It has been a while since I was a regular here but I haven't forgotten about my love of small amps. Wanting a small amplifier for work I decided to get on a project that I had put off for a long time and I'm extremely pleased with the results.   The 12AE7 is, for all intents and purposes, a...

Simple mod actually works!   I used a 12AY7 for my quick test but haven't tested the others yet(exams). Swap in a 8.2 ohm resistor on each LM317 for a CC of 150mA. They end up both going to the same pin(3 I believe) and if you leave one of them alone but send the other one to pin 4(should be...

You know, with a little bit of circuit modding a 12A*7 series tube could work.   The standard circuit is setup for 6.3V across pins 4 and 5, if you were to re-calculate the constant current supply resistors and snip the shield connector at pin 9 you'd not only have the option of any of the 9A...

Strangely enough, if I use a piece of paper underneath the boards it does this, but if I stick a piece of tape underneath it doesn't... tape it is I guess.

It saves a lot of power but I don't think we need to worry about that since these will likely be used with B22s and tube hybrids. Not exactly the most efficient of amplifiers. Holding across reboots isn't going to help much unless you write the current mode to something other than ram in the...

Don't do it cobaltmute! The DCP is essentially a high speed step-up transformer with a built in rectifier. If you cut the traces to the output gnd it won't work at all. These units are designed to have complete isolation so the output hv has no path back to output gnd through input gnd. And...

At 70ma of idle current the DCP020509 is only running at 32% load and is somewhere around 75% efficient giving you a total of 54.25ma. Still missing about 15 tho... How are you going to decouple the 0v? Has anyone gotten the Bantam/Carrie pair cased successfully? I don't know what the heck...

Isn't latched vs normal relay a software change and not a hardware change? You either pulse the output or have a constant on/off.

I get the gist of it but how does the ground amp handle the incoming signal? Is it just canceling it out or does it absorb the signal? If the input to ground does low the ground amp just pushes high right? If that's the case, how do we end up with a DC offset? Wouldn't the ground amp see that...

So the 2426 is just replacing 2 resistors because it doesn't actually flow anything? Now this raises another question, if the opamps run totally independent of virtual ground except for the ground amp reference, why even bother with a virtual ground? Can't you just make the reference at the...

If you are trying to get really specific you have to take a lot of variables into account. Such as your real bottleneck, the rail splitter. According to the datasheet the absolute maximum from that splitter at 10 volts is 100ma. That's 1 watt from the power supply no matter what you do. Now...

I don't disagree at all and that was pretty much what I was getting at. Were you thinking two voltage inputs? If that's the case it works too and you wouldn't need the regulator at all. Especially with stuff like this around. 12V+5V AC Adapter Power Supply HDD HARD DISK DRIVE IDE - eBay (item...

Yes they can be run on 12v. I used ULN2801 chips(same thing as a 2003 but it has 8 I/O instead of 7) for the steppers on my lathe which run 48v@450ma while the control board runs 5v. Just remember that GND on the 2003 is common ground for both the relays and the control, the common...

I've ended up getting everything I need to just completely replace the output stage in my NIKKO. I was going to just replace all the output stage but they don't make the sand used in these old receivers anymore and if you're gonna change the sound you might as well start from scratch. Mine is...

Title of the thread threw me off.