After reading this entire thread I must recommend an email to Tubelab. He hangs out around here at times and I've built his Tubelab SE with both the 2A3 setup and the current 300B. In a word...outstanding. A single evening to wire it all up, minimal parts, outstanding performance feeding into Decware DIY HDT's ( 96 dB/watt) with the highly modified FE206E's.
Tubelab also has a simpler board that uses KT88's, EL34, etc you name it, plug it in, it goes. He has the boards available and an excellent web site. FYI, I am nothing more than a very satisfied customer, no other affiliation. Check it out, his board based approach makes getting into tube amps and modding them far less intimidating than any other kit. Who knows, maybe we could get him to come up with that 300B PP schematic!!!
Another note... an earlier poster stressed try out the COMPLETE system. This should be strongly encouraged. A superb high definition amp feeding crappy low efficiency speakers is not going to sound very good. Realize that once you start down this road ( the whole SE thing) major chunks of your system may well need redoing before you hear the magic that is so unique to class A SE tube amps.
And now to really commit heresy, I'm currently building a Passlabs Zen V9 class A jfet ss amp which I will compare with the Tubelab SE 300 B by the end of March. ... hey, it's my hobby, there is no rationalization....
Tubelab also has a simpler board that uses KT88's, EL34, etc you name it, plug it in, it goes. He has the boards available and an excellent web site. FYI, I am nothing more than a very satisfied customer, no other affiliation. Check it out, his board based approach makes getting into tube amps and modding them far less intimidating than any other kit. Who knows, maybe we could get him to come up with that 300B PP schematic!!!
Another note... an earlier poster stressed try out the COMPLETE system. This should be strongly encouraged. A superb high definition amp feeding crappy low efficiency speakers is not going to sound very good. Realize that once you start down this road ( the whole SE thing) major chunks of your system may well need redoing before you hear the magic that is so unique to class A SE tube amps.
And now to really commit heresy, I'm currently building a Passlabs Zen V9 class A jfet ss amp which I will compare with the Tubelab SE 300 B by the end of March. ... hey, it's my hobby, there is no rationalization....
adwsail said:Tubelab also has a simpler board that uses KT88's, EL34, etc you name it, plug it in, it goes. ... Who knows, maybe we could get him to come up with that 300B PP schematic!!!
...Realize that once you start down this road ( the whole SE thing) major chunks of your system may well need redoing before you hear the magic that is so unique to class A SE tube amps... [/B]
a) do you have a link to tubelab's site? Does he have a site?
b) One reason I have not considered SE is that the OPTs get huge and EXPENSIVE. Most of us using EL34, EL84 and to some extent KT66/KT88 and 6550 are on a limited budget. PP OPTs are a lot smaller and hence cheaper.
wow this realy moved on...
see what you want to see - I should clean my glasses...
I was thinking parallel single ended for the 2x 300b total anode dissipation of the output stage would be about 80w implying 20w actual useful work. (yes?) P-P is more efficient
Correct, To get the most out of the KT88 you need to bias it differently to the EL34 and vice versa. So Ok "interchangable" but perhaps not ideal, for one thing the required anode loads are slightly different. They *will* behave differently in the same application
my earlier point is that you're reasonably free to experiment with the two types without too much risk of meltdown
Andy
tinitus said:
see what you want to see - I should clean my glasses...
I was thinking parallel single ended for the 2x 300b total anode dissipation of the output stage would be about 80w implying 20w actual useful work. (yes?) P-P is more efficient
Johan Potgieter said:
Correct, To get the most out of the KT88 you need to bias it differently to the EL34 and vice versa. So Ok "interchangable" but perhaps not ideal, for one thing the required anode loads are slightly different. They *will* behave differently in the same application
my earlier point is that you're reasonably free to experiment with the two types without too much risk of meltdown
Andy
Navin,
no I havent heard Cain A-50T, I only thought that with Cain you are ensured reliable quality, I didnt say it was the best amp
it uses common tubes, important for a non enthusiast - tubes are EL34 x 12AU7 x 12AX7
There is a A-55T, which uses KT88
TUBELAB
http://www.tubelab.com/SimpleSE.htm
no I havent heard Cain A-50T, I only thought that with Cain you are ensured reliable quality, I didnt say it was the best amp
it uses common tubes, important for a non enthusiast - tubes are EL34 x 12AU7 x 12AX7
There is a A-55T, which uses KT88
TUBELAB
http://www.tubelab.com/SimpleSE.htm
Navin, the little Yarland amp was on a single circuit board, everything crammed into a chassis about 220mm square, that might have contributed to it getting warm.
I put some plant into a factory south of Delhi once, yep it gets warm!
made the motors suffer heat stroke... OTOH I parked it [the amp] on top of a cd player which may also be a contributing factor.
EL509 is quite a good tube but to be boring it has the 350v anode voltage applied though the top cap, is that safe? I admit I've never looked at these in detail so how much protection do the top caps offer?
Do you operate these as Triodes? is there any data for that?
good advice about the HT voltage, if you're buying a kit everything gets expensive at more than 400v Vdc seems to be the cut off for reasonably priced capacitors for sure. Its giving me a pause at the moment...
Andy
I put some plant into a factory south of Delhi once, yep it gets warm!
made the motors suffer heat stroke... OTOH I parked it [the amp] on top of a cd player which may also be a contributing factor.tube-lover said:
EL509 is quite a good tube but to be boring it has the 350v anode voltage applied though the top cap, is that safe? I admit I've never looked at these in detail so how much protection do the top caps offer?
Do you operate these as Triodes? is there any data for that?
good advice about the HT voltage, if you're buying a kit everything gets expensive at more than 400v Vdc seems to be the cut off for reasonably priced capacitors for sure. Its giving me a pause at the moment...
Andy
To Arvin, trying to make a wise choise
Melody H34II, and show picture just because it still looks nice with tube reg
http://www.ornec.com/productimagedetails.php?pimagedescription=100186/10018695-L.jpg
BUT,
just dicovered that this MingDa MC-34A can be run/ordered(?) with KT66 with 12AU7/12AX7
could be a bargain,
BUT customer rating is low, what ever that means
http://www.ornec.com/product/EU/Meixing_MingDa_MC-34A_valve_amplifier/
Please correct, if completely wrong
Runco990 seems to have bought a MC-34B
Melody H34II, and show picture just because it still looks nice with tube reg
http://www.ornec.com/productimagedetails.php?pimagedescription=100186/10018695-L.jpg
BUT,
just dicovered that this MingDa MC-34A can be run/ordered(?) with KT66 with 12AU7/12AX7
could be a bargain,
BUT customer rating is low, what ever that means
http://www.ornec.com/product/EU/Meixing_MingDa_MC-34A_valve_amplifier/
Please correct, if completely wrong
Runco990 seems to have bought a MC-34B
Hi All,
Tubelab is umm, right here: http://www.tubelab.com/
That is what search engines are for...
Great stuff by the way...
Tubelab is umm, right here: http://www.tubelab.com/
That is what search engines are for...
Great stuff by the way...
The job is only part of it. I just got home from work, at 8:30 PM. Today 97 people were laid off in the plant where I work (about 1000 world wide). I have been trying my best to remain competitive in my high tech job, which requires long hours. There are few people my age left.
My mother is in an assisted living facility about 250 miles from here, she is not doing well, which has caused my to make the 500 mile trip every other weekend for the past few months.
These two conditions have caused my Tubelab activities to fall behind. I have been working on the web site and the assembly manuals from the passenger seat of the car. Most of which was posted to the web site last night. The wiring diagrams are not done yet since I just couldn't get them to come out right on the laptop. I don't have the parts list done yet, since I need web access to look up current part numbers. These should be done in a week or two.
I am not permitted to answer Tubelab email at work, and I haven't been home much, so I have fallen behind in answering email. During some weeks I get 50 to 100 emails, some ask a simple question, some ask me to design a unique circuit (PowerDrive usually). I am still trying to catch up on the email. I give priority to email questions from PC board purchasers. I haven't been home much, so I have not sold any boards (with a few exceptions) since November.
If no new surprises come up I will be listing boards on Ebay in a week or two. I still haven't figured out how to make the shopping cart work right yet on my web site.
The TubelabSE was not originally intended to be a construction project, and may not be suitable for beginners. The newer SimpleSE was designed as a beginners project. I may offer full, or partial kits in the future. Please check out the assembly manual (on the web site) to see it either project is withing your capabilities.
So true! I have been building push pull tube amps for at least 10 years, and never paid much attention to the whole SE fad, until I heard a good one, and for the last few years that is all that I have built. That started the addiction, so I had to build a set of speakers that are "SE friendly". Where will it end? I need to build some P-P amps to come back to reality.
That is part of the addiction. At first you are happy with $18 Edcor transformers. Before you know it you are spending the rent money on the latest super magic transformers with silver wire wound on cores made out of pure unobtanium! Actually there are some good transformers out there for a reasonable price, but I don't know what is available on your side of the planet.
That will happen as soon as I get caught up on everything else. Sherri was out of town for 3 weeks (terminally ill family member), So I decided to hook it up to my big speakers and annoy some neighbors. Unfortunately, it blew up. It is now sitting on a shelf, waiting to be fixed.
arvin said:
indirectly heated ANYTHING for me. Makes it either of the top two. I just have doubts about Humm on a DHT triode. never tried but it seems a very dodgy past time
Although you could argue that it immediately gives you the best opportunity to tweak. There are great experts on DHT gear here Not least of whom is Tubelab who also has my best wishes
Andy
DHT is the way to go as far as I'm concerned and life is sweet if those heaters are looking at DC instead of AC. Seriously, my DC DHT Tubelab SE is several dB quieter than any solid state amp I've ever heard. Hum is not an option when you switch over to really efficient speakers. It's part of that whole system integration thing I mentioned earlier.
Most of my music is along the lines of Tangerine Dream, String Cheese Incident, Grateful Dead, and most all chill style music, love that euro newage stuff!!!
Most of my music is along the lines of Tangerine Dream, String Cheese Incident, Grateful Dead, and most all chill style music, love that euro newage stuff!!!
Re: 300B Tubes
Hey Oxaudio,
Thats the big issue for me at the mo. IMO Theres ALWAYS some element of AC on any power supply, rectified or not. Therefore there is the possibility to get hum if its not done properly. I really like the 300b as an envelope - one of the more attractve tubes so are you saying that hum levels are generally acceptable / unnoticable?
This is the primary reason I favour indrectly heated tubes at the moment (ie KT88 or EL34). Although it would take a brave fellow to argue with the 'book' linearity of the 300b I worry that the other PSU artifacts introduced would ruin the deal.
Is there any theoretical basis for this do you know, or is it paranoia? yes / no? I'm quite willing to be put right here or at least appreciate the alternative argument. But, it strikes me that a non DHT tube is likely to be more "cost effective"
than the alternative.
Andy - still leaning towards the PP KT88 option...
OXAUDIO said:
Hey Oxaudio,
Thats the big issue for me at the mo. IMO Theres ALWAYS some element of AC on any power supply, rectified or not. Therefore there is the possibility to get hum if its not done properly. I really like the 300b as an envelope - one of the more attractve tubes so are you saying that hum levels are generally acceptable / unnoticable?
This is the primary reason I favour indrectly heated tubes at the moment (ie KT88 or EL34). Although it would take a brave fellow to argue with the 'book' linearity of the 300b I worry that the other PSU artifacts introduced would ruin the deal.
Is there any theoretical basis for this do you know, or is it paranoia? yes / no? I'm quite willing to be put right here or at least appreciate the alternative argument. But, it strikes me that a non DHT tube is likely to be more "cost effective"
than the alternative.Andy - still leaning towards the PP KT88 option...
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