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Optimizing the Prima Luna Premium Integrated amp

Having had the Prima Luna Premium Integrated for about 7 months now its been one of my goals to retire the CJ PV10A I had been using for pre amp. However from the start the preamp section of the Prima Luna never seemed to measure up to the CJ in deep bass. Recently however I decided it was time to retube the 12AU7's in the CJ, sticking with trusted NOS Mullard CV4003's. Now having 2 pairs of Mullards to play with I was able to do some comparison swapping in the Prima Luna. Lo and behold, putting the Mullards in the rear 12AU7 sockets of the Prima Luna brought the low bass up to where it should be and differences become trivial swapping a variety of 12AU7's between the CJ and the front sockets of the Prima Luna

Mullard NOS CV4003 highly recommended for the back 12AU7 sockets of the Prima Luna Premium integrated. Not so recommended for both socket pairs as the combination becomes too forward in the bass. Funkwerkes 12AU7 and Prima Luna 12AU7 are in use now while I seek a quicker more neutral tube than the Mullard for the front pair.
128x128davide256
wolf_garcia
4,650 posts
 
I love the sound of my recently acquired NOS Mullard 4024s (replaced my JAN Philips 12At7s due to one failing)...and they seem reasonably priced.
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davide256 OP
362 posts
 
so just an update on current tube rolling. The KT-120's continue to sing...just plain better than the cryo GL-KT-88's all around in the amp. And tube distortion in the pre section is more mercilessly exposed. I've acquired some ribbed plate Telefunken 12AU7's for the back pre sockets, cleaner, better bass, more detail that the Siemens I was using. Flipped my entire inventory of 12AU7's through front sockets again with the Teles in back... 12AU7's just sound wrong in the front sockets, low level details fuzzy, more distortion. Had settled on some Mullard 6201's (12AT7) in front, after putting Telefunken in the back sockets they were still detailed but too bright and I isolated them as a source of low level tube distortion. The Amperex world globe 12AT7's are now back in as more musical but their bass waffles, highs are a little rolled. Likely to pop for Tele or better Amperex tubes in the next 30 days.
At this point with the Teles in I have achieved my goal of retiring the CJ PV10A pre and using the PL pre section
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davide256 OP
362 posts
 
Alright, if you have this amp, listen up. Running NOS (1960's)Siemens 12at7 tubes with triple mica in the front sockets and Telefunken 12Au7's in the back sockets is a match made in heaven. Gobs of low level detail, no tube distortion, no edginess and superb low bass tone colors. The CJ PV-10A is completely retired now, sounds veiled compared to the PL integrated with this tube configuration and Rel cap upgrades. Nice to be finally satisfied and ready to focus on other system areas.
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davide256 OP
362 posts
 
Back to this thread after a while. In the past year I have made the following changes

1) the front 0.22UF caps are now clarity CAP MR's
2) the follower 0.1UF caps are Rel CU caps with 0.01 TFT vCAP bypass caps
3) the power tube 0.22UF caps remain Rel theta's because of space limitations but bypassed with Rel Teflon 0.022UF caps

As these changes were made it became clear that the 12AT7's did add distortion, I now run Telefunken 12AU7's for all pre-sockets.

This is detailed, airy but it does not match the CJ for lower midrange weight, had similar criticism when I had Rel 0.22 teflons in the front sockets before the MR's. I have ordered some VCap CU's to replace the Clarity MR's as these are reported to shift balance to improve lower mid range, will report back in a few weeks after they are installed and have some hours on them.
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davide256 OP
362 posts
 
The VCap CU's have been installed now about 5 days and I have about 20 hours on them. This is a very different experience than other capacitors, gobs of impressive but natural background detail. Oddly they seem to require more power for same volume levels but I have seen this before where old gear was masking signal, emphasizing loudest instrument and new gear in showing more detail, and correct harmonic overtones is consuming power across more spectrum. Very pleased, the CJ PV10A pre can no longer compete, sounds colored in comparison. WIll have to be patient as all I read about others use of VCap states 100 hrs as minimum break in time.
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