Newbie question on cheap amp kits

[mastiff]

Ive had a growing interest in making by own tube amp and have finally decided to go for it. I originally thought I could make my first amp by simply reading schematics from different webpages, but I learned that it will take forever to get all the components I needed.

So now Ive started to look at kits. I know everybody loves Bottleheads stuff, but they have a 6 week wait for their kits. I have the DIY bug and I can't wait that long for a kit. I also don't want to spend much more than $500. Can anybody give me some recommendations of good beginner amplifier kits that can be shipped quickly? Thanks.

Andrew

 

[jleaman]

i like qkits.com but there amp is in canadian and it is 1499.00 canadian and a excellent kit too awsome and verry detailed instructions

here is there link fora stereo version of the tube amp

http://www.qkits.com/serv/qkits/velleman/pages/K4040.asp

 

[cowanrg]

um, didnt he just say "i dont want to spend over $500?"

i ran into this when i was starting out... i would say "yeah, under $100" and someone would suggest something that was like $1000....

if he wants something under $500, someone help him out please, and last time i checked $1000 wasnt under $500...

 

[jleaman]

AHEm 500 us or 500 canadian.. and 500 us comes out to be 785

500 * 1.57 = 785 canadian and if he put in about 200 more then he wouold probably get it and you cant say 500 for a cheap stereo kit EXPECIALY TUBE because there expencive right off the start

cowarg you bought a 20 watt amp and spent wht 100 and 10 on a meter you have all cheap stuff that will get yuo buy for now but when you need to do some presise mesuring and proper calculations you need the goods..


J'

 

[cowanrg]

yeah, you are right. but i knew that, i bought cheap stuff to begin with. didnt know if i would like it. but now im getting better stuff.

i have a nice multimeter now, true rms, ALL tests (capacitance, diode, etc...) and its 0.02% accurate. my soldering iron works fine, i dont know why the expensive ones are so great. mine is adjustable, and with heatsinks on components, and proper soldering, it works like a charm... i may get a better one later thats more comfortable, but for soldering, works well for me.

and as far as other tools, i spend a bit of money and got some ok stuff. but i plan to get more. see, i went into it cheap. wasnt gonna get an oscilliscope to build a $20 kit

i am slowing building what i have so i can build something nicer. and actually, that kit was $900 or so. thats $400 more there are decent beginner kits out there im sure that are in his range.

 

[JoeBob]

$500 for a tube amp kit is rather low. I would really sudjest not buying a kit, but doing it from scratch, that way you can purchase parts in your price range. There are plenty of good designs around. And you're in the states, so it really shouldn't be a problem to source parts. Are there any components in specific that you couldn't find a source for?

 

[Aud_Mot]

How about more specs.

You do not specify a tube power amp. What kind of output power do you want/need? That is the big factor in determining a budget.

For a newbie, I would suggest a tube pre-amp. That would be a much better starter project. Typically the voltages are lower and the parts are cheaper and easier to get your hands on. Plus any system would welcome a lucious tube pre-amp.

Aud_Mot

 

[jleaman]

i agree with Aud_Mot he is right .. although qits has a nice preamp too i was going to buy it but i bought my aleph boards instead and my focal drivers..

J'

 

[mastiff]

What Im really trying to get with my first project is a taste of tubes. If I like the sound and effort, I plan to create a second, all tube system. But I want to be able to use by tube project with my current system. I had planned on plugging the tube amps into my receiver to see how I liked it.

If I like the tube sound I will get new speakers with a greater sensitivity than my 85db ones now. I live in an apartment now so I really don't need a lot of power but will need something more than those 3W systems.

I really want to avoid the kit route and build one from somebody elses schematic. My main concern is that I felt I couldn't find all the parts I needed to follow the schematic, I wouldn't know enough about amps to find adequate subsitutions for the components. Maybe thats just a little bit of paranoia, but I feel that I have a lot less chances of messing something up if Im following a kit rather than just a schematic.

 

[planet10]

Mastiff,

With 85 dB speakers you will need to get a PP amp to get the power you need to drive them (note: a PP is about twice as complex as an SE amp -- i actually built new speakers so that i could play with low power amps). 1st thing you need is output transformers (although what you look for is determined by your leanings as to output tube and the power you strive for). These will narrow . Around that flows the rest of the amp. You could but new, a Hammond, ElectraPrint, any number of others. Look around.

With your modest budget you might well go looking for an old integrated amp or receiver to sacrifice for its iron -- call it a semi-kit -- to build a pheonix amp (as in risen from the dead). I am partial to EL84/6BQ5. A Scott, a Dyna, Lafeyette, Pilot, many others, 15-18W in pentode AB all the way up to about 4 W in Class A triode. With a little less power, 6BM8 isn't bad either (there is actually an available semi-kit for a variant of these for $140 USD). 6V6 too - something that uses tubes that they still make. If you get one that is point-to-point wired (ie Scott LK-48 - Al chassis too) then you can even use existing chassis, sockets, et all. Spend up to $200 for the amp leaving you with $300 for parts & contingencies. An good example of what can be done is this 6V6 SE Amp. To get a flavour of what raw material is out there go surf eBay...

dave

 

[mastiff]

Dave,

I like your idea, but I don't think I have the experience to select the right components to match the existing iron in the amp I buy.

I really don't think I will need a push-pull amp. I did a test with me sound level meter in my room and I think SE amps could give me what I want.

I originally created my budget of $500 because i saw kits for $600-700, and I thought I could make one cheaper if I did it myself. After studying it more closely, I realize my budget may be too low. For instance, I found this simple 300B schematic:

http://indigo.ie/~walton/300b.html

Doing an estimation on the cost of all the components recommended would be over $900, and this is for a simple setup. Now all of the components recommended seem top quality, maybe I can reduce the cost by going for cheaper components and then upgrading the amp later.

Andrew

 

[dice45]

Andrew,
1st,
Bottlehead kits have such a long waiting list because they offer an extremely good bang for the buck.

2nd,
one of our member's, Gabevee, offers an amplifier kit right in your budget. to me it seems from what he write on his website he is knowing well what he is doing.
And, i would be glad, selfish me, to have some 1st hand experience report.
If i would be you and could live with a power amp alone, i would definitely go with the tube-rectified version. And i would not hesitate to order the kit with Magnequest transformers. (I am not happy with the Mike the Magnequest guy but his trannies are extraordinarily good; Gabe certainly knows why he is offering them). I would spend those $175.

The amp i am meaning is here

But Gabevee also has two single ended designs which cost slightly more. The reason why i recommend the pushpull amp is because it gives you a wider range of speakers the amp is happy with.

On my open baffle speaker i prefer a Manfred Huber's 2.5W PP amp to any SE amp so far. Better control. The amp has Magnequest nickel trannies BTW.
Dave, you hear me, i am not kidding.

 

[planet10]

On my open baffle speaker i prefer a Manfred Huber's 2.5W PP amp to any SE amp so far. Better control. The amp has Magnequest nickel trannies BTW.
Dave, you hear me, i am not kidding. [/B]

I hear you. Next task is fixing the roof, then it can start raining and i can get in the lab and get some amps built -- i have the raw material for the EL84 PP sitting where i have to look at itnevery day as i walk past.

Have i "seen" Manfred's little amp?

dave

 

[mastiff]

Just wanted to inform everybody that I have ordered a PP kit from Gabevee. I did go with the tube rectifiers and got it without a chassis so I can make my own. Thanks for all the input.

Andrew

 

[Thatch_Ear]

Andrew,
There is a Texas Bottlehead group on Yahoo. Find it and join. There are a number of DIY tube guys in Austin that belong to this group and having gone to a meeting the gear is not just stuff from Doc Bottlehead by any means. You need to get the email for a member whose handle is Twystd or something simular to that. He is or was a dealer of TJ 300Bs. I am sure he would let you listen to his rig.
Not knowing what your speakers are if they are towers with 4 way crossovers of 24db slopes and zobels etc a SE will not work as the cross would suck all the power before it even got to the drivers.
Watts and SPLs can be very misleading. I listened to the new TOTL KEFs yesterday and even though the factory specs rate them at 91 db I don't know that they would sound good on my 300B because of the complex crossover network.
Synergy is all.