Woo Audio WA7TP (tube power supply) Impressions Thread
Sep 27, 2015 at 8:34 PM Post #947 of 1,117
 
First up I am not an engineer so this is just what I could put together from scanning some heavy technical journals I didn't fully understand.
The tube rectifier is a switch , it is on when the positive part of the ac is flowing but then because it will only allow electrons to flow from cathode to plate it is off when the ac goes negative .
An ideal rectifier would switch off and on with a sharp almost square wave so when a number of these wave forms are combined at slightly different timing a flat dc current would result
However tubes react differently to the switching task some switch on fast but off slow some visa versa so some tubes would make sharp bumps some soft bumps
Rectifier circuits use things like chokes and capacitors to smooth out the bumps and produce a clean flat dc supply but it is never perfectly flat as a battery might produce
Some part of the individual character of the tube comes through to the amp in the form of imperfections in the "shape" of the dc stream
How this translates into stronger bass or wider sound stage etc , I have no idea but it most certainly does

Had to read this three times in a row, but I think your explanation makes sense. :) Thanks!
 
Sep 27, 2015 at 8:36 PM Post #948 of 1,117
One of the big differences is in the internal resistance of the power supply as seen by the amp.  Simply by how much does the voltage drop depending on the amount of current being demanded.  A good power supply has a very low output resistance and will output the same voltage regardless of the demand.  Another aspect is much like what was mentioned regarding the amount of ripple in the voltage provided.  A good power supply has no ripple which would translate into a proportional ripple in the output signal of the amplifier depending on how well the amplifier tolerates ripple.  In these sort of no feedback architecture amplifiers ripple is hard to correct for so it is worth beefing up the power supply and filtering to reduce ripple from the get go. We can only assume the choice of tubes in the power supply plays a big role in determining these two qualities.
 
Sep 30, 2015 at 9:39 AM Post #950 of 1,117
Plugged in the Sylvania 6350's to my work rig and woop!  Sounds great was easy to hear a difference immediately.  Bit more instrument separation, extended clearer highs and tighter bass.  All around a more cohesive authoritative sound.
 
Sep 30, 2015 at 2:01 PM Post #951 of 1,117
@groovyd  - exciting stuff, sounds like the 6350s could be a winner.   Head-Fi salutes those pushing the boundaries with extreme tube-rolling.  
 
Are the adapters decent quality ?  
 
As a great man here once said... "Pictures or it didn't happen".....   
popcorn.gif
 
 
Sep 30, 2015 at 7:53 PM Post #952 of 1,117
  Plugged in the Sylvania 6350's to my work rig and woop!  Sounds great was easy to hear a difference immediately.  Bit more instrument separation, extended clearer highs and tighter bass.  All around a more cohesive authoritative sound.


Great to hear you took the plunge with positive results .
Now we just need to work out if the GE , Sylvania and RCA versions are any different
  @groovyd  - exciting stuff, sounds like the 6350s could be a winner.   Head-Fi salutes those pushing the boundaries with extreme tube-rolling.  
 
Are the adapters decent quality ?  
 
As a great man here once said... "Pictures or it didn't happen".....   
popcorn.gif
 

Come on Jeb Listens you're next
As far as the adapters are concerned they seem very well made certainly feel solid , hard to tell what is going on inside
I have three different sets from the same people and they all work flawlessly so I would recommend
 
Oct 1, 2015 at 9:05 AM Post #953 of 1,117
Just plugged in the EH Gold Pins for the first time last night. 
 
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I don't remember the last time a tube upgrade created such a sonic improvement!
 
 
This little cube continues to impress... I was on the fence about whether taking the plunge on this guy would be a worthwhile upgrade over my beloved Pan Am, but every time I listen, I feel better and better about the decision!
 
 
Now if only I could find a buyer for the Pan Am...
 
Oct 1, 2015 at 10:23 PM Post #955 of 1,117
New tubes!

NOS Sylvania JHS-6189

NOS GE 5 star JG5814a

Anyone have any experience with either of these?

EDIT: Figured I'd go ahead and post my impressions:



These GE's are no joke! Coming from the Sylvanias, they have a better all-round low end - more quantity, better quality, and lower reach. Haven't noticed as much difference in the midrange and treble, but I've only had 'em in for 10 minutes. Will post more thoughts later on!
 
Oct 7, 2015 at 12:20 AM Post #956 of 1,117
New tubes!

NOS Sylvania JHS-6189

NOS GE 5 star JG5814a

Anyone have any experience with either of these?

EDIT: Figured I'd go ahead and post my impressions:



These GE's are no joke! Coming from the Sylvanias, they have a better all-round low end - more quantity, better quality, and lower reach. Haven't noticed as much difference in the midrange and treble, but I've only had 'em in for 10 minutes. Will post more thoughts later on!

To follow up:
 
GE 5-star: 8/10 - More midrange/treble oriented than the Sylvania. Because the upper end is a little more refined, I feel like the soundstage and 3D-ness is better. Very clean overall with a more linear low end than the Syl.
 
Sylvania: 8/10 - A little warmer with a bit more thump than the GE. Upper end isn't quite as clear, but bass guitar and kick drums are more fun, so I suppose it's a trade off.
 
Oct 15, 2015 at 7:24 PM Post #958 of 1,117
I don't own the lcd3's but have lcd2's and owned the wa7/tp for about a year and they sounded just great together.. 
 
Oct 16, 2015 at 10:45 PM Post #960 of 1,117
  yes i own 2 sets of WA7/tp and 2 sets of LCD-X/XC and the pairing is great


Need some extra tubes? LOL
 
I thought about doing the same especially with some nicely priced WA7 in classified. I decided to get a Schiit Mjolnir 2 instead for my home amp. My WA7 will be heading to my office. I find myself listening more at work lately. Now I have a full balanced at home and full SE at my office. I also thought about a WA22, but it won't fit in my home setup.
 

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