6v6

The project page for the 6V6 Curly Maple Amplifier is now up and viewable. Take a look and let me know what you think.

As always, questions and comments are welcome.

The TAD 6V6GT-STR “Redbase” Premium tubes showed up and I got them installed in the 6V6 Curly Maple amplifier. I took new voltages and have been listening to the tubes with a variety of music. These tubes are very detailed and musical. They produce a stronger bass than the 6V6Gs and a very even tonality in the ultra linear topology. I would consider these a nice upgrade for any 6V6 amplifier.

Today marks five weeks since I hurt my ankle. And this morning I managed to do my full mile plus morning walk without any issues. My dog was happy about this as well. At 18 years old the definition of “walking it off” after such an injury meant maybe a day. I guess now over 40 years later “walking it off” means five weeks. Who knew?

But I’ve also made a slight deviation with the 6V6 Curly Maple amp.

So I’ve been laying low for the last couple of months and not entirely by my own volition. I finished up the Curly Maple amp on the first of June and have not yet gotten the project page posted. But rest assured, the entire write up on the new amplifier is coming soon.

I haven’t gotten the time to complete the testing on the Curly Maple yet, but I did receive a couple of tubes for which I’ve been waiting so I can try them in the new amp.

The resistors for which I’ve been waiting to finish the amp showed up in the mail yesterday. Today I got the final resistor installed and did a full check on the amplifier.

I took some time yesterday to finish up the 6V6 Curly Maple assembly. Everything is complete and in place except for the main dropping resistor, Rd.

I had a good bit of time to work this morning and I completed the top plate wiring. The next step is to get it affixed to the chassis.

I carved out some more time to work on the amp today. I managed to get the entire power supply section wired in.

In spite of some other things commanding my time, I’ve finally managed to get started on the wiring for the new amplifier.

I took some time this morning, now that the paint is dry on the top plate, to install the mechanical aspects of the amp. The top plate is now fully populated.

While dealing with my other spring chores, I’ve been working to get the finish applied to the amplifier’s top plate. While not perfect, I believe it is acceptable enough for me to proceed.

I keep referring to the new amplifier as the 6V6 “Curly Maple” Amplifier. But is it really?

The chassis has all its coats of oil finish and things started coming together today.

I managed to steal a little time over Easter to do a some work in the shop. The chassis for the new 6V6 “Curly Maple” Amplifier is coming along nicely.

After some delay I have managed to finish all the metal work for the Marblewood Upgrade Amplifier. Hereafter referred to as the 6V6 Curly Maple Amplifier.

I haven’t talked about the new amp in a while so I thought I’d share current progress.

Remember when I said that you can’t always get what you want? Well, it turns out you can. At least in this case. Especially if you are willing to shift some priorities.

Lately I’ve been looking at a revised amplifier design based on the Marblewood project. The intent of the redesign effort is threefold. First, a different and more widely available rectifier tube. Second, an improved, if slightly more complicated, power supply design. And third, some potential improvement in the low frequency response. As it turns out, you can’t always get what you want. But also, two out of three ain’t bad.

After a busy Christmas season, including a brief trip out of state between Christmas and new year, I have finally managed to get the Lacewood amplifier back up and running. As part of this effort I also identified the root cause of the initial failure. And frankly I’m a little angry about it.

Remember a few weeks ago in the post When it Rains, It Pours! I said that the Lacewood V2 reservoir capacitor had likely failed? Well, I was wrong.

Would you believe it? Today while listening to the 6V6 Lacewood V2 I heard a funny little popping sound and a short duration whine. It only lasted a few seconds, then it was gone. But when I walked over to the amp there was a distinct smell of “magic smoke”. Once again, the game’s afoot!

This is a topic that rears its head periodically on vacuum tube forums and discussions. Just a couple of days ago I was reading a forum thread on preamps and someone threw out the suggestion of using a triode strapped 6V6 as a preamp tube. Now this is nothing new. I’ve been hearing this suggestion, on and off, for at least ten years. But using a triode strapped 6v6 (or any beam power tube) as a voltage amplifier is a poor idea which simply doesn’t hold up to technical scrutiny.

Being a proponent of single ended topologies, I am constantly on the lookout for singleton power tubes. Since I’m working on designs with all single ended signal chains, things like matching and bias points as less important to me than tubes which test strong and are reliable. One source containing lots of singleton “New Old Stock” and “Used” power tubes is Ebay. Often I can get a single power tube for far less than buying from one of the more established vacuum tube business on the web. But I have begun to wonder about whether these are really such a great deal after all.

There is something very satisfying about seeing a project really start coming together. I finally got some time today to start working on my 6V6 Marblewood amplifier project. It now looks like an amplifier instead of just a pile of boxes and parts.