Hello
I just got 2 chokes 10H 300mA 50 Ohm and 2 mail trafoes
330VAC 300mA ( ~ 400 VDC with solid state rectifiers ) + 70VAC 25mA (bias) + 6,3V 5A. ( under 80 USD brand new )
I think this is OK for a SE KT88 mono amplifier, but I need a schematic. Can You help me with that.
Regards
Benny
I just got 2 chokes 10H 300mA 50 Ohm and 2 mail trafoes
330VAC 300mA ( ~ 400 VDC with solid state rectifiers ) + 70VAC 25mA (bias) + 6,3V 5A. ( under 80 USD brand new )
I think this is OK for a SE KT88 mono amplifier, but I need a schematic. Can You help me with that.
Regards
Benny
Since I've got new IP for my server a couple of times, the links I've posted to my schematics doesn't work anymore. Here is the new URL: http://81.224.66.34/se_kt88.gif
Should work for you. I think you should be able to use it for starters and modify it for your needs.
Should work for you. I think you should be able to use it for starters and modify it for your needs.
Mikael Abdellah said:Since I've got new IP for my server a couple of times, the links I've posted to my schematics doesn't work anymore. Here is the new URL: http://81.224.66.34/se_kt88.gif
Should work for you. I think you should be able to use it for starters and modify it for your needs.
I can vouch for Mikael's design! I built it as a pair of monoblock power amps rather than integrated and it sounds great. It is simple to build and it appears you have the parts. Mine are biased at 75mA with a B+ of ~400V. (I used tube rectification but with your trafos I think you'll have to go SS to get the 400V.)
The only issue I've had was some oscillation on a particular piece of music. I think I've cured that by following the advice of analog_sa and decoupling the PS ahead of the input tube.
Mikael,
Just one question sir about the cathode resistor (470R/25W), I can't seem to find a source for such a high wattage resistor locally.
Can I use 3 pcs of 1500R/10W in parallel? Are there any special considerations for this resistor? I mean should it be a certain type such as those non-inductive types?
Please bear with me....
Thanks!
JojoD
Just one question sir about the cathode resistor (470R/25W), I can't seem to find a source for such a high wattage resistor locally.
Can I use 3 pcs of 1500R/10W in parallel? Are there any special considerations for this resistor? I mean should it be a certain type such as those non-inductive types?
Please bear with me....
Thanks!
JojoD
There's really no need for 25W. The actual power running through the resistor is closer to 5, but when i tried with 15W it got awfully hot so I put in a 25W instead. It's a regular wirewound kind since low inductive metal film types aren't available at those power ratings. I could send you a pair of 470R/25W if you want. Just let me know. We enthusiasts and diy:ers gotta stick together 
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