| augerpro |
I've never owned a tube before and was thinking of trying one out. I was looking to build a kit, something cheap to get my feet wet. What are your opinions on this: http://www.s5electronics.com/tube12.html
The price is right so I thought I'd give it try. Any cheap upgrades a person could do to it? Any other cheap kits that sound good?
Thanks,
Brandon |
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| MIKET |
| The K-502 from Antique Electronics for $139.50 USD http://www.tubesandmore.com/ is very good for the money and is a single ended design as opposed to the other amp which was push pull. It only puts out 1 watt but thats enough if you have efficent spekers. |
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| Sherman |
There are a bunch of mods for this amp. Most are described on VoltSecond's site. He takes you through the mods but also through the reasons for the mods.
For the price the S 5 Electronics kit is a good introduction to tubes and it sounds good as well.
Another choices-
http://www.lh-electric.4t.com/sta44.htm
I haven't heard this one but again it has a good price and comes with a very nice looking chassis rather than a plain wooden board. |
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| tkifowit |
I bought one of the STA45's from LE (http://www.lh-electric.4t.com/) I love this thing. I packed my K12 away.
This is a cool amp sounds great right out of the box and you can mod it cheaply.
Easy to build also it takes about 2 hours to build. |
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| Runco990 |
I do NOT recomend you build ANY of the above kits. They are great introductions into tube audio and (like myself) will propell you down a dark slippery road you can't leave. And for god's sake DO NOT look at the picture gallery of members amplifiers. I made this crucial mistake, and it's all over.
TRUST ME!!! Once you build and listen to one of these, you are lost forever.
I went in VERY short order from a K-12G kit to an Eico ST-40 which I re-tubed, to a Ming-Da MC34-B new in the box. (Should be here today, I hope)
I am currently reading books on tube amp design and looking on epray for my next victim. And it's ONLY been a MONTH!!!! :eek:
Don't do it, Man!! :D
Marc |
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| tkifowit |
That is the truth!!! Runco990
A year ago i thought a JLH was the best thing in audio.
Two months ago I bought a tube kit.
I now own two kits and one I built from scratch.
I LOVE IT!!:D |
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| jduffy |
My first tube amp was the Bottlehead. It is an amazing bit of kit for the money.
Now I'm working on building a preamp from scratch.
I concur with the above post that claims it is a slippery slope in which one may have difficulty getting back up again, at least without building several more amps, preamps, etc. ;)
Enjoy and good luck with your choices. |
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| frank754 |
I'm fairly newbieish here, my dad was an electronics engineer (passed away in '88), was in WW II.
I'm 52, and have been playing with this stuff off & on since the mid 60's, built kits as a kid & later, got my first ham license in '68.
Built a HF multiband Ham receiver back then from schematic, also some heathkits over the years, but never really knew enough to create a "new" optimized design over what I see others have done, besides mix & match power supplies, and know where I can & cannot change capacitor values, etc.
After a hiatus of over 10 years now, I'm building this stuff again, and it's quite exciting as I haven't failed yet or blown anything up recently.
I've worked on 3 amps lately, and 2 in progress (not done yet), but put together a littler pre-amp which does well too (or seems to do for me in hi-fi with my best sound perception), and is simple, only $85 to build:
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| augerpro |
| quote: | Originally posted by Runco990
I do NOT recomend you build ANY of the above kits. They are great introductions into tube audio and (like myself) will propell you down a dark slippery road you can't leave. And for god's sake DO NOT look at the picture gallery of members amplifiers. I made this crucial mistake, and it's all over.Marc |
Hehe, a kindred spirit ;) I actually took up diy speakerbuilding a few months ago and after at least $3k spent I still haven't built a speaker! But I have a nice woodshop now! Seriously though i know how I am with new hobbies and that's why I just want a simple kit to try out a tube wiht a speaker project I have planned. I don't have the time or money to seriously pursue a new hobby so I have to keep myself from getting in too deep :D
The K502 looks tempting and the price is right. MIKET how did you come with 1 watt? It says 8 max. Would this be about the same or less then the STA45 in reality?
The STA45 looks nice too. I'd make my own chassis from wood so that's not a selling point. Can anyone say what performance advantage there is over the K502 to justify the price difference? I like all the mods at Voltseconds site though, but that is definatley the slippery slope that will suck me in!
I'll check out that Bottlehead too. Thanks everyone for the advice so far! |
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| augerpro |
| quote: | Originally posted by frank754
I've worked on 3 amps lately, and 2 in progress (not done yet), but put together a littler pre-amp which does well too (or seems to do for me in hi-fi with my best sound perception), and is simple, only $85 to build:
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Thanks Frank. It's been years since high school electronics class so I'm thinking a pre made PCB like the kits have is about the level of complexity I'm going for right now. Building a high voltage amp from just the schematic is a bit more than I want to take on right now! |
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| tkifowit |
The STA45 is rated at 5 watts but that is a good usable 5 watts.
I piched the case used an aluminum plate on top a wood base.
You can also add a switch to jump a wire and change a resistor and jump to SET (you have 2 watts).
Easy to mod and play with, also lots of brands of tubes to get a diiferant with. |
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| MIKET |
| quote: | Originally posted by augerpro
Hehe, a kindred spirit ;) I actually took up diy speakerbuilding a few months ago and after at least $3k spent I still haven't built a speaker! But I have a nice woodshop now! Seriously though i know how I am with new hobbies and that's why I just want a simple kit to try out a tube wiht a speaker project I have planned. I don't have the time or money to seriously pursue a new hobby so I have to keep myself from getting in too deep :D
The K502 looks tempting and the price is right. MIKET how did you come with 1 watt? It says 8 max. Would this be about the same or less then the STA45 in reality?
The STA45 looks nice too. I'd make my own chassis from wood so that's not a selling point. Can anyone say what performance advantage there is over the K502 to justify the price difference? I like all the mods at Voltseconds site though, but that is definatley the slippery slope that will suck me in!
I'll check out that Bottlehead too. Thanks everyone for the advice so far! |
The k-502 is the same as the k-12M amplifier here is a link to a review of the K-12M from AudioExpress http://www.audioxpress.com/reviews/...2hansen2145.pdf
It is 8 watts. |
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| augerpro |
| quote: | Originally posted by tkifowit
The STA45 is rated at 5 watts but that is a good usable 5 watts.
I piched the case used an aluminum plate on top a wood base.
You can also add a switch to jump a wire and change a resistor and jump to SET (you have 2 watts).
Easy to mod and play with, also lots of brands of tubes to get a diiferant with. |
I'm thinking I may go with this amp. How exactly do you change to SET? Do you know any other good mods for this amp?
Thanks, Brandon |
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| tkifowit |
To change to an SET you change the R15 (bias resistor) to 270 ohm 2 watt and connect pin 9 at the output tube to pin 7 ( you can put a switch in if you want to switch between the two modes.
Remove c4 (in put cap) and change c11 to a better brand of cap and change it to .33. Change the rect. diodes to FRED's. Try differant tubes. I got some great tubes on e-bay (Holland) for less than 20.00$.
The sound differance for less than 60.00$ is fantastic.
Although it does sound very good stock, this extends the bass alot.
My next step is better tranformers (i just ordered some ubt-2). |
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| kvk |
What is the STA45 when it isn't SET?
Some other Class A topology? |
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| planet10 |
| quote: | Originally posted by kvk
What is the STA45 when it isn't SET?
Some other Class A topology? |
It is a SEP -- SIngle Ended Pentode.
dave |
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| planet10 |
| quote: | Originally posted by tkifowit
The sound differance for less than 60.00$ is fantastic. |
Is this built on a PCB?
dave |
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| G |
| quote: | Originally posted by tkifowit
To change to an SET you change the R15 (bias resistor) to 270 ohm 2 watt and connect pin 9 at the output tube to pin 7 ( you can put a switch in if you want to switch between the two modes.
Remove c4 (in put cap) and change c11 to a better brand of cap and change it to .33. Change the rect. diodes to FRED's. Try differant tubes. I got some great tubes on e-bay (Holland) for less than 20.00$.
The sound differance for less than 60.00$ is fantastic.
Although it does sound very good stock, this extends the bass alot.
My next step is better tranformers (i just ordered some ubt-2). |
I can recommend these.
http://www.magnequest.com/robin_hood_series.htm |
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| DocLorren |
Is this built on a PCB?
Yes it is. |
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| gofar99 |
| Greetings Everyone. I must agree. Once you buy or build a tube amp you are on the glidepath. I have 5 in varying sizes now. The K-502 and K-12 are as virtually the same. There are variations over a period of years in the types of tubes used. There are 10GV8, 11BM8 and 11MS8. There are a few minor differences in the components as well (the plate load and cathode resistors in the drivers come to mind). There are plenty of mods for the amps and with fairly efficient speakers they sound better than the price would indicate. Beware of the mods as they can easily double the cost of the project. I would also caution regarding the new K-8 and K-16 amps. My K-8 is on the spare parts heap. It looks like a good design on paper and perhaps someone else has had better luck with theirs, but mine was far inferior to the K-12. At low power levels (under 2 watts) it was OK, but had no reserve. My HP distortion analyzer indicated it started to go bad around 2 watts and went south very quickly after that. My K-12 ran circles around it. |
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| h00hbt |
If you have the $ i can recomend Audio Note kit 1 SET 300B, i built one and it´s just fantastik, my PP KT88 tube amp is collecting dust now. Trust me this is additive.
/H |
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| JeremyB |
for what its worth.. I am looking into the ST-35 for my first tube amp. DIYTube
| quote: | | I do NOT recomend you build ANY of the above kits. They are great introductions into tube audio and (like myself) will propell you down a dark slippery road you can't leave. And for god's sake DO NOT look at the picture gallery of members amplifiers. I made this crucial mistake, and it's all over. |
I like to think of this ride as a slip-n-slide.. on steroids... i have heard some people claim its more addicting than crack... personally i dont do that.. but i can see the relation... i have 4 sets of speaker boxes built.. and drivers for only 2 of them.. and drawings for 3 more sets on my desk right now.... sigh... i shudder at the thought once i start building amps.
good luck. |
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| whitelabrat |
Not quite a kit but Tubelab's SimpleSE is a excellent beginner's project. For less effort the Diytube ST35 board can be gotten with most of the parts needed from Triode Electronics or such. Either project has satisfying results. You can use Edcor open frame output transformers to save $$$ if that matters. Good OPT's are worth the extra bucks more than fancy pre and power tubes.
Another idea is to get your hands on an old amp with point-to-point wiring and modifying to your desires.
The slippery slope? I started out with a pair of DIY speakers and a 41hz amp4. Quickly realized that SMT soldering is not for me. Followed with a dumpy vintage EL84 amp that is now a pile of dust despite a determined will to repair it. I was given a Marantz 8b that needed a power cord which lead to an Lite Audio ls7b preamp kit and glass-ware stepped attenuator. Bought and repaired a broken Rega P3 and combined several kits to make a phono amp too. Tried two 41hz amp6's instead of the amp4, one failed, one is unassembled. Built a pair of folded horn speakers and a SimpleSE amp. I've also found and repaired a Stromberg-Carlson pa amp and have a ST35 PCB ready for stuffing. Not to mention the large cardboard box full of electronics parts and tubes. This has all happened within one and a half years! Whoops! |
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| JeremyB |
| Whitelebrat.. i have an off topic question or two for you.(amp6) will you email me? |
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| kaan |
I just finished my first tube amp last month.
I made this little baby:
http://lundahl.se/claus_b.html
It is the best amp I ever had.
But you should take the warnings seriously, because soon you will want to know what the fuss is all about with 300b ... and I must admit that that will be my next amp project in a year or so ;) |
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| lousymusician |
| quote: | Originally posted by whitelabrat
I was given a Marantz 8b that needed a power cord ... |
:bigeyes: |
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| electroshock |
| quote: | Originally posted by kaan
I just finished my first tube amp last month.
I made this little baby:
http://lundahl.se/claus_b.html
It is the best amp I ever had.
But you should take the warnings seriously, because soon you will want to know what the fuss is all about with 300b ... and I must admit that that will be my next amp project in a year or so ;) |
Kaan,
Did you make circuit boards or do a point wiring? Can you post some pictures of your completed amp?
Thanks Bill |
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| kaan |
| quote: | Originally posted by electroshock
Kaan,
Did you make circuit boards or do a point wiring? Can you post some pictures of your completed amp?
Thanks Bill |
I did point wireing but I'm thinking of rebuilding it with PCB and better components.
I also did many things "wrong" as this is my first build. Comments from the technicians at the electronics plant where I work includes: "Interesting", "I look forward to hearing if it has any problems" and so on. Their doubts has been put to shame though as there is so little noise from the amp that you can't tell it is on if sitting in the listening position 2 meters from the speakers.
As for some pictures ... well I would love to post a torrent of them, but right now REM is playing and I just can't disconnect before the end of the cd ;) |
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| kvk |
Do I see uninsulated exposed wires on both the primary and secondary of the power transormer? :rolleyes: |
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| kaan |
| quote: | Originally posted by kvk
Do I see uninsulated exposed wires on both the primary and secondary of the power transormer? :rolleyes: |
Yes and it will kill someone some day :xeye: |
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| gofar99 |
| Hi Everyone, Unfortunately with tube gear, exposed high voltages are an ever present hazard. Even if you protected the transformer leads there are numerous other exposed dangerous terminals (plate connections, filters and such). I use two techniques in equipment I build. The first is to create a sub chassis for the power supply. Sort of a metal box inside the main chassis. This is partly because I use wood and plexiglass cases on some projects. Second, I put bottoms on my amps. I have found that the perforated metal sheets that are sold in hardware stores to use as kick panels for screen doors work well. They come in various patterns and colors. The copper ones are particularly nice. For about $20US you can get a piece big enough to cover the bottoms of 4 or 5 projects. The nice thing about them is that they don't impede air flow. Then mount the amp on rubber or metal feet to allow for clearance underneath. |
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