Hi there - I'm thinking of a new project for 2022, and never having owned tube amps I'd like to build something. I've successfully built an Aleph J with help from this group, and think I'm up to building a tube kit. Definitely not interested in flying solo on tubes with a scratch build; need a proven design and kit. Speakers are high sensitivity Zu Omen Def (2x10" full range w/ horn loaded tweeter, rated at 101db 1W/1M, 8 ohm) so I don't need a ton of power. Speakers sound amazing with the Aleph. I'm looking to try the "tube sound" and hoping for more 3D soundstage and "bloom" if that's the right word. Music is wide range, lots of live Grateful Dead, jazz, female vocals. Mix of vinyl and streaming. I'd like to continue to use a pre-amp (currently running a Schiit Freya (solid state) and considering a change to Freya tube or other tube pre in the future)
Right now I'm thinking of maybe the tubes4hifi M-125 monoblocks (http://www.tubes4hifi.com/M125.htm)...but also wondering if I should go for a 300b like the Elekit TU-8600. Obviously these are at sort of opposite ends of the tube spectrum...what do you think I should do and why? Budget should be in the $2-2,500 range but flexible.
Right now I'm thinking of maybe the tubes4hifi M-125 monoblocks (http://www.tubes4hifi.com/M125.htm)...but also wondering if I should go for a 300b like the Elekit TU-8600. Obviously these are at sort of opposite ends of the tube spectrum...what do you think I should do and why? Budget should be in the $2-2,500 range but flexible.
Take a look at what Bottlehead offers, their Stereomour kit might fit your needs. With your budget you can get the amp and the Moreplay preamp. Bottlehead kits offer the best step by step assembly instructions.
Bottleheads a very good choice. I don't think it will change your 'soundstage' though.
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With >100dB high-sensitivity speakers you do not need/want M125 monoblocks, unless you wanted to be prepared for a future change to lower sensitivity speakers. A SE 300b or good 2A3 or EL84 PP amp would match your present speakers better. I have not built one, but see very good reviews and building experiences of Tubelab’s TSE II. George Anderson’s PCB and build instructions are excellent and the Tubelab forum also provides good help and support.
Yes, stay away from high power (over 40W) tube amps. They are much more expensive
and will often not sound as good.
and will often not sound as good.
I have built the Elekit TU-8500 tube pre kit and it was very well designed, affordable and if you swap some audio bypass caps, extremely capable. Instructions were great, nothing was missing and I have seen many other glowing reviews of their kits. I do not think they will exceed what you could build DIY with time/effort and some $$; but if you want a pretty easy and hard-to-mess-up project with proven results, their pre and amps are certainly worth looking at. Of course as others have said, if you are comfortable with a little more DIY, there are some great PCB and kit options out there too... you have the option of buying vintage and restoring a piece too.
The main thing: You need to read the safety section and realize tube amps have lethal voltages... even after they are off. They can be very dangerous if you do not know what you are doing. You'll need a multimeter capable of high voltage (not all of them are) and even better yet, an oscilloscope or access to one. Good luck and enjoy~!
The main thing: You need to read the safety section and realize tube amps have lethal voltages... even after they are off. They can be very dangerous if you do not know what you are doing. You'll need a multimeter capable of high voltage (not all of them are) and even better yet, an oscilloscope or access to one. Good luck and enjoy~!
Thanks all for the great feedback. Agreed on the M125 power...probably overkill. While I probably won't hold on to the Zu forever, I don't see myself going back to "low" efficiency speakers anytime soon. So I'll look at the 300b options and the bottlehead too. Thanks for the safety warning as well, part of my focus on available kits is to minimize experimentation and keep it as simple as possible.
Look at Tubelab boards. While not a true kit they are well documented and there is lots of support here. They sound good and are relatively inexpensive so you can wet your feet in the disease know as tubes! A single ended KT88 or KT120 with 101db speakers will part your hair at 10ft!
I built and love Aleph-J and then built TU-8600R. I run the Aleph-j with nutube preamp. The elekit is next level for me and sufficient output for 95dB speakers but definitely doesn’t go well with nutube preamp (woofers driven by hypex…). Definitely can’t go wrong if it is enough wattage for you and just as easy to build as an Aleph-j for me…
Any thoughts on the 8600S vs the newer 8900E which is also a 300B amp but can also use 2A3 tubes?
Also - if using with a preamp, is there a bipass of the included volume control or do you just set the amp volume at max and it becomes a pass through?
A single 300B tube filament requires 5 Volts at 1.2 Amps.
A single 2A3 tube filament requires 2.5 Volts at 2.5 Amps (1.3 Amps additional current than a 300B).
Filament voltages can be dropped by using a resistor, but filament currents from a transformer can not be increased without consequences.
Most 300B amplifier's power supply transformer can not provide the 2.5 amps filament current that a 2A3 requires.
It will run very hot, if not smoke the enamel off the wire.
Make sure that any amplifier that is made to run Both 2A3 tubes, and 300B tubes has a power transformer that can produce the extra current for the 2A3.
Some use two 2.5V secondaries per tube, and then are used in parallel for 2A3, and in series for 300B. That works.
A single 2A3 tube filament requires 2.5 Volts at 2.5 Amps (1.3 Amps additional current than a 300B).
Filament voltages can be dropped by using a resistor, but filament currents from a transformer can not be increased without consequences.
Most 300B amplifier's power supply transformer can not provide the 2.5 amps filament current that a 2A3 requires.
It will run very hot, if not smoke the enamel off the wire.
Make sure that any amplifier that is made to run Both 2A3 tubes, and 300B tubes has a power transformer that can produce the extra current for the 2A3.
Some use two 2.5V secondaries per tube, and then are used in parallel for 2A3, and in series for 300B. That works.
If this is you first build, might it be worth tackling a cheaper project first, to dial in the skills you need and make the work on the expensive kit more fun? You could buy a set of toroids, some EL84s, a PCB (Tubelab SPP for instance, but maybe a SSE with EL34s might suit your speakers better?), and have something thay plays in the hifi league, just for the price of a pair of budget 300Bs. It could just sit on a piece of wood, it does not have to be a final product. Then you could set the operating points, tune the sound, get familiar with the different systems that all are interworking.
The high voltages are not very forgiving, and some of the most expensive components are the most vulnerable.
The high voltages are not very forgiving, and some of the most expensive components are the most vulnerable.
^^^^^^^^^this. I've built a few 'kits' and they have always spent their first 6 months of life on a breadboard.
I believe the design addresses this issue; according to the Elekit literature:
"Automatic detection of 300B and 2A3 tubes - “300B” and “2A3” tubes look similar but their respective filament voltages and operating parameters are totally different. Their supply voltages need to be adjusted depending on which of these tubes are used in the same amp. In TU-8900, the tubes installed are detected automatically and the correct filament voltage and voltage of B-power are automatically set. When 300B tubes are installed, the LEDs on the sides of the volume knob will light up in blue. If 2A3 tubes are installed, the volume knob LEDs will light up in green. Additionally, these LEDs on the right and left side of the volume knob will turn red when there is excessive current due to defective tubes, etc., and the current is shut down to protect the amplifier. The red LEDs will also diagnose the problematic tube- the right side of the volume knob turns red when excess current occurs in the right channel, and vice versa."
thanks for this, but I'm pretty confident in my ability to put together a kit. I could build a breadboard first...but that's not what I want to do. And ultimately building a breadboard version first doesn't mean you have to be any less careful with the "keeper" version later. However, I'm not looking to experiment with my own design (which I can't do Lol!) and hence the interest in a kit.
I also built an Aleph J with the help of Flohmann’s build guide for noobs. Now I have built an Elekit TU-8900 and a Tubes4HiFi ST-120. Stick to Elekit for service if no other reason. Bob Latino has retired. Elekits are easy to build. The instructions, the fit and finish, the attention to detail is superb. And, you get Victor.
Victor will tell you that the 300B side of the 8900 isn’t quite as nice as the 8600, but with my ~$400 tubes on both sides, the 2A3 sounds WAY better than the 300B. [There may be a different story with $1500 WE tubes. I’m not likely to find out.]. And most reviews that I’ve seen feel that the 8900 2A3 sounds better than the 8600 300B as well.
But, if you read between the lines, Victor believes (I think, but he will never say it) that his Sunvalley SV-S1616D [300B] point to point 300B amp + Hashimoto H-20-3.5U kit with no PCB, etc. is in fact, the best of the bunch for 300B, and it costs about the same. $1,975. I think it’s more difficult to build than the Elekits, but the instructions are just as good, supposedly.
https://www.diyaudio.com/community/threads/sunvalley-sv-s1616d-300b.371736/.
That’s what I will be building next, I think. Either that or the Transcendent Pinnacle. That may have the best 300B sound of all, but you need to buy EIGHT decent 300Bs to find out. The kit for a mono block pair is only $1700 but you will probably want to spend more than that on the tubes.
https://www.transcendentsound.com/pinnacle.html
Victor will tell you that the 300B side of the 8900 isn’t quite as nice as the 8600, but with my ~$400 tubes on both sides, the 2A3 sounds WAY better than the 300B. [There may be a different story with $1500 WE tubes. I’m not likely to find out.]. And most reviews that I’ve seen feel that the 8900 2A3 sounds better than the 8600 300B as well.
But, if you read between the lines, Victor believes (I think, but he will never say it) that his Sunvalley SV-S1616D [300B] point to point 300B amp + Hashimoto H-20-3.5U kit with no PCB, etc. is in fact, the best of the bunch for 300B, and it costs about the same. $1,975. I think it’s more difficult to build than the Elekits, but the instructions are just as good, supposedly.
https://www.diyaudio.com/community/threads/sunvalley-sv-s1616d-300b.371736/.
That’s what I will be building next, I think. Either that or the Transcendent Pinnacle. That may have the best 300B sound of all, but you need to buy EIGHT decent 300Bs to find out. The kit for a mono block pair is only $1700 but you will probably want to spend more than that on the tubes.
https://www.transcendentsound.com/pinnacle.html
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I recently built the Tubes4HiFi.com Dynaco clone ST120.....Fantastic amplifier. A great kit with amazing support for the kit builder......
http://rvbprecision.com/stereo/vta-st120-dynaco-clone-tube-amplifier-build-in-pictures.html
http://rvbprecision.com/stereo/vta-st120-dynaco-clone-tube-amplifier-build-in-pictures.html
This is a real classic. The kit is temporarily out of stock but worth waiting for.
Select the metal film and stainless steel options. You get the tubes from another vendor.
https://www.dynakitparts.com/shop/st-35-kit-120-vac/https://tubedepot.com/products/jj-el84-6bq5-power-vacuum-tubehttps://tubedepot.com/products/jj-ecc832-12dw7-preamp-vacuum-tube
Select the metal film and stainless steel options. You get the tubes from another vendor.
https://www.dynakitparts.com/shop/st-35-kit-120-vac/https://tubedepot.com/products/jj-el84-6bq5-power-vacuum-tubehttps://tubedepot.com/products/jj-ecc832-12dw7-preamp-vacuum-tube
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My first build was Pete Milletts “Engineer amp” - you buy the PCB and order the parts yourself. Was a great introduction, and the instructions were very clear. Plus it uses tubes that are not terribly expensive