Resources saved on this page: MySQL Show 50 post s from this thread on one page. Are there sonic differences between them. I have 45's, 2a3's but no b's. Am I missing something. Starting another build and need to make a decision. The 45 and 2A3 are honest. The B is a "showman".
Lots of folks like the B's euphony, but it IMO generates excessive 2nd order harmonic distortion. What kind of amplifier are you going to build next, Push Pull or Single Ended?
I have built B Push Pull amps that have almost no 2nd harmonic distortion, and almost separation of organic mixture lab report 2nd order intermodulation distortion. Even some Single Ended B amps have low 2nd harmonic distortion. It depends on the plate voltage, plate current, grid bias, transformer primary impedance, and especially not designing it to squeeze too much power out of it.
Unfortunately many use the B to get more power, not to get more finesse. I have built SE 45 amps. But getting quality pairs or quads is hard. I might build parallel 45 amps if I could get inexpensive NOS tubes that match well. Dollars per watt adds up when you have to use 2 or 4 each 45 tubes per mono block. I have built 2A3, 6B4G, and 6A3 amps.
Some of the 6A3 and 2A3 tubes were not strictly made to original design, they were made as mono plates. I would probably build more 2A3 amps if they did not need 2.
6SL7 SRPP / 2A3 Single-Ended Tube Amp Schematic
I use individual self bias, so that is 4 each 2. I believe that 2. I agree that there is a difference between 2A3s and Bs but I have found much more difference in the choice of driver tube and the type of driver circuit than I ever did between power tube types.
That, for me, is for either triode or pentode outputs. Little relative difference. If you change the driver tube or circuit it's a new amp. Maybe it's speaker dependent. VinylSavor: B :. I agree, the driver tube type and circuit values makes a big difference. It was driven by RC coupling from the driver.
Sun Audio 2A3 tube integrated amplifier
The driver has a self bias resistor with a bypass cap. The plate load is a constant current source. The self bias voltage stayed exactly the same, the current stayed exactly the same, the gain stayed almost exactly the same, and only the plate voltage changed. But Wow! What a difference in the sound! The 6DJ8 had a lower plate voltage, as would be expected because of it's lower plate resistance.The Fi 2A3 amplifier is the simplest and most direct amplifier available today.
Wright Sound WPA 3.5 monoblocks Amplifiers
It consists of a single triode voltage amplifier direct coupled to the 2A3 output stage, one of the best output transformers around, all connected with a few inches of pure silver wire.
Anything more is unnecessary and detrimental to sound quality. Any and all attempts at higher output power are for some reason other than sound quality and are misguided. The 2A3 is the most natural and direct of the filamentary triodes B,commercially available and will get you closest to the essence of the music. Forget pentodes. All this purity means low output power, but with efficient speakers the music is lifelike: full, detailed, and above all palpable. These speakers are available and there will be more of them.
The gauntlet is flung. For a while now we've been running ads with a photograph and a few words or a line or two of description. That's all you need to know, we thought.
But many of the responses have been a bit perplexed. Hence, the above. We've been at this a number of years and tend to forget how radical it appears. It's really very simple, not to mention solid and reliable. We'll be around for a while.
Don finally achieved the kind of sound he wanted from a B and so brought the amps to market. The original preamp advertised in Fi magazine and made famous by Art Dudley in Listener magazine was discontinued. When I asked Don why he discontinued a preamp that was widely held to be one of the very best preamplifiers available at any price, he told me that "It was just too expensive to make. That's too expensive I thought, so I discontinued it. Fi Today Don's been busy designing and refining gear to tickle your fancy.
Don's sales are said to be fairly even across the different models in his lineup which presently includes:. Direct-coupled signal path, 6SF5 triode driver stage, a 2A3 directly heated triode output stage, a MagneQuest DS output transformer, Pi filter power supply uses 5V4G rectifier. Chassis are handcrafted from sandblasted and polished aluminum and each amplifier is signed and numbered.Completed kits by customers:.
Read on I have been asked by many of my solder sniffing clients about putting together a kit that would allow them to put together by themselves some of the products that I provide. I have been putting it on the backburner for sometime now mostly due to amount of work orders that I have been getting yeah!
I figured that unless I make a real effort to make it happen, this kit idea will never materialize. So here it goes - I am making it happen. For now, I will only offer kits for amps that I have lots of experience building. They are as follows:. JEL Standalone Linestage. Here is what you get with a kit:. As far as parts selections go, please look here. I will do all the metal work on the chassis according to the layout of your choice.
Here is what you DON't get with a kit:. This includes solder and soldering iron. Remember that tube amps run on lethal volts. The whole point of putting a kit together is to feel the sense of accomplishment. I will not rob you of the pleasure. The lead-time for metal work and compiling all the parts will take about weeks.
Occasionally, there are some parts that need to be imported from abroad that would delay the delivery time. If all this sounds good to you, please contact me and I will give you a quote. Thanks for reading thus far.Angela simple 2A3.
Hi everyone! I have 2 questions : Does anyone have a copy of the Angela 2A3 Simple schematic? Do you consider this schematic is still interesting or we can now build something more up to date? I'm not necessarily looking for the easiest beginner's project but I don't have the skill to realize the most complicated Thanx in advance!
The 2A3 Tube Amplifier - A Tribute to Simplicity and Warm Sound
IMHO there is no reason for a 2A3 amp to be complicated. Good power supply is important. I find that the quality of the rectifier valve affects sound quality quite a bit. Front end can be whatever you fancy, I have seen classic triodes like 6j5 and pentodes used.
The op trannys are important. I have a W. Use the wayback machine to find old web pages! Last edited by rmyauck; 9th January at PM.
The schematic at the bottom of this page may work better. I built this DIY 2A3 Amplifier. Find More Posts by lhgin. BB code is On. Smilies are On. Forum Rules. All times are GMT. The time now is PM. Resources saved on this page: MySQL User Name. Stay logged in? Mark Forums Read. Please consider donating to help us continue to serve you. Thread Tools. Angela simple 2A3 Hi everyone! View Public Profile.
Send a private message to spartiate Find More Posts by spartiate Send a private message to ColinA. Find More Posts by ColinA. Send a private message to rmyauck. Find More Posts by rmyauck. Thanks a lot Rmyauck, your replies are very helpful!Where do you get your meters?
I also like the landscape orientation. I collected some over the last 20 years. Didn't buy any since at least 5 years. Those were pretty much the nicest I have. I miss the days you posted schematics of some of the designs you were doing. There are so many schematics published on this blog, what are you missing? I am not the type who changes things every 6 months.
Many of my amps are using the same concepts since years since they are proven and work. And another important point: It is difficult to earn enough to live if you give away everything for free ;- Use the schematics on my blog as a starting point and develop your own concepts from that.
Very nice looking amps! Thomas, you have probably covered this before, but you can tell us why you prefer to use a separate chassis for the power supplies as opposed to monoblocks with each amp on its own chassis?
Microphonics maybe? The decision about the split always depends on size and budget constraints. Of course there are different philosophies and opinions about this, but for me if budget and available size are limited, a separate power supply and stereo amp is the better choice. This disadvantage is the need for a umbilical. The chassis of those allowed for the extra space needed.
In any case I prefer a good power supply with healthy transformers shared between the channels over monos with wimsy PSUs. Hi Thomas. What made you decide on AC filaments for this build?
You usually go with well filtered choke input DC. Is it a customer request? BTW, the Westons look superb. Expensive even back in the day. I only have one large Weston AC meter for my vintage variac. I build amps to customers size and budget constraints which did not allow for DC filaments ion this case. Hi Rick, I'm the actual owner of this amp.
DC filaments would not work in this scenario so I opted to stick with AC filaments. I see balanced inputs on this case, in the futture I will try this option with a pair of Lundahls LL, what input ratio did you use in the present ptoject? The fact that I can also use 45 and 2A3 tubes is just icing on the cake. Those Tango interstage and output transformers are something special.
I want to thank Thomas for making my audiophile dreams come true. This will be a lifetime investment that I will never sell.
I arrived at Thomas after concluding that he is one of if not the greatest practitioners of transformer coupling in the world which I felt was essential for my dream final system.Simple cheap 2A3 stereo amp.
Hello all, I just put out a site with a schematic for a 2A3 stereo amp and its power supply. It is simple and cheap, inasmuch as it only uses one transformer for all power needs. Have fun!!KT88 - Single Ended Tube Amplifier Build 2018 - Part 1
Find More Posts by Gabevee. Ah, a no-nonsense amplifier, with some practical solutions to otherwise somewhat complicated problems. Find More Posts by Sch3mat1c. The Stereo SE Hi Gabevee!
The only sugestion that i can make In my opinion a resistor and the capacitor in each catode will be a improvement for such a small cost as a resistor and a capacitor! Of corse in this last case the resistor must be doubled in value! In a push pul amp it could be allright as a shared catode resistor in each chanel Thanks for sharing! Jorge PS. IMHO of course! Another drawback is if one tube fail or is geting weak the other will be overbiased! I thought so too, but I have built several different types of single ended amps with a common cathode for both channels.
There is no cross talk because the bypass capacitor takes care of that. If there is cross talk, the actual effect will be that of a sort of imaging enhancement, since any audio that gets past the bypass capacitor will be inverted from the other channel. So if anything, a wider soundstage will be the result.
The thing I do not think you are aware of also is that I need to have a common cathode resistor in order to use only one power supply for both 2A3s. To separate the cathode resistors means using two separate 2. More cost. No budget. Thanks for the input! The 2A3 Circuit. Since it uses a series filament scheme, I think it would be a good idea to use a non-polarized capacitor for the cathode bypass. Another issue is the filiment supply.
Depending on the filiment filter capacitor, the filiment voltage could rise to 7 volts. Wow cool circuit- simple, logical and looks easy to construct. I will definitely give it a go at some stage, I am just in the process of building a 2a3 amp at the moment, if I am not happy with it I will try your circuit.
BTW What is the technical name when the ouput stage is driven from the cathode of the previous stage? I am curious as to your reason for using DC on the 2A3 filaments- some people say there is a huge difference in sound and AC is better?Hi Alex, Interesting article.
I Have some white label, double plate, 2A3 octal. I think it must be Suguang, but there are no signs on the glass. Just only '2A3'. Just to be shure: these tubes works on 2,5 V heater voltage? Bye, Hans. You can always try to see if the heaters will light up on 2. There are no 6B4G marked as 2A3, anyway. If you have more questions, please e-mail me. Regards, Alex. During the final development stages of the RHB amplifier a similar schematics for use with 2A3 tubes has imposed itself as quite feasible and logical.
The 2A3 is a DHT tube just like the B, of similar general characteristics: mu is around 4 in both cases, while plate resistance is between and ohms. The main difference between these two tubes, heaters voltage aside, is maximum ratings — dissipation and voltage. Thus slight downscaling of operating voltage and current to create operating conditions acceptable for 2A3 tubes has been done before with several popular schematics.
Just as in the case of the RHB, at 5. As the schematics is strikingly similar to the RHB, I shall not repeat all considerations related to the schematics itself — the only appoint that should be made, or rather repeated, is that the operating point of the cathode follower tube is determined by the directly coupled grounded cathode driver tube.
Thus it will draw the same current regardless of tube type used — and this time I have chosen to adopt an octal socket, accommodating 6SN7 tubes, but 6SL7, ECC35, and other similar tubes can be used as well — you can go as far as 6BL7, 6BX7… even 6AS7 or While it might elude logic to employ 6AS7,or WE by TungSol due to the relatively low current draw, and keeping in mind that these tubes have very high heater current requirements which would have to be taken into account — the sonic results obtainable with these tubes reflects their known sonic characteristics, and are quite interesting in the scope of this amplifier.
And of course, that is the most logical way to go…. While the 2A3 tube was manufactured as well with 6. The most notable application of these tubes have been the Audio Innovations First and Second amplifiers, as it seems that 2A3 tubes were custom ordered on octal base due to a lack of UX4 sockets at the time.
In my personal opinion, while this is a plausible answer, I guess that commercial concerns were important as well, channeling the supply of spare tubes for the amplifiers. Anyway, a different base just needs a particular socket, and besides complicating life a little bit trying to source 2A3 tubes on octal bases, this would not be much of a twist. In keeping with the inherent universality of my designs, at this point the enters the stage.
The is a direct heated beam tetrode tube on octal socket. It has 2. So far so good - but what about the second grid and the beam forming plates?