Listening Impressions SE vs Push Pull vs Solid State

[tube fanatic]

I am tempted to say it is easier to make a great sounding single-ended amp that any other topology. There are so many good sounding ones available these days. I've been using a little Amp One from GLOW. It's about 5W and very simple and quite inexpensive. It has a lovely listenable sound that offers almost no objections. It's not the absolute clearest tube amp I've had, but even as it is it is shoulders above some very expensive SS amps. It has that effortless quality that I find hard to turn off. Once I start playing it, I just want to keep going.

And then of course the more exotic and full-stop SE amps just get better than that. I may be getting to the point were PP amps just won't do it for me any more. I don't need the power, so there's very little reason to use them in my set up. At some point soon I would like to get something more substantial than the Glow. A higher end SE. For now, this has a delightful sound.

It's worth noting that technically all the gain stages before the power amp are of course always SE class A (except for some differentials used in SS preamps). A string of all class A SE circuits from source to speaker seems to make sense. Keep it simple, keep it single ended!

The under-chassis pix of that Amp One shown in the 6 Moons review are quite impressive! It appears beautifully constructed (another contrast with the pix of the Sophia and the preamp in the Stereophile reviews I posted.) Does it employ any nfb? I find it surprising that some find the sound of SEPs to be enjoyable when none is employed. Personally, I find them too strident without the fb to flatten out the response. One thing which bothers me about so many commercial tube amps these days is the lack of separate R and L volume controls, or a balance control. Listening to a non-centered sound stage really bugs me, especially in a near-field listening environment which highlights everything. In any event, I sure agree about single ended being much more enjoyable to listen to than PP. Thinking back, I don't recall doing any PP amps for anyone for the past 15 or more years.

Maynard

[Cornman]

The guy mentioned that he didn't understand how to configure a single-ended pentode amplifier, or if it was even feasible. I'll openly admit I'm rank amateur, and just explained to the best of my knowledge.

I mentioned "somewhat regulated" because I didn't want someone coming in saying that regulated screen supplies are a must or some such. I mostly work with simple 2 stage single-ended pentode circuits, and have never used regulated supplies for the screens, and have never had screen related issues. You explain why I never have these issues in your post above.

This is why I shouldn't answer these sort of questions. I don't have enough technical knowledge to explain things in the correct manner, but I tried.

I do appreciate the points however, and am not afraid of constructive criticism. I'm always on a learning curve.

With regards to "stirring the pot", and I bring this up with no offense...but you have "tube amp designer" emblazoned above your avatar. I know you may be some sort of electrical or audio engineer just by the way you help folks out around here, and the technical prose of your posts.

But I haven't seen any images of your products or projects, unless I missed them.

I know you have your reasons, but the only reason I'm bringing it up is you called Justin Weber out basically demanding underside images of his amplifiers, which he did.

IMHO, I feel it is only fair that you return the favor and show some of your work...even a above shot of a amplifier. I'm not afraid to show my work, and I am a rank amateur.

I'm not trying to be a jerk about it, I just think fair is fair.

To answer a bit out of order, I didn't call Justin out at all. He has made a point of saying how meticulous his work is and, since he is trying to promote his products, it's always nice to show the world that the claim is justified. His pictures bear out the care that he is taking in constructing his amps. This is not a new marketing concept as many equipment manufacturers include under-chassis pictures on their web sites and in promotional materials. I've shown pictures of beautifully constructed amps and other electronic gear to non-technical folks and they often comment about how neat and organized everything looks in spite of having no idea what they are looking at.

The reason I don't post pictures of my "products" is that I don't have any for sale. Being retired (from the business/monetary standpoint) I now offer prototype services to local audiophiles. So, for example, if someone called me and said "Maynard, I want to experience the sound of a flea powered SET with my CWs. What can you do for me?" I would either bring over a prototype (if I happened to have one on hand), or build one (at my own expense) for the person to try. This is without obligation to the person involved. Basically, if a concept appeals to me, I'll design and build it for fun. If the person likes what he hears and wants to keep it, he may offer me something on trade, offer to replace all the parts which I used, ask me to build an identical amp in some other kind of enclosure (I use a plain aluminum chassis when prototyping), and so on. I'm not interested in making any money on this, and refuse to take anything for my time and effort. My "profit" is seeing the look of sheer joy on the person's face the first time they experience their favorite music through the "musical instrument" which I have created for them. The same goes for my work in vintage amp and antique radio restoration. In the latter two cases, I'll either do the work gratis (if it isn't too costly), or simply give the person a list of the parts needed and where to buy them (or sit down at the computer with them, make up the order, and let them pay for it!) When they have everything, they give the parts to me and I do the job. The amp and radio work is my way of preserving history. Making a 70 year old radio play as it did when new (and many times even better with some circuit modification), or a 50 year old amp deliver a whole new level of musical enjoyment is my return. So, there it is!

I don't normally photograph my creations (no point- I know what they look like ), but have attached a couple of a recently prototyped SET. The guy was quite specific about what he wanted- absolutely no audible hum with his ear against the speaker grille, no hiss if at all possible, cheap and abundant tubes, good bass, and very smooth highs. This was a nice challenge which appealed to me. It required using a separate power supply and runs very highly filtered DC for everything, including the filaments, and a circuit which is simplicity itself. He is extremely happy!

Maynard

Maynard, this is one of the most refreshing concepts from a builder, that I have heard in decades. About as rare as doctors making house calls -remember those days? I tip my hat to you sir, if you would ever like to visit Austin Tx, you will always have a bed here. Sending you a PM soon.

[Cornman]

Thanks to all you builders for sharing (Mark, Justin, Maynard). I willl send each of you a PM.