@gonzoucab - Congratulations on your new Leaf!
A quick search found these two audio sessions with the Leaf Audio PA-03 MKII Preamp+Mono Blocks, another with the only the Leaf Audio PA-03 MKII Preamp...
Leaf Audio: Pre PA-03 MK2 Tube, Monoblook PA-01 Class A 60W/Kênh, Class AB 250W/Kênh - YouTube
The Youtube auto-translate is amusing, it is tough to make out from the translation what he is communicating...
If I Were aBoy ทดสอบ Hifiman HM901R ภาค Dac - YouTube
And, he has a number of other listening sessions using the Leaf Audio PA-03 MKII Preamp:
Jirapong Kusrisomsub - YouTube
Which reviews or listening sessions did you find before ordering that convinced you to purchase the Leaf Audio PA-03 MKII Preamp?
If you enjoy the Leaf Audio PA-03 MKII Preamp in your setup, I wouldn't worry about the measurements, but it sounds like you heard problems in the audio before sending it to Amir?
I've seen these listed on
eBay and
AliExpress. I had an ARC Preamplifier long ago, but the insides of the Leaf didn't remind me of the Audio Research build, and the LS22 had 8x tubes while the PA-03 only has 4x tubes, so I passed it by when scanning for Tube amps to drive my Hifiman HE6SE V2's + HE-Adapter.
It is tough to tell from afar which make/models are worth getting, so I extensively check out the forums, review articles, and youtube videos. Without independent measurements and a listening session (in person) before purchase, it is tough to know for sure what to purchase.
You can return purchases to China sellers, sometimes they have USA warehouses for support / returns, it is worth asking the seller, perhaps
@amirm can ship out the return from his location to beat the return end date? Sellers may give push back, but be insistent and involve eBay/AliExpress Support if needed. If you are past the return period, ask if they will give you credit on another purchase..
As a newbie audiophile I wouldn't be discouraged, as there are ups and downs in learning any new hobby. Perhaps you can tube roll to improve the sound to your liking? If you are unable to return it that might be worth a try before performing more extensive modification surgery.
These are the tubes listed by this
AliExpress seller as compatible:
Standard electron tube: Chinese 6N11 electron tube x 4 can be replaced by E88CC, 6922 and 6DJ8
Here are a couple of suggestions for compatible tubes. The first are NOS (New Old Stock) 1972 - about $50/tube is typical for true NOS tubes - not used pulls but actual New Old Stock never used tubes, and then a Quad of new issue Genalex Lions - about $36/tube:
Matched Quad Tesla NOS/NIB E88CC/6922/6dj8 tubes Gold Pins - 1972 - Tests NOS | eBay - Original Czechoslovakia made
PLATINUM Matched Quad (4) Genalex E88CC/6922/6DJ7 tubes Gold Pins - Russia | eBay
I've found Nikolay is a reliable seller over a number of purchases. He also maintains a tube info site. I can recommend other sources, but Tube Maze is a great start, and he offers 30 day returns:
Tesla E88CC Gold Pins - Tube Maze
Tube Maze - Guides and reviews of vacuum tubes and tube equipment
Those are the recommended budget choices - there are cheaper alternatives, and Rick and Austin at Viva Tubes have been reliable for me as well, they offer 60 day returns:
Brand New Electro-Harmonix 6922 E88CC GOLD PINS Matched Quad (4) Vacuum Tubes 844632064210 | eBay
Gain Matched Quad (4) JJ 6922 / E88CC / 6DJ8 / ECC88 Vacuum Tubes - Brand New | eBay
VIVA TUBES | Thousands of vacuum tubes always tested, matched, and guaranteed
And, there are also more expensive choices:
A
mperex 6922 | eBay
Amperex 6922 tubes are highly desired - you can see the prices - and this listing caught my eye as the measurements indicate NOS 100%+ and are only a little more expensive than the Tesla Yellow label 6922's I listed above. IDK this seller, but he has a
100% rating on 2678 transactions, but doesn't take returns. These are worth a shot, but I'd also get either the Tesla's or the Genalex as backup - and to compare the sound for your tastes.
AMPEREX JAN 6922 E88CC Gold Pin low noise preamp tubes quad 6DJ8 USA | eBay
You might want to start up a conversation with those sellers, explain your situation, perhaps share Amir's review and ask them what tubes they would recommend.
Given my experience with the stock China tubes I can recommend trying tube rolling to improve the sound.
Also, given complaints I've heard about China shipped products from others, it is worth going through the unit to find cold solder joints, unsoldered joints, loose ground lugs, loose fasteners in general, and simply reseating the tubes given they've been jostled about during long shipping voyages. So far I haven't experienced any of these issues, but it is worth checking to make sure.