birdseye maple with ebony splines. Boxes for amp and meters for @FLTWS, once the black jacks and meter housings are in place as well as black tops, the ebony splines will really pop. Not to mention several coats of clear lacquer. Only preliminary sanding is done here, enough to get the splines even with the cabinet frame. Pre-amp out will go directly to the meters, and there is another pre-amp out in parallel so that function is not lost.
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What is better, breakfast or lunch? This question is one that divides the stereotypical audiophiles and diy enthusiasts. One cares about which sounds better in an absolute way, the other which is better suited for a particular application.
They are not really interchangeable especially considering tube amps and each has its own place and time.
SS pro:
- cheap, reliable, easy to use, available, hassle free, super low voltage drop, tiny size, no heat for low power applications, ideal power factor.
SS cons - PIV, fast turn on(no soft start, critical in some applications), reverse recovery in some, may have issues with choke inputs, lack of tuning.
With tubes it’s harder to nail down the same list since they differ so much you’ll find one for each application including voltage drop when considering gas rectifiers. Heater requirements is a drawback but not really, usually it’s around 10W more of power needed, not an issue in the grand scheme of things and there are very good 6W and less available.
You question might be better put this way, a quality SS psu or tube on one? SS psu I’m thinking bridge rectifier with regulation, something like salas or a pete millett module. For tube it has to a FWR, choke input, unregulated for class A. Each has pros and cons again.
Then what about a hybrid bridge, best of both worlds? Each has to decide but I’m a fan of Geezers setups.
Another point to consider, the rectifier is maybe 20% of a PSU, so why so much fuss about just a part of it and not the rest? I’d rather argue the first component after is more important.
Cap input or choke input? This can have the same level of impact on the overall sound as the rectifier type.
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I am getting ready to take off or I would be happy to talk about each point. I will just say this, there are other concepts for tube amp power supplies, they are key to my design. I guess the topic was rectification though. I am not really building with someone else’s idea but my posts got moved here. I tend to do my own design, not so much DIY.
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Appreciate the detail and perspective - helpful for a non-engineer, non-builder. Pros and cons throughout, which must be managed by the designer/builder.
Correlation isn’t causation, but most tube amps that are considered to be TOTL seem to be transformer based with tube rectification. Is it then accurate (versus an oversimplification) to say that tube rectification has a higher sonic performance ceiling, while also having a lower floor.
True, multiple moving parts and elements to consider - with the overall PSU and importance of the cap/choke input.
*Breakfast…yup, breakfast. However, that’s rare for me with intermittent fasting.
For traditional tube amp designs, DNA, EC, Viva etc. using a SS rectifier is major challange due to the start-up procedure. Tube rectifiers even directly heated ones have an in built delay of warm-up. This lets the output tubes heat up before the high voltage is applied.
For SS delaying the high voltage can be done, doing it without switches/relays in the PSU is quite tricky and more expensive than a tube rectifier.
The Axex Pinnacle is a perfect example of an uber SS psu with tube voltage and current amplification.
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How difficult would Spalted Maple be to use on a build like this?
I am guessing that it would probable need to be a veneer due to the nature of SM?
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I have one inch thick spalted maple I hope to use. I have not worked with it yet but I will try one day. I plan to read more before touching it lol. I know enough to wear a quality respirator and I have a portable table saw, I may well work with it outside in the fall rather than take a chance of fungus entering any plenum spaces in my house.
Oh and this build would only be for myself. Wenge can be tricky as well. I hope to use purple heart soon but I know enough to use a finish that is UV protective yet no matter what it does turn brown over time no matter what so all you can do is hope to slow that process.
I am still learning about specific types of wood but I enjoy learning.
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There is just something I love about SM. This is one of my basses (sorry for the crappy pic) and I love the finish.
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Very nice. I could not find a decent picture of splated maple with splines, this one is ok but not the look I am hoping for.
I add splines to all of my Incubus audio cabinets, my problem with spalted maple is I make around thirty cuts and then use a router and sanders but I also have a portable router table.
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Getting back to DIY audio, this is a Bottlehead Crack I did for my son. I hate having controls or jacks on the top next to tubes so I knew before I ever touched one I would change things. This one is piano black lacquer with control knobs off a Fender guitar. Front, back, and top plates are all carbon fiber over aluminum. The cable for the interconnects is no longer available to my knowledge but that is silver braid with a clear jacket. I went about as far as I could go with changing Cracks to my liking but I wanted more power and a limitless high end so I designed my own OTL. I also wanted to design around a 6sn7 because of some blind testing my audiophile group is doing and the fact that many friends own bunches of that tube. I wanted the amp to be able to better differentiate between tube nuances.
Here is an exception to pots being on top, this honey locust was gorgeous and I did not want to have the pots on the front, so I added ladder pots to the top.
the supports for the pots are copper ring terminals for zero gauge wire as I recall, I drilled holes in the back supports to allow for the three wires to each pot. I was playing around and made a Faraday cage for a transformer cover with copper mesh but I will soon make one out of solid copper. Top plate is 1/8 inch copper that weighs right at two pounds, it makes for a nice solid platform, great heat distribution, and easy grounding. The back side is still pure copper, I only patinated the top.
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I had not considered the impact on start-up procedure and warm-up delay, thanks for highlighting.
The Apex Pinnacle SS PSU - uber and medical grade I believe.
@Paladin both of those amps are beautiful. You are truly gifted. Out of interest, what are your favorite 6sn7 tubes? I have a Lyr 3 amp, which is my first experience with tubes. I wasn’t sure if I wanted to dive into the world of NOS tubes, so I bought a Treasure Globe 6SN7-SE as an upgrade, which I’m enjoying.
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My favorites are the Melz 1578 from 1963
Ken-Rad VT-231 black glass
And 1942 RCA grey glass
The first one can still be had as NOS but you have to know what you are doing to buy one and I always replace the solder in the pins on those.The last two are not easy to find NOS, you best be careful of folks that say measures like NOS, not the same thing.
and thanks for the compliment, I do try.
If the virus ever lets up friends and I will be blind testing the top 52 6sn7 and equivalents we could find. In the mix are tubes in the $1,000 to $2,000 range as well as a couple that would be hard to place a value on. They are two from a set of four built in a lab by a friends grandfather who designed for RCA, I received two in a Pelican case and I sweated the whole time I had them. In my mind, knowing the history it was tough to assess them so I will see how they fair in the blind tests. I say equivalents because there may be single triode, and British, Italian and Russian tubes that use a different numbering system.
The 63 Melz
Single triode Sylvania tubes that were the forerunners of dual triode 6sn7’s.
You best love looking at the history if you want to learn about tubes, I have manuals from many companies dating back to the 1930’s. A good modern book is Tube Lore, and you can find it on Amazon but it takes a while to understand such books.
I am old enough to have had tube theory in college.
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I have seen many a post lamenting the scarcity of good NOS 6SN7s. It’s obvious now who has them…
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Thanks @Paladin for the interesting answer. I originally saw the first version of your response (which was the first 3 lines), and that was helpful all by itself. But luckily I returned to this thread later on, and can see you’ve edited it and added some euphonic color to your original neutral answer. Fascinating, at least to a tube ignoramus like me.
And this was one of the reasons I decided to look at new tubes, and bought the Treasure Globe 6SN7-SE. I assumed that the NOS population would dwindle and the prices would soar.
I like my Treasure Globe, currently using it and a 5998 for this weeks listening. Last week was Psvane 6SN7- UK with a Cetron 7236 in the power position.
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I hope you are smiling when you say that. 
There are people who own 10,000 tubes up and much of the interest in 6sn7’s probably stems from Schiit using them in the Freya, Saga, and Lyr 3.
There are also companies making a living selling tubes so they have buyers watching for bargains. Viva Tubes, Lowtechelec, et alia.
I send out two tubes per amp and the blind testing I am talking about is probably 90 % tubes owned by individuals in the audiophile group I belong to. For a couple years I have replaced the solder in some of the Russian tubes that have issues with solder in the pins, at no charge, and I generally pay shipping back.
That being said some Russian tubes considered very good are made by Melz and Foton. The Foton ribbed plate tubes from the early fifties are quite good and used to run about $20 each or less. The 1958 smooth plate is still out there and once the solder is replaced, they are very fine tubes.
If buying the Melz 1578 you really have to know what you are doing. Some of the NOS in desirable years can run $120 per tube and you wait about two months to get them from Russia.
There is a lot of research involved in knowing what to buy and what to pay. Many folks serious about tubes own vintage tube testers and have spent years in this hobby. If a person just starts buying tubes off of Ebay they can get burned pretty quickly.
You can still find NOS tubes but often you have to wait and wait and watch for them, and hope you trust the seller.Not everyone wants to put in that kind of work. You can also find NOS equivalents if you know what you are doing, I found 7A4’s that were a forerunner to 6j5 single triode tubes. You need an adapter but they can still be found NOS, same with 6J5’s. Dual triode tubes require shielding to prevent cross talk (6sn7 is dual triode) single triode tubes are used in pairs and have the same specs and they offer a bit better channel separation. IMHO
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Indeed these are some of the better tubes you can buy NOS, the Russians are doing some reproductions as well and many of them are certainly usable. The Tung Sol 5998 is very popular in Bottlehead Cracks and I use them in my personal amps, when you can find them, NOS can be $160 up but there are plenty of Svetlana winged C tubes and RCA 6as7g NOS that are decent power tubes. 6080, 6AS7G, 5998’s, and 7236 are all interchangeable power tubes with different gain levels. More often than not I send the Svetlana winged C and 1958 Foton with my amps. They are very available as NOS and very respected in some circles
. I have a hard time using a tube in a Vali 2 that costs more than the amp itself but with adapter they can handle a 6sn7. You want to be very careful that you do not exceed the filament current rating on the amp when swapping tube types. The Bottlehead Crack can handle them with adapter, and the original tube was a 12AU7.
A Western Electric 421 A and a pair of single triode GEC L63’s in one of my early Incubus Elegan amps that I built sideways for a buddy, he did the patina on the transformer cover, that is some sort of paint that resembles a patina, the top plate has the real thing.
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I’ve had most of the popular 6SN7s while I was on my gotta catch’em all craze before I came to my senses. Some of my favorites: ECC32, ECC33, B65, TS BGRP, Bad Boy 3 hole, 13D2, reliatron. They all carry a slightly different sound flavour, among the most refined and composed was the french made visseaux.
One crucial aspect, tubes sound different in different circuits/amps. Unless the circuit is dead neutral which none really are the resulting amp/6SN7 is what we’re hearing, not the tube itself. That’s why all the conflicting opinions of how tubes sound. I’ve started to sell mine after all the effort to collect them.
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Excellent points! I went out of my way to design an amp that made the 6sn7 the star, and some pretty serious tube critics I know seem to think I succeeded. I will not mention any brands of tube amps but some of them might as well be solid state IMHO, they lack the tube sound I crave. I have plenty of 6sn7’s and my audiophile group has most anything I lack. I would enjoy seeing a list with prices if you want to pm me one, I can show it to friends.
Since I work in the field, I rarely pay much for any electronics myself or my investment pays dividends. I paid about $2,000 for my first computer but I took the monitor apart and studied the design and became the second person in Indiana to set up and do repair on them. I had as many as six techs and made a decent living for ten years. Another project paid my son $50 an hour when he was in his teens and paid for his college.
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