Tube regulators and noise ?

woody · 18th October 2003, 01:06 PM

I just bought most of the parts for a little differential line stage that needs 140-150 vdc at 60 ma. Would a pair of oa3,s have less noise than say a 2 75v 10w zeners with a good 100uf bypass cap. Or could I follow the oa3,s with say a 10 ohm resistor and a good 100 uf cap. and not have it go into osilation?

Thanks,
woody

45guy · 18th October 2003, 05:52 PM

Hi Woody,

Try an OD3 with no caps, or something very small after it. That tube works well in my E80CC linestage, actually 2 of them in series for 300v B+. They are nice and quiet and I love the glow! Can you get 185-195v out of your PT before the tubes? You are correct that a 100uF after the VR tube will cause problems. Try not to add any more resistance in the PS than you really have to. The current set resistor won't be noticable since the VR tube/s are shunts and keep impedance low. Hey, that gives me an idea...
More later on the idea part.

Tom

Paul Barker · 18th October 2003, 06:32 PM

I don't find vr tubes noisy either but they sure make things sound good.

analog_sa · 18th October 2003, 06:54 PM

The VR tubes are a lot more capricious than zeners to get working but they sure sound better. No idea about the noise; i use several in a phono stage with no noise issues.

fdegrove · 18th October 2003, 07:18 PM

Hi,

Most VR tubes oscillate when they have a shunt cap bigger than 0.1µF across them.

I never noticed any noise issues but yes, they can be a little harder to get working but that's due to the fact that a lot of people do not read through the datasheet properly.

Other than that they just work and work and work...

Cheers,

Original Burnedfingers · 18th October 2003, 07:57 PM

I have used VR regulators thanks to Frank's help. In my 5687 line stage it sounds much better and the difference is very apparent. In my 5692 line stage I use a set of 0D3 and 0B3's for each channel. I never tried this one without the VR's as I am sold on them. As stated in other post not more than .1 cap.

18th October 2003, 01:06 PM	#1
woody diyAudio Member Join Date: Jan 2002 Location: Tyrone Ga. U.S.A.	Tube regulators and noise ? I just bought most of the parts for a little differential line stage that needs 140-150 vdc at 60 ma. Would a pair of oa3,s have less noise than say a 2 75v 10w zeners with a good 100uf bypass cap. Or could I follow the oa3,s with say a 10 ohm resistor and a good 100 uf cap. and not have it go into osilation? Thanks, woody

18th October 2003, 05:52 PM	#2
45guy diyAudio Member Join Date: Mar 2003 Location: Midwest	Try an OD3 Hi Woody, Try an OD3 with no caps, or something very small after it. That tube works well in my E80CC linestage, actually 2 of them in series for 300v B+. They are nice and quiet and I love the glow! Can you get 185-195v out of your PT before the tubes? You are correct that a 100uF after the VR tube will cause problems. Try not to add any more resistance in the PS than you really have to. The current set resistor won't be noticable since the VR tube/s are shunts and keep impedance low. Hey, that gives me an idea... More later on the idea part. Tom

18th October 2003, 07:18 PM	#5
fdegrove diyAudio Senior Member Join Date: Aug 2002 Location: Belgium	Hi, Most VR tubes oscillate when they have a shunt cap bigger than 0.1µF across them. I never noticed any noise issues but yes, they can be a little harder to get working but that's due to the fact that a lot of people do not read through the datasheet properly. Other than that they just work and work and work... Cheers, __________________ Frank

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18th October 2003, 06:32 PM	#3
Paul Barker diyAudio Member Join Date: Aug 2003 Location: Scarborough	I don't find vr tubes noisy either but they sure make things sound good.

18th October 2003, 06:54 PM	#4
analog_sa diyAudio Member Join Date: Aug 2002 Location: Sofia	The VR tubes are a lot more capricious than zeners to get working but they sure sound better. No idea about the noise; i use several in a phono stage with no noise issues.

18th October 2003, 07:57 PM	#6
Original Burnedfingers diyAudio Member Join Date: Nov 2002	I have used VR regulators thanks to Frank's help. In my 5687 line stage it sounds much better and the difference is very apparent. In my 5692 line stage I use a set of 0D3 and 0B3's for each channel. I never tried this one without the VR's as I am sold on them. As stated in other post not more than .1 cap.

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