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Old 21st May 2010, 12:11 PM   #31
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Originally Posted by Nick122147 View Post
If tubelife is 10000 hours, it would equal 415 days if constantly on. I think that not too many people would be comfortable with keeping an amplifier on 24/7all year. if if it only cost you 10-20EUR a year.
not only that. The decrease of tube performance will move faster --- so my views of persistent switched ON have meanwhile changed. But though that I will let the buffer amp still persistent ON. Just for some days till a solution is found I am baking electron-pizzas night and day
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Old 21st May 2010, 02:42 PM   #32
rhing is offline rhing  United States
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Well I tried connecting my Klipsch Forte II speakers to my tube buffer/TA2020 amp yesterday after I turned it on, and no pops as expected. I inserted an OS RCA 12AU7A clear top with side getter in the tube buffer. I have to say that the sound quality was very impressive with a tall, wide and deep holographic soundstage. Arjen is right in his eBay ad that this does smooth the T-amp's sound without sacrificing detail. I didn't hear any tube hiss or hum, although I could hear a faint hiss when I put my ear up to the speaker, but in my listening position about 8 feet away, I couldn't hear anything other than music.

I would say that this combination competes well with my modified EL84 P-P amp and runs cooler too. I have another OS tube--I think it's a Tung-Sol 12AU7 with black plates--to try in the buffer. I think this combination of tube buffer and T-amp has tremendous potential and I am hopeful that Arjen can come up with a solution to the turn-on/turn-off pops. Having to disconnect my speakers from the T-amp before switching it off is not my idea of fun. I'm certainly not going to kill my tubes leaving the buffer and amp turned on. They are both powered by a single regulated Power-One SMPS that I modded.
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Old 28th May 2010, 09:11 AM   #33
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Cured pop on/off problem by fitting two small 'Lorlin' rotary switches to the 13v feed to the tube buffer and ampliifier. First switch switches buffer, second switches amplifier. Turn on switch one, wait a few seconds. Turn on switch two no pop!. Turning off is a reversal of above. Switches off eBay 2 pack Rotary Mains Switch - High Inrush Current on eBay (end time 28-May-10 11:12:22 BST).
4.49 to save your speakers seems a bargain!
Note my buffer is the Mk 1, but same problem existed!

BITF
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Old 28th May 2010, 01:26 PM   #34
rhing is offline rhing  United States
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Hi borninthefifties,

I was thinking about using this:

New AC Selector Switch

and now your post pretty much confirms that the ability to switch the power on to the tube buffer followed with turning on the T-amp is probably the way to go. Thanks for the information.

With the exception of the turn-on and turn-off pop problem, the MkII tube buffer really does improve the sound quality of the T-amp, especially when rolling in a good OS tube like the RCA black plate 12AU7 or RCA clear top 12AU7. The soundstage gains depth and loses the slight edginess inherent in many Class D amps. The overall presentation is smoother and more natural.
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Old 29th May 2010, 07:57 AM   #35
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Originally Posted by rhing View Post
Hi borninthefifties,

I was thinking about using this:

New AC Selector Switch

and now your post pretty much confirms that the ability to switch the power on to the tube buffer followed with turning on the T-amp is probably the way to go. Thanks for the information.

With the exception of the turn-on and turn-off pop problem, the MkII tube buffer really does improve the sound quality of the T-amp, especially when rolling in a good OS tube like the RCA black plate 12AU7 or RCA clear top 12AU7. The soundstage gains depth and loses the slight edginess inherent in many Class D amps. The overall presentation is smoother and more natural.
Hi rhing

That switch looks a neater one switch option and should work well.
At the moment I am using the cheapo chinese tube that came with the buffer, not that up on tube technology, so will have to do a bit of research into a quality replacement now that the pop problem is rectified.

Rgds BITF
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Old 29th May 2010, 01:51 PM   #36
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Default No pop

I have Arjen's 12AU7 buffer board in front of Yuanjing TA2020 amp (similar to the one pictured) and never had any pops, neither when turning on nor off.
Both are fed from the same external 12V 3.33A supply that came from an LCD display.

With 90dB bookshelf speakers 1 meter away even when volume pots are not down nothing is heard when switching on, with 96dB floorstanders I routinely turn the volume down on both buffer and amp anyway and never heard any pops or cracks.

As for the tube choice, I find Sylvania Jan 5963 sweeter sounding than RCA 12AU7 cleartop in this this board. It definitely has warmer and slightly deeper bass.
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Old 9th June 2010, 12:54 AM   #37
reo is offline reo  Canada
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Hi all
to solve the on and off pop .... i didn't have any electronic equipment to adjust my trim pot so what i did , is use a stand alone cheap speaker and hooked it on to left or right channel ,
had the (-) wire connected to speaker ,

i tapped the (+) positive wire on and off the positive wire on the speaker... imitating the off and off switching of the amp and at the same time adjusted the trimpot screw till popping noise is heard no more ,

did the same with the other channel and now that pop problem is solved . Now i can hook up proper speakers to the amp without fear of inflicting damage to speakers .
reo
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Old 9th June 2010, 01:03 AM   #38
Ipanema is offline Ipanema  Malaysia
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Hi Reo,

I don't quite understand your description. Are you adjusting the offset adjustment pot? How does this relate to power ON pop?
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Old 9th June 2010, 01:06 AM   #39
Ipanema is offline Ipanema  Malaysia
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Hi Dovla,

What is the electrolytes value on the TA2020 board? The mention 6800uF, which I doubt it. Anyway, how's the sound compared to Arjen's board?
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Old 9th June 2010, 02:30 AM   #40
reo is offline reo  Canada
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Hi Ipanema
Ah , i had my good speakers hooked up and everytime i turned on the amp and the mk2 buffer , i had this loud pop and disconected my speakers and put on a small stand alone speaker and started fiddling with the offset adjustments and got the noise to go down to almost no noise . i didn't even know what offset adjustments was before you mentionned it , but i had to try something to stop that pop and that procedure as mentionned on the above tread worked for me .
reo
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