Hi All
I am designing a KT88 type tube amplifier with the following specifications:
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For the moment I want to focus on the balanced input side of things. If I can get this sorted, I'll search how to incorporate unbalanced inputs.
The limitation I want to place on the amount of coupling caps, is to limit phase shift and signal degradation.
Searching the 'net, I found the following design that looks very good
at http://www.mennovanderveen.nl/eng/pr20he-s2.html
Unfortunately the amplifier uses a noval driver, so I am looking for a 6SL7 and 6SN7 design. The 6SL7 has the same gain as the 12AT7, but cannot drive as much current as the 12AT7. That will be a problem to drive two KT88's to max power output without distortion. Unless I can find an octal equivalent to the 12AT7, I'll have to consider other designs.
A thread on DIYaudio had this schematic of a design
The above design uses 12AX7 and 12AU7, but could be easily converted to 6SL7 and 6SN7 tubes, since these are electronically quite similar. I have built an amplifier using dc coupled drivers, and I liked the punch of the cathode followers. The only problem was microphonics. The main culprit would be the 6SL7, so maybe I should consider using rubber mountings or use a 5751(or similar) as the voltage amplifier.
What would you do?
I am designing a KT88 type tube amplifier with the following specifications:
- aim for 50watt per channel
- must sound better than Mars Stereo 70
- ideally use octal pre-amp tubes, at least octal driver tubes
- balanced and unbalanced inputs
[/list]
For the moment I want to focus on the balanced input side of things. If I can get this sorted, I'll search how to incorporate unbalanced inputs.
The limitation I want to place on the amount of coupling caps, is to limit phase shift and signal degradation.
Searching the 'net, I found the following design that looks very good
at http://www.mennovanderveen.nl/eng/pr20he-s2.html
Unfortunately the amplifier uses a noval driver, so I am looking for a 6SL7 and 6SN7 design. The 6SL7 has the same gain as the 12AT7, but cannot drive as much current as the 12AT7. That will be a problem to drive two KT88's to max power output without distortion. Unless I can find an octal equivalent to the 12AT7, I'll have to consider other designs.
A thread on DIYaudio had this schematic of a design
The above design uses 12AX7 and 12AU7, but could be easily converted to 6SL7 and 6SN7 tubes, since these are electronically quite similar. I have built an amplifier using dc coupled drivers, and I liked the punch of the cathode followers. The only problem was microphonics. The main culprit would be the 6SL7, so maybe I should consider using rubber mountings or use a 5751(or similar) as the voltage amplifier.
What would you do?
