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Old 3rd April 2010, 04:31 AM   #381
Salas is offline Salas  Greece
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Quote:
Originally Posted by quanghao View Post
This is not good. I think OD3 for shunt, the sound is not good!
OK we hear you. But you are being absolute now.
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Old 3rd April 2010, 04:43 AM   #382
regal is offline regal  United States
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Quote:
Originally Posted by Salas View Post
What is bad? A CCS and a couple of OB3s? Naahh. Sounds silky. Its just lacks resolution and impact but not bad. Have you used that circuit, CCS and tube ''zeners'' exactly?
isn't the problem with regulator tubes is it makes the PS have a high output impedance?
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Old 3rd April 2010, 04:47 AM   #383
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Quote:
Originally Posted by quanghao View Post
This is not good. I think OD3 for shunt, the sound is not good!
OK guys. I am planning to try Salas PSU with in next few days. Then I could give a fair comparison I guess.
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Old 3rd April 2010, 04:59 AM   #384
Salas is offline Salas  Greece
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Quote:
Originally Posted by regal View Post
isn't the problem with regulator tubes is it makes the PS have a high output impedance?
Quote:
Originally Posted by coolzero View Post
OK guys. I am planning to try Salas PSU with in next few days. Then I could give a fair comparison I guess.
Guys I don't know so many applications of the SSHV on DHTs. The classic road is OD, a ballast resistor or tube CCS, heavily a depletion Mosfet CCS for the super modernist.

Cygnus X1 said some words on DHT and the SSHV once.

Is it worth using anything other than DHTs for preamps?

Don't know, prove him right or wrong, by DIYing one and testing. Its a nice hobby.
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Old 3rd April 2010, 03:33 PM   #385
Sheldon is offline Sheldon  United States
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Originally Posted by coolzero View Post
Your guess is right. I tried it without the dropping resistor but CCS couldn't handle the flow. This way it works. As long as I keep the dropping resistor in place, nothing much of heat generated in CCS. Tested it for couple of hours and it was quite OK with running both the channels together. Current through the tube is close to 6ma. CCS is with a 3W heat sink btw. If my memory is correct, K&K's suggestion was to use the CCS after the VR's initially. I tried both the ways and felt there is slightly more resolution to the sound with latter. What do you think?

Sorry, it was a mistake mentioning both VR tube as OB3. Actually the first tube I am using is an OA2. Voltage is around 240 volts on plate chokes.

Since you are in the experimental mode, why not try a choke input supply? Just eliminate C3. That will lower the voltage to the CCS to something around 270V. Then you can eliminate the dropping resistor. This applies whether using the VR tubes or Salas's regulator.

Sheldon
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Old 3rd April 2010, 03:39 PM   #386
Sheldon is offline Sheldon  United States
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Quote:
Originally Posted by regal View Post
isn't the problem with regulator tubes is it makes the PS have a high output impedance?

High compared to what, and applied how? In this circuit, the supply is feeding a plate choke, which is a sort of CCS. The impact of the preceding impedance will be less than it would be for a resistor loaded circuit. Better, worse? Preferred sound is a subjective thing. If technical performance (impedance, distortion) were the only issue, we wouldn't bother with tubes.

Sheldon

edit: BTW, I'm with Salas here. It's DIY. So TIY (Try It Yourself).

Last edited by Sheldon; 3rd April 2010 at 03:47 PM.
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Old 4th April 2010, 02:38 PM   #387
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Quote:
Originally Posted by Salas View Post
Guys I don't know so many applications of the SSHV on DHTs. The classic road is OD, a ballast resistor or tube CCS, heavily a depletion Mosfet CCS for the super modernist.

Cygnus X1 said some words on DHT and the SSHV once.

Is it worth using anything other than DHTs for preamps?

Don't know, prove him right or wrong, by DIYing one and testing. Its a nice hobby.
Salas,

I agree with Cygnus X1 about your SSHV; it is certainly one of the best PSU's I have tested with my 26 so far. Easy to build and spot on with results. I couldn't agree more with Cygnus X1 about the things he mentioned of this PSU; it makes 26 pre sounds more musically accurate for sure. It is dead silent too. Anyone who wants to build a 26 pre without putting much of sweat to do R&D for a better B+ supply, this is a clear winner. Only drawback is to have bigger heat sinks. When compared to the results this issue is negligible I would say. A Big thank to Salas to put his effort to design this.

On the other note, I did few more trial and error kind of testing with my B+ supply, without thinking much about engineering behind it. I just placed 2 K&K CCS's (DN2540/IXTP01N100D) before and after the VR tubes in my current PSU (image attached). This gave me totally an unexpected result. Sound became more focus, accurate and well imaged. B+ became totally silent too. If someone is bit lazy to build Salas, this I would say the next best alternate. Don't ask me why I have done this and I didn’t bother to understand the theory behind. I was too tired and just wanted to enjoy the sound: D
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File Type: jpg Current PSU.jpg (161.3 KB, 648 views)

Last edited by coolzero; 4th April 2010 at 02:40 PM.
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Old 4th April 2010, 02:47 PM   #388
Salas is offline Salas  Greece
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About your comments and thanks you are welcome. Try it with an IRF9610 in SSHV's CCS too if you didn't already. Its a an alternative to taste. Was it the Simpler Simplistic with Jfet in the Norton Vref? Heatsink can be minimum possible if just 25mA is reserved over max draw, and just 15Vin-VOut is fixed. Any picture by the way?

For your second experiment, the right hand part fixed the current through the anode load. You effectively put sand in your anode loop!
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Old 4th April 2010, 06:35 PM   #389
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Either add some series resistance to the gas tubes, or decrease the 0.47uF cap in parallel with them. You are inviting oscillations with that large a cap.
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Old 5th April 2010, 09:52 AM   #390
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Originally Posted by zigzagflux View Post
Either add some series resistance to the gas tubes, or decrease the 0.47uF cap in parallel with them. You are inviting oscillations with that large a cap.
There is a 10R in series already whcih I forgot to metnion in the image. should it be enough though?
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