Tube socket savers. Helps with tube rolling but impacts sound?

[sleepyguy24]

Hey everyone.

My nervosa is acting up but this time with tube sockets and tube rolling. StereoNut has been very kind to loan me his Eastern Electric Minimax DAC to audition. I'm leaning towards buying it as I've had great success with using 12AT7 tubes with it.

Now I have a bunch of 12AU7s and 12AT7s and am fighting to just keeps thing as is but the itch to tube roll is there. That little devil is on my shoulder urging me to make changes.

I'm thinking to preserve the tube socket in the EE Minimax DAC I would get a gold pin socket saver as I've had to wiggle the stock 12AU7 tube out to get my 12AT7 tube in. I'm paranoid when I start tube rolling that I would be wiggling the tube out repeatedly and damage the socket over time.

Here is the socket savers I was thinking of getting.



So long story short has anyone ever used a tube socket saver like this? Anyone experience sound degradation or further changes with them in place? Am I just being paranoid about the tube socket in the EE Minimax or about tube sockets in general?

Thanks in advance.

[richidoo]

The extender will add some resistance due to the added pin contacts, but I don't know if that will effect anything, probably not very noticable, but you should compare your final tube selections without  the enxtender if you plan to not use it later. It's more important to make sure all the pins are clean and tight, that's bigger source of pin contact resistance.

But the extender would make it easier to get a grip on the tube when removing it. The stock socket positions the installed tube a bit low inside the case making tube removal difficult, iirc.

I wouldn't worry about wearing out the socket. You can always tighten it up by bending the contacts closer. It is probably the same 9 pin socket used in the Minimax preamp which is famous for prodigious tube rolling, and nobody ever mentioned a socket getting loose. Even when using the extender, you still don't know if just the tube or the tube and extender will pull out.  Maybe removing the DAC cover will make removing the tubes easier during the rolling. Power off when swapping, of course.

Do the opamp rolling before you do the tube, because the opamps are always in the circuit, even when the tube is engaged, and the opamps will have a big effect on SQ. The stock opamps are LM4562, my least favorite for music - stuffy.

Incidentally, my favorite 12AU7 tube is the stock EE tube that comes with their 9 pin products. It is not lush or warm, but very accurate and clean without thinning or harshness and it has decent bass. Excellent tube for $10. Of course there are better, but if you like clean tube sound, add it to the mix of your comparisons.

I personally would not spend a lot of money for a NOS Mullard or something exotic like that when there is an opamp coming after it. Any opamp compatible with the EE DAC will have 100dB of negative feedback built in. Some do it better than others, but you'll never hear the tube as you would in a no feedback, all tube design. There are some good threads here and AC about what opamps sound best in this DAC.

When I auditioned the DAC I preferred no tube setting. But iirc that was the version 1 of the DAC, with stock opamps, and I don't know what tube was in it. Other people preferred the tube switched in.

12AT7 will give you more gain than 12AU7, so make sure your preamp VC is not too low when playing a loud signal like a pop tune.

[sleepyguy24]

Hi Rich

I really appreciate the in depth help. Your detailed explanation made me think about a bunch of things from comparison of preamp tubes to even just how I do things when I get anything tube related.

At first I just wanted to put the tube socket saver in place on the EEMM DAC and then role tubes. I like what you said about picking the tube first and then putting the socket saver in place with the tube. I can determine if there is a change in the sonics by establishing a benchmark first. Well I did what you said and I just ended up loving the cryo treated GE 6201 12AT7 type tube in the EEMM DAC. I really liked it over some Mullard 12AT7s I got. That GE tube isn't going anywhere now. If the 6201 tube goes I'm in trouble. The spare I had got damaged due to my mishandling.

To your points about OpAmp swapping. I'm to chicken to do that mod. With my luck I just may damage something. Tube rolling is the most tweaking I would want to make at this time. I've done some lite research on the different OpAmps to be used in the EEMM DAC and I don't think I want to mess with all the combinations. My nervosa and curiosity about different combinations may want me to make more tweaks than just listening to music. Don't want to have my computer on and making a spreadsheet noting combinations and findings. Not fun. I did something like that with my Jolida amp when I first got it. Rolled power tubes, preamp tubes till I just said enough is enough.

Also thanks for the notes on the stock EE 12AU7 tube. I'm normally very bad when it comes to the stock tubes of the equipment I buy. Since I buy used I often read what other users have said in regards to their tube findings. I'll sometimes even ask about their associated gear to see if it similar to mine so I can get an idea if it worth for me to getting that tube. When the tube gear gets to me I often pull the stock tubes and roll right off the bat. I pretty much did that with the EEMM DAC. Gave it a listen and then put in the 12AT7.

You are very right about the volume on the EEMM DAC. I've had to make some adjustments to get it right. Between setting the volume on it and lowering the gain on my preamp depending on the amps I use I've had to make adjustments. I finally have everything adjusted now.

Thanks again for the help.