I’m Never Giving up Valve Amps

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colin.hepburn
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#1 I’m Never Giving up Valve Amps

Post by colin.hepburn »

Well for a time anyway when I first started out on this project the JE.,labs EL34 SE Amp I mean with a big thank you to all on here and WD who helped me get to an amp that sounded very good in my system and room

With your help it underwent a few tweaks and valve changes I ended up with a 400vHT and using any of the valves from the EL34 5881 and KT 66 all worked very well but my favourers were the 5881s/KT66s I had a very detailed and magical tone in the room with no worries on power from the system it filled the room and still had more to give :D

So I am now thinking if my first amp sounds this good I began to start thinking with delight on an upgrade path and think I would like to try PSE so started to gather parts for this using the Russian 6P3S/6L6 and I also liked the idea of 807s mono blocks perhaps as an end result
Then one night the JE labs Amps Mains TX burnout still don't rely know why but won't go into that here :shock:

However trying to recover the amp with what I had I replaced the old TX with a lower voltage Hammond 260G this gave an HT of 336 volts and a change to the cathode Resistors back to their 680R this alloyed the use of the 6L6Gs so in fact I now have a JE.labs 6L6 SE Amp
But now this amp has lost the magic the EL34/5881/Kt66
had the 6l6 just sounds under power and flat and or gray sounding with vinyl is the only way to describe it or the true way is it sounds shit even using the new 6p3s valve did not help so it wasn't the 6l6s wearing out as I first thought

With CD it is much better but no gain so wont fill the room but to be fare this could be the FET buffer I added to my eBay DAC
The only valve that is better is the 5881s but still not good enough
So the JE amp with 400HT is magical and with the lower 336v HT it's lost
Right I know with different valves we are into load lines which I still need to get my head around but I an afraid its back to my Solid state NAD 352C for a time and to start again by first retraining my ears back to where they were because as of this moment in time there are scrambled

So for now I will look at the idea of a 6P3S PSE with my big WAD Tor 0.45mA TX so will open a new thread 6P3S PSE and I hope you will all continue the help me yes I know I can be a pain and like bear with a sore head but that's just who I am and no offence is intender or should be taken by anyone by the way I may reply to a post :?
Ho and anyway here's the voltages for the JE.Labs 5881 as it is running now


JE Amp with 5881s
B+336v
HT.Anode 327vHT
Cathode L channel 26v/680R=38mA
R Channel 24v/680=35mA
6SL7
Anode HT. L channel 143volts
R channel 141volts
Cathode L channel 1.45v/1000R=1.45mA
R channel 1.41v/1000R=1.41mA
PSU
Hammond TX260G 173VA
550CT@200mA
Current drawn DMM across first Resistor 150R
12v/150R=80mA
All Valves idle current 75.86mA 8)
Last edited by colin.hepburn on Mon Mar 12, 2012 5:26 pm, edited 3 times in total.
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pre65
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#2

Post by pre65 »

My advice. :wink:

Buy yourself another mains transformer and get the KT66 amp back in working order.

You know you like it and it's so nice to have a good amp as a reference to compare with any future amp builds.

Do not argue, just do it. :lol: :lol:
The only thing necessary for the triumph of evil is for good men to do nothing.

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G-Popz THE easy listening connoisseur. (Philip)
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colin.hepburn
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#3

Post by colin.hepburn »

Yes Philip
Your advice has been taken
Slaps wrist for posting that first post but it is how I felt about it all yesterday so last night while out with the dog I gave it some thought and decided to try one more time before wiring the NAD amp back in to the system

So thinking what I can do now when I get back well as I have the 6l 6 cathode resistors at 680R so I tacked in a 3K across the 680Rs and on checking the values of the 680Rs I discovered there are not matched one was correct at 680R the other 673R adding the 3K gave me 549R and 554R
so
This gave me 26v/549R=47mA and 24v/554R=43mA on the 6L6Gs
So connected the CD in the amp jumped into life and is working well now even with vinyl the Sylvania 6L6G a sound rather good as do the Russian 6P3S now just by adding a little more current
So all is well again :o :D :D

But now the 260G Main TX is pulling more current which has gone up from the i had 80mA to 133mA so not too sure on this what would be considered a safe operating current for a 200mA DC TX to run at :?
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#4

Post by pre65 »

colin.hepburn wrote:
But now the 260G Main TX is pulling more current which has gone up from the i had 80mA to 133mA so not too sure on this what would be considered a safe operating current for a 200mA DC TX to run at :?
I would not rate that as "unsafe" Colin.

Does it get hot ?

PS we all have "bad" days so don't worry too much. :wink:
The only thing necessary for the triumph of evil is for good men to do nothing.

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Mike H
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#5

Post by Mike H »

If it helps my AM wireless started out with a 6L6 as SEP stage, never thought it was that marvellous TBH, but occasionally fiddled with it trying to make it better.

Then noticed it getting very 'tired' (strange colours inside the glass) so swapped it for 6V6 which I had by then, as a sperrymint, in comparison the 6V6 is the pooch's dangly bits. :D

So may just be that your KT66's run rings around your 6L6's :?:

So, what Phil said :D
 
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colin.hepburn
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#6

Post by colin.hepburn »

Does it get hot well yes it feels a bit hotter than before but I can still keep my hand on it after about three hour of use

so hoping I should be ok until I get one or maybe a pair of the Antek AS-4T360 but I see there out of stock at the moment give me time to find the cash I suppose thou :)
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#7

Post by Paul Barker »

colin.hepburn wrote:Does it get hot well yes it feels a bit hotter than before but I can still keep my hand on it after about three hour of use

so hoping I should be ok until I get one or maybe a pair of the Antek AS-4T360 but I see there out of stock at the moment give me time to find the cash I suppose thou :)
Sounds alright then.
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#8

Post by Paul Barker »

Is it possible to change the title Collin, I feel like looking for an Oak trea and a strong roap just looking at it.
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colin.hepburn
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#9

Post by colin.hepburn »

Well Paul I have an Oak tree nearby but I don't have any roap :cry:
I know I was close to giving up valves yesterday but we can't really do that can we :D 8)
They say it happens in threes well if that's true it has and should be over now
1 transformer burnout
2 my fav pioneer 801 CD player :shock:
3 my pioneer 801 CD player I got for spares for the other one both have same fault :x :x
Would you believe it?
Title Changed
Last edited by colin.hepburn on Mon Mar 12, 2012 5:30 pm, edited 1 time in total.
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#10

Post by Paul Barker »

:occasion5:
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Mike H
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#11

Post by Mike H »

colin.hepburn wrote:I know I was close to giving up valves yesterday but we can't really do that can we :D 8)
Solid state isn't simple either :D
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
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colin.hepburn
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#12

Post by colin.hepburn »

Mike H wrote:
colin.hepburn wrote:I know I was close to giving up valves yesterday but we can't really do that can we :D 8)
Solid state isn't simple either :D
Yep it's likely more so for me anyway but cheaper to fix no worries thou the valves are staying 8)
I do travel on many a rock road in the world of diy HiFi just got some big rocks in the way for now but I will get there :)
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#13

Post by Mike H »

Well if it's any consolation, was the same for me about 30 - 40 years ago :lol:
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
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