Maybe the SET Fraternity is Right!

[edwinr]

Oh, No! []

[Duke Spinner]

Troublemaker .....

i'm gonna SET mr. parrot on ya ......[]

[codhead]

SET Fraternity test CD?

[codhead]

SET Fraternity meeting. Hey, I own a few - and I still think these threads are entertaining!

[neo33]

Did someone mention SET?

[djk]

Closet horn freak Nelson Pass has designed a new 10W single ended amp using the Lovoltech power J-FET that has the same transfer curves as a triode tube.

He has two designs, one with, and one without feedback.

Should be very interesting. In quantity the J-FET sells for less than $1.

What's it take for a 10W SET?

How much did you say that 300B cost you?

And your Magnequest iron?

[edwinr]

Okay. A couple of months ago I heard Audio Note Quest 300B monoblocs. I was unimpressed. Yeech!!! I thought they were colored, lacking dynamics... yuck!

However, I have since had another listen. A longer one this time. System was a pair of Avantgarde Duo 2.0 horn loaded loudspeakers (with active subwoofers), fed by Wilson Benesch ACT One T/T. This time a smaller room and the monoblocs had been retubed (ouch! expensive process).

Now we're cooking with gas!

With the Avantegardes, while I like the mids and up, I'm not a fan of the bass. It's a bit artificial and has a tendancy to dominate. It's not that well integrated either. I think the Klipschorn is better in that regard. But I'm just being picky - these are still fine loudspeakers. With over 100db for 1 watt sensitivity, the Duo's were easily driven to reasonable listening levels in the smaller room.

What I heard was a magical midrange that was quite extraordinary. Everything was there. The imaging, the soundstage. Very nice. Even the frequency extremes sounded okay. I'm not talking about the sort of bandwidth you'd get out of a very powerful s/s amplifier, but it was there.

Don't take my above comments as totally endorsing the use of very low powered SET amplifiers by all and sundry. All I'm admitting is that there are horse for courses. With very carefully selected matching components, and a realisation that ultimate listening levels will be limited, low powered SET amplifiers may be an option.

I can't believe I said that! [:$]

Where's Paul, when I need him? [:^)]

[edwinr]

Troublemaker .....

i'm gonna SET mr. parrot on ya ......[]

Too late, Duke. I've just got a 'please explain' PM from the Parrot. [:S]

Now I'm in trouble!

[Erik Mandaville]

Edwin:

I have no hesitation in saying I can understand your enjoyment of the lower powered amps in what seems to have been a good application of the technology. However, one might also say -- and many do -- that Klipsch Heritage horns are an equally good match for single-ended triode amps. Yet again, though, we also know that not everyone feels or hears or thinks that SET amplifiers can even qualify as amplifiers; but are rather anti-amplifiers! That's fine, though.

I had been using an amazingly inexpensive, light-weight, and far more powerful amp in place of my single-ended amplifiers for a few months. I'm talking about the 30-watt, 3-channel Teac digital amplifier. It was and absolutely STILL is quite ideally, IMO, suited for use as the front stage amplifier in a multi-speaker surround system, and I was constantly amazed by how well it performed -- straight out of the box, with no modifications or 'upgrades' to speak of. In another recent thread, I also described the Teac as being sort of 'flawless to a fault.' I want to qualify that remark: The 'fault' has to do with me, not the component itself! It's the first amp in many years that as far as I was concerned needed nothing in terms of hopeful improvements as far as performance. I did nothing with it but use it to listen to music. I completely forgot about that aspect of my system. I also seriously doubt that I ever pushed that amp as far as a single watt in terms of output, which has made me think, as has also been mentioned many times in the past, that the concept of dynamic headroom is more important an element in an audio system than I may have thought it to be. I just simply began to miss both working on and listening to my own amps as the primary amplifiers in our system.

I just began to really miss the sound of the amps that I not only spent a siginificant amount of money on for parts, but also spent many hours putting together. Every one of of these amps, like the 300B product to which you listened, happens to be a single-ended-amplifier using the ancient 2A3. I had purchased the Teac for a few reasons, among which was the fact that I thought it would be a very good match with our Lexicon processor, which doubtless it is was! An incredibly fine match, actually! The first Moth circuit I built simply did not work well at all with the Lex, and so was honestly a disappointment. During the time I spent away from posting on the forum, and after lots of thinking, I completely rebuilt the Moth amp, front to back. The details of that would be boring for most, but the end result is that, after a ton of work and experimentation with some different grounding schemes, I have a truly nearly dead-quiet SET amplifier that works marvelously well with the digital processor and Klipschorns as the main two speakers in our system. With KR Enterprise 2A3s, running at much higher plate voltages than NOS 2A3s can withstand, the Moth might not sound too unlike the 300B amp you heard and seemed to like. I think it's great that you found something there worthy of some closer attention!

My point here is that I believe a well-designed SET amplifier -- meaning one that relies on very good circuit design rather than 'audiophile grade' capcitors and resistors (for me this is what's important) -- can, in the right listening environment and for a certain 'personality' of listener, be an outstanding match with high efficiency horns. I'm going to pull the Ultrapath cathode return trick on the Moth, as well as install one of the coolest upgrades I know for SET amps -- grid chokes from MagneQuest -- and then be done with it. The 'Ultrapath capacitor,' as R. Welborne calls it, is going to be a high voltage oil capacitor, very much like what Bob C. uses on his crossovers. I had the chance to modify a 45 Welborne Labs DRD amp, using oil capacitors in that spot over the film/foil caps that came with it, and I think there may indeed have been an improvement as far as refinement and capturing of fine musical detail.

Edwin: You might be interested in having a look at the Welborne Labs DRD 300B amp. The DRDs are incredibly silent and transparent amps, and the 300B has received particularly good reviews. The 45 has too, but at about 1.5 watts output, may not be of interest to you. Ron Welborne's products are of extremely high quality, and what one gets for the investment is very hard to beat. I'm also very familiar with and have owned and heard equipment from Bottlehead (formerly Electronic Tonalities), and their amps employ the output circuit known as parallel or shunt feed. This can be a very definite step up, depending on the design being stepped-up-from, to conventional output transformer coupling. The parts and build quality are a little different from Welborne Labs, but this hobby is constantly about compromises. One has the opportunity to choose what's best on a personal and/or individual basis -- and this certainly includes the choice between higher power push-pull amplification, or what one may find what one likes from low output single-ended triodes.

Erik

[maxg]

Welcome back Erik!!!

Just a quick question - it wasnt clear from the text (to me at least). Do you now prefer the modded tube amp over the Teac?

Actually that does raise another question. Having switched from one amp to another and back, do you find you tend to listen to different music on each setup?

To put that another way do you find the SET amp to be better at some things and not at others - better always, or worse always?

[Erik Mandaville]

Hi, Max -- thanks for the welcome back.

You always ask good questions! I don't have the Teac in the system right now. Overall, for listening enjoyment, the Teac for me is more versatile in the sense that it was good with ALL types of music. As I said, I could just forget about the equipment and listen to music. The problem with me (if it's a problem, maybe it's just how I am...) is that I'm constantly curious in terms of 'what-if' sort of possibilities. With the Teac, there was nothing like that even considered. I was aware of modifications some were having done to their Teacs, but I wasn't comfortable spending 3 times the cost of the amp when, for me, it already sounded very good. Those guys who have had some of the mods in the power supply performed say they were worth the cost, and I don't doubt what they are saying. It's just not something I found necessary.

Erik

[NOSValves]

I'm not going to do it......I'm not going to do it.......I'm not going to do it........ Biting my tongue []

[maxg]

There is a lot to be said for ease of use. I recently swapped my Shelter 901 cartridge with a Denon 103 on the TQI arm.

In any other setup I would imagine there would be no comparison between the 2 but the simple synergy of the 103 with the arm means that it is 95% of the 901 in any area and actually better in some aspects.

Were music quality (whatever that means) the only guide I would have swapped back by now. As it is the 901 would not play a goodly proportion of my records (or need constant adjustment - even during playback). With the 103 I kinda fire and forget - side after side, record after record.

The bottom line result is that I enjoy listening that much more. Of course - that is not to say my quest is at an end. I now have a very good idea of what cartridge specs would work on my setup and have identified a number of likely suspects.

When funds permit I just might plump for the ZYX R100. According to its specs it is almost ideal for the arm. I just need to find/justify another $1000.

This is just not all that easy to do right now - as the Denon cost me $130 and delivers so much of what I am looking for.

Decisions, decisions.....

[Erik Mandaville]

Craig:

There's not reason to hold back voicing your opinion on this -- please do so. I can present my opinion as well without having to resort to some of what used to take place on this topic. There isn't an absolute right or wrong with this. I'm interested in hearing what you have to say.

Max: Sure I understand the continued quest. For me, it's not so much for pre-finished products as it is in increasing my own understanding of what I can do to possibly find improved performance. Sometimes the exact opposite happens, but I will try an idea if it seems possible and appropriate. Things can always be changed back to what they were if an experiment doesn't work out.

The cathode return connection (AKA Ultrapath) and MagneQuest grid chokes are two modifications I know from experience are for the better, and although those little chokes are costly, they work fantastically well in the Horus -- as they did in the Moondogs when I tried them there. It's very easy to take out the usual grid-leak resistor and plop the chokes down in their place. If JFL is still at work with Pantheon Audio, that's where I'm going for them.

I'm also interested in who here with SET amps has experimented or tried the 4 ohm output taps. I think LeoK has mentioned this a few times, and I can see some benefit in lower the lower output impedance with an 8 ohm load. I don't have convenient output tap terminals, but will just need to reconfigure the wiring of the OPTs, themselves.

Erik

[edwinr]

I'm not going to do it......I'm not going to do it.......I'm not going to do it........ Biting my tongue []

That's VERY unusual for you Craig... biting your tongue, that is! []

Thanks for your comments, Eric. I haven't heard anything featuring the old 2A3 yet. I'm trying to listen to everything I can.

What I find even more interesting, is that you seem to get that ability to generate midrange magic in either the lower powered SET amplifiers, or the higher powered PP tube and 100 plus watt per channel S/S. But nothing in between. Maybe Trey is on the right track. He suggested some time ago that only very high powered S/S can compete with the fluidity and transparency of well designed tube amplifiers.

I get the impression that Duke Spinner believes this too.

[seti]

After hearing my set amps on the cornwalls in Hope I understand why

some people really don't like them. They sounded totally different than

on my Belles at home in my room. They most definitely require the

higher efficiency speakers and totally horn loaded heritage line

especially for the bass. I was glad to have the opportunity to hear this

for myself thanks again guys.

I'm not sure what it is about tube amplifiers I like so much perhaps

it's part nostalgia. I really enjoyed the Fisher, Scott and

especially dynaco amps that I heard in hope.

[Duke Spinner]

well ... EdwinR ....you are correct on the S/S thing ....

BUT .....

the amp Must have a very clean milliwatt rating

crossover distortion will destroy the sound....

amps that make the grade ......

krell

odessey

audio research

QSC plx series , not rmx series

bgw

crest

crown

a switching power supply seems to be important, too

perhaps it emulates the effect gained by tube rectification

or .. to look at it another way ... avoids the 45000 hz noise of a diode bridge

[NOSValves]

Erik,

My only observation about your comments is your need to put some other top quality topologies into the equation. I just can't imagine the Teac being able to compete if the competion was let's say just a little more diverse.

Craig

[Erik Mandaville]

Seti:

There are a number of Cornwall owners with SET amps that like the combination very much. It's good that you found out they are not for you with those particular speakers, because there are many different amps available from which to choose.

Erik

[seti]

Eric,

I forgot to mention that the room was a good size which could also have been a factor.

All that really matters is that people like what they hear.