Ref6 tube rolling
- Thread starter Golum
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After many years of playing with HiFi gears, my impression is we are listening to the electricity. It is the electricity can make the sound, the music signal is to tune the sound.
You can imagine HiFi system is a musical instrument, say a guitar, electricity is the finger pick on the string and music signal is the score which the tones are played. This explains why changes in power line can have profound effect on the sound.
Vacuum tube and transistor are valves, they open and close to let current flow, very much like the turning of water tap on your toilet. The flow comes from the power supply and the turning of tap comes from the music signal. So it is not entirely true that you mention the tubes in the power section is not in the signal path. They are, more so than in the signal tubes.
I would say the music signal modulates the electricity.
But yes, as Vladimir Lamm will tell you, a power supply is an integral part of the signal path.
Great info! I put NOS 6h30's and GE 6550's in my Anniversary 40 the second I got it and never looked back. After reading this thread, I went thru all my 6550's and found a brand new pair of Tung Sol grey plate, 3 hole from January1965. Incredible! That mid range magic was there from the beginning, but after a couple days of burning in, I think they are the perfect tube for the Anni. Worth a try and maybe a larger difference than changing out the 6h30's.
Ajajjaja seems like screwdriver needs to be deployed again to check what happens when 6550 and coresponding 6n30 gets swapped
Micro, how exactly do you match your tubes in the Ref 10 or 40 Anniversary? My understanding is V1-V4 are the tubes for the R&L balanced gain stage and V5-V8 are cathode followers.
Is matching Mu is somewhat more important for the gain stage, and Gm is more important for the cathode followers?
Since the 6H30s are 2 sections tubes run in parallel, what percentage target variation is acceptable, for you, within a tube? What percentage variation for pairs of tubes, say V1 and V3? I would assume you might use the same standard for matching the right channel, V1-V3 to the left channel, V2-V4.
Thanks for your thoughts on this.
Is matching Mu is somewhat more important for the gain stage, and Gm is more important for the cathode followers?
Since the 6H30s are 2 sections tubes run in parallel, what percentage target variation is acceptable, for you, within a tube? What percentage variation for pairs of tubes, say V1 and V3? I would assume you might use the same standard for matching the right channel, V1-V3 to the left channel, V2-V4.
Thanks for your thoughts on this.
Probably it is why the L2ref preamplifier sounds so good - very elaborate tube power supply with solid state signal amplification.
I test them in similar conditions as they are being used ~ 180V regulated power supply at 9 mA each triode. I match first for similar plate intensity each triode, than Gm. As you say I select the best Gm match for gain (~2% variation) and use others for the cathode followers. I discard tubes having more than 3% variation in IP for each triode and showing any noise. BTW, I only test them after 100 hours burn-in - they need some time to stabilize and reduce (or very few times increase ...) low frequency noise.
Surely the same care for left and right. No politics in WBF ...
One other quick question, micro. What are your average Mu and Gm readings for your 6H30 matching set-up that corresponds to in-circuit operations? Just trying to confirm other operating parameters.
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My gig has no absolute calibration, only relative. I inject a 1V peak to peak signal and measure the output.
The DC measurements are carried with a Fluke, all else with an audio analyser / generator.
Unfortunately my regular tube tester does not accept 6h30's, I can't get a calibration point and I never did the calculus of Gm for my home built tester.
Congratulation. Those NOS Tung Sol 6550 is really good. 3 hole grey plate has a slightly faster sound than the smooth plate ones but still much better than modern tubes.
I used Anniversary 40 before changing to Ref 10 and agree with you. The 6550 has the largest effect in the sound. 6h30 in the power section is second and all other 6h30 in the output stage is only third. For those who wants to start tube rolling should follow this order for maximum result.
This is exactly how I use them for my ARC Ref 10 and Ref 10 phono. Tung Sol 6550 black plate with 6n6p in the power supply and 6H30DR in the main unit. I found it have the best on both worlds.
6n6p is very musical regardless on where it is installed.
Key two letters here are “DR” not crappy new production 6n30
Well .... okay, I'll take that smiley. :-o
The issue with the 6H30DR is availability. I was in contact with the fellow (Conus Audio) who brought the last of them from Russia to North America but that was several years back and they're long gone. The trick was to buy them (~$35usd) before they really went up in price. No doubt individual users may have stashes, but nowadays they seem largely unobtanium. There are conterfeits.
Recognizing Original 6N30 ?? - 6H30 DR Tubes
Edit:
Fwiw - 2010 WBF thread on 6H30DR:
6H30's--Are the more expensive/megabuck versions worth the money?
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Exactly as you said.
DRs are super heavy to find and even if you find them prices are insane. Just seen the matched quartet on eBay for almost 1.3k$. So comparing 6n6p with those is kind of pointless as 6n6p you can easily find (still) and pay 20-25$/matched quartet.
Even getting them just for trial purpose and fun makes a lot of sense for all ARC (BAT, Ayon) users as there is a huge chance they'll end up liking what they will hear.
Just my 2 cents..
DRs are super heavy to find and even if you find them prices are insane. Just seen the matched quartet on eBay for almost 1.3k$
. So comparing 6n6p with those is kind of pointless as 6n6p you can easily find (still) and pay 20-25$/matched quartet.Even getting them just for trial purpose and fun makes a lot of sense for all ARC (BAT, Ayon) users as there is a huge chance they'll end up liking what they will hear.
Just my 2 cents..
I tried a matched pair of 6H30 DRs in my Ref40 Anniversary power supply back in 2012. Different compared to the Sovteks, but not better to my ears, in my set-up.
Buying NOS is a real crap shoot. Yes, price and availability are both problematic, but quality is a big issue too.
Buying NOS is a real crap shoot. Yes, price and availability are both problematic, but quality is a big issue too.
TLI, which year is printed on your 6h30dr? If it is before 81, than it’s the best you can find. But very difficult. I have still 10 of them from year 78.
concerning 6550 black plate, it´s true they were the best , especially with 3 getters. But the grey plate of the early 60´s, without holes were more musical. But this is a question of taste..
concerning 6550 black plate, it´s true they were the best , especially with 3 getters. But the grey plate of the early 60´s, without holes were more musical. But this is a question of taste..
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