[walkern]

I just ordered a 2A SE from Lloyd, and while I'm waiting for him to build and ship it I figured I'd check with everyone here to see what tweaks, mods or upgrades seem to be favored.
Any recommendations regarding power cords, umbilical cords, bypass or coupling cap upgrades, volume control upgrades, and in particular any 6 or 12SN7 suggestions would be greatly appreciated.

Neil

[Tyson]

Upgrade the umbilical for sure.  Tungsol 6sn7's and sylvania 12sn7's are the best I've heard so far and ken rad is a very good rectifier tube, better than the tungsol I tried.

[rajacat]

I bypassed the output caps with Russian T1 Teflon caps to good effect.



I also replaced the stock Alps Blue attenuator with a SMD stepped unit. This too was an audible improvement. I had the Mapletree 3A which has a stereo attenuator. I think that Valab also has mono units which would fit your 2A.
http://cgi.ebay.com/DACT-Type-23-Stepped-Attenuator-Potentiometer-100K-el34_W0QQitemZ290309210988QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4397c7036c&_trksid=p4634.c0.m14.l1262&_trkparms=|301%3A0|293%3A1|294%3A30



-Roy

[Berndt]

I had the RAL umbilical, Black gate PS cap and black gate coupling caps.
Was curious about tantalum resistors.
I was happy in the end with Sylvania/ratheon 6sn7's, or Japanese 12sn7's mazdas or channel masters.
Wouldn't suggest the black gate on the PS as it made the bass overripe.
Great bang for the buck, I still have some 12sx7's and 12sn7's I am no longer using if anyone is interested.
regards, Bill

[Berndt]

I use the russian caps in my current pre and phono stage as well, another good buy.

[walkern]

Thanks Tyson, Roy and Bill! 

And, does anyone know of an alternate (but still better than stock) umbilical besides the RAL.  I was hoping not to have to spend that much, but will if that is the best choice.

I was planning on using the Platinum Teflon .01 mf cap for the bypass on the coupling caps, but will certainly consider the Russian ones.  Anyone got a good source for them?

Thanks again all.

Neil

[Bigfish]

I followed the advice of TopRound and had Lloyd move the location of the fuse to prevent it from interfering with the fit of after market power cord plugs.  Lloyd's normal location for the fuse is directly beside the power cord connector.  With the large plugs of some cords you will get an interference.

Ken.

PS.  I had Lloyd upgrade the Caps in the pre and in the power supply.  You will want to experiment with tube rolling.  12SN7's are typically 1/2 the price of 6SN7's and sonically are identical.

[walkern]

Thanks Ken for the advice about having Lloyd relocate the fuse holder.  I will drop him an e-mail since I certainly can't resist toying with some after market power cords.

I think I will tinker with caps on my own rather than have Lloyd install anything exotic.  I have had "mixed" results with some caps (Black Gates in particular) depending on how well they compliment the component they are going in.

And speaking of power cords, does anyone have a favorite?  I recently bought a Kaplan PC for my Aksa amp, and was stunned at how much better it was than anything I've tried before.   I am hoping to spend less for the PC for the Mapletree.

Thanks too for the advice regarding the 12 vs 6 SN tubes.  I've been scoping out various tube vendors looking for good deals, and if the 12s are as good as the 6s, what the heck... I'll save myself some $ to use for other tweaks.

Neil

[rajacat]

  In my system I found that the 12sx7s' occupied the midpoint between the 12sn7 and 6sn7s'. I finally ended up using some Sylvania 6ns7 brown bases as my main tubes. They seemed to be more dynamic, detailed and exciting than the 12....s'. Of course much of this is system dependent.

-Roy

[droht]

walkern, what did you end up ordering?  What is timing?

I may be going this route as well.  I'll be very curious to read your impressions.

[AudioSoul]

  Whooo there boy ! You want to know what tweeks to use in a preamp that is new and you dont even own yet? Isn't that a little premature? Why dont you listen to it let it breakin, then decide what you dont like about it then address those issues......

[walkern]

I've had my order in for a few weeks now, and my preamp is under construction.  Lloyd seems to think it will be shipping out from Canada today.  Wooo Hoooo!

And, although I appreciate the advice regarding leaving well enough alone (particularly with a brand new piece of electronics), I respect the owners who've had time to play with theirs and am happy to tweak anything if it will result in a more musical outcome.  I will undoubtedly start off listening to the stock unit (using an upgraded power cord though... I have an assortment to try, and stock cords are generally throw ins), and then consider tweaking after the unit has had a chance to settle in and reveal its strengths.


Thanks again to everyone who has contributed ideas and suggestions


Neil

[Tyson]

A couple more things - the grounds of all inputs are all tied together using the case itself, this is OK, unless one of the RCA input jack connectors comes a little loose, then you lose ground.  A good option is to simply solder a wire across the inputs to have a more solid ground connection.

Second, the tubes used on the output must be well matched or you will get a channel imbalance.  The design uses the tubes in a one-per-channel configuration.  In other words, it uses both triodes in a single tube for a single channel.  If your tubes are poorly matched, you will get some center drift in the audio image.  Most reputable dealers will be happy to send you a matched pair, if they have some.  I just had a Sylvania 12sn7 tube start to lose its life and the image shifted dramatically to the left.  Swapped the tube positions and the image followed the tube to the right side.

On one hand, it could be bad because it might leave you with one good NOS tube and no matching one.  On the other hand, I think this actually helps identify weak tubes right away and get them out of the preamp.  Other designs are less obvious and thus you might have a sub-optimal tube longer than you might want (and thus less than optimal sound that you don't notice, because it degrades gradually over time).  I also think this design choice is one of the reasons the 2A SE sounds so good.