Is it possible to use the ISS with the DG300B? If so, should parts of the soft-start on the power supply board be omitted?
Sure. You can do that. Just short out the CL-90 on the DG300B supply board. You can omit the relay on the DG300B supply board as well.
Take the mains output of the ISS from terminals 1 and 4 on the transformer primary connector. Bring those to the mains input terminals of the DG300B supply board.
It sounds more complicated than it is. 🙂
Tom
Take the mains output of the ISS from terminals 1 and 4 on the transformer primary connector. Bring those to the mains input terminals of the DG300B supply board.
It sounds more complicated than it is. 🙂
Tom
I'm down to 11 DG300B board sets, by the way.
If you prefer to avoid the SMD soldering, I have six of the 5.0 V and seven of the 6.3 V versions of the Filament Regulator in stock.
Tom
If you prefer to avoid the SMD soldering, I have six of the 5.0 V and seven of the 6.3 V versions of the Filament Regulator in stock.
Tom
The last board set has sold and the DG300B is retired. Thank you to everybody who has supported this project through the years, and especially to those who bought circuit boards.
Thanks,
Tom
Thanks,
Tom
DG300B PCB Gerbers
Sorry to join the discussion late. Tom, would you consider making the Gerbers available for the DG300B circuit board?
Sorry to join the discussion late. Tom, would you consider making the Gerbers available for the DG300B circuit board?
No. I don't like to give away my work.
If you're interested in organizing a group buy and you're willing to buy at least 12 board sets and handle all the support, toss me a line. You would need to figure something out for the DC heater/filament supply, though. I'm not starting the Universal Filament Regulator back up. I have plenty of 21st Century Maida Boards. That part of the project is still going strong.
Tom
If you're interested in organizing a group buy and you're willing to buy at least 12 board sets and handle all the support, toss me a line. You would need to figure something out for the DC heater/filament supply, though. I'm not starting the Universal Filament Regulator back up. I have plenty of 21st Century Maida Boards. That part of the project is still going strong.
Tom
Hallo Tom
You seem to know a lot about audio technology. ;-)
When I read the threads here, your products get a lot of praise from your customers.
You worked with valve and class-D technology.
My I ask if you are intereseted in combining these in one amplifier? A hybrids with driver tubes at the input and class-D technology at the output.
I like what tubes do with music. But I consider tubes to be suboptimal for final amplification in the sense of resource conservation.
You seem to know a lot about audio technology. ;-)
When I read the threads here, your products get a lot of praise from your customers.
You worked with valve and class-D technology.
My I ask if you are intereseted in combining these in one amplifier? A hybrids with driver tubes at the input and class-D technology at the output.
I like what tubes do with music. But I consider tubes to be suboptimal for final amplification in the sense of resource conservation.
Sorry to break it to you, but tubes and resource (energy) conservation don't exactly jive. The DG300B consumed about 100 W at idle to deliver 2x10 W to the speaker. 🙂
If you like the tube sound but not the energy consumption, I suggest trying a simple JFET buffer stage. Just keep lowering the supply voltage until you get the "tubeness" you want. Nelson Pass has a circuit like that.
You can also get lots of second order harmonic distortion if you make a gentle clipping circuit that only clips on one half of the cycle. An opamp gain stage with a diode across the feedback resistor would be a crude example of such a circuit. It'll sound "tubey" to many. Reproducing the exact signature of a specific tube will require much more work, though, and may not be possible.
Or, as you say, use a tube preamp. I have no plans to pursue a design that involves tubes. I've had my fun. Designing the DG300B was a fun experience - especially as I at the time was working full-time at the completely opposite end of the spectrum designing precision timing chips for the cellphone infrastructure.
Tom
If you like the tube sound but not the energy consumption, I suggest trying a simple JFET buffer stage. Just keep lowering the supply voltage until you get the "tubeness" you want. Nelson Pass has a circuit like that.
You can also get lots of second order harmonic distortion if you make a gentle clipping circuit that only clips on one half of the cycle. An opamp gain stage with a diode across the feedback resistor would be a crude example of such a circuit. It'll sound "tubey" to many. Reproducing the exact signature of a specific tube will require much more work, though, and may not be possible.
Or, as you say, use a tube preamp. I have no plans to pursue a design that involves tubes. I've had my fun. Designing the DG300B was a fun experience - especially as I at the time was working full-time at the completely opposite end of the spectrum designing precision timing chips for the cellphone infrastructure.
Tom
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Now available, unsupported, for DIY use only. Licensing for commercial use is available.
DG300B – Neurochrome
Tom
DG300B – Neurochrome
Tom
Hey Tom, now that last Spring's ice hockey season has resumed, how do you find time to work on projects?
Well... The Leafs are out, so I default to following the Flames and the Canucks, but work does ultimately take priority. More importantly, recreational hockey has started back up, so I'm playing again, which is good both physically and mentally.
Tom
Tom