Upgraded Leak

[bhobba]

Hi Guys

In another thread I mentioned how impressed I was with a heavily upgraded Leak I heard (see attached pickie).

Got one myself and thought it might be interesting documenting my experiences upgrading it here.

Got some supposed gun valves from a real valve aficionado - they are supposed the bee knees - don't know too much myself - hopefully some here can :

3 - 1950s /60s NOS new in box Siemens 5751= E83CC / 12AX7 / ECC83 Triple Mica Tubes.

3 - 1950s /60s NOS new in box Siemens 5814A =E82CC / 12Au7 / ECC82 Triple Mica Tubes.

4 - 1950s /60s NOS Mullard EL84 Tubes.

1 -1950s/60s NOS  Mullard GZ34 Tube.

Can report what they do when I get a bit of time.  At the moment the power chord that came with the Leak needs to have an Australian plug to work.

Thanks
Bill

[rollo]

   Looking good there Bill. Some nice tubes as well. I see lots of Duelunds in there buddy. Good listening my friend.


charles

[Response Audio]

Looking real good
Very clean work inside.

[rollo]

Looking real good
Very clean work inside.

  Especially if it was hooked up to one of your preamps oh my !  But but Bill does not use a preamp, bad boy he is.



charles

[bhobba]

Hi Guys

Heard the Leak for the first time yesterday.

With the supplied tubes one of the best valve amps I have heard - but, as you would expect, not up there with the the heavily modified one I head at the GTG that so impressed me. Lovely sound - but speed was the issue in comparison to the Arion 500's.

Changed to the better valves.  Instantly better - a lot closer to the one at the GTG - but still not quite there yet.  Cleaner and clearer - but again speed didn't quite match the Arion. 

Decided to use Duelund VSF Copper because I don't think the Cast will fit, and have ordered them.  When they arrive will get them installed and have the resistors upgraded and the electrolytics changed probably to Jenson, then see what that does.

Very promising so far.

Thanks
Bill

[bhobba]

Especially if it was hooked up to one of your preamps oh my !  But but Bill does not use a preamp, bad boy he is.

I really am a naughty boy - can I be diciplined - please - please   .

Seriously I have a new DAC on order called the Killer that has a valve output stage that is the perfect match for the Leak. The input sensitivity of the Leak will be adjusted to match.

This is a very special DAC, using the legendary Phillips Double Crown chips, and people have been waiting a long time for me to get mine.  Those into this DAC generally prefer valve gear and are a lot happier with the Leak being used with it than my usual Arions.

Of course I will try it with both.

Thanks
Bill

[bhobba]

Looking real good :drool:Very clean work inside.

Yea - great looking work.

But I didn't make it clear - this is a picture of the upgraded Leak I heard that impressed me so greatly.  

I hope to bring mine up to that standard - maybe even beyond - time will tell.

Thanks
Bill

[Triode Pete]

Good Luck, Bill! It should really sound great when you're done with it! 

Enjoy!
Pete

[rollo]

  Is something leaking around here. Curious minds need to know.


charles

[bhobba]

Is something leaking around here. Curious minds need to know.

Good one.

Ordered the VSF Copper to replace the .25 coupling caps to the output valves, and Jensons for the power supply electrolytics from the local Duelund dealer.

Had a chat to the guys whose upgraded Leaks I heard, and they said they used whatever they had lying around such as Allen Bradleys for the resistors and Duelund Alexanders for some of the coupling caps.

I don't have parts lying around so decided on a more scientific approach.  Had a look at the circuit diagram and removed the grid resistor into the input valve because it will be replaced by a pad to adjust sensitivity.  This left some 10k resistors in the signal path at the output valve grids and after the coupling caps - am getting the best resistor I know for that - naked Z-Foils.  The rest will be 2 watt Amtrans carbon films.

Here is an interesting comparison between the two:
http://www.diyaudio.com/forums/tubes-valves/190095-resistor-test-tx7525-amrg-cmf55.html

The Z-Foil sounds really open. Big bass sound, the strings of my stratocaster seemed to come out more out of the speakers, very good separation of the single string, rich in detail, reminded to a piece of wire. They have the tendency not to make sound. On the other hand, they are the most technically sounding resistors. At some cathodes I liked these most, but not at all places. As always a matter of taste.

These black beauties (Amtrans) sounded very open, airy with a little sweet touch, in a musical sense wonderful, but a little sound making. Big bass too. At some places I loved these most, but not everywhere.

I was told an interstage .1uf coupling capacitor wasn't that critical so decided on an Obligato Gold rather than the whole hog of a Duelund.  The 50uf electrolytic bypass capacitors will use Jensens - but may switch to film if space permits.

Small capacitors will be silver mica's.

Will get some high end wire from a local speaker maker that he wires all his speakers with and change terminals etc to Eichmann.

Anyway that's it for now.

Have to wait for the parts to arrive for the new amp to take shape.  Since its Christmas no use ordering now anyway - will wait for the New Year.

But this is only a start - I have been by those really into it its a never ending process.

Thanks
Bill

[rollo]

  Someone has been a busy Bee. Sounds good Bill. Bill if ya did not order the Eichmans yet please consider Furutech or Vampire Xshadow. No plastic parts. The Vampires are the Cats meow.
   The Z-Foils are neutral alright. Maybe a tad thin in certain locations as you know.
     As far as speaker cable I think its time to send you a pair to play with. I used the copper foil from our buddy until the others came along. No turning back.
   Looks like its fun fun fun for ya. Cool stuff.



charles
   

[bhobba]

Bill if ya did not order the Eichmans yet please consider Furutech or Vampire Xshadow. No plastic parts. The Vampires are the Cats meow.

Yea - some guys have been telling me about those and some other stuff has a slight edge over the Eichmann.

Thing is Eichmann is a local outfit having their factory here in Brisbane at Coorparoo.  Because of that they are a dead cinch to get a hold of where I am. 

What I thought was to use them as a start and take it from there.

Thanks
Bill

[DaveC]

I agree about Furutech or Xhadow over Eichmann. Eichmann plugs are ok but the ground connection is far too small, it's best to minimize resistance in the grounds...

Interstage coupling caps make a pretty big difference, if you don't want to spring for Duelunds I would go with another copper foil cap. I am using RelCap PCUs and am very happy with them.

For wire, of course I think Neotech and Duelund are tops... 

[bhobba]

Interstage coupling caps make a pretty big difference,

They certainly do.

Its just to start with in that spot - will see if Duelunds there make a big enough difference to be worth it later - along with lot of other stuff.

Interesting times ahead.

Thanks
Bill

[bhobba]

Hi Guys
 
Well the first stage of my Leak upgrade has been finished.
 
This was everything except the power supply electrolytics which will be replaced with Jensens, and the interstage coupling caps that are Russian Paper In Oil at the moment but will be changed to Duelund VSF Copper.
 
This is one fine sounding amp.  It's very transparent an neutral. 
 
I compared it to an upgraded Prima Luna and my initial reaction was the Leak was slightly more neutral and fluid, the Prima Luna Luna slightly more lively and sweet.  The Leak did it for me just a bit better.  But a lot more listening will be required.
 
Thanks
Bill