helo everybody....
maybe this is not real place for my question, but there is a half of schematic (joes amp) regarding chip amp...other half is tube buffer, and that is a part that i need...basicly....which values of resistors and caps can I use and of course which is the best transistor to use????
my english is bad....
thanks
maybe this is not real place for my question, but there is a half of schematic (joes amp) regarding chip amp...other half is tube buffer, and that is a part that i need...basicly....which values of resistors and caps can I use and of course which is the best transistor to use????
my english is bad....
thanks
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Nuuk said:
Hmm.. there's 2 tubes in your VIGC. Is this another secret?
Shoog
If you go with this approach be very aware that you are introducing DC into the Zen as the buffers warm up. In mine it went from 20V at the speakers and dropped to about 100mv over about 30 seconds. This could be damaging to the type of speakers which tend to partner Zens. There are ways round this problem.
Consider using a FET buffer. NUUK considered this to be about the same in effect with none of the disadvantages associated with the Valve buffer.
Shoog
If you go with this approach be very aware that you are introducing DC into the Zen as the buffers warm up. In mine it went from 20V at the speakers and dropped to about 100mv over about 30 seconds. This could be damaging to the type of speakers which tend to partner Zens. There are ways round this problem.
Consider using a FET buffer. NUUK considered this to be about the same in effect with none of the disadvantages associated with the Valve buffer.
Shoog
Just to clarify that, I still found some DC offset while the opamp buffer powered up but nowhere near as much (and for so long) as with the valve buffer.
It should go without saying that anything you build should be measured for DC offset on thge output and suitable precautions taken to protect the next item in the chain whether that be power amp and/or speakers.
Good point. I have to say that my Valve buffer is working fine with suitable precautions.
I also realised after posting that message that the Zen has output capacitors which should protect the speakers from the worst effects of power ups, though not from the terrible noise of warm up.
However there is a fully worked up constant current, constant voltage Fet buffer (ie a FET version of the full Valve version) which should give superior results over the DIY valve buffer which doesn't have the benefits of the constant current, constant voltage. I haven't got the link to the full FET version, maybe someone would pipe in with it as a matter of interest. I intend to build that one next as a comparison.
Shoog
I also realised after posting that message that the Zen has output capacitors which should protect the speakers from the worst effects of power ups, though not from the terrible noise of warm up.
However there is a fully worked up constant current, constant voltage Fet buffer (ie a FET version of the full Valve version) which should give superior results over the DIY valve buffer which doesn't have the benefits of the constant current, constant voltage. I haven't got the link to the full FET version, maybe someone would pipe in with it as a matter of interest. I intend to build that one next as a comparison.
Shoog
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