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PostPosted: 19 Mar 2017, 20:37 
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Joined: 23 Feb 2017, 02:02
Posts: 204
Regulated DC sounds better than AC.
DC has less distortion thefore gives you more clear sound.
DC gives you more tube taste.
I perfer Regulated DC more than AC

Most of the time you should be able to directly replace your AC heater with A Regulated DC.
I have refrenced my heater to 75V and directly replaced my AC heater without any plorbems.

I am using regulated dc in my tube pre amp with two 6n4 and one 6z4.
6V DC makes my tubes draw over their rated current at 6.3V AC. and I am using a small resistor to drop the voltage to 5.77V DC and keep the current 2 to 3% less than the rated norminal heater current.
At 6v the tubes gets slightly black.


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PostPosted: 19 May 2017, 16:10 
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Joined: 26 Oct 2012, 21:00
Posts: 190
Location: ontario canada
no problems with polarization effects?


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PostPosted: 19 May 2017, 20:39 
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Joined: 08 Aug 2009, 03:11
Posts: 2229
Location: Chilliwack, BC
IME, depends on the tube.

Indirectly heated tubes don't seem to care. DC is preferred for noise considerations (CV or CC).

Directly heated tubes can be different animals. IME and to my customers ears, constant-current DC seems to be the overall winner.

Cheers!

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* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
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PostPosted: 17 Jun 2017, 23:02 
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Joined: 23 Feb 2017, 02:02
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turk 182 wrote:
no problems with polarization effects?

I never change the polarity, but yeah.

I never had any plorbem with polarization effect.

I actually did some mods on this preamp, I increaded the idle current for the output buffer stage from 2.7mA to 9.14mA, also fixed up my gain stage too.
The sound quality I am getting from these mods are much more significant than having dc vs ac heater.
If someone is looking for best sound in tube amps I suggest them to look for the best schematic. The schematic is the heart of the sound. I had used good tubes like gold lion ecc83 and shuguang 12ax7-t in a low quality circuit.

The good circuit with cheap tubes sound bettter than the bad circuit with good tubes.

I also forggot to mension one ofthe main reason in making this thread.
One of the main reason is that I read online about people saying that the best tube pre amps they heard uses regulated dc.


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PostPosted: 18 Jun 2017, 01:32 
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Joined: 08 Aug 2009, 03:11
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Location: Chilliwack, BC
KochiyaYamato wrote:
One of the main reason is that I read online about people saying that the best tube pre amps they heard uses regulated dc.


What's more important though is what do YOUR ears tell you? ;)

Cheers!

_________________
-= Gregg =-
* Ratings are for transistors - tubes have guidelines*
Home: GeeK ZonE
Work: Classic Valve Design


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