What is the "best" tube amp / speaker / source you have ever used?

[Tubelab_com]

Well, you are the only person to completely build one although My "breadboard" still works when fed from bench supplies and still gets hooked up from time to time. Last time it was turned on it was running triode wired KT88's. Now that I have built some more efficient speakers I want to go back to a fully differential class A triode output circuit.

I think Tubelab is being rather generous when he says we 'co-designed' the amp.

Well I got someone to build and test some of my ideas and eventually make an amp out of them. At work I have had people claim to have co-designed or even "architected" some of my creations. One particular "systems architect" is a master of powerpoint, totally useless at anything else.

I will usually go out of my way to help someone who wants to learn. I have no use for someone who just wants you to solve his little problem, then get the f%*@ out of the way.

 

[chrish]

Thanks Tubelab,

I am proud to be a 'Tubelab Beta Tester'! For what it is worth, my (now) wife is an extremely talented classical musician with a very good ear. She likes the amps! The exercise took some time, but I certainly learned a lot along the way. Hopefully some others did too while they followed the progress. Unfortunately my employer, once a national symbol of excellence in engineering, customer service and safety, is now hell-bent on pursuing 'worlds best practice' of extreme cost cutting. As a backup plan I have been working part time on a law degree just in case things get really bad. Unfortunately this leaves little time for fun electronics projects, so I have not been able to give back as much as I would like to the forum.

As an aside, my 15 year old son has seen me building all of this stuff and asked how did I learn to do it. Well, it has been thanks to the helpful members of this forum. A few years ago he thought I was a bit of a geek, now it has sparked his interest and he wants to be an engineer. He just told me a few days ago that he and a buddy have designed a CNC router setup they want to build. I said 'great', 'you can build my chassis for me'

Sorry for the thread drift, but once again 'thanks'

Chris

 

[a.wayne]

There are many good things out there, at some point, there's only "different", not "better". I personally like my self made Duetta speakers, designed by Audio Design Wohlgemuth very much and wouldnt exchange them for anything. And I've never heard them play as nicely as when I tested my KT88 Hafler Style Amp with them. I'm realy looking forward to the day, when they are finaly ready, I havent had any time to work on them for over a year. That'll be just gorgeous...

Hafler KT88 .. do you mean Dynaco?

Sorry, I did not elaborate on the 'Tubelab Sandcastle amp'. As the topology bears a resemblance to Morgan Jones 'Crystal Palace' amp using solid state in places where Morgan Jones uses tubes, it sounded like a good name. I think Tubelab is being rather generous when he says we 'co-designed' the amp. Tubelab was extremely patient helping me adapt his design to the specific tubes and transformers I had. After a little teething trouble setting them up (due to my building techniques and some early parts failures, not due to design) I have about a year's worth of trouble free daily driver listening on them. They look and sound great.

Thanks Tubelab!

Ahem pics .........................

 

[chrish]

As requested...

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[a.wayne]

Sweeeet .........

 

[ttan98]

Chrish,

A very complicated circuit to get about 15watts/channel. Congrats for a job well done for someone with no electrical experience.

It can get expensive when you change tubes/valves next time.

Cheers.

 

[chrish]

Thanks. I think I was shooting for about 30 watts/channel and ended up with just over 25. I just built it in 'modules'. The most diffucult part was the regulated power supply with no PC board, the rest of the point to point and smaller perf board modules were quite easy to construct. These amps were about my 7th tube amp project and prior to that I had constructed some chip amps and other 'kit' projects.

Cheers,

Chris

 

[SY]

Chris, that's a very nice piece of work, and quite beautiful as well! At what voltage swing does the driver stage poop out?

 

[chrish]

Thanks Sy,

Looking at my notes, it looks like I got a max output from the driver of 134 volts peak to peak with an input of 1.2 volts. I know that Tubelab has put a 6SL7 in the front end and cap coupled the two stages to get more drive for his experiments.

Chris

 

[andyjevans]

Here's my latest amp which supercedes all others. I'm very pleased with this one - very clean, authentic tone on acoustic instruments, and some very low level detail is now audible. The Hammond 126C can be substituted for the LL1692A - sounds very good and much cheaper. O-netics is Level 1 3.3K

Haven't constructed the ideal speaker however - I have a couple of Alpair 10 units and the speaker will certainly be a full range unit of some sort.

Andy

 

[Bandersnatch]

PPP has only a measley 2 votes for this technology. One from myself.....surely one can do better than this ?

I don't see the need for PPP, just get bigger finals. I tried this first with 4E27's with 75 W of plate dissipation. I do keep the finals well into Class A( well past it actually ) to make things easier on the PS. I tried 813's in the same amp and they'd like more B+ to make the same power( probably want 700V where the 4E27's are happy with 580. This with the same modified S265Q output trans.
cheers,
Douglas

 

[a.wayne]

Here's my latest amp which supercedes all others. I'm very pleased with this one - very clean, authentic tone on acoustic instruments, and some very low level detail is now audible. The Hammond 126C can be substituted for the LL1692A - sounds very good and much cheaper. O-netics is Level 1 3.3K

Haven't constructed the ideal speaker however - I have a couple of Alpair 10 units and the speaker will certainly be a full range unit of some sort.

Andy

Interesting this 10 watt high sensitivity speaker approach

Many moons ago i spent some dinnertime with the Ongaku People in NYC (china town) and the first watt most important watt conversation dominated the night, the food was good so i stayed....

 

[TheGimp]

PPP has a manufacturing advantage (1) when minimizing parts stocking is desirable, and (2) when bigger tubes are impractical (numerous guitar amps use PPP).