When I first saw it I had the thought it wasn't the sort of thing I'd seen you do before but then I thought "Well, he's creative enough to do really different styles. . . ."
Looking at your design above the only thing I question is the volume control and signal input (presumably output too) wiring in the power supply enclosure when it's not necessary. Otherwise , Kool ! Kind of Bang/Olufsen from The Cyberiad.
There will be a third pipe going up the back. That one will send power up to the separate preamp boards. The signal wires will go from the volume and selector to the separate boards through the pipes on the left and right.
The outputs of the boards will come out of each box.
The outputs of the boards will come out of each box.
The transistor is a current amplifier , it is false to say that just the tube is amplifying so gain is higher than mu . Because of this only a bipolar transistor can be used .
Or demonstrate with measurements .
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"it is false to say that just the tube is amplifying so gain is higher than mu ."
I don't think anybody is saying that , are they? As I read it, the gain is being ascribed to the stage circuit, which includes both CCS and BJT together with the triode and importantly the gain set resistor.
Don't think that I was doing anything other than making a builder level suggestion whereby the OP could get increased preamplifier output from relatively simple modifications to an existing circuit, by which he might preserve enough of the sound signature he likes (and ascribes to the 6080). It might or might not give him what he wants. It's all just try and listen . . . . . which is the way I do it.
Thanks for taking issue with this. You forced me to look up the definition of "gain stage" . It's a term I've used a few times, heard a lot, thought I understood, but didn't. It clarifies things.
I don't think anybody is saying that , are they? As I read it, the gain is being ascribed to the stage circuit, which includes both CCS and BJT together with the triode and importantly the gain set resistor.
Don't think that I was doing anything other than making a builder level suggestion whereby the OP could get increased preamplifier output from relatively simple modifications to an existing circuit, by which he might preserve enough of the sound signature he likes (and ascribes to the 6080). It might or might not give him what he wants. It's all just try and listen . . . . . which is the way I do it.
Thanks for taking issue with this. You forced me to look up the definition of "gain stage" . It's a term I've used a few times, heard a lot, thought I understood, but didn't. It clarifies things.
He made the statement that triode gain is higher than miu , only depending on tube gm , while avoiding like a lying lawyer 😀 to say that the transistor is amplifying too ... technical stuff should be objective.
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Hi there,
Concerning SRPP circuits, I need some help for understanding the difference between RL impedance and output impedance...
According to John Broskie tubecad pages, we can optmize RL for a specific application such as a 300 ohms headphone, for example.
But RL impedance is different from output impedance, and preamplifiers are supposed to have an output impedance 10 times smaller than the amplifier input impedance.
So, when does RL impedance matter, and when does output impedance matter?
I would like to build a 1 channel amp with 6 Pcl82 in parallel, so Im wondering to use 2 triodes in srpp to feed the 6 pentodes in parallel, and the other 2 couples of triodes for a stereo preamp or a headphone amp.
Thanks in advance for any help!
Rgds
Concerning SRPP circuits, I need some help for understanding the difference between RL impedance and output impedance...
According to John Broskie tubecad pages, we can optmize RL for a specific application such as a 300 ohms headphone, for example.
But RL impedance is different from output impedance, and preamplifiers are supposed to have an output impedance 10 times smaller than the amplifier input impedance.
So, when does RL impedance matter, and when does output impedance matter?
I would like to build a 1 channel amp with 6 Pcl82 in parallel, so Im wondering to use 2 triodes in srpp to feed the 6 pentodes in parallel, and the other 2 couples of triodes for a stereo preamp or a headphone amp.
Thanks in advance for any help!
Rgds
Ok, I’m back at this preamp business! I decided not to build the Akido for my desk. But there is a new wrinkle. Here are the chassis parts I want to use.
The black control panel will be for input selection and volume, the tube box will be for all the tubes, and the handles will be used for, well, handles.
So what good preamp tubes will fit in the 8 pin socks and what rectifier tube will fit in the smaller sockets?
The black control panel will be for input selection and volume, the tube box will be for all the tubes, and the handles will be used for, well, handles.
So what good preamp tubes will fit in the 8 pin socks and what rectifier tube will fit in the smaller sockets?
I created an SRPP calculator, see:
https://www.diyaudio.com/community/threads/how-to-bias-a-srpp-circuit.346079/#post-5994955
https://www.diyaudio.com/community/threads/how-to-bias-a-srpp-circuit.346079/#post-5994955