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Old 24th March 2013, 03:32 PM   #2921
iko is offline iko  Canada
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That's awesome news! Enjoy your new preamp!

All this activity in this thread made my solder gun itchy, hence my glow tubes are back in as of yesterday. Chose a sample VR150 and VR75 each, in series, such that I get about 220V DC on the top of the gyrator, which is adjusted then for 150V DC on the plate of the 26. I chose the two on purpose because I like both the purple and the orange glow. Shallow, I know.

And all this thanks to Andy! -- who stirred the waters about DHTs on this planet. He'll go down in history as 26-Andy!
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Old 24th March 2013, 03:36 PM   #2922
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Seems do you like, enjoy

Mine VR150 are on the way.

Last edited by merlin el mago; 24th March 2013 at 03:40 PM.
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Old 24th March 2013, 04:17 PM   #2923
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Quote:
Originally Posted by iko View Post
That's awesome news! Enjoy your new preamp!

All this activity in this thread made my solder gun itchy, hence my glow tubes are back in as of yesterday. Chose a sample VR150 and VR75 each, in series, such that I get about 220V DC on the top of the gyrator, which is adjusted then for 150V DC on the plate of the 26. I chose the two on purpose because I like both the purple and the orange glow. Shallow, I know.

And all this thanks to Andy! -- who stirred the waters about DHTs on this planet. He'll go down in history as 26-Andy!
Thanks!

Yep, that purple and orange glow looks awesome indeed! I see glow tubes in my future
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Old 24th March 2013, 05:24 PM   #2924
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For the 26 you could use the octal 0D3 or the 7 pin 0A2 to get 150v. I've used both. Any views on relative merits of either?
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Old 25th March 2013, 04:11 AM   #2925
mthoi is offline mthoi  Malaysia
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I almost got mine fully assembled, just need to mount the volume control and RCA connectors. Initial testing has been positive - no hum, no microphonics. Sounds great.

Click the image to open in full size.

The thread has been very helpful - Tx.
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Old 25th March 2013, 04:19 AM   #2926
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Originally Posted by mthoi View Post
I almost got mine fully assembled, just need to mount the volume control and RCA connectors. Initial testing has been positive - no hum, no microphonics. Sounds great.

Click the image to open in full size.

The thread has been very helpful - Tx.
Nice build! Any reason why you are using two K&K Shunt regulator(1 per tube) instead of only one?

I use the same sockets. For resistors(filament bias), I have mine inside as well but i use aluminum plates to shield the heat flow to the chassis. The aluminum plates are lifted about 5mm.

Click the image to open in full size.
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Old 25th March 2013, 04:47 AM   #2927
mthoi is offline mthoi  Malaysia
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Amandarae - ditto on your nice build too.

I thought having a dedicated regulated B+ for each channel will further reduce B+ noise.
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Old 25th March 2013, 05:37 AM   #2928
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Amandarae - ditto on your nice build too.

I thought having a dedicated regulated B+ for each channel will further reduce B+ noise.
I see. Thanks!

Abe
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Old 25th March 2013, 10:11 AM   #2929
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Quote:
Originally Posted by mthoi View Post
I almost got mine fully assembled, just need to mount the volume control and RCA connectors. Initial testing has been positive - no hum, no microphonics. Sounds great.

Click the image to open in full size.

The thread has been very helpful - Tx.
Nice build congrats, only one box?
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Old 25th March 2013, 11:16 AM   #2930
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Originally Posted by mthoi View Post
I almost got mine fully assembled, just need to mount the volume control and RCA connectors. Initial testing has been positive - no hum, no microphonics. Sounds great. The thread has been very helpful - Tx.
I see you are using aluminium clad cathode resistors. You may want to consider something better. I tested out a whole lot of resistors for filament bias a while ago, and to my ears the best were types such as this:

Ohmite Wirewound Resistors 20 Watts 10 Ohms | eBay

Very tasty if you're in the USA. I'd go for them!
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