Great first projectAnd here is my First project. Under construction.
An externally hosted image should be here but it was not working when we last tested it.
,are you building as pre as well .There are some great looking very professional work being done in the DIY community .
CHeers
@ quadtech, mhouston, Bassivus:
Thank you...Hvala vam mnogo!
Bassivus: Excellent woodwork! What kind of wood is that?
Its a maple for violin back
I got it as the present from a friend who is a Luthier, as well as a special pigments I stained it with
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finally.....
input tube is a 12BY7, ltp drivers are paralleled 12BH7's, this is a non-global negative feedback amplifier, the KT88's are run as triodes so that the resulting low plate resistance from parallel operation negates the need for global negative feedback.....
biasing at -47v power consumption was:
backing down a bit to -50volts yeilded this power consumption and seemed to be stable, no drifting was noticed and the tubes were surprisingly within 2mA of each other....
setup psu and amplifier block combo for a listening test:
input tube is a 12BY7, ltp drivers are paralleled 12BH7's, this is a non-global negative feedback amplifier, the KT88's are run as triodes so that the resulting low plate resistance from parallel operation negates the need for global negative feedback.....
biasing at -47v power consumption was:
backing down a bit to -50volts yeilded this power consumption and seemed to be stable, no drifting was noticed and the tubes were surprisingly within 2mA of each other....
setup psu and amplifier block combo for a listening test:
i did not measure, but 75watts into 8ohms i guess......
i did not spend anything on this project, an audiophile friend came to me with an old amp to gut down and a lot of new parts and asked what can be done...of course everything was his idea, i merely did as i was told.....
the only limit imposed was that we use the old irons as these were stripped M6 goss irons....
that is why i decided to go the triode route.....
the output KT88's are not stressed imho so we expect them to last long...
no, push-pull......
B+ is about 410volts at -50volts bias.......opt connection to 16 ohms reflects a primary impedance of about 1600ohms anode to anode....
maybe the experts here can do the math....
so many caps? he had 12 of those 1000ufd/450volts caps and asked to put them in.......i used a 15amp fwb rectifier, a CRCRCRC filtering with froward biased !N5408 to the final 2 sets of caps for each channel......i series connected those caps since the off load standby can go as high as 480 volts....
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Here is an amp at the other end of the scale, 6S45P single triode.
It is still in progress, the rear is missing, and no wiring yet.
read more on my blog: TAO of Tubes: Building the 6S45P amplifier part two
It is still in progress, the rear is missing, and no wiring yet.
read more on my blog: TAO of Tubes: Building the 6S45P amplifier part two
I am also planning an amplifier to take over in the living room, driving Magnepan SMGa´s. It is going to live next to my Empire Scientific Troubadour 598 turntable, so I am designing it to match. It will be PP 20W based on 6L6 og 807 or such. Here is a rendering drawn in Sketchup and rendered in Kerkythia It is available at the google warehouse.
Great first project
There are some great looking very professional work being done in the DIY community .
CHeers
Those in the back will be for the second set of amps
). I have just pait the advance for the second set of opt's. I'm still faaaaaaar from the finish line.I am also planning an amplifier to take over in the living room, driving Magnepan SMGa´s. It is going to live next to my Empire Scientific Troubadour 598 turntable, so I am designing it to match. It will be PP 20W based on 6L6 og 807 or such. Here is a rendering drawn in Sketchup and rendered in Kerkythia It is available at the google warehouse.
Hi Trondaro
Google sketchup is a great free tool to use and it helps you to get an idea of how things fit & scale,heres some renders I done .
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
CHeers