Vacuum Tube Valley 6SN7 preamp

[Bas Horneman]

5U4G rectifiers to supply a nice preamp

You can substitute the 6x5 with the 5U4G..(In my schematic that is..)

Cheers,
Bas

 

[Elkaid]

Hi !

I'm currently finishing my shopping list and I would like your comment on your favorite 6SN7 tube.

Electro Harmonix seems to have a nice one :
http://thetubestore.com/ehx6sn7.html
They compare them to the red base RCA... ???

Sovtek
http://thetubestore.com/sovtek6sn7.html

So, any differences between 6SN7GT(sovtek) and 6SN7EH (electroharmonix) beside the price ?

Thanks !

 

[Bas Horneman]

So, any differences between 6SN7GT(sovtek) and 6SN7EH (electroharmonix) beside the price

Yes major. The EH has Top getter, looks like thicker glas...shorter (less microphonic theoretically compared to the longish Sovteks) The list goes on..but that is not the most important thing ...I think..

I have never heard either. (have some Sovtek's (or same type of build) at home..will send a pair of them to you for free if you like, just send me an email with your address)

Sovteks 6SN7 as pictured
The general consensus is that these suck! (But I have also read reports by some that say...that their amps sound absolutely great...with them in)

The EH 6SN7 ..has had favourable reports and would be the tube I would buy if I wanted to buy a 6SN7...(NOS 6SN7's are not an area I would like to get into...being a relative newcomer to the scene)(appears like a copy of the tungsol 6sn7 according to triodeelectronics)


Cheers,
Bas

 

[Elkaid]

will send a pair of them to you for free if you like

Thanks for the offer. I will not abuse from your generosity

The first step will be to build a working Power Supply, then a working preamp and when everything will be working fine, then I'll try some different tubes.... Lucky as I am, I'll probably make some caps to explode or something similar.

Thank you !

 

[Elkaid]

Hi guys !

Posted by Bas Horneman
Here is a nice psu you might consider...
http://www.diyaudio.com/forums/attachment.php?s=&postid=398021

Slowly starting but still playing a little with various configuration and I'd like to try the power supply you were describing previously (the one using DN2540). However, I have a few questions :

1. Is my 260-CT-260V transformer still suitable ? I guess so but I'd like to be sure

2. Is there any drop-in replacement for DN2540. I can't find them anywhere.

3. Also, I can't find datasheet for 0A2 & 0B2 tube... Numbers of pins, filament voltage & current etc...

4. On the schematics, it's written 255VAC at the output of the 0A2 tubes... Is that a typo since I need around 250VDC?

5. I suppose that I'm still okay with 400VDC caps right ?

6. Finally, there's a resistor identified "?"... what should be its value in order to reach 25mA ? 1/4 watt enough ?

Sorry, I'm really newbish. Well, thanks for your help !

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[Elkaid]

Ooops, I made an error in my previous post...

In fact I need 370VDC and not 250VDC as previously stated...

 

[ALBQ]

VTV 6SN7 Linestage

Actual B+ for the VTV 6SN7 is 330V. The 370V mentioned in the article was a typo. Transformer called for is a Hammond 270BX and with 5Y3 rectifier yields ~330V B+.
Cheer -ALBQ

http://mywebpages.comcast.net/gillespie147/AlbuquerqueAudio-MainPage.html

 

[Elkaid]

Thanks

Omg, it was late when I wrote that post...

I really need 250VDC and not 370VDC....

Still, some of my question in Post #45 are still unanswered and your help would be greatly appreciated

Thank you !

 

[fdegrove]

Hi,

3. Also, I can't find datasheet for 0A2 & 0B2 tube... Numbers of pins, filament voltage & current etc...

Cold cathode tubes don't sport a heater, 7 pins, OA2 = 150V, OB2 105V both 30mA, I think...will check if I can zip you a datasheet later.

Cheers,

 

[fdegrove]

Hi,

Useful data:

OA2, etc.

PINOUT

Cheers,