Alex Kitic

You are mostly correct, since in the end it gets to kits or partial assembly. Very few embark on projects from scratch, because these require two different skill sets - soldering/layout, and box building. Few can muster both. Nevertheless, when you build it yourself you can be proud of your accomplishment, and if the project is valid you will most probably have saved a lot, or better - allowed yourself to enjoy a piece of equipment way above your budget (as compared to buying finished products).

I can imagine myself winding the grid, or iserting the filamentary cathode assembly... but the glass working part eludes me completely: that would require tools that one cannot use at home. DIY today looks more like assembly of semi-finished pieces: just imagine having to solder SMD components (something I am preparing to do: I am planning a USB input board, and a slightly more complex DAC with tube I/V)...

You seem to be either lazy or overworked?Maybe you just did not want to become an engineer, but were forced by family and state to become an economist - like me? Well the tubes are 813 - direct heated beam tetrodes, and obviously I do not have the ability or equipment to manufacture vacuum tubes. Those pictured are WWII era... As for the amp, I designed and built it myself: it's pictured in breadboard stage, but all parts are actually fully assembled as components that I can insert in a box. It's a breadboarding-prototyping technique I have developed over the years to spare time and get to check on the results quicker.

I did cut and shorten it a little bit, but this experience summarizes what I am trying to convey as a message: besides SE tube amp technology, it's DIY. The performance/cost ratio is immensely superior, because not only you cut out the middle man, you cut out the manufacturer, and the designer has already "given" you the schematics pro bono... Of course, not everyone can build from scratch, but buying a few PCB and similar stuff to facilitate your work is not a sinn, actually you csn give something in return to the people who designed the piece you are building. By DIY in this sense I do not mean kits like Audio Note Kits - besides being expensive, it's basically letting you do their assembly work (they skip paying the workers in the assembly line and skip the checking of finished products - think of ISO standards, which costs even more). But it's a good source of inspiration on how to execute projects, how to make it easier for yourself.

Mains is 230V where I live, but I guess you must plug your equipment into mains anyway? As for the DIY part, it is definitely potentially dangerous to build equipment for electronic tubes, or better, checking the various points once it is built and you need to make sure everything works as supposed. The 1000+V myth does not hold water: I guess 400V is just as dangerous, although the real danger is AC... the mains you use every day can kill you - if connections are not sound, properly isolated. As an aside, you can always play with low voltage technology: DACs and SS preamps rarely exceed 24V in total (+12/-12). Safe enough, I guess?

This thread seems to be dying, while I am reluctant to leave it at amp A vs amp B. It is much deeper than that, but most commercial amps are rather equalised by the use of standard feedback schematics and components, aimed at sounding HiFi or HiEnd... With all frankness I can say that the mere names of commercial products give me some sort of cramps. Are the differences mere cosmetics? Of course, the market is aimed at its consumer groups, not at knowledgeable engineers. It has so little to do with the DIY scene.

Thank you for your impolite answer?! Neither it was your problem, nor will it be my loss. BTW, was neither my problem, actually... whose problem was it? Ever seen my blog? Maybe you should check out whether I need to follow your advice. No comment. We obviously do not speak the same language? For the rest of the audience on the forum: The speakers in question are EPOS ES22, 87dB/W/m, 6 ohm nominal impedance, slightly on the inefficient side with 8W per channel amplifiers. Beside not being loud as he is used to (with his former JBL monitors 96dB/W/m), there are no relevant flaws. Thus the speakers are not a "difficult load", but plain simple not enough efficient.

You mention well designed, while the discussion was about adding the SE amp in front of ANY SS amp (first thing off the shelf) and beautifying it with the sound of 300B... As for advantages, tubes are easy to replace and you do not need a soldering iron to do that. Plus, you can indulge in tube rolling which is a fun part missing to SS. Caps have 2-3k hours guaranteed performance lifetime, while most preamp tubes might run longer and stay in the performance frame. Not to mention the shelf life of caps?! On the other hand, most fancy tube stuff has few caps and they might (or should) be large oil in can (polypropylene in can) motor run caps that would last a lifetime (human generation) in the tube amp: take a good look at pictures of my RH813 and check out the type of caps used. SS amps, on the contrary, are made with electrolytics...

It's not going to happen for him, and I am way past the need to play around with such stuff. I know what are you referring to, know what would the result be, and know of better ways (even cheaper, maybe) to achieve that type of result. BTW, I do not have any SS amps in my home, excluding the ones in the TVs). My amps take difficult loads as good as any "normal" amp, although they are SE tube amps. The "difficult speaker load" is something that needs better defining. Are you referring to wildly varying impedance and phase that the speaker designer should have designed better, but decided to leave as they are "for the sake of sound" (because it would be expensive to correct, and the manufacturer needs to increase profits) - or is it a very insensitive speaker that needs loads of power to start delivering some decent sound?

He's got no SS amp right now, but I understand he's getting a Studer amp console from a studio. And of course that is just an interim solution. As for trying the mix of fish and meat, I don't think so. I don't think SS amps are incapable, on the contrary: but less is more. SS amps are more often than not plagued by complications, feedback loops, and have lots of active components in the signal path. There is no SE amp with transistors consisting of 2 transistors, or 3?! Consider why's that? No wonder SE tube amps sound better. As for the sound of tube amps, it has nothing to do with warmth, or at least it should not. I am unable to build such a muffled warm sounding unit, but I know what are you referring to. Tube preamps in particular tend to be very transparent, unless they are Chinese concoctions with ECC83 and feedback loops to keep gain low. Thus adding a tube front is not going to warm up the sound. Likewise, why a tube buffer for CD players sounds better than op-amps? Maybe because there is one tube involved against a horde of transistors? That said, most tube buffers are actually silly...

As for your solution, he wouldn't: it's either meat or fish, and he does not eat fish because he doesn't eat stuff that has died (while red meat comes from the slaughtered animals). Jokes aside, I wouldn't either, what's the point? Burning excess power from your tube amp on a resistor and imagining that the cheap SS amp is an ideal transducer?! What would the SE amp do, pose for a preamp? What he is going to do for the moment is use an SS amp instead of the 300B SE, and have enough power while keeping his tubes for better times later.

So from tubes vs. transistors we have gotten to horns vs. the rest... Yesterday evening I went to see a friend, who happens to be an audiophile with a few DIY aspirations... he is currently "stranded" with a pair of nice but rather inefficient 3-way EPOS speakers, without the funds to build the boxes for another pair of JBL professional monitors (he's got a set of 15inch JBL woofers and horns, as well as the original crossovers - the resulting speakers are 96dB/W/m efficient, which means that in a "normal" room you can have plenty of volume and fun with 8W of power). He used to have a pair of these, but had to sell them and now has to listen his 300B mono-blocks on inefficient speakers (and his amps are no-feedback, so give or take 8W per channel). Well, his wisdom is - "if you are into SE amps, you have to choose efficient speakers. If you cannot afford those, better find a 100W per channel SS amp of decent lineage... because you just cannot fool yourself by using SE amps with inefficient speakers." Than I told him that I agree in general - but then you can have a very powerful SE amp, something like 25W or more... "Come-on", he said, "a 25W SE is not an SE amp - I accept only 2A3 and 300B amps in that category!". Well, probably a bit radical for my taste and experience, but I guess many would agree.

Now that we agree on the power one really needs, it's easier to get to terms with amplifier type or topologies. Obviously, I prefer tube SE amps, not necessarily DHT or triode. But I consider my amps (RH) superior both in performance and sonics to the no-feedback SE amps. More power with the same or similar tube type, better bass and definition overall, better soundstage. As for triode vs pentode, the lusher midrange od the 300B or 2A3 might or might not counterbalance the richer tone of pentodes. I guess few know what an I talking about.

There is no Holy Grail in life, likewise in sound/music reproduction. Not even a given type of system would work for everyone - due to laws of physics, or taste.

There is no troubleshooting if you build based on a good design, and you don't make mistakes. I don't recall having to troubleshoot anything I built. But since I build only my own designs, that's to be expected.