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EL34 tubes- alternates to matched octet for Primaluna HP dialogue premium

I have the Primaluna Dialogue Premium HP power amp that uses 8 EL34 tubes.  I am currently using the stock EL34s, but have noticed a nice improvement in imaging when I switched to NOS mullards 12au7s.

As I look at playing around with different power tubes, (especially NOS Varieties) I see numerous sets of matched quads out there, but never matched octets, unless they are new production.

my question is this:  what do I lose sonically by using unmatched tubes, or two sets of matched quads, or four sets of matched pairs?  Wondering if since the Primaluna is self biasing, if it is less sensitive to non-matched tubes than other amps? 


meiatflask
bluesy41
211 posts
 
@lloydc sorry I misread power tubes. I was speaking in terms of NOS 12au7’s. 

Cheers 
meiatflask OP
151 posts
 
bluesy41- in what way are the KT150 better than the stock EL34?  midrange warmth, imaging, detail, soundstage, bass?   are they a "blow me away" change? and who's KT150s are you using?

tooblue & lloydc- are the Shuguang 6CA7-Z 50 Year Treasure Tubes a "nice improvement" over the stock EL34s or a "blow me away" change?

the NOS mullards 12au7 was a blow me away change in terms of soundstage and imaging.  I am wondering if I can find a similar improvement in the power tubes.  And I am not opposed to spending a few bucks.  After all, the other option to serious upgrade is a better amp, which is a whole lot more money than tubes.
dazzlingmd
71 posts
 
I had that exact amp for a while and had a lot of fun doing some shootouts with various EL-34s and KT-120s.  The clear standouts were the NOS RFT EL-34s and the PSVane EL-34s.  I could have lived happily with either set and they made a huge difference over the stock tubes.  Huge.  Particularly in the highs (less harsh than the stock tubes—but my system is very resolving and accentuates sharp highs when they are present), and much warmer miss and overall fuller richer sound.  

I didn’t have the guts (money) to spring for anything like NOS Mullards or Siemens.  Those are crazy expensive.  RFT manufactures EL-34s for Siemens and others back in the day so I think it’s a good way to try something that should be in the same league for a lot less money and see what you think.  A matched quad of those is $250 or less on eBay.   I stuck with those and never looked back.  Until I switched amps of course (that was 3 amps ago).  The journey never ends.  Enjoy yours.  
bluesy41
211 posts
 
@meiatflask - I have Magnepan 20.7 Planar speakers and so my amps came with stock EL 34 which were very warm and gave me that very intimate tube sound that we all love, but lacked in the area of bass and dynamics compared to the KT150’s. I also believe the 150’s expands the soundstage a few rows further than the EL34’s. More like being in the 5th row. You do lose some of the subtle nuances and inner detail that the EL34’s give but I’m talking a fraction. I have the Tung-Sol KT150’s and IMHO they are simply bad-ass.

Cheers
tooblue
1,927 posts
 
For me the 50 year Treasure tubes are  a blow me away change.
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