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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

Showing 3 responses by bluesy41

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

Cheers 
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
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