~10wpc single ended PCB's?

[wa2ise]

The way to an excellent circuit is to build it point to point. Building point to point allows you many more options with components than filling a circuit board. Your layout of components and transformers can be maximized for less electrical and magnetic interactions. ...

+1 here. The only real advantage of PCBs is for large production runs. For onezie twozies, point to point with a metal chassis is a better method. Much easier to change the circuit (no cut traces). And stands up to tube heat better. Surface mount passive parts are rarely used in tube circuits, the parts we do use in tube circuits were designed for point to point work. And the metal chassis creates shielding against hum (but don't route any currents thru the chassis else you can get ground loops). Use dedicated return wiring for the B- ground lines.

 

[gadget73]

Anyone familiar with these tubes? I found some on that auction site....wondering if I should try em. They are inexpensive...

I've run them in place of an EL84 before, in an amp that was fairly gentle with the voltages. They actually sounded pretty good, though its been a long time and I never measured what they did for performance. I bought them because they were really cheap and thought I might be able to use them in place of an EL84 in a couple of table radios I own. In push-pull, you can probably get around 10 watts out of a pair. SE, I'd figure maybe around 3. I remember reading somewhere that they have really nice triode curves, and were highly suggested triode-strapped single ended as a headphone amp, making around 1w per channel.

 

[asilker]

I appreciate the preference for point to point construction. However, I still have a Fender 5E3 deluxe on the bench that I built from scratch - and that puppy has some mad oscillation problems. My interest in PCB's is because I know from experience that I am not ready to assemble point to point without very clear assembly models.

 

[gadget73]

I've personally had more trouble with "simple" designs than more involved ones. I find the ones that have very low component count and very simplistic circuitry are way more fussy about wire routing, component placement, tolerances, and every other little thing you can imagine than stuff that has more parts. I wouldn't necessarily use that Fender as an absolute indicator that you can't assemble an amp that won't behave itself.

 

[for_p1]

I've run them in place of an EL84 before, in an amp that was fairly gentle with the voltages. They actually sounded pretty good, though its been a long time and I never measured what they did for performance. I bought them because they were really cheap and thought I might be able to use them in place of an EL84 in a couple of table radios I own. In push-pull, you can probably get around 10 watts out of a pair. SE, I'd figure maybe around 3. I remember reading somewhere that they have really nice triode curves, and were highly suggested triode-strapped single ended as a headphone amp, making around 1w per channel.

These Russian tubes are very close to EL83. And -EB suffix usually means long life version.

 

[primosounds]

I appreciate the preference for point to point construction. However, I still have a Fender 5E3 deluxe on the bench that I built from scratch - and that puppy has some mad oscillation problems. My interest in PCB's is because I know from experience that I am not ready to assemble point to point without very clear assembly models.

I agree with gadget about the guitar amp model being a poor example of point to point wiring abilities. Those amps are far more complex than a simple single ended. But, i don't agree about the fussiness factor with se amps. I mean layout and careful wiring techniques are part and parcel of every tube amp assembly. I have made more than a handfull of single ended amps and have not had any trouble with any fussiness at all. The techniques that i follow and use were the techniques that i learned from making and repairing push pull amps. There is nothing special in construction that one has over the other. Although i will say that a pp amp by virtue of its taking 2 mirror imaged signals and recombining it in the output transformer can mask noise and hum generated in the circuit. But that should not take the place of careful assembly techniques..
And one should not assume that a circuit board will be free from problems and poor performance. As with all things the widespread acceptance and documentation of a circuit is also a consideration

 

[Shadowdog]

George Anderson of tubelab.com just recently retired from Motorola after many years there as an EE and he's also musician
so knows enough to make nice sounding amps as there are many happy builders on his forum @ diyaudio for about 12 years.

 

[Nyjblbob]

I'm pretty sure the KT 150's can produce at least 10 watts in triode