Coleman regs on IDHT

[mr ed]

Has anyone used Rod Colemans filament regulators on indirectly heated triodes?
I have a pair from an old 2a3 amp project build I never built and am thinking about heating for tubes in a preamp build.
Thanks
Ed

 

[WntrMute2]

I used Pete Millett's regulated boards for my IDH driver and follower tubes (3C24 build) due to space (I like Coleman's regulators). I still have a little hum with one phono-stage source so it probably is not the drivers. I'm going to do the same on my 300B rebuild. At least I don't have to worry about hum from those tubes.

 

[mr ed]

I used Pete Millett's regulated boards for my IDH driver and follower tubes (3C24 build) due to space (I like Coleman's regulators). I still have a little hum with one phono-stage source so it probably is not the drivers. I'm going to do the same on my 300B rebuild. At least I don't have to worry about hum from those tubes.

Me being cheap and experimenting I was thinking.. since I have these.

 

[WntrMute2]

I was just commenting on the use of DC regulation for IDH tubes. Not so much who's regulators to use.

 

[swich401]

The Coleman regs should work well for IDHT tubes (a bit overkill, but if you have them and have the space to install them then go for it!). Don't forget that with tube swaps you'll need to re-adjust the Coleman reg current to get the right voltage.

 

[mr ed]

I guess i just need to do the math and change the resistors then.
Room is no use on a bread board, might be different in final build... 🙂

 

[Rod Coleman]

They work just fine for idhts. The sense resistor R1 is set at 1/Ih (R1 ohms, ih Amps).
I can't promise any sound upgrade, of course!

 

[mr ed]

Thanks Rod.
I am going to give it a go.
12b4a heaters

 

[euro21]

1. Trim pot.
2. Try 4R resistor as load (5V, 1.25A). It's enough for testing.

BTW why do you think that this LTSpice schematic is -any- R.C. regulator?