board?
Let me ask and get this right, you will one board per heater. You cannot parallel or serial multiple tubes with one board?
I used the MachMat VCCS (DC version) because I wanted to use a CRC filter before the regulator. In this case the MacMat was the better choice.
At 1.5 amps the VCCS needs an input voltage that is 4V above the output, this means you have to have a serious heatsink.
My experiments can be found here:
Heater supply part 4
If you want to upgrade the heater supply of an existing amp I think the Tentlabs module would be the preferred choice because of the lower voltage drop.
At 1.5 amps the VCCS needs an input voltage that is 4V above the output, this means you have to have a serious heatsink.
My experiments can be found here:
Heater supply part 4
If you want to upgrade the heater supply of an existing amp I think the Tentlabs module would be the preferred choice because of the lower voltage drop.
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