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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
lloydc's avatar
lloydc
755 posts
 
Matched modern power tubes are fine.  8 matched NOS power tubes would cost way too much, and besides, you won’t really find 8 matched tubes- there aren’t enough of them to sort and match them like they can new production.  The recommendation for 8 premium matched Shuguang Treasure tubes is a viable answer to your question, but is almost absurd; too expensive to put so many in a budget amp.   
   The small signal tubes make the most difference and the cost is justifiable (to an audiophile, hah!)
   If you must, Mesa can sell you a set of matched Siemens EL 34’s.
bluesy41
211 posts
 
@lloydc - you must have never been to Upscale Audio store or website. They have plenty of matched NOS tubes. I just bought 8 NOS Mullard CV4003 12AU7 and will order 12 new high grade Brimar’s for my amps. I definitely stay away from eBay sellers for tubes and go to UA. 

@meiatflask - I would definitely reach out to Kevin Deal and team for advice on the sound improvements you’re seeking. I have KT150 in my PL HP monoblock amps and they sound incredible.

Cheers
lloydc's avatar
lloydc
755 posts
 
Blues41, Small signal tubes are plentiful and to some degree afordable.  I was referring to power tubes. 8 old matched Mullard el34’s?  You can’t be serious.
bluesy41
211 posts
 
@lloydc sorry I misread power tubes. I was speaking in terms of NOS 12au7’s. 

Cheers 
meiatflask OP
155 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.
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