Well my friend who built me the amp found the power transfer dead on its HT side, and he sourced another toroidal and installed it for me. He also put two EZ81 INSTEAD of the bridge rectifier for me on my request.
Ever since then, I foudn the left right channel thrown out, not just by imbalancing, but different FR all together at that.
I measure the OPT and foudn them still perfectly balanced with each other.
This whole thing put me off and I haven't touched it for amost like what ...... 5 years!! In the interrim, I broke two of my EL153 tubes.
Yikes!!!!!Now I'm back at it, having bought many otehr tube gears as well.
Next, I'd like to adopt the design other members mentioned here in this thread since it has received good reviews.
I thank all of you for your expressed enjoyment of the tube EL153 and revelation that has been given to me.
Later.....
Terence
All right, my last post of today's says I am at the project again.
Now I'd like to copy our dear Romanian master's design [my big thank!!], except that I dun have any EF80.
I like EF86, ECC88, 12SL7, 12SN7, 6CG7, or 5687 for their usually good quality and designs. The 12SL7 is especially intersting to me coz it is so so cheap and very few ppl use it as pre-stage tube, probably due to its 12V filament requirment, making it available on eBay vastly at throw-away prices. But if I use a separate filament transformer with 6-0-6 output taps, this can be solved.
Can someone help me with re-designing the pre-stage around one of those tubes above?
Thanks.
Now I'd like to copy our dear Romanian master's design [my big thank!!], except that I dun have any EF80.
I like EF86, ECC88, 12SL7, 12SN7, 6CG7, or 5687 for their usually good quality and designs. The 12SL7 is especially intersting to me coz it is so so cheap and very few ppl use it as pre-stage tube, probably due to its 12V filament requirment, making it available on eBay vastly at throw-away prices. But if I use a separate filament transformer with 6-0-6 output taps, this can be solved.
Can someone help me with re-designing the pre-stage around one of those tubes above?
Thanks.
Hello, everybody!
About the voltage of the EF80 - I think the anode current is important...not the voltage applied through one high value resistor.
I have the author's permission to post another schematics for driving these tubes...at the beginning I asked him to draw the schematics for other driver, me too didn't have new/nos EF80's. In the meantime I got a pair of new Tungsram EF80 - also the used ones I had for the first build were still good enough, about 80% emission. The tube we agreed to use for driving EL153 was EL803, I have two of them NIB and it was a nice idea to use only TFK tubes. But this is for future plans...I intend to build the pentode version, to have enough signal swing for old sources I use with this amplifier.
Instead of EL803 one can use EL83, they are cheap on the market, sold as the little sister of EL84, (but quite different in this position!), or even can use 6P15P if you like the russian way. I also have somewhere schematics for EL803S, a bit different than the simple EL803, if you have some of these, write me and I'll try to find this schematic also - basically the same, but with slightly different component values.
About the voltage of the EF80 - I think the anode current is important...not the voltage applied through one high value resistor.
I have the author's permission to post another schematics for driving these tubes...at the beginning I asked him to draw the schematics for other driver, me too didn't have new/nos EF80's. In the meantime I got a pair of new Tungsram EF80 - also the used ones I had for the first build were still good enough, about 80% emission. The tube we agreed to use for driving EL153 was EL803, I have two of them NIB and it was a nice idea to use only TFK tubes. But this is for future plans...I intend to build the pentode version, to have enough signal swing for old sources I use with this amplifier.
Instead of EL803 one can use EL83, they are cheap on the market, sold as the little sister of EL84, (but quite different in this position!), or even can use 6P15P if you like the russian way. I also have somewhere schematics for EL803S, a bit different than the simple EL803, if you have some of these, write me and I'll try to find this schematic also - basically the same, but with slightly different component values.
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